KR20230021548A - Method and apparatus for updating configuration for conditional pscell change in next generation mobile communication system - Google Patents

Abstract

The present invention relates to a communication technique that combines a 5G communication system with an IoT technology to support a higher data transmission rate after a 4G system and a system thereof. The present invention can be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety related services, etc.) based on a 5G communication technology and an IoT-related technology. The present invention provides a method for updating setup of a conditional PSCell change and a device thereof.

Description

Conditional PSCell change setting update method and apparatus in next-generation mobile communication system

The present disclosure relates to a next-generation mobile communication system or a wireless communication system. Specifically, the present disclosure relates to an operation of updating configuration of a conditional PSCell change when a configuration of a source primary secondary cell group (SCG) cell (PSCell) is changed in conditional mobility operation of a UE.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system to meet the growing demand for wireless data traffic after the commercialization of the 4G communication system. For this reason, the 5G communication system or pre-5G communication system is being called a Beyond 4G Network communication system or a Post LTE system.

In order to achieve a high data rate, the 5G communication system is being considered for implementation in a mmWave band (eg, a 60 gigabyte (60 GHz) band). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used in 5G communication systems. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, to improve the network of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), and an ultra-dense network , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation etc. are being developed. In addition, in the 5G system, advanced coding modulation (Advanced Coding Modulation: ACM) methods FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), advanced access technologies FBMC (Filter Bank Multi Carrier), NOMA (non orthogonal multiple access) and SCMA (sparse code multiple access) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network in which humans create and consume information to an Internet of Things (IoT) network in which information is exchanged and processed between distributed components such as things. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with a cloud server, etc., is also emerging. In order to implement IoT, technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, sensor networks for connection between objects and machine to machine , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new values in human life by collecting and analyzing data generated from connected objects can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliances, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. will be. The application of the cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of convergence of 5G technology and IoT technology.

Meanwhile, with the development of mobile communication systems, a demand for a method for efficiently updating the conditional cell change setting is increasing.

Technical problems to be achieved in the embodiments of the present disclosure are as follows. In the case of an inter-SN (secondary node) conditional PScell change, if the configuration of the source pscell is changed in a situation where the configuration of the conditional pscell change is already given to the terminal, the current MCG (master cell group group) reflects the corresponding configuration change ), MN (master node) settings, and target pscell settings must all be able to be changed.

Currently, the signaling system between source SN, MN, and target SN nodes has only two procedures: setting inter-SN CPC (conditional PSCell Change) or updating source SN settings. . Among these procedures, the inter-SN CPC configuration cannot change the MN/MCG configuration, and the source SN configuration update procedure cannot update the CPC configuration of the target SN. Therefore, a procedure enabling both of these updates must exist so that MN/MCG configuration update and CPC configuration update of the target SN will be possible for the source SN configuration change of inter-SN.

The present invention for solving the above problems is a control signal processing method in a wireless communication system, comprising: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second control signal generated based on the processing to the base station.

According to embodiments of the present disclosure for solving the above-described problem, when the configuration of the source SN is changed, the source SN notifies the MN, and if the source SN previously transmits the CPC configuration to the UE, the source SN Notifies the MN including the relevant CPC setting update indicator. The MN sees this indicator, updates the MN/MCG settings, requests the target SN to update the CPC settings, receives the update information back, and delivers the updated source SN/MN/MCG settings and CPC settings to the terminal. there is.

According to these embodiments, in the case of dual connectivity (dual connection, dual connectivity, or DC), when inter-SN CPC is configured for a UE, MN/MCG configuration reflecting a change in source SN configuration through the inter-node signal, and The CPC settings of the target-SN can be updated, and each updated setting can be transmitted as one RRC message, so that the CPC settings of the UE and the target SN can be synchronized.

1 is a diagram illustrating the structure of an LTE system according to an embodiment of the present disclosure.
2 is a diagram illustrating a radio protocol structure of an LTE system according to an embodiment of the present disclosure.
3 is a diagram illustrating the structure of a next-generation mobile communication system according to an embodiment of the present disclosure.
4 is a diagram illustrating a radio protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.
5 is a diagram illustrating a secondary node (SN) setting update process related to an embodiment of the present disclosure.
6 is a diagram illustrating a process of updating SN settings related to an embodiment of the present disclosure.
7 is a diagram illustrating a process of updating SN settings related to an embodiment of the present disclosure.
8 is a block diagram illustrating the structure of a terminal according to an embodiment of the present disclosure.
9 is a block diagram illustrating the structure of a base station according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. At this time, it should be noted that the same components in the accompanying drawings are indicated by the same reference numerals as much as possible. In addition, detailed descriptions of well-known functions and configurations that may obscure the subject matter of the present invention will be omitted.

In describing the embodiments in this specification, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention without obscuring it by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated. Also, the size of each component does not entirely reflect the actual size. In each figure, the same reference number is assigned to the same or corresponding component.

Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

At this time, it will be understood that each block of the process flow chart diagrams and combinations of the flow chart diagrams can be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment are described in the flowchart block(s). It creates means to perform functions. These computer program instructions may also be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular way, such that the computer usable or computer readable memory The instructions stored in are also capable of producing an article of manufacture containing instruction means that perform the functions described in the flowchart block(s). The computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to generate computer or other programmable data processing equipment. Instructions for performing processing equipment may also provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is possible for the functions mentioned in the blocks to occur out of order. For example, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in reverse order depending on their function.

