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WO2024162705A1 - Handling measurements for lower layer triggered mobility in telecommunication network - Google Patents

Handling measurements for lower layer triggered mobility in telecommunication network Download PDF

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Publication number
WO2024162705A1
WO2024162705A1 PCT/KR2024/001292 KR2024001292W WO2024162705A1 WO 2024162705 A1 WO2024162705 A1 WO 2024162705A1 KR 2024001292 W KR2024001292 W KR 2024001292W WO 2024162705 A1 WO2024162705 A1 WO 2024162705A1
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WO
WIPO (PCT)
Prior art keywords
ltm
csi
ssb
measurements
configuration
Prior art date
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PCT/KR2024/001292
Other languages
French (fr)
Inventor
Aby Kanneath ABRAHAM
Seungri Jin
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Samsung Electronics Co., Ltd.
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Publication date
Application filed by Samsung Electronics Co., Ltd. filed Critical Samsung Electronics Co., Ltd.
Publication of WO2024162705A1 publication Critical patent/WO2024162705A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
    • H04W36/0085—Hand-off measurements
    • H04W36/0094—Definition of hand-off measurement parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0055—Transmission or use of information for re-establishing the radio link

Definitions

  • the present invention generally relates to wireless communication networking and more particularly relates to a method and system for configuring, performing measurements and reporting measurements for Lower layer Triggered Mobility (LTM) in a telecommunication network.
  • LTM Lower layer Triggered Mobility
  • Fifth generation (5G) mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6 gigahertz (GHz)” bands such as 3.5GHz, but also in “Above 6GHz” bands referred to as millimeter wave (mmWave) including 28GHz and 39GHz.
  • GHz sub 6 gigahertz
  • mmWave millimeter wave
  • 6G mobile communication technologies referred to as Beyond 5G systems
  • THz terahertz
  • V2X Vehicle-to-everything
  • NR-U New Radio Unlicensed
  • UE user equipment
  • NTN Non-Terrestrial Network
  • IIoT Industrial Internet of Things
  • IAB Integrated Access and Backhaul
  • DAPS Dual Active Protocol Stack
  • RACH random access channel
  • 5G baseline architecture for example, service based architecture or service based interface
  • NFV Network Functions Virtualization
  • SDN Software-Defined Networking
  • MEC Mobile Edge Computing
  • multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and Artificial Intelligence (AI) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.
  • FD-MIMO Full Dimensional MIMO
  • OFAM Orbital Angular Momentum
  • RIS Reconfigurable Intelligent Surface
  • AI-based communication technology for implementing system optimization by utilizing satellites and Artificial Intelligence (AI) from the design stage and internalizing end-to-end AI support functions
  • UE User Equipment
  • RRC_CONNECTED Radio Resource Control
  • RRC radio resource control
  • Handover in the NR usually consists of three steps: handover preparation step, handover execution step and handover completion step.
  • the gNB may configure the UE to report measurements.
  • the gNB Based on the reported measurements or based on its own understanding of a network topology, the gNB sends a RRC Reconfiguration message to handover the UE to another cell called a target cell from a source cell. The UE accesses the target cell and sends the RRC Reconfiguration complete message.
  • the gNB may configure the UE with the execution conditions for triggering handover and once the execution conditions are satisfied, the UE may move to the target cell and sends the RRC Reconfiguration complete.
  • the 3GPP is also introduced a new handover called Dual Active Protocol Stack (DAPS) handover in release 16.
  • DAPS Dual Active Protocol Stack
  • the UE performs the handover by sending layer 3 (RRC) messages which causes considerable signalling overhead and latency issues.
  • RRC layer 3
  • the handover and conditional handover (CHO) refer as layer 3 mobility.
  • the UE may perform a PSCellChange or a Conditional PSCellChange.
  • PSCellChange or Conditional PSCellChange also as layer 3 mobility. That is, the Handover, the Conditional Handover, the PSCellChange, the Conditional PSCellChange etc. refer to the L3 mobility.
  • the PSCellChange or the Conditional PSCellChange refer as SCG layer 3 mobility and the handover and CHO as Master Cell Group (MCG) layer 3 mobility in the context of dual connectivity.
  • MCG Master Cell Group
  • the L3 mobility may be performed based on L3 measurements reported in RRC messages.
  • the UE may receive RRC configuration for updating some of security parameters.
  • RRC configuration for updating some of security parameters.
  • 3GPP specifications such as TS38.300, TS38.331, TS 38.321 V17.3.0 as relevant background.
  • the 3GPP release 18 is considering Lower Layers (L1/L2 layers) Triggered Mobility, also known as Lower layer Triggered Mobility (LTM) to solve the problem related to latency, signalling overhead etc. associated with layer 3 mobility.
  • LTM Lower Layer Triggered Mobility
  • the network e.g., gNB
  • the network may configure the UE with multiple candidate cells to allow fast application of configurations for candidate cells.
  • the network may further send Medium Access Control (MAC) Control Element (CE) or L1 signalling to dynamically switch the UE from the source cell to one of the configured candidate cells.
  • MAC Medium Access Control
  • CE Medium Access Control Element
  • LTM can be triggered based on L1 measurements rather than L3 measurements.
  • the present disclosure relates to wireless communication systems and, more specifically, the invention relates to methods and wireless network for handling measurements for lower layer triggered mobility in telecommunication network.
  • the principal object of the embodiments herein is to provide a method and a UE for managing measurements for LTM in a telecommunication network.
  • Another object of the embodiments herein is to receive a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network.
  • Another object of the embodiments herein is to perform Layer 1 (L1) measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • Another object of the embodiments herein is to report the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • Another object of the embodiments herein is to receive a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements.
  • Another object of the embodiments herein is to perform a switch to the LTM candidate cell based on the MAC CE.
  • Another object of the embodiments herein is to provide that the network apparatus (e.g., gNB or the like) that configures the UE whether a CSI-RS resource (i.e. which CSI-RS resources) can be used for LTM measurements and the list of candidate cells that are associated to a CSI resource.
  • a CSI-RS resource i.e. which CSI-RS resources
  • Another object of the embodiments herein is to provide that the network apparatus (e.g., gNB or the like) that configures the UE with the SSB frequency, subcarrier spacing and a bitmap for configuring the SSB resources.
  • the network apparatus e.g., gNB or the like
  • Another object of the embodiments herein is to provide that the UE moves to an RRC_IDLE when the UE receives the cell switch command before the AS security is activated.
  • Embodiments disclosed herein provide a method for managing measurements for LTM in a telecommunication network.
  • the method includes receiving, by a UE, a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network. Further, the method includes performing, by the UE, Layer 1 (L1) measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the method includes reporting, by the UE, the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • L1 Layer 1
  • the method includes receiving, by the UE, a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements. Further, the method includes performing, by the UE, a switch to the LTM candidate cell based on the MAC CE.
  • Embodiments disclosed herein provide a UE for managing measurements for LTM in a telecommunication network.
  • the UE includes a L1 measurement controller coupled to a memory and a processor.
  • the L1 measurement controller is configured to receive a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network. Further, the L1 measurement controller is configured to perform L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the L1 measurement controller is configured to report the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • the L1 measurement controller is configured to receive a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements. Further, the L1 measurement controller is configured to perform a switch to the LTM candidate cell based on the MAC CE.
  • the L1 measurements is one of CSI based L1-RSRP measurements, CSI based L1-SINR measurements and SSB based L1-RSRP measurement.
  • the LTM CSI resource configuration includes a CSI resource to be used for the L1 measurements and a list of one or more candidate cells that are associated to the CSI resource.
  • the LTM SSB configuration includes a SSB frequency, a subcarrier spacing and a bitmap of SSB positions in a burst for configuring SSB resources provided within a LTM candidate cell configuration.
  • the LTM CSI resource configuration is for the one or more LTM candidate cells and the LTM SSB configuration is per LTM candidate cell.
  • the SSB positions in burst are provided using 4 bits, 8 bits or 64 bits for the SSB frequency and subcarrier spacing.
  • reporting the L1 measurements for all the plurality of candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration includes performing, by the UE, the L1 measurements for all the plurality of candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration, and transmitting, by the UE, the L1 measurements to the network apparatus for the LTM.
  • reporting the L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration includes performing, by the UE, the L1 measurements for the one more candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration, and transmitting, by the UE, the L1 measurements for the one or more candidate cell to the source cell of the network apparatus for the LTM.
  • the LTM CSI resource configuration is received in a RRC reconfiguration message.
  • the method includes receiving, by the UE, a cell switch command from the network apparatus. Further, the method includes determining, by the UE, whether an Access Stratum (AS) security is activated. Further, the method includes transitioning, by the UE to RRC_IDLE state with release cause 'other' when the AS security is not activated.
  • AS Access Stratum
  • a method of a user equipment (UE) in a wireless communication system comprising: receiving, from a network apparatus (200), a radio resource control (RRC) message including a lower layer triggered mobility (LTM) channel state information (CSI) resource configuration for one or more LTM candidate cells and a LTM synchronization signal block (SSB) configuration for each LTM candidate cell; performing layer 1 (L1) measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration; transmitting, to the network apparatus (200), an L1 measurement report for the one or more candidate cells based on theL1 measurements; based on the transmission of the L1 measurements, receiving, from the network apparatus (200), a medium access control control-element (MAC CE) to perform a LTM cell switch procedure; and performing the LTM cell switch procedure based on the MAC CE.
  • RRC radio resource control
  • LTM lower layer triggered mobility
  • SSB LTM synchronization signal block
  • a user equipment (UE) in a wireless communication system comprising: a transceiver; and a processor configured to: receive, from a network apparatus (200), a radio resource control (RRC) message including a lower layer triggered mobility (LTM) channel state information (CSI) resource configuration for one or more LTM candidate cells and a LTM synchronization signal block (SSB) configuration for each LTM candidate cell, perform layer 1 (L1) measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration, transmit, to the network apparatus (200), an L1 measurement report for the one or more candidate cells based on theL1 measurements, based on the transmission of the L1 measurements, receive, from the network apparatus (200), a medium access control control-element (MAC CE) to perform a LTM cell switch procedure, and perform the LTM cell switch procedure based on the MAC CE.
  • RRC radio resource control
  • LTM lower layer triggered mobility
  • SSB LTM synchronization signal block
  • FIG. 1 illustrates a telecommunication network for managing measurements for LTM, according to the embodiments disclosed herein.
  • FIG. 2 shows various hardware components of a UE, according to the embodiments as disclosed herein.
  • FIG. 3 is a flow chart illustrating a method for managing measurements for the LTM in the telecommunication network, according to the embodiments disclosed herein.
  • FIG. 4 illustrates a sequence diagram of a LTM configuration, according to the embodiments disclosed herein.
  • FIG. 5 illustrates a flow diagram of a CSI reporting for LTM based on AS security activation, according to the embodiments disclosed herein.
  • FIG. 6 illustrates a flow diagram of a CSI reporting for LTM based on radio bearer configuration, according to the embodiments disclosed herein.
  • FIG. 7 illustrates a flow diagram of a cell switch command handling without AS security activation, according to the embodiments disclosed herein.
  • the 3GPP proposes to perform the LTM, without reset of lower layers like MAC to avoid data loss and to reduce the additional delay of data recovery wherever it is possible.
  • the gNB may provide a LTMCandidateConfiguration, i.e. configure LTM candidate cells through one RRCReconfiguration message for a candidate target cell or through one CellGroupConfig for each candidate target cell or through any similar RRC structure or IE containing the similar fields (for e.g. a new IE LTM-CandidateConfig can be defined as ASN.1 sequence containing CellGroupConfig and some other information elements in the RRCReconfiguration).
  • the gNB may further release or modify the candidate configurations.
  • the UE may store the LTM configuration of other candidate cells even after moving to a candidate cell through the LTM.
  • the gNB also may provide the UE with configuration for performing LTM measurements for different candidate frequencies and candidate cells and reporting based on the performed LTM measurements.
  • Each cell in the candidate cell configuration can be identified by a candidate cell identifier (e.g. LTMCandidateCellIdentifier or LTMCandidateCellIndex).
  • LTMCandidateCellIdentifier or LTMCandidateCellIndex An example structure is given below:
  • the gNB may command the UE to switch the cell to any of the candidate cells. This could be done by sending a Medium Access Control Control-Element (MAC CE) or L1 signaling.
  • MAC CE Medium Access Control Control-Element
  • L1 signaling used for switching to another candidate cell in the LTM is called a cell switch command.
  • the cell switch command can contain an identifier for the candidate cell such as the candidate cell identifier (e.g., LTMCandidateCellIdentifier or LTMCandidateCellIndex as mentioned above).
  • CSI Measurements In NR R17, the UE reports the L1 measurements using Channel State Information (CSI) measurement reports.
  • the gNB configures the UE for the CSI measurements using RRC IE CSI_MeasConfig as defined below.
  • nzp-CSI-RS-ResourceToAddModList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-Resource OPTIONAL, -- Need N
  • nzp-CSI-RS-ResourceToReleaseList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-ResourceId OPTIONAL, -- Need N
  • nzp-CSI-RS-ResourceSetToAddModList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSet
  • nzp-CSI-RS-ResourceSetToReleaseList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetId
  • csi-IM-ResourceToAddModList SEQUENCE (SIZE (1..maxNrofCSI-IM-Resources)) OF CSI-IM-Resource OPTIONAL, -- Need N
  • csi-IM-ResourceToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-IM-Resources)) OF CSI-IM-ResourceId OPTIONAL, -- Need N
  • csi-IM-ResourceSetToAddModList SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSets)) OF CSI-IM-ResourceSet OPTIONAL, -- Need N
  • csi-IM-ResourceSetToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSets)) OF CSI-IM-ResourceSetId OPTIONAL, -- Need N
  • csi-SSB-ResourceSetToAddModList SEQUENCE (SIZE (1..maxNrofCSI-SSB-ResourceSets)) OF CSI-SSB-ResourceSet OPTIONAL, -- Need N
  • csi-SSB-ResourceSetToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-SSB-ResourceSets)) OF CSI-SSB-ResourceSetId OPTIONAL, -- Need N
  • csi-ResourceConfigToAddModList SEQUENCE (SIZE (1..maxNrofCSI-ResourceConfigurations)) OF CSI-ResourceConfig
  • csi-ResourceConfigToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-ResourceConfigurations)) OF CSI-ResourceConfigId
  • sCellActivationRS-ConfigToAddModList-r17 SEQUENCE (SIZE (1..maxNrofSCellActRS-r17)) OF SCellActivationRS-Config-r17 OPTIONAL, -- Need N
  • sCellActivationRS-ConfigToReleaseList-r17 SEQUENCE (SIZE (1..maxNrofSCellActRS-r17)) OF SCellActivationRS-ConfigId-r17 OPTIONAL -- Need N
  • NZP-CSI-RS-Resource :: SEQUENCE ⁇
  • pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
  • pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
  • reportSlotOffsetList SEQUENCE (SIZE (1.. maxNrofUL-Allocations)) OF INTEGER(0..32),
  • reportSlotOffsetList SEQUENCE (SIZE (1..maxNrofUL-Allocations)) OF INTEGER(0..32)
  • subbands15 BIT STRING(SIZE(15)),
  • reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
  • reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
  • reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
  • reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
  • PUCCH-CSI-Resource :: SEQUENCE ⁇
  • rank6-8 SEQUENCE(SIZE(6)) OF PortIndex8 OPTIONAL, -- Need R
  • rank3-4 SEQUENCE(SIZE(3)) OF PortIndex4 OPTIONAL, -- Need R
  • rank4-4 SEQUENCE(SIZE(4)) OF PortIndex4 OPTIONAL -- Need R
  • PortIndex8:: INTEGER (0..7)
  • PortIndex4:: INTEGER (0..3)
  • PortIndex2:: INTEGER (0..1)
  • csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
  • servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
  • the UE reports the channel state information (CSI) reports including SSB Reference Signal Received Power (RSRP), CSI RSRP, synchronization signal block (SSB) Signal to Interference & Noise Ratio (SINR), CSI SINR etc. in Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH) as configured by the network.