At this time, the term '~unit' used in this embodiment means software or a hardware component such as FPGA or ASIC, and '~unit' performs certain roles. However, '~ part' is not limited to software or hardware. '~bu' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Therefore, as an example, '~unit' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Functions provided within components and '~units' may be combined into smaller numbers of components and '~units' or further separated into additional components and '~units'. In addition, components and '~units' may be implemented to play one or more CPUs in a device or a secure multimedia card.

A term used in the following description to identify a connection node, a term referring to network entities, a term referring to messages, a term referring to an interface between network entities, and a term referring to various types of identification information. Etc. are illustrated for convenience of description. Therefore, the present invention is not limited to the terms described below, and other terms indicating objects having equivalent technical meanings may be used.

For convenience of description below, the present invention uses terms and names defined in the 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) standard and NR (new radio) standard. However, the present invention is not limited by the above terms and names, and may be equally applied to systems conforming to other standards.

In various embodiments of the present invention, a master node (MN) can be interpreted as a master base station, and a secondary node (SN) can be interpreted as a secondary base station. . In addition, in various embodiments of the present invention, MN and SN can be interpreted as different base stations and base stations using different radio access technologies (RATs), and in some cases, can be used as base stations using the same RAT. The MN and SN may be distinguished using general expressions such as a first base station and a second base station.

In various embodiments of the present invention, a radio resource control (RRC) message transmitted by an MN may be referred to as an MN RRC message. In addition, the RRC message generated by the SN may be named SN RRC message.

1 is a diagram showing the structure of an LTE system according to an embodiment of the present invention.

Referring to FIG. 1, as shown, the radio access network of the LTE (Long Term Evolution) system includes a next-generation base station (Evolved Node B, hereinafter ENB, Node B or base station) (1-05, 1-10, 1-15, 1-20), Mobility Management Entity (MME) (1-25), and S-GW (1-30, Serving-Gateway). A user equipment (UE or terminal) 1-35 can access an external network through ENBs 1-05 to 1-20 and S-GW 1-30.

In FIG. 1, ENBs 1-05 to 1-20 may correspond to existing Node Bs of the UMTS system. The ENB is connected to the UE (1-35) through a radio channel and can perform a more complex role than the existing Node B. In the LTE system, all user traffic including real-time services such as VoIP (Voice over IP) through Internet protocol can be serviced through a shared channel. Therefore, a device for performing scheduling by collecting status information such as buffer status, available transmission power status, and channel status of UEs is required, and ENBs 1-05 to 1-20 can be in charge of this. One ENB can typically control multiple cells. For example, in order to implement a transmission rate of 100 Mbps, an LTE system may use Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology in a 20 MHz bandwidth, for example. In addition, an adaptive modulation & coding (AMC) method for determining a modulation scheme and a channel coding rate according to the channel condition of the terminal may be applied. The S-GW 1-30 is a device that provides a data bearer, and can create or remove a data bearer under the control of the MME 1-25. The MME 1-25 is a device in charge of various control functions as well as a mobility management function for the terminal 1-35, and may be connected to a plurality of base stations 1-05 to 1-20.

2 is a diagram showing a radio protocol structure of an LTE system according to an embodiment of the present invention.

Referring to FIG. 2, the radio protocols of the LTE system are Packet Data Convergence Protocol (PDCP) (2-05, 2-40) and Radio Link Control (RLC) ( 2-10, 2-35) and Medium Access Control (MAC) (2-15, 2-30). The PDCPs 2-05 and 2-40 may be in charge of operations such as IP header compression/restoration. The main functions of PDCP (2-05, 2-40) can be summarized as follows.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

- Order reordering function (For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM

- Retransmission of PDCP SDUs at handover and, for split bearers in DC, of PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

Radio Link Control (RLC) (2-10, 2-35) may perform an automatic repeat request (ARQ) operation by reconstructing a PDCP Packet Data Unit (PDU) into an appropriate size. . The main functions of RLC (2-10, 2-35) can be summarized as follows.

- Transfer of upper layer PDUs

- ARQ function (Error Correction through ARQ (only for AM data transfer))

- Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

- Re-segmentation of RLC data PDUs (only for AM data transfer)

- Reordering of RLC data PDUs (only for UM and AM data transfer)

- Duplicate detection (only for UM and AM data transfer)

- Error detection function (Protocol error detection (only for AM data transfer))

- RLC SDU discard function (RLC SDU discard (only for UM and AM data transfer))

- RLC re-establishment

The MACs 2-15 and 2-30 are connected to several RLC layer devices configured in one terminal, and can perform operations of multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of the MACs 2-15 and 2-30 can be summarized as follows.

- Mapping between logical channels and transport channels

- Multiplexing/demultiplexing of MAC SDUs belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels

- Scheduling information reporting

- HARQ (hybrid automatic repeat request) function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function (Padding)

The physical layer (PHY layer) (2-20, 2-25) channel-codes and modulates upper-layer data, converts it into OFDM symbols, and transmits it through a radio channel, or demodulates OFDM symbols received through a radio channel and channel-decodes them. You can perform an operation that forwards to the upper layer.

3 is a diagram showing the structure of a next-generation mobile communication system according to an embodiment of the present invention.

Referring to FIG. 3, a radio access network of a next-generation mobile communication system (hereinafter NR or 5g) includes a next-generation base station (New Radio Node B, hereinafter gNB or NR NB or NR gNB or NR base station) 3-10 and a next-generation radio core. It can be composed of a network (New Radio Core Network, NR CN) (3-05). A next-generation radio user equipment (New Radio User Equipment, NR UE or terminal) 3-15 can access an external network through the NR gNB 3-10 and the NR CN 3-05.

In FIG. 3, NR gNBs 3-10 may correspond to evolved Node Bs (eNBs) of the existing LTE system. The NR gNB (3-10) is connected to the NR UE (3-15) through a radio channel and can provide superior service to the existing Node B. In a next-generation mobile communication system, all user traffic can be serviced through a shared channel. Therefore, a device for performing scheduling by collecting status information such as buffer status, available transmission power status, and channel status of UEs is required, and the NR NB 3-10 can take charge of this. One NR gNB can control multiple cells. In a next-generation mobile communication system, a bandwidth higher than the current maximum bandwidth may be applied in order to implement high-speed data transmission compared to current LTE. In addition, beamforming technology may be additionally applied by using Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology. In addition, an adaptive modulation & coding (AMC) method for determining a modulation scheme and a channel coding rate according to a channel condition of a terminal may be applied. The NR CN (3-05) can perform functions such as mobility support, bearer setup, and quality of service (QoS) setup. The NR CN 3-05 is a device in charge of various control functions as well as a mobility management function for a terminal, and may be connected to a plurality of base stations. In addition, the next-generation mobile communication system can interwork with the existing LTE system, and the NR CN (3-05) can be connected to the MME (3-25) through a network interface. The MME 3-25 may be connected to the existing eNB 3-30.

4 is a diagram showing a radio protocol structure of a next-generation mobile communication system according to an embodiment of the present invention.

Referring to FIG. 4, the radio protocols of the next-generation mobile communication system are NR Service Data Adaptation Protocol (SDAP) (4-01, 4-45) and NR PDCP (4-05, 4-05, 4-40), NR RLC (4-10, 4-35), and NR MAC (4-15, 4-30).

The main functions of the NR SDAPs 4-01 and 4-45 may include some of the following functions.

-Transfer of user plane data

-Mapping between a QoS flow and a data radio bearer (DRB) for both DL and UL for uplink and downlink

- Marking QoS flow ID for uplink and downlink (marking QoS flow ID in both DL and UL packets)

-Function of mapping relective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

For the SDAP layer device, the UE uses a Radio Resource Control (RRC) message for each PDCP layer device, each bearer, or each logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device can be set. When the SDAP header is set, the UE sets the Non-Access Stratum (NAS) Quality of Service (QoS) reflection setting 1-bit indicator (NAS reflective QoS) of the SDAP header and the Access Stratum (AS) QoS With the reflective setting 1-bit indicator (AS reflective QoS), the terminal may be instructed to update or reset mapping information for uplink and downlink QoS flows and data bearers. The SDAP header may include QoS flow ID information indicating QoS. QoS information may be used as data processing priority and scheduling information to support smooth service.

The main functions of the NR PDCP (4-05, 4-40) may include some of the following functions.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- PDCP PDU reordering for reception

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

In the above description, the reordering function of the NR PDCP device may refer to a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP sequence number (SN). The reordering function of the NR PDCP device may include a function of forwarding data to a higher layer in the rearranged order, or may include a function of directly forwarding data without considering the order, and rearranging the order may cause loss It may include a function of recording lost PDCP PDUs, a function of reporting the status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs. there is.

The main functions of the NR RLCs 4-10 and 4-35 may include some of the following functions.

- Transfer of upper layer PDUs

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection

- Error detection function (Protocol error detection)

- RLC SDU discard function (RLC SDU discard)

- RLC re-establishment

In the above description, the in-sequence delivery function of the NR RLC device may refer to a function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. Originally, when one RLC SDU is divided into several RLC SDUs and received, the in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering them.

The in-sequence delivery function of the NR RLC device may include a function of rearranging received RLC PDUs based on an RLC sequence number (SN) or a PDCP sequence number (SN), and rearranging the order results in loss It may include a function of recording lost RLC PDUs, a function of reporting the status of lost RLC PDUs to the transmitting side, and a function of requesting retransmission of lost RLC PDUs. there is.

In-sequence delivery of the NR RLC device may include, when there is a lost RLC SDU, a function of sequentially delivering only RLC SDUs prior to the lost RLC SDU to a higher layer.

In-sequence delivery of the NR RLC device, if a predetermined timer expires even if there is a lost RLC SDU, all RLC SDUs received before the timer starts can be sequentially delivered to the upper layer. there is.

The in-sequence delivery function of the NR RLC device may include a function of sequentially delivering all RLC SDUs received so far to a higher layer if a predetermined timer expires even if there is a lost RLC SDU.

The NR RLC device may process RLC PDUs in the order in which they are received regardless of the order of sequence numbers (out-of sequence delivery) and deliver them to the NR PDCP device.