  • CSI channel state information
  • RSRP Reference Signal Received Power
  • CSI RSRP CSI Reference Signal Received Power
  • SSB synchronization signal block
  • SINR Signal to Interference & Noise Ratio
  • PUCCH Physical Uplink Control Channel
  • PUSCH Physical Uplink Shared Channel
  • the UE is allowed to perform the validation (such as checking whether message is encoded according to the proper syntax and semantics) of LTM candidate cells either at the time of reception of the LTM candidate cell configuration, or at the time of execution of LTM cell switch.
  • the validation such as checking whether message is encoded according to the proper syntax and semantics
  • circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like.
  • circuits constituting a block may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block.
  • a processor e.g., one or more programmed microprocessors and associated circuitry
  • Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the invention.
  • the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the invention.
  • the gNB and the NR UE are also exemplary and the embodiments are equally applicable for 6G or any other technology. That is, the gNB can be any network node and the UE can be of any technology.
  • Embodiments disclosed herein provide a method and UE for managing measurements for LTM in a telecommunication network.
  • the method includes receiving, by a UE, a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network. Further, the method includes performing, by the UE, L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the method includes reporting, by the UE, the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • the method includes receiving, by the UE, a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements. Further, the method includes performing, by the UE, a switch to the LTM candidate cell based on the MAC CE.
  • the proposed disclosure presents a novel solution for configuring the UE for LTM measurements, specifically in terms of CSI resource and SSB reference signal configuration, by the network apparatus.
  • the invention also addresses methods for reporting LTM measurements to the network apparatus and performing LTM cell switch.
  • the network apparatus is responsible for configuring the UE with information on which CSI-RS resources can be used for LTM measurements, as well as providing a list of candidate cells associated with a CSI resource. Additionally, the network apparatus configures the UE with SSB frequency, subcarrier spacing and a bitmap for configuring the SSB resources.
  • the UE In the event that the UE receives a cell switch command before AS security is activated, the UE will move to RRC_IDLE.
  • the proposed method involves the configuration of resources by the network apparatus (such as gNB) for lower layer triggered mobility measurements, which are received by the UE.
  • the actions of both the gNB and UE during the configuration, performance, and reporting of LTM measurements are disclosed.
  • the network apparatus (such as gNB) informs the UE (via an RRC message) whether a CSI-RS resource can be utilized for LTM measurements and/or provides a list of candidate cells associated with a CSI resource.
  • the network apparatus also provides the UE with cell identifiers (such as physical cell identity or a temporary identifier) associated with the CSI-RS resource.
  • the network apparatus and the UE perform LTM without resetting lower layers (such as MAC) to prevent data loss and minimize the additional delay of data recovery.
  • FIGS. 1 through 7 where similar reference characters denote corresponding features consistently throughout the figures, there are shown example embodiments.
  • FIG. 1 illustrates a telecommunication network (1000) for managing measurements for LTM, according to the embodiments disclosed herein.
  • the telecommunication network (1000) may encompass various forms, including but not restricted to a fourth generation (4G) network, a fifth generation (5G) network, a 6G network, an Open Radio Access Network (ORAN), or similar systems.
  • the telecommunication network (1000) comprises a UE (100) and a network apparatus (200).
  • telecommunication network (1000) and wireless communication system can be used interchangeably.
  • the UE (100) may comprise a diverse range of devices, including but not limited to laptops, smartphones, desktop computers, notebooks, Device-to-Device (D2D) devices, vehicle to everything (V2X) devices, foldable phones, smart TVs, tablets, immersive devices, and internet of things (IoT) devices.
  • the network apparatus (200) may comprise a variety of devices, such as gNBs, eNBs, new radio (NR) trans-receivers, or similar equipment.
  • the network apparatus (such as a gNB or similar device) (200) communicates to the UE (100) (which receives the information via an RRC message) regarding the availability of a CSI-RS resource for LTM measurements and/or a list of potential LTM candidate cells associated with a CSI resource.
  • the network apparatus (200) configures the UE (100) with the CSI-RS configuration for performing measurements for the LTM and for reporting the measured values.
  • the configuration could be provided to the UE (100), either embedded within the RRCReconfiguration for individual LTM candidate configuration (e.g.
  • Including the CSI configuration in LTM candidate cell configuration requires additional coordination between network nodes in case of split architecture, and it doesn't allow sharing of the CSI configurations across LTM candidate cells, but it is simpler for UE implementations as it doesn't require early protocol validations. Thus, this could be a suitable way for the CSI resource configuration for performing LTM measurements. Including the CSI configuration in LTM configuration, outside the LTM candidate configurations avoids early protocol validation and will allow the sharing of the configuration across multiple LTM candidate cells. Thus, it could be a suitable way for the CSI resource configuration for providing the CSI resources for reporting LTM measurements.
  • the network appratus such as a gNB or similar device (200), communicates to the UE (100) the cell identifiers linked with CSI-RS resources.
  • These identifiers may consist of a physical cell identity (PCI), a combination of PCI and frequency, a temporary identifier for the candidate cell, or the candidate cell identifier in the LTM candidate cell configuration.
  • PCI physical cell identity
  • An illustrative configuration is provided below.
  • NZP-CSI-RS-Resource :: SEQUENCE ⁇
  • LTMPCIList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMPCIIndex-r18 OPTIONAL -- Need R
  • the UE (100) conducts measurements on the CSI-RS resource that has been configured as described above, and subsequently relays the L1 CSI-RS RSRP to the network apparatus (e.g. gNB or similar) (200).
  • the CSI-RS RSRP is conveyed through either a PUCCH, PUSCH or UL MAC CE, and encompasses both the candidate cell's identifier and the CSI RSRP measurements.
  • the CSI-RS resource is measured for all candidate cells featuring the PCI in the LTMPCIList-r18.
  • the network apparatus e.g., gNB or the like (200) may provide a list of a combination (e.g., in tandem ASN.1 SEQUENCE) of frequency and PCI values.
  • the network apparatus (such as a gNB) (200) can instruct the UE (100) to receive the LTMCandidateCellIdentifier or LTMCandidateCellIndex as the candidate cell index in the CSI-RS resource configuration.
  • the UE (100) can effectively identify the CSI-RS to be measured for CSI reporting for the candidate cell configured with the aforementioned index (in lieu of the LTMPCIIndex-r18 utilized in the previous embodiment).
  • the network apparatus (200) configures to the UE (100) and the UE (100) receives whether a SSB resource set mapped to the CSI-RS report as in NR RRC IE CSI-SSB-ResourceSet (CSI-SSB-ResourceSet in the proposed method is synonymous with SSB resource set mapped to the CSI-RS report) can be used for LTM measurements.
  • CSI-SSB-ResourceSet in the proposed method is synonymous with SSB resource set mapped to the CSI-RS report
  • the network apparatus (200) configures the UE (100) with the list of identifiers which identifies the candidate cells such as PCI Indices or the list of PCI or other identifiers which identifies the candidate neighbor cells or the list of one or more candidate cell indices, LTMCandidateCellIdentifier or LTMCandidateCellIndex mapping to the LTM candidate cell configurations in CSI-SSBResourceSet.
  • UE (100) performs the L1 measurements and sends the CSI report including the SSB RSRP (in an example, as in NR R17 IE ssb-Index-RSRP) in the CSI report for the cells for which the indices are provided.
  • the network apparatus (200) can provide LTM SSB configuration to the UE (100). For e.g. this may be provided either embedded within the RRCReconfiguration for individual LTM candidate configuration (e.g. within LTMCandidateConfiguration in the background) or within the LTM candidate configuration but outside the RRC Reconfiguration (e.g. within CandLTM-Reconfig in the background) or outside all the LTM candidate configurations (e.g. inside RRCReconfiguration message from the source cell, but outside all CandLTM-Reconfig).
  • LTM candidate configuration e.g. within LTMCandidateConfiguration in the background
  • the RRC Reconfiguration e.g. within CandLTM-Reconfig in the background
  • All the LTM candidate configurations e.g. inside RRCReconfiguration message from the source cell, but outside all CandLTM-Reconfig.
  • Each of these approaches have its own pros and cons, just like in CSI resource configurations.
  • Embedding SSB configuration for LTM within the RRCReconfiguration for individual LTM candidate configuration simplifies the network implementation, especially in the split architectures where gNB is split into Centralized Unit (CU) and Distributed Unit (DU) but for a UE this brings in additional complexities since it requires early decoding of the RRCReconfiguration for the LTM candidate cells.
  • Including the LTM SSB configuration in the LTM candidate cell configuration requires additional coordination between network nodes in case of split architecture, and it doesn't allow sharing of the LTM SSB configurations across LTM candidate cells, but it is simpler for UE implementations as it doesn't require early protocol validations. But such an approach may make linking the LTM SSB configuration and LTM CSI resource configuration complex.
  • Including the CSI configuration in LTM configuration, outside the LTM candidate configurations avoids early protocol validation and will allow the sharing of the configuration across multiple LTM candidate cells and this will be suitable for linking LTM CSI resource configuration and LTM SSB configuration in a signalling efficient way.
  • PCI Physical Cell Identifier
  • csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
  • servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
  • the PCI is the PCI of the serving cell in which the CSI-SSB-ResourceSet is defined;
  • the value is additionalPCIIndex-r17 of an SSB-MTC-AdditionalPCI-r17 configured using the additionalPCI-ToAddModList-r17 in ServingCellConfig
  • the PCI is the additionalPCI-r17 in the SSB-MTC-AdditionalPCI-r17 .
  • gNB includes PCI of candidate cells (including non-serving cells) in the additionalPCI-ToAddModList-r17.
  • the PCI indices of the neighbor cells can be configured in CSI-SSB-ResourceSet using a new list in addition to the servingAdditionalPCIList-r17 in RRC messages like RRC Reconfiguration or RRC Resume.
  • UE (100) receives two separate lists-one for serving cells and one for candidate neighbor cells. The list for the serving cells can be used for R17 Inter Cell Beam Management (ICBM) while the list for candidate neighbor cells could be used for LTM, and in a specific embodiment for ICBM also.
  • ICBM Inter Cell Beam Management
  • csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
  • servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
  • LTMCandidatePCIList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMCandidatePCI Index-r18 OPTIONAL -- Need R
  • a candidate cell information list is provided as an alternative to providing the PCI list.
  • the Candidate cell information list contains list of frequency (ARFCN) and the PCI of the neighboring candidate cells.
  • csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
  • servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
  • LTMCandidateCellInfoList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMCandidateCellInfoIndex-r18 OPTIONAL -- Need R
  • LTM_CandidateCellInformationList SEQUENCE (SIZE(1.. MaxNrCandidateCells)) OF LTMCandidateCellInfo
  • a LTMCandidateCellInfoList-r18 contains the list of indices to the LTM_CandidateCellInformationList.
  • the UE (100) measures the candidate cells (frequency (NR-ARFCN) + PCI) as identified by the indexed in the LTM_CandidateCellInformationList. If the NR-ARFCN is absent, the frequency is considered to be the serving frequency.
  • the LTMCandidateCellInfoList contains a list of LTMCandidateCellIdentifier or LTMCandidateCellIndex as defined in the background.
  • the gNB may configure CSI-SSB-ResourceSet for LTM or Inter Cell Beam Management (NR R17 ICBM).
  • gNB includes servingAdditionalPCIList-r17 in the RRC IE.
  • gNB includes LTMCandidatePCIList-r18 or LTMCandidateCellInfoList-r18 (or similar IEs).
  • the gNB may configure LTM/ICBM both, by including both servingAdditionalPCIList-r17 and LTMCandidatePCIList-r18/LTMCandidateCellInfoList-r18 in reconfiguration message send to the UE (100).
  • the candidate cell when the candidate cell is a serving cell, it may be included only in LTMCandidatePCIList-r18 or only in LTMCandidateCellInfoList-r18 or in both the lists.
  • the SSB frequency may not be included.
  • LTMCandidatePCIList-r18 and LTMCandidateCellInfoList-r18 are exemplary names in these embodiments and represent the list of candidate cells to be measured provided to the UE (100) in different ways.
  • the gNB includes (and the UE (100) receives) the total number of entries in the servingAdditionalPCIList-r17 and the LTMCandidatePCIList-r18/LTMCandidateCellInfoList-r18 as equal to the number of entries in csi-SSB-ResourceList.
  • First entry of the LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 corresponds to the N+1th entry of csi-SSB-ResourceList and the second entry of the LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 corresponds to the N+2th entry of csi-SSB-ResourceList and so on till M entries of LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18.
  • gNB provides one or more of the below IEs to a NR UE (100) for identifying the reference signal on which the L1 measurements to be performed.
  • Information elements are RRC IEs as defined in TS 38.331 v17.3.0. An example is given as below:
  • measCycleSCell ENUMERATED ⁇ sf160, sf256, sf320, sf512, sf640, sf1024, sf1280 ⁇ OPTIONAL -- Need R
  • measCyclePSCell-r17 ENUMERATED ⁇ ms160, ms256, ms320, ms512, ms640, ms1024, ms1280, spare1 ⁇
  • NR-ARFCN and subcarrier spacing provides the frequency domain information of the SSB to be measured for LTM to the UE.
  • the bitmaps included in the SSB-ToMeasure provide the SSB indices to be measured. Depending on the number of beams or the number of SSB indices, one of shortBitmap, mediumBitmap or longBitmap may be used. For e.g. if the cell supports 4 beams, a short bit map is sufficient, if the cell supports 8 beams medium bit map may be used, if the cell supports 64 beams long bit map may be used. In higher frequencies such as frequency range 2 (FR2) long bit map could be useful while in lower frequencies short or medium bit map could be used.
  • the SSB indices could be provided as a list of integers. While this reduces the processing overhead in both network and the UE, it will increase the signalling overhead.
  • the list of PCI indices (or other indices such as candidate cell indices of candidate neighbor cells) of the neighbor cells are configured in CSI-SSB-ResourceSet are mapped to a new list of csi-SSBResourceList for candidate cells.
  • csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
  • servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
  • csi-CandidateSSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
  • LTMCandidatePCIList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMCandidatePCI Index-r18 OPTIONAL -- Need R
  • a candidate cell information list, LTMCandidateCellInfoList-r18 as defined in the previous embodiment is provided as an alternative to providing the PCI list, LTMCandidatePCIList-r18. All the aspects described for the LTMCandidateCellInfo in the previous embodiment is reused. i.e. the gNB includes the IEs for configuring the UE (100) with the reference signal details as given in sections [46],[47] in an embodiment also.
  • a candidate cell information list is provided as an alternative to providing the PCI list as in the previous embodiment, for e.g.
  • LTMCandidateCellInfoList contains a list of LTMCandidateCellIdentifier or LTMCandidateCellIndex as explained defined in the background, instead of the PCI list.