When the NR RLC device receives a segment, it may receive segments stored in a buffer or to be received later, reconstruct it into one complete RLC PDU, and then transmit it to the NR PDCP device.

The NR RLC layer may not include a concatenation function, and may perform a function in the NR MAC layer or may be replaced with a multiplexing function of the NR MAC layer.

In the above description, the out-of-sequence delivery of the NR RLC device may mean a function of immediately delivering RLC SDUs received from a lower layer to an upper layer regardless of order. Out-of-sequence delivery of the NR RLC device may include a function of reassembling and delivering, when originally one RLC SDU is divided into several RLC SDUs and received. The out-of-sequence delivery function of the NR RLC device may include a function of storing RLC SNs or PDCP SNs of received RLC PDUs and arranging the order to record lost RLC PDUs.

NR MACs (4-15, 4-30) can be connected to several NR RLC layer devices configured in one device, and the main functions of NR MACs (4-15, 4-30) include some of the following functions can do.

- Mapping between logical channels and transport channels

- Multiplexing/demultiplexing of MAC SDUs

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function (Padding)

The NR physical layer (NR PHY layer) (4-20, 4-25) channel-codes and modulates upper layer data, converts it into OFDM symbols and transmits it through a radio channel, or demodulates OFDM symbols received through a radio channel and channel It can perform an operation of decoding and forwarding to a higher layer.

In various embodiments of the present invention, when referred to as dual connection, when the core network is an evolved packet core (EPC), it may include both LTE-NR dual connectivity (ENDC) and multi-RAT dual connectivity (MRDC) of 5gc. and includes the operation of the network and terminal according to the RAT of the MN and SN. In case of NR-DC, the core network is 5GC.

Hereinafter, the following abbreviations may be used in the present disclosure.

SN: secondary node

MN: master node

MCG: master cell group

SCG: secondary cell group

Pcell: primary cell

Pscell: Primary SCG (secondary cell group)cell

SCell: secondary cell

SpCell: special cell

CHO: conditional handover

CPC: conditional pscell change

S-SN: source SN

T-SN: target SN

SNModReq: SN Modification Required message

SNChangeReq: SN Change Required message

SNAddReq: SN Addition Request message

SNAddReqACK; SN Addition Request Acknowledge message

SNModConfirm: SN Modification Confirm message

5 is a diagram illustrating a secondary node (SN) setting update process related to an embodiment of the present disclosure. 5 is a case of updating CPC settings using an S-SN Modification Required message.

After the CPC setting is given to the terminal, that is, in a situation where the CPC setting for the corresponding terminal is maintained/managed in the S-SN, MN, and T-SN, a case in which the S-SN setting is changed will be described.

- The S-SN may transmit the configuration change request information by delivering the SNModReq message to the MN. The SNModReq message may include the following information.

- Information requesting SCG bearer modification/release, SCG RLC bearer of split bearer modification/release, or Pscell change (for security key change, PDCP recovery, etc.) in the X2/Xn related field.

- As information included in the RRC container part, as S-SN configuration information, it may include RRC configuration information (octet string) to be changed.

- In X2/Xn related fields, CPC configuration update indication is included.

- The operation of the MN receiving the message may include the following.

- The MN reflects the SCG configuration change request information existing in the X2/Xn part and performs modification on the current MN configuration information. This modification can be add/mod/release of the bearer, and can be related to PDCP recovery, PDCP version change instruction, and bearer type change to split bearer. During this process, the MN can send the SN modification request back to the SN, if necessary, to perform the necessary request. In addition, MCG configuration information provided by the MN to the UE may be updated.

- If the CPC configuration update indication is included, the RRC configuration information to be changed of the received S-SN is delivered to the T-SN that operates each candidate target pscell corresponding to the existing CPC configuration of the corresponding terminal indicated in the received message and, for each candidate target pscell, request to update the existing CPC configuration based on the configuration information of the received S-SN.

- At this time, the message used when the MN delivers to the T-SN can be SNAddReq. Or it can be a separate new X2/Xn message.

- When the SNAddReq message is used for CPC update, the CPC candidate target cell id and frequency information previously set in the terminal can be included in the SNAddReq message.

- The SNAddReq message may include an indicator indicating CPC configuration modification. Upon receiving this indicator, the T-SN updates previously configured CPC candidate target cell configuration information based on the new configuration information of the received S-SN for the candidate target pscell that has been admitted for the corresponding UE.

- The T-SN may transmit the updated CPC configuration information to the MN by including it in the SNAddReqACK message. In this case, an updated RRC message may be included for each admitted candidate target cell, or if the update is not performed, a 1-bit indicator indicating that the configuration is the same as the previous setting may be included for each candidate target cell.

- Upon receiving the above message from the T-SN, the MN can store the following information in its own RRCReconfigureation message and deliver it to the terminal.

- A: S-SN configuration information to be updated, that is, a delta signal compared to the existing S-SN configuration

- B: updated setting information of MN considering S-SN update, delta signal compared to existing MCG setting

- C: updated setting information of candidate target pscell reflecting S-SN setting update

-D: updated configuration information of MCG reflecting the updated configuration information of C, that is, candidate target pscell

- Among them, C and D are included in the conditionalReconfiguratoin field, indicated by a specific id, and applied when a specific condition associated with one candidate target pscell is met. The specific id is a condtional reconfiguration id determined by the MN, and if the terminal already has a conditional reconfiguration indicated by the corresponding id, it is updated with the newly received C and D.

After receiving the RRCReconfiguration message, applying the given configuration and updating the conditionalReconfiguration, the UE transfers the RRCReconfigurationComplete message to Mn. After receiving this message, the MN may transmit an SN Modification Confirm (Complete) message to the S-SN to notify that all requested S-SN configuration changes have been completed.

6 is a diagram illustrating a process of updating SN settings related to an embodiment of the present disclosure. 6 is a case of updating CPC settings using an S-SN Change Required message.

After the CPC setting is given to the terminal, that is, in a situation where the CPC setting for the corresponding terminal is maintained/managed in the S-SN, MN, and T-SN, a case in which the S-SN setting is changed will be described.

- The S-SN may transmit the setting change request information by transferring the SNChangeReq message to the MN. The SNChangeReq message may include the following information.

- Information requesting SCG bearer modification/release, SCG RLC bearer of split bearer modification/release, or Pscell change (for security key change, PDCP recovery, etc.) in the X2/Xn related field.

For reference, in addition to the above information, information described in Table 1 below may be included as SN setting change request information. For a description of the information described in Table 1, TS 38.423 can be referred to.

PDCP Change Indication PDU Session Resources To Be Modified List >PDU Session Resources To Be Modified Item >>PDU Session ID >>PDU Session Resource Modification Required Info - SN terminated >>PDU Session Resource Modification Required Info - MN terminated PDU Session Resources To Be Released List >PDU Session Resources To Be Released Item >PDU sessions to be released List - SN terminated >PDU sessions to be released List - MN terminated Required Number of DRB IDs Location Information at S-NODE MR-DC Resource Coordination Information RRC Config Indication

As information included in the RRC container, it may include RRC configuration information (octet string) to change the S-SN.

- In the Xn part, the CPC configuration update indication is included.

- The operation of the MN receiving the message may include the following.

- The MN reflects the SCG configuration change request information existing in the X2/Xn part and performs modification on the current MN configuration information. This modification can be add/mod/release of the bearer, and can be related to PDCP recovery, PDCP version change instruction, and bearer type change to split bearer. During this process, the MN can send the SN modification request back to the SN, if necessary, to perform the necessary request. In addition, MCG configuration information provided by the MN to the UE may be updated.

- If the CPC configuration update indication is included, the RRC configuration information to be changed of the received S-SN is delivered to the T-SN that operates each candidate target pscell corresponding to the existing CPC configuration of the corresponding terminal indicated in the received message and, for each candidate target pscell, request to update the existing CPC configuration based on the configuration information of the received S-SN.

- At this time, the message used when the MN delivers to the T-SN can be SNAddReq. Or it can be a separate new Xn message.

- When the SNAddReq message is used for CPC update, the CPC candidate target cell id and frequency information previously set in the terminal can be included in the SNAddReq message.

- The SNAddReq message may include an indicator instructing CPC condifuration update. Upon receiving this indicator, the T-SN updates previously configured CPC candidate target cell configuration information based on the new configuration information of the received S-SN for the candidate target pscell that has been admitted for the corresponding UE.

- The T-SN may transmit the updated CPC configuration information to the MN by including it in the SNAddReqACK message. In this case, an updated RRC message may be included for each admitted candidate target cell, or if the update is not performed, a 1-bit indicator indicating that the configuration is the same as the previous setting may be included for each candidate target cell.

- Upon receiving the above message from the T-SN, the MN can store the following information in its own RRCReconfigureation message and deliver it to the terminal.

- A: S-SN configuration information to be updated, that is, a delta signal compared to the existing S-SN configuration

- B: updated setting information of MN considering S-SN update, delta signal compared to existing MCG setting

- C: updated setting information of candidate target pscell reflecting S-SN setting update

-D: updated configuration information of MCG reflecting the updated configuration information of C, that is, candidate target pscell

- Among them, C and D are included in the conditionalReconfiguratoin field, indicated by a specific id, and applied when a specific condition associated with one candidate target pscell is met. The specific id is a condtional reconfiguration id determined by the MN, and if the terminal already has a conditional reconfiguration indicated by the corresponding id, it is updated with the newly received C and D.

- After receiving the RRCReconfiguration message, applying the given configuration and updating the conditionalReconfiguration, the UE delivers the RRCReconfigurationComplete message to Mn. After receiving this message, the MN may transmit an SN change Complete message to the S-SN to notify that all requested S-SN configuration changes have been completed.

7 is a diagram illustrating a process of updating SN settings related to an embodiment of the present disclosure. 7 shows a case of setting a new CPC reflecting the setting to be updated of the S-SN after releasing the CPC setting.

A case in which the S-SN setting is changed after the CPC setting is given will be described.

- The S-SN delivers the SNModReq message to the MN. At this time, information to be modified (information mentioned in the previous figure) is included, and update configuration information of the S-SN is included.

- In addition, delivery including CPC release indication. This indication should be included in the Xn/X2 field part.

- The MN receives the message and updates the configuration information of the MN and MCG in relation to the modification request information of the corresponding S-SN. In addition, the updated MN/MCG configuration information and the received S-SN configuration information may be included in RRCReconfiguration and transmitted to the UE. At this time, a release command may be issued for all CPC settings that the UE currently has in the MCG configuration information.