  • gNB when LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 is configured as in the above embodiment, gNB includes (and UE (100) receives) the total number of entries in LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 as equal to the number of entries in the SSB-ResourceList for candidate cells, csi-CandidateSSB-ResourceList.
  • the first entry of the LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 indicates the value of the PCI for the first entry of csi-CandidateSSB-ResourceList
  • the second entry of the list indicates the value of the PCI for the second entry of csi-CandidateSSB-ResourceList, and so on for all the entries in the list.
  • the gNB may send (UE may receive) the candidate cell indices or any other identifier such as PCI itself or any temporary identifiers mapped to the SSB resource list for all the above embodiments.
  • any identifier or index that can map to the given candidate cell can be included in LTMCandidatePCIList-r18 or similar structure in place of PCI indices.
  • the index could be LTMCandidateCellIdentifier or LTMCandidateCellIndex.
  • the gNB sends the SSB configuration and the SSB indices of the neighboring cell in RRC messages such as RRC Reconfiguration send from the source cell.
  • the UE (100) applies the configuration thus received for performing L1 measurements and reporting to the source cell for LTM.
  • target gNB sends the SSB configuration and the SSB indices of the neighboring cell in LTM candidate configuration.
  • the UE (100) applies the SSB configuration and the SSB indices received LTM candidate configuration for performing L1 measurements and reporting to the source cell for the LTM.
  • the UE (100) evaluates the received LTM configuration for a candidate cell before performing the L1 measurements/ before reporting the L1 measurements for the candidate cell.
  • the gNB provides one or more information elements in the following information for the LTM measurement reporting to the UE (100) with reference to NR R17 specification TS 38.331 v17.0.
  • UE (100) identifies the reference signals to be measured through one or more information elements (IE) in the following information.
  • IE information elements
  • one or more IEs from the below are mapped to a candidate cell or a list of candidate cells.
  • measCycleSCell ENUMERATED ⁇ sf160, sf256, sf320, sf512, sf640, sf1024, sf1280 ⁇ OPTIONAL -- Need R
  • measCyclePSCell-r17 ENUMERATED ⁇ ms160, ms256, ms320, ms512, ms640, ms1024, ms1280, spare1 ⁇
  • ReferenceSignalConfig above could include the below (reference to TS 38.331 V17.3.0) for SSB
  • ReferenceSignalConfig above could include the below (reference to TS 38.331 V17.3.0) for the CSI-RS:
  • csi-RS-CellList-Mobility SEQUENCE (SIZE (1..maxNrofCSI-RS-CellsRRM)) OF CSI-RS-CellMobility,
  • nrofPRBs ENUMERATED ⁇ size24, size48, size96, size192, size264 ⁇ ,
  • the gNB configures the UE (100) to report the CSI reports including report quantities such as SSB Index RSRP, CRI RSRP, CRI SINR etc. based on the reference signal configuration configured through measurement object configuration, such as measObjectNR in NR specifications.
  • the gNB provides a mapping between the CSI report identifier and the measurement object identifier.
  • the gNB also may provide list of candidate cells UE (100) measures the reference signals configured through measurement object configuration such as measObjectNR for the LTM candidate cells and reports the same in the CSI reports.
  • pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
  • pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
  • reportSlotOffsetList SEQUENCE (SIZE (1.. maxNrofUL-Allocations)) OF INTEGER(0..32),
  • reportSlotOffsetList SEQUENCE (SIZE (1..maxNrofUL-Allocations)) OF INTEGER(0..32)
  • subbands15 BIT STRING(SIZE(15)),
  • reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
  • reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
  • reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
  • reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
  • reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
  • candidateCellList-r18 SEQUENCE (SIZE (1.. maxNrofcandidateCell-r18)) OF candidateCellId
  • the UE (100) measures the candidate cells in the received candidateCellList-r18 using the reference signals configured within the mapped measurement object (MeasObjectId) and reports using the CSI reports configured through reportConfigId.
  • the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM and has not received Access Stratum (AS) security configuration (or more specifically has not activated AS security configuration), defers sending the layer 1 measurements of candidate cells in CSI reports till AS security is activated as shown in FIG. 5.
  • AS Access Stratum
  • UE (100) defers sending the layer 1 measurements of candidate cells only if they are non-serving cells.
  • UE (100) sends the layers 1 measurements of candidate cells.
  • the measurements reported for above scenario can be SSB RSRP, CSI-RS RSRP or SINR.
  • the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
  • the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM and has not received AS security configuration (or more specifically has not activated AS security configuration), sends the layer 1 measurements of candidate cells in CSI reports even when the AS security is not activated.
  • the measurements reported for above scenario can be SSB RSRP, CSI-RS RSRP or SINR.
  • the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
  • the gNB which has received CSI reports containing LTM measurements defers sending cell switch command till the AS security is activated.
  • the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM and has not received at least one of SRB2 or DRB or MRB configuration (or more specifically has not activated SRB2 or DRB or MRB), defers sending the layer 1 measurements of candidate cells in CSI reports till SRB2 or DRB or MRB is activated.
  • UE (100) defers sending the layer 1 measurements of candidate cells only if they are non-serving cells.
  • UE (100) sends the layers 1 measurements of candidate cells.
  • the measurements reported/deferred for above scenario can be SSB RSRP, CSI RSRP or SINR.
  • the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
  • the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM at least one of SRB2 or DRB or MRB configuration, sends the layer 1 measurements of candidate cells in CSI reports even when the SRB2 or DRB or MRB is not activated.
  • the measurements reported for above scenario can be SSB RSRP, CSI-RS RSRP or SINR.
  • the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
  • the gNB which has received CSI reports containing LTM measurements defers cell switch till at least one of SRB2 or DRB or MRB configuration has been successfully applied at the UE (100).
  • the UE (100) which has received a cell switch command before AS security is activated moves to RRC_IDLE state.
  • UE (100) moves to RRC_IDLE with the release cause "other".
  • the UE (100) only accepts a cell switch command only when AS security has been activated. UE (100) rejects cell switch command if the AS security has not been activated.
  • the gNB sends the LTM candidate cell configuration to the UE (100) only when AS security has been activated, and SRB2 with at least one DRB or multicast MRB or, for IAB, SRB2, are setup and not suspended.
  • FIG. 2 shows various hardware components of the UE (100), according to the embodiments as disclosed herein.
  • the UE (100) includes a processor (110), a communicator (120), a memory (130) and a L1 measurement controller (140).
  • the processor (110) is coupled with the communicator (120), the memory (130) and the L1 measurement controller (140).
  • the L1 measurement controller (140) receives the LTM CSI resource configuration from the source cell for the one or more candidate cells in the LTM and the LTM SSB configuration for each candidate cell in the LTM from the network apparatus (200).
  • the LTM CSI resource configuration is received in the RRC reconfiguration message.
  • the LTM CSI resource configuration includes the CSI resource to be used for the L1 measurements (i.e. for performing L1 measurements or for performing L1 measurement reporting) and the list of one or more candidate cells that are associated to the CSI resource.
  • the LTM CSI resource configuration received when the LTM CSI resource configuration received is for the LTM CSI resources for performing L1 measurements, it may be provided for each LTM candidate cell and may be included in the LTM candidate cell configuration (e.g.
  • the LTM CSI resource configuration received is for the LTM CSI resources for reporting LTM measurements, it may be included in the LTM configuration, for e.g. outside LTM candidate cell configuration.
  • the LTM CSI resource configuration is for the one or more LTM candidate cells and the LTM SSB configuration is per LTM candidate cell.
  • the LTM SSB configuration includes the SSB frequency, the subcarrier spacing and the bitmap of SSB positions in the burst for configuring SSB resources provided within the LTM candidate cell configuration.
  • the SSB positions in burst are provided using 4 bits, 8 bits or 64 bits for the SSB frequency and subcarrier spacing (SSB positions in the burst is for the SSB frequency + subcarrier spacing pair).
  • the L1 measurement controller (140) performs the L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • the L1 measurements are one of the CSI based L1-RSRP measurements, the CSI based L1-SINR measurements and the SSB based L1-RSRP measurement.
  • the L1 measurement controller (140) reports the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration. In an embodiment, the L1 measurement controller (140) performs the L1 measurements for all the plurality of candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration. Further, the L1 measurement controller (140) transmits the L1 measurements to the network apparatus (200) for the LTM.
  • the L1 measurement controller (140) performs the L1 measurements for the one more candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration. Further, the L1 measurement controller (140) transmits the L1 measurements for the one or more candidate cell to the source cell of the network apparatus (200) for the LTM.
  • the L1 measurement controller (140) receives the MAC CE to perform switching to the LTM candidate cell from the source cell based on the L1 measurements. Further, the L1 measurement controller (140) performs the switch to the LTM candidate cell based on the MAC CE.
  • the L1 measurement controller (140) receives the cell switch command from the network apparatus (200). Further, the L1 measurement controller (140) determines whether the AS security is activated. Further, the L1 measurement controller (140) transitions the UE (100) to the RRC_IDLE state with release cause 'other' when the AS security is not activated.
  • the L1 measurement controller (140) is a innovative hardware incorporated in the UE (100) through the use of analog and/or digital circuits, including logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive and active electronic components, optical components, hardwired circuits, and the like. Additionally, it may be optionally powered by firmware.
  • This cutting-edge hardware L1 measurement controller (140) is purposefully integrated within the UE to handle measurements for lower layer triggered mobility in telecommunication networks.
  • the L1 measurement controller (140) is seamlessly integrated as a circuit or an additional core that adeptly configures the UE (100) for LTM measurements, specifically the CSI resource and SSB reference signal configuration, as directed by the network apparatus (200).
  • the L1 measurement controller (140) also efficiently reports the LTM measurements to the network apparatus (200) and performs LTM cell switching.
  • the processor (110) may include one or a plurality of processors.
  • the one or the plurality of processors may be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and/or an AI-dedicated processor such as a neural processing unit (NPU).
  • the processor (110) may include multiple cores and is configured to execute the instructions stored in the memory (130).
  • the processor (110) is configured to execute instructions stored in the memory (130) and to perform various processes.
  • the communicator (120) is configured for communicating internally between internal hardware components and with external devices via one or more networks.
  • the memory (130) also stores instructions to be executed by the processor (110).
  • the memory (130) may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories.
  • EPROM electrically programmable memories
  • EEPROM electrically erasable and programmable
  • the memory (130) may, in some examples, be considered a non-transitory storage medium.
  • non-transitory may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term “non-transitory” should not be interpreted that the memory (130) is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache).
  • RAM Random Access Memory
  • the communicator (120) includes an electronic circuit specific to a standard that enables wired or wireless communication.
  • the communicator (120) is configured to communicate internally between internal hardware components of the UE (100) and with external devices via one or more networks.
  • FIG. 2 shows various hardware components of the UE (100) but it is to be understood that other embodiments are not limited thereon. In other embodiments, the UE (100) may include less or more number of components. Further, the labels or names of the components are used only for illustrative purpose and does not limit the scope of the invention. One or more components can be combined together to perform same or substantially similar function in the UE (100).
  • FIG. 3 is a flow chart (S300) illustrating a method for managing measurements for the LTM in the telecommunication network (1000), according to the embodiments disclosed herein.
  • the operations (S302-S310) are handled by the L1 measurement controller (140).
  • the method includes receiving the LTM CSI resource configuration from the source cell for the one or more candidate cells in the LTM and the LTM SSB configuration for each candidate cell in the LTM from the network apparatus (200).
  • the method includes performing the L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • the method includes reporting the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration.
  • the method includes receiving the MAC CE to perform switching to the LTM candidate cell from the source cell based on the L1 measurements.
  • the method includes performing the switch to the LTM candidate cell based on the MAC CE.
  • FIG. 4 illustrates a sequence diagram of the LTM configuration, according to the embodiments disclosed herein.
  • the RRC of the gNB sends the RRC Reconfiguration including the CSI-MeasConfig with mapping of LTM candidate cells to the reference signals to be measured in the CSI-RS resource configuration/CSI-report configuration, the CSI SSB resource set configuration etc., to the RRC of the UE (100).
  • the RRC of the UE (100) sends the RRC Reconfiguration complete to the RRC of gNB.
  • L1/L2 of the UE (100) performs the LTM measurements (e.g., L1 measurements).
  • the L1/L2 of the UE (100) sends the L1 measurements to the source -L1/L2.
  • the source -L1/L2 triggers the LTM to the L1/L2 of UE (100).
  • FIG. 5 illustrates a flow diagram (S500) of the CSI reporting for the LTM based on the AS security activation, according to the embodiments disclosed herein.
  • the operations (S502-S510) are handled by the L1 measurement controller (140).
  • the method includes receiving the configuration for the CSI reporting for the candidate cells in the LTM.
  • the method includes performing the L1 measurements.
  • the method includes determining whether the AS security is active?
  • the method includes reporting the CSI measurements for all the candidate cells.
  • the method includes deferring reporting the CSI measurements for the non-serving candidate cells till the AS security is activated. The method includes reporting the CSI measurements for serving candidate cells.
  • FIG. 6 illustrates a flow diagram (S600) of the CSI reporting for LTM based on radio bearer configuration, according to the embodiments disclosed herein.
  • the operations (S602-S610) are handled by the L1 measurement controller (140).
  • the method includes receiving the configuration for the CSI reporting for the candidate cells in the LTM.
  • the method includes performing the L1 measurements.
  • the method includes determining whether the SRB2 and the DRB or MRB is active?
  • the method includes reporting the CSI measurements for all the candidate cells.
  • the method includes deferring reporting the CSI measurements for non-serving candidate cells till AS security is activated. The method includes reporting the CSI measurements for serving candidate cells.
  • FIG. 7 illustrates a flow diagram (S700) of the cell switch command handling without AS security activation, according to the embodiments disclosed herein.
  • the operations (S702-S708) are handled by the L1 measurement controller (140).
  • the method includes receiving the cell switch command.
  • the method includes determining whether the AS security is active?
  • the method includes performing LTM cell switch to the indicated candidate cell.
  • the method includes moving the UE (100) to the RRC_IDLE.
  • the proposed solution addresses methods for configuring the UE (100) for LTM measurements, specifically the CSI resource and SSB reference signal configuration, by the network apparatus (200).
  • the proposed solution also addresses methods for reporting the LTM measurements to the network apparatus (200) and performing LTM cell switch.

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Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method of a user equipment (UE) in a wireless communication system, the method comprising: receiving, from a network apparatus (200), a radio resource control (RRC) message including a lower layer triggered mobility (LTM) channel state information (CSI) resource configuration for one or more LTM candidate cells and a LTM synchronization signal block (SSB) configuration for each LTM candidate cell; performing layer 1 (L1) measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration; transmitting, to the network apparatus (200), an L1 measurement report for the one or more candidate cells based on theL1 measurements; based on the transmission of the L1 measurements, receiving, from the network apparatus (200), a medium access control control-element (MAC CE) to perform a LTM cell switch procedure; and performing the LTM cell switch procedure based on the MAC CE.

Description

HANDLING MEASUREMENTS FOR LOWER LAYER TRIGGERED MOBILITY IN TELECOMMUNICATION NETWORK
The present invention generally relates to wireless communication networking and more particularly relates to a method and system for configuring, performing measurements and reporting measurements for Lower layer Triggered Mobility (LTM) in a telecommunication network.
Fifth generation (5G) mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6 gigahertz (GHz)" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as millimeter wave (mmWave) including 28GHz and 39GHz. In addition, it has been considered to implement sixth generation (6G) mobile communication technologies (referred to as Beyond 5G systems) in terahertz (THz) bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.