- When commanding the conditional reconfiguration release, an indication to release all CPC configs may be delivered, or a release may be requested by directly indicating each condReconfig Id.

- In addition, the current S-SN configuration may include an indicator for releasing measurement configuration information associated with the CPC configuration in the measurement configuration.

* The terminal receiving the RRCReconfiguraiton applies the MN/MCG/SCG configuration information as it is received, and deletes all CPCs according to the release instruction,

* S-Sn uses a new source configuration and performs a general CPC setup procedure. That is, while transmitting the SN Change Required message to the MN, the CPC setting indicator is also delivered to the MN. This message may include a list of candidate target pscells selected by the S-SN and conditions for performing CPC for each pscell. In addition, the current S-SN configuration may be included as an RRC octet string.

* Upon receiving this information, the MN transmits a SNAddReq message to the candidate target T-SN corresponding to the candidate target pscell included in the received message. This message includes the list of candidate target pscells selected by the S-SN, and the current configuration of the S-SN. If the T-SN receiving this message confirms that the message is a terminal that has previously maintained CPC configuration information, it deletes all CPC configuration information it has maintained, and among the candidate target pscell list of the received S-SN, Together, the final candidate target pscell is selected based on the measurement result value transmitted from the S-SN to the MN. Then, CPC configuration is made based on the S-SN configuration information for the selected pscells. In addition, the CPC settings made for the selected candidate target pscells are delivered to the MN, and the MN provides the execution conditions for each candidate target cell selected in the conditionalReconfiguartion field, settings in the target cell, and MCG settings when these settings are applied. etc. can be mapped to one conditional Reconfiguratin id and delivered to the terminal.

* The terminal receiving this message can store the corresponding conditional reconfiguration information and perform measurement operations according to the execution conditions.

In the case of the flowcharts of FIGS. 5 and 6 , when the MN transmits the CPC configuration modification indicator in the SNAddReq message to the T-SN, the T-SN can update the previously set CPC configuration. At this time, if the settings are the same as those of the existing CPC, the T-SN includes CG-Config (RRC message meaning CPC setting) of 0 size in the field containing the CPC setting of the SNAddReqACK message, or CPC setting of the SNAddReqACK message altogether May not include fields that contain . Upon receiving the SNAddReqACK message including the container field of the 0 size CG-Config or the omitted CG-Config, the MN can recognize that the CPC setting of the corresponding candidate target pscell is the same as that previously possessed by the terminal. MN can recognize that the CPC configuration information of the candidate target pscell is the same as the previously transmitted content if it recognizes a 0 size CG-Config field or if a field including CPC configuration is not included in SNAddReqACK.

If the container field including the CPC setting of each candidate target pscell in the SNAddReqACK message is included as mandatory, another method is that the T-SN adds the ignore indicator to the SNAddReqACK message in association with the CPC setting of each candidate target pscell in the SNAddReqACK message. It can be transmitted by including it in the X2/Xn field. In this case, the received MN sees the ignore indicator and knows that there is no change compared to the existing CPC.

There is a separate CPC setting change vacancy handling indicator in the MN's SNAddReq message, and when this indicator is put in the SNAddReq message and delivered to the T-SN, the T-SN transmits a response message to the MN. CPC information may not be included, an ignore indicator may be included, or a CG-Config message of 0 bit size may be attached.

5 and 6, in the RRCReconfiguration message finally received from the MN, the current S-SN configuration information (A), the current MN configuration information and MCG configuration information (B) considering A, and the conditional reconfiguration field SCG configuration (C) included in the RRCReconfiguration message associated with id indicating a specific candidate target pscell, that is, CPC configuration and MCG configuration (D) configured considering the CPC configuration may be included. When the terminal adds or modifies a specific id of the conditional reconfiguration field included in the RRCReconfiguration message finally received, there is a case where only C or D is changed compared to the existing one. For example, if the MN requests CPC setting or sends a SNAddReq message requesting a CPC setting change, and receives a SNAddReqACK message without CPC setting information from the T-SN, the MN recognizes that there is no change information compared to the existing one. can perceive However, if the request for CPC configuration information update is originally a configuration change of the S-SN, and the current MN/MCG configuration is changed due to the configuration change of the S-SN, D based on the current MCG configuration, that is, the CPC configuration MCG setting information within can also be changed. That is, C does not change, but D may change. In this case, the MN stores the C information to be changed in the MCG configuration field in the RRCReconfiguration message to be overwritten for each candidate target pscell related id to be modified in the conditional reconfiguration field in the final RRCReconfiguration message, and the D information without change Also, the existing D information may be put into the SCG configuration field again and delivered to the terminal. Likewise, if C information does not need to be changed according to Mn's judgment, but new configuration information with D information changed is received from T-SN, MN will change each candidate target pscell related id to be modified in the RRCReconfiguration message to be overwritten. D information can be stored in the SCG setting field, and C information without change can also be delivered to the terminal by putting the existing C information into the MCG setting field again. When receiving add/modification information of the conditional reconfiguration field, the terminal may replace the entire RRCReconfiguration message corresponding to the id.