At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive multi input multi output (MIMO) for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BandWidth Part (BWP), new channel coding methods such as a Low Density Parity Check (LDPC) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.
Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as Vehicle-to-everything (V2X) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, New Radio Unlicensed (NR-U) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, new radio (NR) user equipment (UE) Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.
Moreover, there has been ongoing standardization in air interface architecture/protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, Integrated Access and Backhaul (IAB) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and Dual Active Protocol Stack (DAPS) handover, and two-step random access for simplifying random access procedures (2-step random access channel (RACH) for NR). There also has been ongoing standardization in system architecture/service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.
As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting Augmented Reality (AR), Virtual Reality (VR), Mixed Reality (MR) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.
Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and Artificial Intelligence (AI) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.
In wireless technologies like Fifth Generation (5G) New Radio (NR), devices (e.g., User Equipment (UE) or the like) can move across different cells. Mobility is performed using a procedure called cell reselection in an RRC_IDLE mode. Till NR R17, mobility is performed using a procedure called handover in an RRC_CONNECTED mode. Network controlled mobility applies to the UE in the RRC_CONNECTED and requires explicit radio resource control (RRC) signaling to be triggered by a gNB in the NR. Handover in the NR usually consists of three steps: handover preparation step, handover execution step and handover completion step. The gNB may configure the UE to report measurements. Based on the reported measurements or based on its own understanding of a network topology, the gNB sends a RRC Reconfiguration message to handover the UE to another cell called a target cell from a source cell. The UE accesses the target cell and sends the RRC Reconfiguration complete message. In an alternative way introduced in Third Generation Partnership Project (3GPP) NR release 16, the gNB may configure the UE with the execution conditions for triggering handover and once the execution conditions are satisfied, the UE may move to the target cell and sends the RRC Reconfiguration complete. The 3GPP is also introduced a new handover called Dual Active Protocol Stack (DAPS) handover in release 16. In all these methods, the UE performs the handover by sending layer 3 (RRC) messages which causes considerable signalling overhead and latency issues. Further, the handover and conditional handover (CHO) refer as layer 3 mobility. In case of dual connectivity, the UE may perform a PSCellChange or a Conditional PSCellChange. In the context of the dual connectivity, the patent disclosure refers PSCellChange or Conditional PSCellChange also as layer 3 mobility. That is, the Handover, the Conditional Handover, the PSCellChange, the Conditional PSCellChange etc. refer to the L3 mobility. Further, the PSCellChange or the Conditional PSCellChange refer as SCG layer 3 mobility and the handover and CHO as Master Cell Group (MCG) layer 3 mobility in the context of dual connectivity. The L3 mobility may be performed based on L3 measurements reported in RRC messages.
Further, the UE may receive RRC configuration for updating some of security parameters. For the purpose of patent disclosure, consider the 3GPP specifications such as TS38.300, TS38.331, TS 38.321 V17.3.0 as relevant background.
Further, the 3GPP release 18 is considering Lower Layers (L1/L2 layers) Triggered Mobility, also known as Lower layer Triggered Mobility (LTM) to solve the problem related to latency, signalling overhead etc. associated with layer 3 mobility. As per 3GPP, the goal of LTM is to enable a serving cell change via L1/L2 signalling, in order to reduce the latency, overhead and interruption time. The network (e.g., gNB) may configure the UE with multiple candidate cells to allow fast application of configurations for candidate cells. The network may further send Medium Access Control (MAC) Control Element (CE) or L1 signalling to dynamically switch the UE from the source cell to one of the configured candidate cells. Further, the LTM can be triggered based on L1 measurements rather than L3 measurements.
The present disclosure relates to wireless communication systems and, more specifically, the invention relates to methods and wireless network for handling measurements for lower layer triggered mobility in telecommunication network.
The principal object of the embodiments herein is to provide a method and a UE for managing measurements for LTM in a telecommunication network.
Another object of the embodiments herein is to receive a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network.
Another object of the embodiments herein is to perform Layer 1 (L1) measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration.
Another object of the embodiments herein is to report the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration.
Another object of the embodiments herein is to receive a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements.
Another object of the embodiments herein is to perform a switch to the LTM candidate cell based on the MAC CE.
Another object of the embodiments herein is to provide that the network apparatus (e.g., gNB or the like) that configures the UE whether a CSI-RS resource (i.e. which CSI-RS resources) can be used for LTM measurements and the list of candidate cells that are associated to a CSI resource.
Another object of the embodiments herein is to provide that the network apparatus (e.g., gNB or the like) that configures the UE with the SSB frequency, subcarrier spacing and a bitmap for configuring the SSB resources.
Another object of the embodiments herein is to provide that the UE moves to an RRC_IDLE when the UE receives the cell switch command before the AS security is activated.
Embodiments disclosed herein provide a method for managing measurements for LTM in a telecommunication network. The method includes receiving, by a UE, a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network. Further, the method includes performing, by the UE, Layer 1 (L1) measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the method includes reporting, by the UE, the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the method includes receiving, by the UE, a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements. Further, the method includes performing, by the UE, a switch to the LTM candidate cell based on the MAC CE.
Embodiments disclosed herein provide a UE for managing measurements for LTM in a telecommunication network. The UE includes a L1 measurement controller coupled to a memory and a processor. The L1 measurement controller is configured to receive a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network. Further, the L1 measurement controller is configured to perform L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the L1 measurement controller is configured to report the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the L1 measurement controller is configured to receive a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements. Further, the L1 measurement controller is configured to perform a switch to the LTM candidate cell based on the MAC CE.
In an embodiment, the L1 measurements is one of CSI based L1-RSRP measurements, CSI based L1-SINR measurements and SSB based L1-RSRP measurement.
In an embodiment, the LTM CSI resource configuration includes a CSI resource to be used for the L1 measurements and a list of one or more candidate cells that are associated to the CSI resource.
In an embodiment, the LTM SSB configuration includes a SSB frequency, a subcarrier spacing and a bitmap of SSB positions in a burst for configuring SSB resources provided within a LTM candidate cell configuration.
In an embodiment, the LTM CSI resource configuration is for the one or more LTM candidate cells and the LTM SSB configuration is per LTM candidate cell.
In an embodiment, the SSB positions in burst are provided using 4 bits, 8 bits or 64 bits for the SSB frequency and subcarrier spacing.
In an embodiment, reporting the L1 measurements for all the plurality of candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration includes performing, by the UE, the L1 measurements for all the plurality of candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration, and transmitting, by the UE, the L1 measurements to the network apparatus for the LTM.
In an embodiment, reporting the L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration includes performing, by the UE, the L1 measurements for the one more candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration, and transmitting, by the UE, the L1 measurements for the one or more candidate cell to the source cell of the network apparatus for the LTM.
In an embodiment, the LTM CSI resource configuration is received in a RRC reconfiguration message.
In an embodiment, the method includes receiving, by the UE, a cell switch command from the network apparatus. Further, the method includes determining, by the UE, whether an Access Stratum (AS) security is activated. Further, the method includes transitioning, by the UE to RRC_IDLE state with release cause 'other' when the AS security is not activated.
These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the scope thereof, and the embodiments herein include all such modifications.
In an embodiment, a method of a user equipment (UE) in a wireless communication system, the method comprising: receiving, from a network apparatus (200), a radio resource control (RRC) message including a lower layer triggered mobility (LTM) channel state information (CSI) resource configuration for one or more LTM candidate cells and a LTM synchronization signal block (SSB) configuration for each LTM candidate cell; performing layer 1 (L1) measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration; transmitting, to the network apparatus (200), an L1 measurement report for the one or more candidate cells based on theL1 measurements; based on the transmission of the L1 measurements, receiving, from the network apparatus (200), a medium access control control-element (MAC CE) to perform a LTM cell switch procedure; and performing the LTM cell switch procedure based on the MAC CE.
In another embodiment, a user equipment (UE) in a wireless communication system, the UE comprising: a transceiver; and a processor configured to: receive, from a network apparatus (200), a radio resource control (RRC) message including a lower layer triggered mobility (LTM) channel state information (CSI) resource configuration for one or more LTM candidate cells and a LTM synchronization signal block (SSB) configuration for each LTM candidate cell, perform layer 1 (L1) measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration, transmit, to the network apparatus (200), an L1 measurement report for the one or more candidate cells based on theL1 measurements, based on the transmission of the L1 measurements, receive, from the network apparatus (200), a medium access control control-element (MAC CE) to perform a LTM cell switch procedure, and perform the LTM cell switch procedure based on the MAC CE.
Advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
FIG. 1 illustrates a telecommunication network for managing measurements for LTM, according to the embodiments disclosed herein.
FIG. 2 shows various hardware components of a UE, according to the embodiments as disclosed herein.
FIG. 3 is a flow chart illustrating a method for managing measurements for the LTM in the telecommunication network, according to the embodiments disclosed herein.
FIG. 4 illustrates a sequence diagram of a LTM configuration, according to the embodiments disclosed herein.
FIG. 5 illustrates a flow diagram of a CSI reporting for LTM based on AS security activation, according to the embodiments disclosed herein.
FIG. 6 illustrates a flow diagram of a CSI reporting for LTM based on radio bearer configuration, according to the embodiments disclosed herein.
FIG. 7 illustrates a flow diagram of a cell switch command handling without AS security activation, according to the embodiments disclosed herein.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
The 3GPP proposes to perform the LTM, without reset of lower layers like MAC to avoid data loss and to reduce the additional delay of data recovery wherever it is possible. Further, the gNB may provide a LTMCandidateConfiguration, i.e. configure LTM candidate cells through one RRCReconfiguration message for a candidate target cell or through one CellGroupConfig for each candidate target cell or through any similar RRC structure or IE containing the similar fields (for e.g. a new IE LTM-CandidateConfig can be defined as ASN.1 sequence containing CellGroupConfig and some other information elements in the RRCReconfiguration). The gNB may further release or modify the candidate configurations. The UE may store the LTM configuration of other candidate cells even after moving to a candidate cell through the LTM. The gNB also may provide the UE with configuration for performing LTM measurements for different candidate frequencies and candidate cells and reporting based on the performed LTM measurements. Each cell in the candidate cell configuration can be identified by a candidate cell identifier (e.g. LTMCandidateCellIdentifier or LTMCandidateCellIndex). An example structure is given below:
CandLTM-Reconfig ::= SEQUENCE {
LTMCandidateCellIdentifier INTEGER (1..MaxNrCandidateCells)
<CELL GROUP CONFIG and other IEs for the candidate cell configuration>
}
Based on the received LTM measurements, the gNB may command the UE to switch the cell to any of the candidate cells. This could be done by sending a Medium Access Control Control-Element (MAC CE) or L1 signaling. The MAC CE or the L1 signaling used for switching to another candidate cell in the LTM is called a cell switch command. The cell switch command can contain an identifier for the candidate cell such as the candidate cell identifier (e.g., LTMCandidateCellIdentifier or LTMCandidateCellIndex as mentioned above).
CSI Measurements: In NR R17, the UE reports the L1 measurements using Channel State Information (CSI) measurement reports. The gNB configures the UE for the CSI measurements using RRC IE CSI_MeasConfig as defined below.
CSI-MeasConfig ::= SEQUENCE {
nzp-CSI-RS-ResourceToAddModList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-Resource OPTIONAL, -- Need N
nzp-CSI-RS-ResourceToReleaseList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-Resources)) OF NZP-CSI-RS-ResourceId OPTIONAL, -- Need N
nzp-CSI-RS-ResourceSetToAddModList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSet
OPTIONAL, -- Need N
nzp-CSI-RS-ResourceSetToReleaseList SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourceSets)) OF NZP-CSI-RS-ResourceSetId
OPTIONAL, -- Need N
csi-IM-ResourceToAddModList SEQUENCE (SIZE (1..maxNrofCSI-IM-Resources)) OF CSI-IM-Resource OPTIONAL, -- Need N
csi-IM-ResourceToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-IM-Resources)) OF CSI-IM-ResourceId OPTIONAL, -- Need N
csi-IM-ResourceSetToAddModList SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSets)) OF CSI-IM-ResourceSet OPTIONAL, -- Need N
csi-IM-ResourceSetToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-IM-ResourceSets)) OF CSI-IM-ResourceSetId OPTIONAL, -- Need N
csi-SSB-ResourceSetToAddModList SEQUENCE (SIZE (1..maxNrofCSI-SSB-ResourceSets)) OF CSI-SSB-ResourceSet OPTIONAL, -- Need N
csi-SSB-ResourceSetToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-SSB-ResourceSets)) OF CSI-SSB-ResourceSetId OPTIONAL, -- Need N
csi-ResourceConfigToAddModList SEQUENCE (SIZE (1..maxNrofCSI-ResourceConfigurations)) OF CSI-ResourceConfig
OPTIONAL, -- Need N
csi-ResourceConfigToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-ResourceConfigurations)) OF CSI-ResourceConfigId
OPTIONAL, -- Need N
csi-ReportConfigToAddModList SEQUENCE (SIZE (1..maxNrofCSI-ReportConfigurations)) OF CSI-ReportConfig OPTIONAL, -- Need N
csi-ReportConfigToReleaseList SEQUENCE (SIZE (1..maxNrofCSI-ReportConfigurations)) OF CSI-ReportConfigId
OPTIONAL, -- Need N
reportTriggerSize INTEGER (0..6) OPTIONAL, -- Need M
aperiodicTriggerStateList SetupRelease { CSI-AperiodicTriggerStateList } OPTIONAL, -- Need M
semiPersistentOnPUSCH-TriggerStateList SetupRelease { CSI-SemiPersistentOnPUSCH-TriggerStateList } OPTIONAL, -- Need M
...,
[[
reportTriggerSizeDCI-0-2-r16 INTEGER (0..6) OPTIONAL -- Need R
]],
[[
sCellActivationRS-ConfigToAddModList-r17 SEQUENCE (SIZE (1..maxNrofSCellActRS-r17)) OF SCellActivationRS-Config-r17 OPTIONAL, -- Need N
sCellActivationRS-ConfigToReleaseList-r17 SEQUENCE (SIZE (1..maxNrofSCellActRS-r17)) OF SCellActivationRS-ConfigId-r17 OPTIONAL -- Need N
]]
}
ASN1START
TAG-NZP-CSI-RS-RESOURCE-START
NZP-CSI-RS-Resource ::= SEQUENCE {
nzp-CSI-RS-ResourceId NZP-CSI-RS-ResourceId,
resourceMapping CSI-RS-ResourceMapping,
powerControlOffset INTEGER (-8..15),
powerControlOffsetSS ENUMERATED{db-3, db0, db3, db6} OPTIONAL, -- Need R
scramblingID ScramblingId,
periodicityAndOffset CSI-ResourcePeriodicityAndOffset OPTIONAL, -- Cond PeriodicOrSemiPersistent
qcl-InfoPeriodicCSI-RS TCI-StateId OPTIONAL, -- Cond Periodic
...
}
TAG-NZP-CSI-RS-RESOURCE-STOP
ASN1STOP
ASN1START
TAG-CSI-RS-RESOURCEMAPPING-START
CSI-RS-ResourceMapping ::= SEQUENCE {
frequencyDomainAllocation CHOICE {
row1 BIT STRING (SIZE (4)),
row2 BIT STRING (SIZE (12)),
row4 BIT STRING (SIZE (3)),
other BIT STRING (SIZE (6))
},
nrofPorts ENUMERATED {p1,p2,p4,p8,p12,p16,p24,p32},
firstOFDMSymbolInTimeDomain INTEGER (0..13),
firstOFDMSymbolInTimeDomain2 INTEGER (2..12) OPTIONAL, -- Need R
cdm-Type ENUMERATED {noCDM, fd-CDM2, cdm4-FD2-TD2, cdm8-FD2-TD4},
density CHOICE {
dot5 ENUMERATED {evenPRBs, oddPRBs},
one NULL,
three NULL,
spare NULL
},
freqBand CSI-FrequencyOccupation,
...
}
ASN1START
TAG-CSI-REPORTCONFIG-START
CSI-ReportConfig ::= SEQUENCE {
reportConfigId CSI-ReportConfigId,
carrier ServCellIndex OPTIONAL, -- Need S
resourcesForChannelMeasurement CSI-ResourceConfigId,
csi-IM-ResourcesForInterference CSI-ResourceConfigId OPTIONAL, -- Need R
nzp-CSI-RS-ResourcesForInterference CSI-ResourceConfigId OPTIONAL, -- Need R
reportConfigType CHOICE {
periodic SEQUENCE {
reportSlotConfig CSI-ReportPeriodicityAndOffset,
pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
},
semiPersistentOnPUCCH SEQUENCE {
reportSlotConfig CSI-ReportPeriodicityAndOffset,
pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
},
semiPersistentOnPUSCH SEQUENCE {
reportSlotConfig ENUMERATED {sl5, sl10, sl20, sl40, sl80, sl160, sl320},
reportSlotOffsetList SEQUENCE (SIZE (1.. maxNrofUL-Allocations)) OF INTEGER(0..32),
p0alpha P0-PUSCH-AlphaSetId
},
aperiodic SEQUENCE {
reportSlotOffsetList SEQUENCE (SIZE (1..maxNrofUL-Allocations)) OF INTEGER(0..32)
}
},
reportQuantity CHOICE {
none NULL,
cri-RI-PMI-CQI NULL,
cri-RI-i1 NULL,
cri-RI-i1-CQI SEQUENCE {
pdsch-BundleSizeForCSI ENUMERATED {n2, n4} OPTIONAL -- Need S
},
cri-RI-CQI NULL,
cri-RSRP NULL,
ssb-Index-RSRP NULL,
cri-RI-LI-PMI-CQI NULL
},
reportFreqConfiguration SEQUENCE {
cqi-FormatIndicator ENUMERATED { widebandCQI, subbandCQI } OPTIONAL, -- Need R
pmi-FormatIndicator ENUMERATED { widebandPMI, subbandPMI } OPTIONAL, -- Need R
csi-ReportingBand CHOICE {
subbands3 BIT STRING(SIZE(3)),
subbands4 BIT STRING(SIZE(4)),
subbands5 BIT STRING(SIZE(5)),
subbands6 BIT STRING(SIZE(6)),
subbands7 BIT STRING(SIZE(7)),
subbands8 BIT STRING(SIZE(8)),
subbands9 BIT STRING(SIZE(9)),
subbands10 BIT STRING(SIZE(10)),
subbands11 BIT STRING(SIZE(11)),
subbands12 BIT STRING(SIZE(12)),
subbands13 BIT STRING(SIZE(13)),
subbands14 BIT STRING(SIZE(14)),
subbands15 BIT STRING(SIZE(15)),
subbands16 BIT STRING(SIZE(16)),
subbands17 BIT STRING(SIZE(17)),
subbands18 BIT STRING(SIZE(18)),
...,
subbands19-v1530 BIT STRING(SIZE(19))
} OPTIONAL -- Need S
} OPTIONAL, -- Need R
timeRestrictionForChannelMeasurements ENUMERATED {configured, notConfigured},
timeRestrictionForInterferenceMeasurements ENUMERATED {configured, notConfigured},
codebookConfig CodebookConfig OPTIONAL, -- Need R
dummy ENUMERATED {n1, n2} OPTIONAL, -- Need R
groupBasedBeamReporting CHOICE {
enabled NULL,
disabled SEQUENCE {
nrofReportedRS ENUMERATED {n1, n2, n3, n4} OPTIONAL -- Need S
}
},
cqi-Table ENUMERATED {table1, table2, table3, table4-r17} OPTIONAL, -- Need R
subbandSize ENUMERATED {value1, value2},
non-PMI-PortIndication SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourcesPerConfig)) OF PortIndexFor8Ranks OPTIONAL, -- Need R
...,
[[
semiPersistentOnPUSCH-v1530 SEQUENCE {
reportSlotConfig-v1530 ENUMERATED {sl4, sl8, sl16}
} OPTIONAL -- Need R
]],
[[
semiPersistentOnPUSCH-v1610 SEQUENCE {
reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
} OPTIONAL, -- Need R
aperiodic-v1610 SEQUENCE {
reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
} OPTIONAL, -- Need R
reportQuantity-r16 CHOICE {
cri-SINR-r16 NULL,
ssb-Index-SINR-r16 NULL
} OPTIONAL, -- Need R
codebookConfig-r16 CodebookConfig-r16 OPTIONAL -- Need R
]],
[[
cqi-BitsPerSubband-r17 ENUMERATED {bits4} OPTIONAL, -- Need R
groupBasedBeamReporting-v1710 SEQUENCE {
nrofReportedGroups-r17 ENUMERATED {n1, n2, n3, n4}
} OPTIONAL, -- Need R
codebookConfig-r17 CodebookConfig-r17 OPTIONAL, -- Need R
sharedCMR-r17 ENUMERATED {enable} OPTIONAL, -- Need R
csi-ReportMode-r17 ENUMERATED {mode1, mode2} OPTIONAL, -- Need R
numberOfSingleTRP-CSI-Mode1-r17 ENUMERATED {n0, n1, n2} OPTIONAL, -- Need R
reportQuantity-r17 CHOICE {
cri-RSRP-Index-r17 NULL,
ssb-Index-RSRP-Index-r17 NULL,
cri-SINR-Index-r17 NULL,
ssb-Index-SINR-Index-r17 NULL
} OPTIONAL -- Need R
]],
[[
semiPersistentOnPUSCH-v1720 SEQUENCE {
reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
} OPTIONAL, -- Need R
aperiodic-v1720 SEQUENCE {
reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
} OPTIONAL -- Need R
]],
[[
codebookConfig-v1730 CodebookConfig-v1730 OPTIONAL -- Need R
]]
}
CSI-ReportPeriodicityAndOffset ::= CHOICE {
slots4 INTEGER(0..3),
slots5 INTEGER(0..4),
slots8 INTEGER(0..7),
slots10 INTEGER(0..9),
slots16 INTEGER(0..15),
slots20 INTEGER(0..19),
slots40 INTEGER(0..39),
slots80 INTEGER(0..79),
slots160 INTEGER(0..159),
slots320 INTEGER(0..319)
}
PUCCH-CSI-Resource ::= SEQUENCE {
uplinkBandwidthPartId BWP-Id,
pucch-Resource PUCCH-ResourceId
}
PortIndexFor8Ranks ::= CHOICE {
portIndex8 SEQUENCE{
rank1-8 PortIndex8 OPTIONAL, -- Need R
rank2-8 SEQUENCE(SIZE(2)) OF PortIndex8 OPTIONAL, -- Need R
rank3-8 SEQUENCE(SIZE(3)) OF PortIndex8 OPTIONAL, -- Need R
rank4-8 SEQUENCE(SIZE(4)) OF PortIndex8 OPTIONAL, -- Need R
rank5-8 SEQUENCE(SIZE(5)) OF PortIndex8 OPTIONAL, -- Need R
rank6-8 SEQUENCE(SIZE(6)) OF PortIndex8 OPTIONAL, -- Need R
rank7-8 SEQUENCE(SIZE(7)) OF PortIndex8 OPTIONAL, -- Need R
rank8-8 SEQUENCE(SIZE(8)) OF PortIndex8 OPTIONAL -- Need R
},
portIndex4 SEQUENCE{
rank1-4 PortIndex4 OPTIONAL, -- Need R
rank2-4 SEQUENCE(SIZE(2)) OF PortIndex4 OPTIONAL, -- Need R
rank3-4 SEQUENCE(SIZE(3)) OF PortIndex4 OPTIONAL, -- Need R
rank4-4 SEQUENCE(SIZE(4)) OF PortIndex4 OPTIONAL -- Need R
},
portIndex2 SEQUENCE{
rank1-2 PortIndex2 OPTIONAL, -- Need R
rank2-2 SEQUENCE(SIZE(2)) OF PortIndex2 OPTIONAL -- Need R
},
portIndex1 NULL
}
PortIndex8::= INTEGER (0..7)
PortIndex4::= INTEGER (0..3)
PortIndex2::= INTEGER (0..1)
TAG-CSI-REPORTCONFIG-STOP
ASN1STOP
ASN1START
TAG-CSI-SSB-RESOURCESET-START
CSI-SSB-ResourceSet ::= SEQUENCE {
csi-SSB-ResourceSetId CSI-SSB-ResourceSetId,
csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
...,
[[
servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
]]
}
ServingAdditionalPCIIndex-r17 ::= INTEGER(0..maxNrofAdditionalPCI-r17)
TAG-CSI-SSB-RESOURCESET-STOP
ASN1STOP
Further, the UE reports the channel state information (CSI) reports including SSB Reference Signal Received Power (RSRP), CSI RSRP, synchronization signal block (SSB) Signal to Interference & Noise Ratio (SINR), CSI SINR etc. in Physical Uplink Control Channel (PUCCH) or Physical Uplink Shared Channel (PUSCH) as configured by the network.
Further, the UE is allowed to perform the validation ( such as checking whether message is encoded according to the proper syntax and semantics) of LTM candidate cells either at the time of reception of the LTM candidate cell configuration, or at the time of execution of LTM cell switch.
For the purpose of the patent disclosure, consider TS 38.331,TS 38.321,TS 38.300 and all other specifications in TS 38.3XX series are referred as relevant background. The 3GPP release v17.3.0 of the above mentioned specifications serve as version for the background.
The above information is presented as background information only to help the reader to understand the present invention. Applicants have made no determination and make no assertion as to whether any of the above might be applicable as prior art with regard to the present application.
Various embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. In the following description, specific details such as detailed configuration and components are merely provided to assist the overall understanding of these embodiments of the present disclosure. Therefore, it should be apparent to those skilled in the art that various changes and modifications of the embodiments described herein can be made without departing from the scope of the present disclosure. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.
Herein, the term "or" as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
As is traditional in the field, embodiments may be described and illustrated in terms of blocks which carry out a described function or functions. These blocks, which may be referred to herein as units or modules or the like, are physically implemented by analog or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits, or the like, and may optionally be driven by firmware. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like. The circuits constituting a block may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the invention. Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the invention.
The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
In the patent disclosure, the gNB and the NR UE are also exemplary and the embodiments are equally applicable for 6G or any other technology. That is, the gNB can be any network node and the UE can be of any technology.
Embodiments disclosed herein provide a method and UE for managing measurements for LTM in a telecommunication network. The method includes receiving, by a UE, a LTM CSI resource configuration from a source cell for one or more candidate cells in the LTM and a LTM SSB configuration for each candidate cell in LTM from a network apparatus in the telecommunication network. Further, the method includes performing, by the UE, L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the method includes reporting, by the UE, the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration. Further, the method includes receiving, by the UE, a MAC CE to perform switching to a LTM candidate cell from the source cell based on the L1 measurements. Further, the method includes performing, by the UE, a switch to the LTM candidate cell based on the MAC CE.
The proposed disclosure presents a novel solution for configuring the UE for LTM measurements, specifically in terms of CSI resource and SSB reference signal configuration, by the network apparatus. The invention also addresses methods for reporting LTM measurements to the network apparatus and performing LTM cell switch.
The network apparatus is responsible for configuring the UE with information on which CSI-RS resources can be used for LTM measurements, as well as providing a list of candidate cells associated with a CSI resource. Additionally, the network apparatus configures the UE with SSB frequency, subcarrier spacing and a bitmap for configuring the SSB resources.
In the event that the UE receives a cell switch command before AS security is activated, the UE will move to RRC_IDLE.
The proposed method involves the configuration of resources by the network apparatus (such as gNB) for lower layer triggered mobility measurements, which are received by the UE. The actions of both the gNB and UE during the configuration, performance, and reporting of LTM measurements are disclosed.
In one embodiment, the network apparatus (such as gNB) informs the UE (via an RRC message) whether a CSI-RS resource can be utilized for LTM measurements and/or provides a list of candidate cells associated with a CSI resource. The network apparatus also provides the UE with cell identifiers (such as physical cell identity or a temporary identifier) associated with the CSI-RS resource.
Moreover, the network apparatus and the UE perform LTM without resetting lower layers (such as MAC) to prevent data loss and minimize the additional delay of data recovery.
Referring now to the drawings, and more particularly to FIGS. 1 through 7, where similar reference characters denote corresponding features consistently throughout the figures, there are shown example embodiments.
FIG. 1 illustrates a telecommunication network (1000) for managing measurements for LTM, according to the embodiments disclosed herein. The telecommunication network (1000) may encompass various forms, including but not restricted to a fourth generation (4G) network, a fifth generation (5G) network, a 6G network, an Open Radio Access Network (ORAN), or similar systems. In one embodiment, the telecommunication network (1000) comprises a UE (100) and a network apparatus (200). In this disclosure, telecommunication network (1000) and wireless communication system can be used interchangeably.
The UE (100) may comprise a diverse range of devices, including but not limited to laptops, smartphones, desktop computers, notebooks, Device-to-Device (D2D) devices, vehicle to everything (V2X) devices, foldable phones, smart TVs, tablets, immersive devices, and internet of things (IoT) devices. Similarly, the network apparatus (200) may comprise a variety of devices, such as gNBs, eNBs, new radio (NR) trans-receivers, or similar equipment.
Configuration of CSI-RS resource to be measured: In an embodiment, the network apparatus (such as a gNB or similar device) (200) communicates to the UE (100) (which receives the information via an RRC message) regarding the availability of a CSI-RS resource for LTM measurements and/or a list of potential LTM candidate cells associated with a CSI resource. The network apparatus (200) configures the UE (100) with the CSI-RS configuration for performing measurements for the LTM and for reporting the measured values. There are multiple ways by which the configuration could be provided to the UE (100), either embedded within the RRCReconfiguration for individual LTM candidate configuration (e.g. within LTMCandidateConfiguration in the background) or within the LTM candidate configuration but outside the RRC Reconfiguration (e.g. within CandLTM-Reconfig in the background) or outside all the LTM candidate configurations (e.g. inside RRCReconfiguration message from the source cell, but outside all CandLTM-Reconfig). Each of these approaches have its own pros and cons, embedding CSI configuration for the LTM within the RRCReconfiguration for individual LTM candidate configuration simplifies the network implementation, especially in the split architectures where gNB is split into Centralized Unit (CU) and Distributed Unit (DU) but for the UE (100) this brings in additional complexities since it requires early decoding of the RRCReconfiguration for the LTM candidate cells. Including the CSI configuration in LTM candidate cell configuration requires additional coordination between network nodes in case of split architecture, and it doesn't allow sharing of the CSI configurations across LTM candidate cells, but it is simpler for UE implementations as it doesn't require early protocol validations. Thus, this could be a suitable way for the CSI resource configuration for performing LTM measurements. Including the CSI configuration in LTM configuration, outside the LTM candidate configurations avoids early protocol validation and will allow the sharing of the configuration across multiple LTM candidate cells. Thus, it could be a suitable way for the CSI resource configuration for providing the CSI resources for reporting LTM measurements.