5 and 6, the Xn/X2 message informing the MN of the S-SN configuration change, causing the MN to request the T-SN and CPC configuration, and allowing the MN to receive the result, is SN Modification Required or SN In addition to the Change Required message, it may be a new message of Xn/X2 that means a separate CPC setting update. In this case, each piece of information included in the initiation message of FIGS. 5 and 6 may be included in this new message as it is.

Hereinafter, a new embodiment related to conditional PScell addition/change (CPAC) will be described separately from the above-described content. When the UE performs CPAC, when the given T304 timer expires while performing random access to the target cell, pscell addition/change failure may occur. In this case, the terminal may select a new candidate target pscell from among given CPAC candidate target pscells based on the following, and perform pscell addition/change to the selected cell.

* After selecting the same cell as the cell selection procedure performed in the idle/inactive state, if the selected cell is one of each candidate target pscell associated with CPAC configuration, the candidate target pscell

* Among each candidate target pscell associated with each CPAC setting, the candidate target cell with the highest measured cell signal strength

* Among each candidate target pscell associated with each CPAC setting, any cell among candidate target cells whose measured cell signal strength is greater than a given threshold

* Among each candidate target pscell associated with each CPAC setting, the cell with the highest strength among candidate target cells whose measured cell signal strength is greater than a given threshold

* Among each candidate target pscell associated with each CPAC setting, among candidate target cells whose measured cell signal strength is greater than a given threshold, the number of beams exceeding the threshold of a specific beam is greater than or equal to a predetermined number

* Any cell selected by the terminal among candidate target pscells associated with each CPAC setting

If there is no cell that satisfies the above criteria, the UE may perform the SCGFailureInformation procedure. Alternatively, when the above criteria are satisfied or when the following conditions are satisfied in addition to the case where the cell selected by the UE exists, the UE may perform the SCGFailureInformation procedure.

* If there is a cell that satisfies the above criteria and a failure occurs while performing the pscell addition/change procedure with that cell,

* When there is a cell that satisfies the above-mentioned criteria, and a predefined number of pscell addition/change procedures are attempted with that cell, and finally all attempts to perform during that number of times fail (For reference, after one failed attempt, the T304 timer is restarted, and when this timer expires, it can be considered a failure.)

* If the result of performing pscell addition/change to a cell satisfying by applying the above criteria is failure, the terminal may repeat the pscell addition/change operation by applying the above criteria again at the time of failure. If the terminal repeats this operation more than the defined number of times,

This procedure transfers the SCGFailureInformation message to the SN through the link of the MN, and the SCGFailureInformation message may include measurement result values for each cell and each beam of the serving cell and neighboring cell. If conditional or non-conditional pscell addition/change fails after performing conditional or non-conditional pscell addition/change, the terminal may include an indicator indicating conditional or non-conditional pscell addition/change failure in the corresponding message. In addition, an SCGFailureInformation message including an indicator of the failed pscell (for example, at least one of ARFCN, CGI, PCI, or related conditional reconfiguration ID) may be delivered to the SN.

8 is a block diagram illustrating the internal structure of a terminal according to an embodiment of the present invention.

Referring to the drawing, the terminal may include a radio frequency (RF) processing unit 5-10, a baseband processing unit 5-20, a storage unit 5-30, and a control unit 5-40. can Also, the control unit 5-40 may further include a multi-connection processing unit 5-42.

The RF processing unit 5-10 performs functions for transmitting and receiving signals through a wireless channel, such as band conversion and amplification of signals. That is, the RF processing unit 5-10 up-converts the baseband signal provided from the baseband processing unit 5-20 into an RF band signal, transmits it through an antenna, and transmits the RF band signal received through the antenna. down-convert to a baseband signal. For example, the RF processor 5-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), and the like. can In the figure, only one antenna is shown, but the terminal may include multiple antennas. Also, the RF processor 5-10 may include a plurality of RF chains. Furthermore, the RF processor 5-10 may perform beamforming. For the beamforming, the RF processor 5 - 10 may adjust the phase and magnitude of signals transmitted and received through a plurality of antennas or antenna elements. Also, the RF processing unit may perform MIMO, and may receive multiple layers when performing the MIMO operation.

The baseband processor 5-20 performs a conversion function between a baseband signal and a bit string according to the physical layer standard of the system. For example, during data transmission, the baseband processor 5-20 generates complex symbols by encoding and modulating a transmission bit stream. Also, upon receiving data, the baseband processing unit 5-20 demodulates and decodes the baseband signal provided from the RF processing unit 5-10 to restore a received bit string. For example, in the case of orthogonal frequency division multiplexing (OFDM), during data transmission, the baseband processing unit 5-20 encodes and modulates a transmission bit stream to generate complex symbols, and transmits the complex symbols to subcarriers. After mapping to, OFDM symbols are configured through inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 5-20 divides the baseband signal provided from the RF processing unit 5-10 into OFDM symbol units and maps them to subcarriers through fast Fourier transform (FFT). After restoring the received signals, a received bit stream is restored through demodulation and decoding.