The network appratus, such as a gNB or similar device (200), communicates to the UE (100) the cell identifiers linked with CSI-RS resources. These identifiers may consist of a physical cell identity (PCI), a combination of PCI and frequency, a temporary identifier for the candidate cell, or the candidate cell identifier in the LTM candidate cell configuration. An illustrative configuration is provided below.
NZP-CSI-RS-Resource ::= SEQUENCE {
nzp-CSI-RS-ResourceId NZP-CSI-RS-ResourceId,
resourceMapping CSI-RS-ResourceMapping,
powerControlOffset INTEGER (-8..15),
powerControlOffsetSS ENUMERATED{db-3, db0, db3, db6} OPTIONAL, -- Need R
scramblingID ScramblingId,
periodicityAndOffset CSI-ResourcePeriodicityAndOffset OPTIONAL, -- Cond PeriodicOrSemiPersistent
qcl-InfoPeriodicCSI-RS TCI-StateId OPTIONAL, -- Cond Periodic
...,
[[
LTMPCIList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMPCIIndex-r18 OPTIONAL -- Need R
]]
}
LTMPCIIndex-r18 ::= INTEGER(0..maxNrofPCI-r18)
maxNrofPCI-r18 ::= 8
Additionally, the UE (100) conducts measurements on the CSI-RS resource that has been configured as described above, and subsequently relays the L1 CSI-RS RSRP to the network apparatus (e.g. gNB or similar) (200). The CSI-RS RSRP is conveyed through either a PUCCH, PUSCH or UL MAC CE, and encompasses both the candidate cell's identifier and the CSI RSRP measurements. The CSI-RS resource is measured for all candidate cells featuring the PCI in the LTMPCIList-r18.
In an embodiment, rather a list of PCIs, the network apparatus (e.g., gNB or the like) (200) may provide a list of a combination (e.g., in tandem ASN.1 SEQUENCE) of frequency and PCI values.
Rather than relying on the PCI index, the network apparatus (such as a gNB) (200) can instruct the UE (100) to receive the LTMCandidateCellIdentifier or LTMCandidateCellIndex as the candidate cell index in the CSI-RS resource configuration. By utilizing this configuration, the UE (100) can effectively identify the CSI-RS to be measured for CSI reporting for the candidate cell configured with the aforementioned index (in lieu of the LTMPCIIndex-r18 utilized in the previous embodiment).
Configuration of SSB resource to be measured for LTM: In an embodiment, the network apparatus (200) configures to the UE (100) and the UE (100) receives whether a SSB resource set mapped to the CSI-RS report as in NR RRC IE CSI-SSB-ResourceSet (CSI-SSB-ResourceSet in the proposed method is synonymous with SSB resource set mapped to the CSI-RS report) can be used for LTM measurements. In an embodiment, the network apparatus (200) configures the UE (100) with the list of identifiers which identifies the candidate cells such as PCI Indices or the list of PCI or other identifiers which identifies the candidate neighbor cells or the list of one or more candidate cell indices, LTMCandidateCellIdentifier or LTMCandidateCellIndex mapping to the LTM candidate cell configurations in CSI-SSBResourceSet. UE (100) performs the L1 measurements and sends the CSI report including the SSB RSRP (in an example, as in NR R17 IE ssb-Index-RSRP) in the CSI report for the cells for which the indices are provided.
Similar to the case of the CSI resource configuration for the LTM, there are multiple ways by which the network apparatus (200) can provide LTM SSB configuration to the UE (100). For e.g. this may be provided either embedded within the RRCReconfiguration for individual LTM candidate configuration (e.g. within LTMCandidateConfiguration in the background) or within the LTM candidate configuration but outside the RRC Reconfiguration (e.g. within CandLTM-Reconfig in the background) or outside all the LTM candidate configurations (e.g. inside RRCReconfiguration message from the source cell, but outside all CandLTM-Reconfig). Each of these approaches have its own pros and cons, just like in CSI resource configurations. Embedding SSB configuration for LTM within the RRCReconfiguration for individual LTM candidate configuration simplifies the network implementation, especially in the split architectures where gNB is split into Centralized Unit (CU) and Distributed Unit (DU) but for a UE this brings in additional complexities since it requires early decoding of the RRCReconfiguration for the LTM candidate cells. Including the LTM SSB configuration in the LTM candidate cell configuration requires additional coordination between network nodes in case of split architecture, and it doesn't allow sharing of the LTM SSB configurations across LTM candidate cells, but it is simpler for UE implementations as it doesn't require early protocol validations. But such an approach may make linking the LTM SSB configuration and LTM CSI resource configuration complex. Including the CSI configuration in LTM configuration, outside the LTM candidate configurations avoids early protocol validation and will allow the sharing of the configuration across multiple LTM candidate cells and this will be suitable for linking LTM CSI resource configuration and LTM SSB configuration in a signalling efficient way.
In an example, Physical Cell Identifier (PCI) indices (or other indices such as candidate cell indices of candidate neighbor cells) of the neighbor cells can be configured in CSI-SSB-ResourceSet using the existing IE servingAdditionalPCIList-r17.
TAG-CSI-SSB-RESOURCESET-START
CSI-SSB-ResourceSet ::= SEQUENCE {
csi-SSB-ResourceSetId CSI-SSB-ResourceSetId,
csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
...,
[[
servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
]]
}
ServingAdditionalPCIIndex-r17 ::= INTEGER(0..maxNrofAdditionalPCI-r17)
If the value of ServingAdditionalPCIIndex-r17 is zero, the PCI is the PCI of the serving cell in which the CSI-SSB-ResourceSet is defined;
otherwise, the value is additionalPCIIndex-r17 of an SSB-MTC-AdditionalPCI-r17 configured using the additionalPCI-ToAddModList-r17 in ServingCellConfig, and the PCI is the additionalPCI-r17 in the SSB-MTC-AdditionalPCI-r17. In an embodiment, gNB includes PCI of candidate cells (including non-serving cells) in the additionalPCI-ToAddModList-r17.
TAG-CSI-SSB-RESOURCESET-STOP
Configuration of SSB resource to be measured for LTM: In an embodiment, the PCI indices of the neighbor cells can be configured in CSI-SSB-ResourceSet using a new list in addition to the servingAdditionalPCIList-r17 in RRC messages like RRC Reconfiguration or RRC Resume. In an embodiment, UE (100) receives two separate lists-one for serving cells and one for candidate neighbor cells. The list for the serving cells can be used for R17 Inter Cell Beam Management (ICBM) while the list for candidate neighbor cells could be used for LTM, and in a specific embodiment for ICBM also.
TAG-CSI-SSB-RESOURCESET-START
CSI-SSB-ResourceSet ::= SEQUENCE {
csi-SSB-ResourceSetId CSI-SSB-ResourceSetId,
csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
...,
[[
servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
]],
[[
LTMCandidatePCIList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMCandidatePCI Index-r18 OPTIONAL -- Need R
]]
}
LTMCandidatePCI Index-r18 ::= INTEGER(0..maxNrof LTMCandidatePCI-r18)
TAG-CSI-SSB-RESOURCESET-STOP
In an embodiment, a candidate cell information list is provided as an alternative to providing the PCI list. The Candidate cell information list contains list of frequency (ARFCN) and the PCI of the neighboring candidate cells.
TAG-CSI-SSB-RESOURCESET-START
CSI-SSB-ResourceSet ::= SEQUENCE {
csi-SSB-ResourceSetId CSI-SSB-ResourceSetId,
csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
...,
[[
servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
]],
[[
LTMCandidateCellInfoList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMCandidateCellInfoIndex-r18 OPTIONAL -- Need R
]]
}
LTM_CandidateCellInfo ::= SEQUENCE {
LTMCandidateCellInfoIndex-r18 INTEGER (0..MaxNrCandidateCells)
CandidateAdditionalPCI SSB-MTC-AdditionalPCI-r17 OPTIONAL
ssbFrequency ARFCN-ValueNR OPTIONAL - Need M
}
MaxNrCandidateCells := 8
LTM_CandidateCellInformationList SEQUENCE (SIZE(1.. MaxNrCandidateCells)) OF LTMCandidateCellInfo
A LTMCandidateCellInfoList-r18 contains the list of indices to the LTM_CandidateCellInformationList. The UE (100) measures the candidate cells (frequency (NR-ARFCN) + PCI) as identified by the indexed in the LTM_CandidateCellInformationList. If the NR-ARFCN is absent, the frequency is considered to be the serving frequency. In an alternate embodiment, the LTMCandidateCellInfoList contains a list of LTMCandidateCellIdentifier or LTMCandidateCellIndex as defined in the background.
The gNB may configure CSI-SSB-ResourceSet for LTM or Inter Cell Beam Management (NR R17 ICBM). For configuring the ICBM, gNB includes servingAdditionalPCIList-r17 in the RRC IE. For configuring LTM, gNB includes LTMCandidatePCIList-r18 or LTMCandidateCellInfoList-r18 (or similar IEs). The gNB may configure LTM/ICBM both, by including both servingAdditionalPCIList-r17 and LTMCandidatePCIList-r18/LTMCandidateCellInfoList-r18 in reconfiguration message send to the UE (100). In an embodiment, when the candidate cell is a serving cell, it may be included only in LTMCandidatePCIList-r18 or only in LTMCandidateCellInfoList-r18 or in both the lists.
For Intrafrequency, i.e. the candidate cell has the same frequency as the serving PCell, the SSB frequency may not be included.
It is to be noted that the LTMCandidatePCIList-r18 and LTMCandidateCellInfoList-r18 are exemplary names in these embodiments and represent the list of candidate cells to be measured provided to the UE (100) in different ways.
When the LTMCandidatePCIList-r18 or the LTMCandidateCellInfoList-r18 is configured as in the above embodiment, the gNB includes (and the UE (100) receives) the total number of entries in the servingAdditionalPCIList-r17 and the LTMCandidatePCIList-r18/LTMCandidateCellInfoList-r18 as equal to the number of entries in csi-SSB-ResourceList.
Let us consider the case where there are N entries in the servingAdditionalPCIList-r17 and M entries in the LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18. Total number of entries in the csi-SSB-ResourceList will be N+M. First entry of the servingAdditionalPCIList-r17 corresponds to the first entry of csi-SSB-ResourceList and the second entry of the servingAdditionalPCIList-r17 corresponds to the second entry of csi-SSB-ResourceList and so on till N entries. First entry of the LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 corresponds to the N+1th entry of csi-SSB-ResourceList and the second entry of the LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 corresponds to the N+2th entry of csi-SSB-ResourceList and so on till M entries of LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18.
In an embodiment, gNB provides one or more of the below IEs to a NR UE (100) for identifying the reference signal on which the L1 measurements to be performed. Information elements are RRC IEs as defined in TS 38.331 v17.3.0. An example is given as below:
LTM_CandidateCellInfo ::= SEQUENCE {
LTMCandidateCellInfoIndex-r18 INTEGER (0..MaxNrCandidateCells)
CandidateAdditionalPCI SSB-MTC-AdditionalPCI-r17 OPTIONAL -Need R
ssbFrequency ARFCN-ValueNR OPTIONAL - Need M
ssbSubcarrierSpacing SubcarrierSpacing OPTIONAL, -- Cond SSBorAssociatedSSB
smtc1 SSB-MTC OPTIONAL, -- Cond SSBorAssociatedSSB
smtc2 SSB-MTC2 OPTIONAL, -- Cond IntraFreqConnected
refFreqCSI-RS ARFCN-ValueNR OPTIONAL, -- Cond CSI-RS
referenceSignalConfig ReferenceSignalConfig,
absThreshSS-BlocksConsolidation ThresholdNR OPTIONAL, -- Need R
absThreshCSI-RS-Consolidation ThresholdNR OPTIONAL, -- Need R
nrofSS-BlocksToAverage INTEGER (2..maxNrofSS-BlocksToAverage) OPTIONAL, -- Need R
nrofCSI-RS-ResourcesToAverage INTEGER (2..maxNrofCSI-RS-ResourcesToAverage) OPTIONAL, -- Need R
quantityConfigIndex INTEGER (1..maxNrofQuantityConfig),
offsetMO Q-OffsetRangeList,
...,
[[
freqBandIndicatorNR FreqBandIndicatorNR OPTIONAL, -- Need R
measCycleSCell ENUMERATED {sf160, sf256, sf320, sf512, sf640, sf1024, sf1280} OPTIONAL -- Need R
]],
[[
smtc3list-r16 SSB-MTC3List-r16 OPTIONAL, -- Need R
rmtc-Config-r16 SetupRelease {RMTC-Config-r16} OPTIONAL, -- Need M
smtc4list-r17 SSB-MTC4List-r17 OPTIONAL, -- Need R
measCyclePSCell-r17 ENUMERATED {ms160, ms256, ms320, ms512, ms640, ms1024, ms1280, spare1}
OPTIONAL, -- Cond SCG
}
SSB-ToMeasure ::= CHOICE {
shortBitmap BIT STRING (SIZE (4)),
mediumBitmap BIT STRING (SIZE (8)),
longBitmap BIT STRING (SIZE (64))
}
NR-ARFCN and subcarrier spacing provides the frequency domain information of the SSB to be measured for LTM to the UE. The bitmaps included in the SSB-ToMeasure provide the SSB indices to be measured. Depending on the number of beams or the number of SSB indices, one of shortBitmap, mediumBitmap or longBitmap may be used. For e.g. if the cell supports 4 beams, a short bit map is sufficient, if the cell supports 8 beams medium bit map may be used, if the cell supports 64 beams long bit map may be used. In higher frequencies such as frequency range 2 (FR2) long bit map could be useful while in lower frequencies short or medium bit map could be used. As an alternative to providing bit maps, the SSB indices could be provided as a list of integers. While this reduces the processing overhead in both network and the UE, it will increase the signalling overhead.
Configuration of SSB resource to be measured for LTM: In an embodiment, the list of PCI indices (or other indices such as candidate cell indices of candidate neighbor cells) of the neighbor cells are configured in CSI-SSB-ResourceSet are mapped to a new list of csi-SSBResourceList for candidate cells.
TAG-CSI-SSB-RESOURCESET-START
CSI-SSB-ResourceSet ::= SEQUENCE {
csi-SSB-ResourceSetId CSI-SSB-ResourceSetId,
csi-SSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
...,
[[
servingAdditionalPCIList-r17 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF ServingAdditionalPCIIndex-r17 OPTIONAL -- Need R
]],
csi-CandidateSSB-ResourceList SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF SSB-Index,
[[
LTMCandidatePCIList-r18 SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourcePerSet)) OF LTMCandidatePCI Index-r18 OPTIONAL -- Need R
]]
}
LTMCandidatePCI Index-r18 ::= INTEGER(0..maxNrof LTMCandidatePCI-r18)
TAG-CSI-SSB-RESOURCESET-STOP
In an embodiment, a candidate cell information list, LTMCandidateCellInfoList-r18 as defined in the previous embodiment is provided as an alternative to providing the PCI list, LTMCandidatePCIList-r18. All the aspects described for the LTMCandidateCellInfo in the previous embodiment is reused. i.e. the gNB includes the IEs for configuring the UE (100) with the reference signal details as given in sections [46],[47] in an embodiment also. In an embodiment, a candidate cell information list is provided as an alternative to providing the PCI list as in the previous embodiment, for e.g. as defined in section [38],[39].In an embodiment, LTMCandidateCellInfoList contains a list of LTMCandidateCellIdentifier or LTMCandidateCellIndex as explained defined in the background, instead of the PCI list.
In an embodiment, when LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 is configured as in the above embodiment, gNB includes (and UE (100) receives) the total number of entries in LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 as equal to the number of entries in the SSB-ResourceList for candidate cells, csi-CandidateSSB-ResourceList.
The first entry of the LTMCandidatePCIList-r18/ LTMCandidateCellInfoList-r18 indicates the value of the PCI for the first entry of csi-CandidateSSB-ResourceList, the second entry of the list indicates the value of the PCI for the second entry of csi-CandidateSSB-ResourceList, and so on for all the entries in the list.
Configuration of SSB resource to be measured for LTM: Alternative to sending PCI indices, the gNB may send (UE may receive) the candidate cell indices or any other identifier such as PCI itself or any temporary identifiers mapped to the SSB resource list for all the above embodiments. In other words, any identifier or index that can map to the given candidate cell can be included in LTMCandidatePCIList-r18 or similar structure in place of PCI indices. In an embodiment, the index could be LTMCandidateCellIdentifier or LTMCandidateCellIndex.
The gNB sends the SSB configuration and the SSB indices of the neighboring cell in RRC messages such as RRC Reconfiguration send from the source cell. The UE (100) applies the configuration thus received for performing L1 measurements and reporting to the source cell for LTM.
In an embodiment, target gNB sends the SSB configuration and the SSB indices of the neighboring cell in LTM candidate configuration. The UE (100) applies the SSB configuration and the SSB indices received LTM candidate configuration for performing L1 measurements and reporting to the source cell for the LTM.
In an embodiment, the UE (100) evaluates the received LTM configuration for a candidate cell before performing the L1 measurements/ before reporting the L1 measurements for the candidate cell.
In an embodiment, the gNB provides one or more information elements in the following information for the LTM measurement reporting to the UE (100) with reference to NR R17 specification TS 38.331 v17.0. UE (100) identifies the reference signals to be measured through one or more information elements (IE) in the following information. In an embodiment, one or more IEs from the below are mapped to a candidate cell or a list of candidate cells.
ssbSubcarrierSpacing SubcarrierSpacing OPTIONAL, -- Cond SSBorAssociatedSSB
smtc1 SSB-MTC OPTIONAL, -- Cond SSBorAssociatedSSB
smtc2 SSB-MTC2 OPTIONAL, -- Cond IntraFreqConnected
refFreqCSI-RS ARFCN-ValueNR OPTIONAL, -- Cond CSI-RS
referenceSignalConfig ReferenceSignalConfig,
absThreshSS-BlocksConsolidation ThresholdNR OPTIONAL, -- Need R
absThreshCSI-RS-Consolidation ThresholdNR OPTIONAL, -- Need R
nrofSS-BlocksToAverage INTEGER (2..maxNrofSS-BlocksToAverage) OPTIONAL, -- Need R
nrofCSI-RS-ResourcesToAverage INTEGER (2..maxNrofCSI-RS-ResourcesToAverage) OPTIONAL, -- Need R
quantityConfigIndex INTEGER (1..maxNrofQuantityConfig),
offsetMO Q-OffsetRangeList,
...,
[[
freqBandIndicatorNR FreqBandIndicatorNR OPTIONAL, -- Need R
measCycleSCell ENUMERATED {sf160, sf256, sf320, sf512, sf640, sf1024, sf1280} OPTIONAL -- Need R
]],
[[
smtc3list-r16 SSB-MTC3List-r16 OPTIONAL, -- Need R
rmtc-Config-r16 SetupRelease {RMTC-Config-r16} OPTIONAL, -- Need M
smtc4list-r17 SSB-MTC4List-r17 OPTIONAL, -- Need R
measCyclePSCell-r17 ENUMERATED {ms160, ms256, ms320, ms512, ms640, ms1024, ms1280, spare1}
OPTIONAL, -- Cond SCG
ReferenceSignalConfig above could include the below (reference to TS 38.331 V17.3.0) for SSB
ssb-ToMeasure SetupRelease { SSB-ToMeasure } OPTIONAL, -- Need M
deriveSSB-IndexFromCell BOOLEAN,
ss-RSSI-Measurement SS-RSSI-Measurement OPTIONAL, -- Need M
...,
[[
ssb-PositionQCL-Common-r16 SSB-PositionQCL-Relation-r16 OPTIONAL, -- Cond SharedSpectrum
ssb-PositionQCL-CellsToAddModList-r16 SSB-PositionQCL-CellsToAddModList-r16 OPTIONAL, -- Need N
ssb-PositionQCL-CellsToRemoveList-r16 PCI-List OPTIONAL -- Need N
]],
[[
deriveSSB-IndexFromCellInter-r17 ServCellIndex OPTIONAL, -- Need R
ssb-PositionQCL-Common-r17 SSB-PositionQCL-Relation-r17 OPTIONAL, -- Cond SharedSpectrum2
ssb-PositionQCL-Cells-r17 SetupRelease {SSB-PositionQCL-CellList-r17} OPTIONAL -- Need M
]],
SSB-ToMeasure ::= CHOICE {
shortBitmap BIT STRING (SIZE (4)),
mediumBitmap BIT STRING (SIZE (8)),
longBitmap BIT STRING (SIZE (64))
}
ReferenceSignalConfig above could include the below (reference to TS 38.331 V17.3.0) for the CSI-RS:
subcarrierSpacing SubcarrierSpacing,
csi-RS-CellList-Mobility SEQUENCE (SIZE (1..maxNrofCSI-RS-CellsRRM)) OF CSI-RS-CellMobility,
CSI-RS-CellMobility ::= SEQUENCE {
cellId PhysCellId,
csi-rs-MeasurementBW SEQUENCE {
nrofPRBs ENUMERATED { size24, size48, size96, size192, size264},
startPRB INTEGER(0..2169)
},
density ENUMERATED {d1,d3} OPTIONAL, -- Need R
csi-rs-ResourceList-Mobility SEQUENCE (SIZE (1..maxNrofCSI-RS-ResourcesRRM)) OF CSI-RS-Resource-Mobility
}
CSI-RS-Resource-Mobility ::= SEQUENCE {
csi-RS-Index CSI-RS-Index,
slotConfig CHOICE {
ms4 INTEGER (0..31),
ms5 INTEGER (0..39),
ms10 INTEGER (0..79),
ms20 INTEGER (0..159),
ms40 INTEGER (0..319)
},
associatedSSB SEQUENCE {
ssb-Index SSB-Index,
isQuasiColocated BOOLEAN
} OPTIONAL, -- Need R
frequencyDomainAllocation CHOICE {
row1 BIT STRING (SIZE (4)),
row2 BIT STRING (SIZE (12))
},
firstOFDMSymbolInTimeDomain INTEGER (0..13),
sequenceGenerationConfig INTEGER (0..1023),
...,
[[
slotConfig-r17 CHOICE {
ms4 INTEGER (0..255),
ms5 INTEGER (0..319),
ms10 INTEGER (0..639),
ms20 INTEGER (0..1279),
ms40 INTEGER (0..2559)
} OPTIONAL -- Need R
]]
}
CSI-RS-Index ::= INTEGER (0..maxNrofCSI-RS-ResourcesRRM-1)
Configuration of reference signals to be measured for LTM: In an embodiment, the gNB configures the UE (100) to report the CSI reports including report quantities such as SSB Index RSRP, CRI RSRP, CRI SINR etc. based on the reference signal configuration configured through measurement object configuration, such as measObjectNR in NR specifications.
Referring to FIG. 7, the gNB provides a mapping between the CSI report identifier and the measurement object identifier. The gNB also may provide list of candidate cells UE (100) measures the reference signals configured through measurement object configuration such as measObjectNR for the LTM candidate cells and reports the same in the CSI reports.
An example embodiment is given below:
CSI-ReportConfig ::= SEQUENCE {
reportConfigId CSI-ReportConfigId,
carrier ServCellIndex OPTIONAL, -- Need S
resourcesForChannelMeasurement CSI-ResourceConfigId,
csi-IM-ResourcesForInterference CSI-ResourceConfigId OPTIONAL, -- Need R
nzp-CSI-RS-ResourcesForInterference CSI-ResourceConfigId OPTIONAL, -- Need R
reportConfigType CHOICE {
periodic SEQUENCE {
reportSlotConfig CSI-ReportPeriodicityAndOffset,
pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
},
semiPersistentOnPUCCH SEQUENCE {
reportSlotConfig CSI-ReportPeriodicityAndOffset,
pucch-CSI-ResourceList SEQUENCE (SIZE (1..maxNrofBWPs)) OF PUCCH-CSI-Resource
},
semiPersistentOnPUSCH SEQUENCE {
reportSlotConfig ENUMERATED {sl5, sl10, sl20, sl40, sl80, sl160, sl320},
reportSlotOffsetList SEQUENCE (SIZE (1.. maxNrofUL-Allocations)) OF INTEGER(0..32),
p0alpha P0-PUSCH-AlphaSetId
},
aperiodic SEQUENCE {
reportSlotOffsetList SEQUENCE (SIZE (1..maxNrofUL-Allocations)) OF INTEGER(0..32)
}
},
reportQuantity CHOICE {
none NULL,
cri-RI-PMI-CQI NULL,
cri-RI-i1 NULL,
cri-RI-i1-CQI SEQUENCE {
pdsch-BundleSizeForCSI ENUMERATED {n2, n4} OPTIONAL -- Need S
},
cri-RI-CQI NULL,
cri-RSRP NULL,
ssb-Index-RSRP NULL,
cri-RI-LI-PMI-CQI NULL
},
reportFreqConfiguration SEQUENCE {
cqi-FormatIndicator ENUMERATED { widebandCQI, subbandCQI } OPTIONAL, -- Need R
pmi-FormatIndicator ENUMERATED { widebandPMI, subbandPMI } OPTIONAL, -- Need R
csi-ReportingBand CHOICE {
subbands3 BIT STRING(SIZE(3)),
subbands4 BIT STRING(SIZE(4)),
subbands5 BIT STRING(SIZE(5)),
subbands6 BIT STRING(SIZE(6)),
subbands7 BIT STRING(SIZE(7)),
subbands8 BIT STRING(SIZE(8)),
subbands9 BIT STRING(SIZE(9)),
subbands10 BIT STRING(SIZE(10)),
subbands11 BIT STRING(SIZE(11)),
subbands12 BIT STRING(SIZE(12)),
subbands13 BIT STRING(SIZE(13)),
subbands14 BIT STRING(SIZE(14)),
subbands15 BIT STRING(SIZE(15)),
subbands16 BIT STRING(SIZE(16)),
subbands17 BIT STRING(SIZE(17)),
subbands18 BIT STRING(SIZE(18)),
...,
subbands19-v1530 BIT STRING(SIZE(19))
} OPTIONAL -- Need S
} OPTIONAL, -- Need R
timeRestrictionForChannelMeasurements ENUMERATED {configured, notConfigured},
timeRestrictionForInterferenceMeasurements ENUMERATED {configured, notConfigured},
codebookConfig CodebookConfig OPTIONAL, -- Need R
dummy ENUMERATED {n1, n2} OPTIONAL, -- Need R
groupBasedBeamReporting CHOICE {
enabled NULL,
disabled SEQUENCE {
nrofReportedRS ENUMERATED {n1, n2, n3, n4} OPTIONAL -- Need S
}
},
cqi-Table ENUMERATED {table1, table2, table3, table4-r17} OPTIONAL, -- Need R
subbandSize ENUMERATED {value1, value2},
non-PMI-PortIndication SEQUENCE (SIZE (1..maxNrofNZP-CSI-RS-ResourcesPerConfig)) OF PortIndexFor8Ranks OPTIONAL, -- Need R
...,
[[
semiPersistentOnPUSCH-v1530 SEQUENCE {
reportSlotConfig-v1530 ENUMERATED {sl4, sl8, sl16}
} OPTIONAL -- Need R
]],
[[
semiPersistentOnPUSCH-v1610 SEQUENCE {
reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
} OPTIONAL, -- Need R
aperiodic-v1610 SEQUENCE {
reportSlotOffsetListDCI-0-2-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r16 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..32) OPTIONAL -- Need R
} OPTIONAL, -- Need R
reportQuantity-r16 CHOICE {
cri-SINR-r16 NULL,
ssb-Index-SINR-r16 NULL
} OPTIONAL, -- Need R
codebookConfig-r16 CodebookConfig-r16 OPTIONAL -- Need R
]],
[[
cqi-BitsPerSubband-r17 ENUMERATED {bits4} OPTIONAL, -- Need R
groupBasedBeamReporting-v1710 SEQUENCE {
nrofReportedGroups-r17 ENUMERATED {n1, n2, n3, n4}
} OPTIONAL, -- Need R
codebookConfig-r17 CodebookConfig-r17 OPTIONAL, -- Need R
sharedCMR-r17 ENUMERATED {enable} OPTIONAL, -- Need R
csi-ReportMode-r17 ENUMERATED {mode1, mode2} OPTIONAL, -- Need R
numberOfSingleTRP-CSI-Mode1-r17 ENUMERATED {n0, n1, n2} OPTIONAL, -- Need R
reportQuantity-r17 CHOICE {
cri-RSRP-Index-r17 NULL,
ssb-Index-RSRP-Index-r17 NULL,
cri-SINR-Index-r17 NULL,
ssb-Index-SINR-Index-r17 NULL
} OPTIONAL -- Need R
]],
[[
semiPersistentOnPUSCH-v1720 SEQUENCE {
reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
} OPTIONAL, -- Need R
aperiodic-v1720 SEQUENCE {
reportSlotOffsetList-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-2-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL, -- Need R
reportSlotOffsetListDCI-0-1-r17 SEQUENCE (SIZE (1.. maxNrofUL-Allocations-r16)) OF INTEGER(0..128) OPTIONAL -- Need R
} OPTIONAL -- Need R
]],
[[
codebookConfig-v1730 CodebookConfig-v1730 OPTIONAL -- Need R
]],
[[
mappedMeasConfigForRefSignal-r18 MeasObjectId,
candidateCellList-r18 SEQUENCE (SIZE (1.. maxNrofcandidateCell-r18)) OF candidateCellId
]]
}
candidateCellId::= INTEGER(0..maxNrof CandidateCellId-18)
maxNrof CandidateCellId-18::=8
The UE (100) measures the candidate cells in the received candidateCellList-r18 using the reference signals configured within the mapped measurement object (MeasObjectId) and reports using the CSI reports configured through reportConfigId.
Actions while configuring, performing measurements and reporting measurements for the LTM under various conditions: In an embodiment, the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM and has not received Access Stratum (AS) security configuration (or more specifically has not activated AS security configuration), defers sending the layer 1 measurements of candidate cells in CSI reports till AS security is activated as shown in FIG. 5. In an embodiment, for the above scenario, UE (100) defers sending the layer 1 measurements of candidate cells only if they are non-serving cells. In an embodiment, for the above scenario, if the neighbor candidate cells are serving cells, UE (100) sends the layers 1 measurements of candidate cells. In an embodiment, the measurements reported for above scenario can be SSB RSRP, CSI-RS RSRP or SINR. In an embodiment, the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
In an embodiment, the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM and has not received AS security configuration (or more specifically has not activated AS security configuration), sends the layer 1 measurements of candidate cells in CSI reports even when the AS security is not activated. In an embodiment, the measurements reported for above scenario can be SSB RSRP, CSI-RS RSRP or SINR. In an embodiment, the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
In an embodiment, the gNB which has received CSI reports containing LTM measurements defers sending cell switch command till the AS security is activated.