The baseband processing unit 5-20 and the RF processing unit 5-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 5-20 and the RF processing unit 5-10 may be referred to as a transmitter, a receiver, a transmitter/receiver, a transmitter/receiver, or a communication unit. Furthermore, at least one of the baseband processing unit 5-20 and the RF processing unit 5-10 may include a plurality of communication modules to support a plurality of different wireless access technologies. Also, at least one of the baseband processing unit 5-20 and the RF processing unit 5-10 may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (eg, IEEE 802.11), a cellular network (eg, LTE), and the like. In addition, the different frequency bands may include a super high frequency (SHF) (eg, 2.NRHz, NRhz) band and a millimeter wave (eg, 60 GHz) band.

The storage unit 5-30 stores data such as a basic program for operation of the terminal, an application program, and setting information. In particular, the storage unit 5 - 30 may store information related to a second access node performing wireless communication using the second wireless access technology. And, the storage unit 5-30 provides the stored data according to the request of the control unit 5-40.

The controller 5-40 controls overall operations of the terminal. For example, the controller 5-40 transmits and receives signals through the baseband processor 5-20 and the RF processor 5-10. Also, the control unit 5-40 writes and reads data in the storage unit 5-40. To this end, the controller 5-40 may include at least one processor. For example, the control unit 5 - 40 may include a communication processor (CP) that controls communication and an application processor (AP) that controls upper layers such as application programs. Also, the control unit 5-40 may control the operation of a terminal or an entity corresponding thereto according to various embodiments of the present disclosure.

9 is a block diagram showing the configuration of a base station according to an embodiment of the present invention.

As shown in the figure, the base station includes an RF processing unit 6-10, a baseband processing unit 6-20, a backhaul communication unit 6-30, a storage unit 6-40, and a control unit 6-50. can include The control unit 6-50 may further include a multi-connection processing unit 6-52.

The RF processing unit 6-10 performs functions for transmitting and receiving signals through a wireless channel, such as band conversion and amplification of signals. That is, the RF processing unit 6-10 upconverts the baseband signal provided from the baseband processing unit 6-20 into an RF band signal, transmits the signal through an antenna, and transmits the RF band signal received through the antenna. down-convert to a baseband signal. For example, the RF processor 6-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. In the figure, only one antenna is shown, but the first access node may include multiple antennas. Also, the RF processor 6-10 may include a plurality of RF chains. Furthermore, the RF processor 6-10 may perform beamforming. For the beamforming, the RF processor 6-10 may adjust the phase and size of signals transmitted and received through a plurality of antennas or antenna elements. The RF processing unit may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processing unit 6-20 performs a conversion function between a baseband signal and a bit stream according to the physical layer standard of the first wireless access technology. For example, during data transmission, the baseband processor 6-20 generates complex symbols by encoding and modulating a transmission bit stream. Also, when data is received, the baseband processing unit 6-20 demodulates and decodes the baseband signal provided from the RF processing unit 6-10 to restore a received bit string. For example, according to the OFDM method, when data is transmitted, the baseband processing unit 6-20 generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then performs IFFT OFDM symbols are constructed through operation and CP insertion. In addition, when receiving data, the baseband processing unit 6-20 divides the baseband signal provided from the RF processing unit 6-10 into OFDM symbol units, and restores signals mapped to subcarriers through FFT operation. After that, the received bit string is restored through demodulation and decoding. The baseband processing unit 6-20 and the RF processing unit 6-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 6-20 and the RF processing unit 6-10 may be referred to as a transmitter, a receiver, a transmitter/receiver, a transmitter/receiver, a communication unit, or a wireless communication unit.

The backhaul communication unit 6-30 provides an interface for communicating with other nodes in the network. That is, the backhaul communication unit 6-30 converts a bit string transmitted from the base station to another node, for example, an auxiliary base station, a core network, etc. into a physical signal, and converts a physical signal received from the other node into a bit string. convert to

The storage unit 6-40 stores data such as a basic program for operation of the base station, an application program, and setting information. In particular, the storage unit 6-40 may store information about a bearer allocated to a connected terminal, measurement results reported from the connected terminal, and the like. In addition, the storage unit 6-40 may store information that is a criterion for determining whether to provide or stop multiple connections to the terminal. And, the storage unit 6-40 provides the stored data according to the request of the control unit 6-50.

The controller 6-50 controls overall operations of the base station. For example, the control unit 6-50 transmits and receives signals through the baseband processing unit 6-20 and the RF processing unit 6-10 or through the backhaul communication unit 6-30. In addition, the control unit 6-50 writes and reads data in the storage unit 6-40. To this end, the controller 6-50 may include at least one processor. Also, the control unit 6-50 may control the operation of a base station or an entity corresponding thereto according to various embodiments of the present disclosure.

Embodiments of the present invention disclosed in this specification and drawings are only presented as specific examples to easily explain the technical content of the present invention and help understanding of the present invention, and are not intended to limit the scope of the present invention. It is obvious to those skilled in the art that other modified examples based on the technical idea of the present invention can be implemented in addition to the embodiments disclosed herein.

And the embodiments disclosed in this specification and drawings are only presented as specific examples to easily explain the content of the present invention and aid understanding, and are not intended to limit the scope of the present invention. Therefore, the scope of the present invention should be construed as including all changes or modifications derived based on the technical features of the present invention in addition to the embodiments disclosed herein.

Claims (1)

A control signal processing method in a wireless communication system,
Receiving a first control signal transmitted from a base station;
processing the received first control signal; and
and transmitting a second control signal generated based on the processing to the base station.

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