Referring to FIG. 6, the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM and has not received at least one of SRB2 or DRB or MRB configuration (or more specifically has not activated SRB2 or DRB or MRB), defers sending the layer 1 measurements of candidate cells in CSI reports till SRB2 or DRB or MRB is activated. In an embodiment, for the above scenario, UE (100) defers sending the layer 1 measurements of candidate cells only if they are non-serving cells. In an embodiment, for the above scenario, if the neighbor candidate cells are serving cells, UE (100) sends the layers 1 measurements of candidate cells. In an embodiment, the measurements reported/deferred for above scenario can be SSB RSRP, CSI RSRP or SINR. In an embodiment, the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
In an embodiment, the UE (100) which is configured for sending CSI reports containing the candidate cell's measurements for LTM at least one of SRB2 or DRB or MRB configuration, sends the layer 1 measurements of candidate cells in CSI reports even when the SRB2 or DRB or MRB is not activated. In an embodiment, the measurements reported for above scenario can be SSB RSRP, CSI-RS RSRP or SINR. In an embodiment, the measurements reporting for the above scenario can be periodic CSI reporting, aperiodic CSI reporting or semi persistent CSI reporting or event triggered CSI reporting or MAC reporting for LTM.
In an embodiment, the gNB which has received CSI reports containing LTM measurements defers cell switch till at least one of SRB2 or DRB or MRB configuration has been successfully applied at the UE (100).
Referring to FIG. 7, the UE (100) which has received a cell switch command before AS security is activated moves to RRC_IDLE state. UE (100) moves to RRC_IDLE with the release cause "other".
In an embodiment, the UE (100) only accepts a cell switch command only when AS security has been activated. UE (100) rejects cell switch command if the AS security has not been activated.
In an embodiment, the gNB sends the LTM candidate cell configuration to the UE (100) only when AS security has been activated, and SRB2 with at least one DRB or multicast MRB or, for IAB, SRB2, are setup and not suspended.
FIG. 2 shows various hardware components of the UE (100), according to the embodiments as disclosed herein. In an embodiment, the UE (100) includes a processor (110), a communicator (120), a memory (130) and a L1 measurement controller (140). The processor (110) is coupled with the communicator (120), the memory (130) and the L1 measurement controller (140).
The L1 measurement controller (140) receives the LTM CSI resource configuration from the source cell for the one or more candidate cells in the LTM and the LTM SSB configuration for each candidate cell in the LTM from the network apparatus (200). The LTM CSI resource configuration is received in the RRC reconfiguration message. In an embodiment, the LTM CSI resource configuration includes the CSI resource to be used for the L1 measurements (i.e. for performing L1 measurements or for performing L1 measurement reporting) and the list of one or more candidate cells that are associated to the CSI resource. In an embodiment, when the LTM CSI resource configuration received is for the LTM CSI resources for performing L1 measurements, it may be provided for each LTM candidate cell and may be included in the LTM candidate cell configuration (e.g. in CandLTM-Reconfig) or alternatively it may be included in the RRCReconfiguration message for the LTM candidate cell (for e.g. LTMCandidateConfiguration). In an embodiment, when the LTM CSI resource configuration received is for the LTM CSI resources for reporting LTM measurements, it may be included in the LTM configuration, for e.g. outside LTM candidate cell configuration. The LTM CSI resource configuration is for the one or more LTM candidate cells and the LTM SSB configuration is per LTM candidate cell. In an embodiment, the LTM SSB configuration includes the SSB frequency, the subcarrier spacing and the bitmap of SSB positions in the burst for configuring SSB resources provided within the LTM candidate cell configuration. The SSB positions in burst are provided using 4 bits, 8 bits or 64 bits for the SSB frequency and subcarrier spacing (SSB positions in the burst is for the SSB frequency + subcarrier spacing pair).
Further, the L1 measurement controller (140) performs the L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. In an embodiment, the L1 measurements are one of the CSI based L1-RSRP measurements, the CSI based L1-SINR measurements and the SSB based L1-RSRP measurement.
Further, the L1 measurement controller (140) reports the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration. In an embodiment, the L1 measurement controller (140) performs the L1 measurements for all the plurality of candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration. Further, the L1 measurement controller (140) transmits the L1 measurements to the network apparatus (200) for the LTM.
In another embodiment, the L1 measurement controller (140) performs the L1 measurements for the one more candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration. Further, the L1 measurement controller (140) transmits the L1 measurements for the one or more candidate cell to the source cell of the network apparatus (200) for the LTM.
Further, the L1 measurement controller (140) receives the MAC CE to perform switching to the LTM candidate cell from the source cell based on the L1 measurements. Further, the L1 measurement controller (140) performs the switch to the LTM candidate cell based on the MAC CE.
In an embodiment, further, the L1 measurement controller (140) receives the cell switch command from the network apparatus (200). Further, the L1 measurement controller (140) determines whether the AS security is activated. Further, the L1 measurement controller (140) transitions the UE (100) to the RRC_IDLE state with release cause 'other' when the AS security is not activated.
The L1 measurement controller (140) is a innovative hardware incorporated in the UE (100) through the use of analog and/or digital circuits, including logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive and active electronic components, optical components, hardwired circuits, and the like. Additionally, it may be optionally powered by firmware. This cutting-edge hardware L1 measurement controller (140) is purposefully integrated within the UE to handle measurements for lower layer triggered mobility in telecommunication networks. The L1 measurement controller (140) is seamlessly integrated as a circuit or an additional core that adeptly configures the UE (100) for LTM measurements, specifically the CSI resource and SSB reference signal configuration, as directed by the network apparatus (200). The L1 measurement controller (140) also efficiently reports the LTM measurements to the network apparatus (200) and performs LTM cell switching.
The processor (110) may include one or a plurality of processors. The one or the plurality of processors may be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and/or an AI-dedicated processor such as a neural processing unit (NPU). The processor (110) may include multiple cores and is configured to execute the instructions stored in the memory (130).
Further, the processor (110) is configured to execute instructions stored in the memory (130) and to perform various processes. The communicator (120) is configured for communicating internally between internal hardware components and with external devices via one or more networks. The memory (130) also stores instructions to be executed by the processor (110). The memory (130) may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory (130) may, in some examples, be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted that the memory (130) is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache).
In an embodiment, the communicator (120) includes an electronic circuit specific to a standard that enables wired or wireless communication. The communicator (120) is configured to communicate internally between internal hardware components of the UE (100) and with external devices via one or more networks.
Although the FIG. 2 shows various hardware components of the UE (100) but it is to be understood that other embodiments are not limited thereon. In other embodiments, the UE (100) may include less or more number of components. Further, the labels or names of the components are used only for illustrative purpose and does not limit the scope of the invention. One or more components can be combined together to perform same or substantially similar function in the UE (100).
FIG. 3 is a flow chart (S300) illustrating a method for managing measurements for the LTM in the telecommunication network (1000), according to the embodiments disclosed herein. The operations (S302-S310) are handled by the L1 measurement controller (140).
At S302, the method includes receiving the LTM CSI resource configuration from the source cell for the one or more candidate cells in the LTM and the LTM SSB configuration for each candidate cell in the LTM from the network apparatus (200). At S304, the method includes performing the L1 measurements for the one or more candidate cell based on the LTM SSB configuration and the LTM CSI resource configuration. At S306, the method includes reporting the L1 measurements for the one or more candidate cell to the source cell based on the LTM SSB configuration and the LTM CSI resource configuration.
At S308, the method includes receiving the MAC CE to perform switching to the LTM candidate cell from the source cell based on the L1 measurements. At S310, the method includes performing the switch to the LTM candidate cell based on the MAC CE.
FIG. 4 illustrates a sequence diagram of the LTM configuration, according to the embodiments disclosed herein. At step 1, the RRC of the gNB sends the RRC Reconfiguration including the CSI-MeasConfig with mapping of LTM candidate cells to the reference signals to be measured in the CSI-RS resource configuration/CSI-report configuration, the CSI SSB resource set configuration etc., to the RRC of the UE (100). At step 2, the RRC of the UE (100) sends the RRC Reconfiguration complete to the RRC of gNB. At step 3, L1/L2 of the UE (100) performs the LTM measurements (e.g., L1 measurements). At step 4, the L1/L2 of the UE (100) sends the L1 measurements to the source -L1/L2. At step 5, the source -L1/L2 triggers the LTM to the L1/L2 of UE (100).
FIG. 5 illustrates a flow diagram (S500) of the CSI reporting for the LTM based on the AS security activation, according to the embodiments disclosed herein. The operations (S502-S510) are handled by the L1 measurement controller (140).
At S502, the method includes receiving the configuration for the CSI reporting for the candidate cells in the LTM. At S504, the method includes performing the L1 measurements. At S506, the method includes determining whether the AS security is active?
In response to determining that the AS security is active, at S508, the method includes reporting the CSI measurements for all the candidate cells. In response to determining that the AS security is not active, at S510, the method includes deferring reporting the CSI measurements for the non-serving candidate cells till the AS security is activated. The method includes reporting the CSI measurements for serving candidate cells.
FIG. 6 illustrates a flow diagram (S600) of the CSI reporting for LTM based on radio bearer configuration, according to the embodiments disclosed herein. The operations (S602-S610) are handled by the L1 measurement controller (140).
At S602, the method includes receiving the configuration for the CSI reporting for the candidate cells in the LTM. At S604, the method includes performing the L1 measurements. At S606, the method includes determining whether the SRB2 and the DRB or MRB is active? In response to determining that the SRB2 and the DRB or MRB is active, at S608, the method includes reporting the CSI measurements for all the candidate cells. In response to determining that the SRB2 and the DRB or MRB is not active then, at S610, the method includes deferring reporting the CSI measurements for non-serving candidate cells till AS security is activated. The method includes reporting the CSI measurements for serving candidate cells.
FIG. 7 illustrates a flow diagram (S700) of the cell switch command handling without AS security activation, according to the embodiments disclosed herein. The operations (S702-S708) are handled by the L1 measurement controller (140).
At S702, the method includes receiving the cell switch command. At S704, the method includes determining whether the AS security is active? In response to determining that the AS security is active, at S706, the method includes performing LTM cell switch to the indicated candidate cell. In response to determining that the AS security is not active, then, At S708, the method includes moving the UE (100) to the RRC_IDLE.
The proposed solution addresses methods for configuring the UE (100) for LTM measurements, specifically the CSI resource and SSB reference signal configuration, by the network apparatus (200). The proposed solution also addresses methods for reporting the LTM measurements to the network apparatus (200) and performing LTM cell switch.
The various actions, acts, blocks, steps, or the like in the flow charts (S300 to S700) may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like may be omitted, added, modified, skipped, or the like without departing from the scope of the invention.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

Claims (15)

  1. A method of a user equipment (UE) in a wireless communication system, the method comprising:
    receiving, from a network apparatus (200), a radio resource control (RRC) message including a lower layer triggered mobility (LTM) channel state information (CSI) resource configuration for one or more LTM candidate cells and a LTM synchronization signal block (SSB) configuration for each LTM candidate cell ;
    performing layer 1 (L1) measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration;
    transmitting, to the network apparatus (200), an L1 measurement report for the one or more candidate cells based on theL1 measurements;
    based on the transmission of the L1 measurements, receiving, from the network apparatus (200), a medium access control control-element (MAC CE) to perform a LTM cell switch procedure; and
    performing the LTM cell switch procedure based on the MAC CE.
  2. The method of claim 1, wherein the LTM CSI resource configuration comprises a CSI resource to be used for the L1 measurements and a identifier (ID) list of one or more candidate cells that are associated to the CSI resource.
  3. The method of claim 1, wherein the LTM SSB configuration comprises a SSB frequency, a subcarrier spacing and a bitmap of SSB positions in burst for configuring SSB resources provided within a LTM candidate cell configuration.
  4. The method of claim 1, wherein the LTM CSI resource configuration is for the one or more LTM candidate cells and the LTM SSB configuration is per LTM candidate cell.
  5. The method of claim 3, wherein the bitmap of SSB positions in burst are provided using 4 bits, 8 bits or 64 bits for the SSB frequency and subcarrier spacing.
  6. The method of claim 1, wherein the L1 measurements is one of CSI based L1-RSRP (reference signal received power) measurements, CSI based L1-SINR(signal to interference plus noise ratio) measurements and SSB based L1-RSRP measurement.
  7. The method of claim 1, wherein reporting the L1 measurements for all the plurality of LTM candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration comprises:
    performing the L1 measurements for all the plurality of LTM candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration; and
    transmitting the L1 measurements to the network apparatus (200) for the LTM cell switch.
  8. The method of claim 1, comprising:
    receiving the LTM cell switch command from the network apparatus (200);
    determining whether an access stratum (AS) security is activated; and
    transitioning to a radio resource control idle (RRC_IDLE) state in case that the AS security is not activated
    wherein reporting the L1 measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration comprises:
    performing the L1 measurements for the one more candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration; and
    transmitting the L1 measurements for the one or more candidate cells for the LTM cell switch.
  9. A user equipment (UE) in a wireless communication system, the UE comprising:
    a transceiver; and
    a processor configured to:
    receive, from a network apparatus (200), a radio resource control (RRC) message including a lower layer triggered mobility (LTM) channel state information (CSI) resource configuration for one or more LTM candidate cells and a LTM synchronization signal block (SSB) configuration for each LTM candidate cell,
    perform layer 1 (L1) measurements for the one or more LTM candidate cells based on the LTM SSB configuration and the LTM CSI resource configuration,
    transmit, to the network apparatus (200), an L1 measurement report for the one or more candidate cells based on theL1 measurements,
    based on the transmission of the L1 measurements, receive, from the network apparatus (200), a medium access control control-element (MAC CE) to perform a LTM cell switch procedure, and
    perform the LTM cell switch procedure based on the MAC CE.
  10. The UE of claim 9, wherein the LTM CSI resource configuration comprises a CSI resource to be used for the L1 measurements and a identifier(ID) list of one or more candidate cells that are associated to the CSI resource.
  11. The UE of claim 9, wherein the LTM SSB configuration comprises a SSB frequency, a subcarrier spacing and a bitmap of SSB positions in burst for configuring SSB resources provided within a LTM candidate cell configuration.
  12. The UE of claim 9, wherein the LTM CSI resource configuration is for the one or more LTM candidate cells and the LTM SSB configuration is per LTM candidate cell.
  13. The UE of claim 11, wherein the bitmap of SSB positions in burst are provided using 4 bits, 8 bits or 64 bits for the SSB frequency and subcarrier spacing.
  14. The UE of claim 9, wherein the L1 measurements is one of CSI based L1-RSRP(reference signal received power) measurements, CSI based L1-SINR(signal to interference plus noise ratio) measurements and SSB based L1-RSRP measurement.
  15. The UE of claim 9, wherein the processor is further configured to:
    perform the L1 measurements for all the plurality of LTM candidate cells based on the LTM CSI resource configuration and the LTM SSB configuration, and
    transmit the L1 measurements to the network apparatus (200) for the LTM cell switch.
PCT/KR2024/001292 2023-01-31 2024-01-26 Handling measurements for lower layer triggered mobility in telecommunication network WO2024162705A1 (en)

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