CN118488499A

CN118488499A - LTM switching condition determining method and device and network side equipment

Info

Publication number: CN118488499A
Application number: CN202310121318.4A
Authority: CN
Inventors: 王鹏飞; 杨坤; 姜大洁; 鲍炜
Original assignee: Vivo Mobile Communication Co Ltd
Current assignee: Vivo Mobile Communication Co Ltd
Priority date: 2023-02-13
Filing date: 2023-02-13
Publication date: 2024-08-13

Abstract

The embodiment of the application discloses a method and a device for determining LTM switching conditions and network side equipment, belonging to the technical field of communication, wherein the method for determining the LTM switching conditions comprises the following steps: the CU sends a first message to the first DU, or the CU receives a second message sent by a second DU, and the CU sends the first message to the first DU based on the second message; the first message is used for determining a first LTM switching condition, the first LTM switching condition is configured by the CU for the first DU, the second message includes a second LTM switching condition, and the second LTM switching condition includes a LTM switching condition of the second DU.

Description

LTM switching condition determining method and device and network side equipment

Technical Field

The application belongs to the technical field of communication, and particularly relates to a method and a device for determining a mobility (L1/2-TRIGGERED MOBILITY, LTM) switching condition triggered by a layer 1 or a layer 2 and network side equipment.

Background

An access network of a New air interface (NR) system splits a next generation node B (the next generation Node B, gNB) into a Central Unit (CU) and a Distributed Unit (DU), the CU and the DU are connected through an F1 interface, and the CU and the DU may belong to different vendors.

The LTM switching is to configure candidate target cells for the terminal in advance by the CU, the DU issues an LTM switching command to the terminal, and the terminal switches to the target cells based on the LTM switching command indication and radio resource control (Radio Resource Control, RRC) pre-configuration.

In the related art, when the LTM switch is determined by the DU, a ping-pong switch between a plurality of DUs may be caused, for example, when the DU1 and the DU2 are connected to the same CU, the DU1 and the DU2 determine the LTM switch condition by themselves, and after the terminal is switched from the DU1 to the DU2, the DU2 switches the terminal back to the DU1 soon, which affects the service continuity and stability of the terminal.

Disclosure of Invention

The embodiment of the application provides a method, a device and network side equipment for determining LTM switching conditions, which can solve the problems that LTM switching in the related technology easily causes ping-pong switching among a plurality of DUs and influences service continuity and stability of a terminal.

In a first aspect, a method for determining an LTM handover condition is provided, including: the CU sends a first message to the first DU, or the CU receives a second message sent by a second DU, and the CU sends the first message to the first DU based on the second message; the first message is used for determining a first LTM switching condition, the first LTM switching condition is configured by the CU for the first DU, the second message includes a second LTM switching condition, and the second LTM switching condition includes a LTM switching condition of the second DU.

In a second aspect, a method for determining an LTM handover condition is provided, including: the method comprises the steps that a first DU receives a first message from a CU, wherein the first message is used for determining a first LTM switching condition; the first LTM switch condition is that the CU is configured for the first DU; or, the first message is generated based on a second message sent by a second DU, where the second message is used to indicate an LTM switching condition of the second DU.

In a third aspect, a method for determining an LTM handover condition is provided, including: the second DU sends a second message to the CU, where the second message is used to indicate a second LTM switching condition of the second DU, and part or all of information of the second message is included in the first message, and the first message is used to determine a first LTM switching condition of the first DU.

In a fourth aspect, there is provided a device for determining an LTM switching condition, including: a sending module, configured to send a first message to a first DU, or a receiving module, configured to receive a second message sent by a second DU, and a sending module, configured to send the first message to the first DU based on the second message; the first message is used for determining a first LTM switching condition, the first LTM switching condition is configured by the device for the first DU, the second message includes a second LTM switching condition, and the second LTM switching condition includes a LTM switching condition of the second DU.

In a fifth aspect, there is provided a device for determining an LTM switching condition, including: a receiving module, configured to receive a first message from a CU, where the first message is used to determine a first LTM switching condition; the first LTM switch condition is that the CU is configured for the device; or, the first message is generated based on a second message sent by a second DU, where the second message is used to indicate an LTM switching condition of the second DU.

In a sixth aspect, there is provided an apparatus for determining an LTM switching condition, including: and a sending module, configured to send a second message to the CU, where the second message is used to indicate a second LTM switching condition of the device, and part or all of information of the second message is included in the first message, where the first message is used to determine a first LTM switching condition of the first DU.

In a seventh aspect, a network side device is provided, comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the method according to any of the first to third aspects.

An eighth aspect provides a network side device, including a processor and a communication interface, where the communication interface is configured to send a first message to a first DU, or receive a second message sent by a second DU, and send the first message to the first DU based on the second message; the first message is used for determining a first LTM switching condition, the first LTM switching condition is configured for the first DU by the network side device, the second message includes a second LTM switching condition, and the second LTM switching condition includes an LTM switching condition of the second DU.

A ninth aspect provides a network side device, including a processor and a communication interface, where the communication interface is configured to receive a first message from a CU, where the first message is used to determine a first LTM handover condition; the first LTM switching condition is that the CU is configured for the network side equipment; or, the first message is generated based on a second message sent by a second DU, where the second message is used to indicate an LTM switching condition of the second DU.

In a tenth aspect, a network side device is provided, including a processor and a communication interface, where the communication interface is configured to send a second message to a CU, where the second message is used to indicate a second LTM switching condition of the network side device, and part or all of information of the second message is included in a first message, and the first message is used to determine a first LTM switching condition of a first DU.

In an eleventh aspect, there is provided a readable storage medium having stored thereon a program or instructions which when executed by a processor realizes the steps of the method according to any of the first to third aspects.

In a twelfth aspect, there is provided a wireless communication system comprising: a terminal and a network side device operable to perform the steps of the method according to any of the first to third aspects.

In a thirteenth aspect, there is provided a chip comprising a processor and a communication interface coupled to the processor for running a program or instructions implementing the steps of the method according to any of the first to third aspects.

In a fourteenth aspect, there is provided a computer program/program product stored in a storage medium, the computer program/program product being executed by at least one processor to implement the steps of the method according to any one of the first to third aspects.

In the embodiment of the application, the CU sends the first message to the first DU, the first message can be used for configuring the first LTM switching condition for the first DU, and the LTM switching condition of each DU is uniformly determined and configured by the CU, so that the problem of ping-pong switching can be avoided, and the service continuity and stability of the terminal are improved; or, the first message is generated based on the second message from the second DU, the second message is used for indicating the LTM switching condition of the second DU, and in this embodiment, the CU can coordinate the LTM switching condition of each DU centrally, so that the ping-pong switching problem can be avoided, and the service continuity and stability of the terminal are improved.

Drawings

Fig. 1 is a schematic diagram of a wireless communication system according to an embodiment of the present application;

fig. 2 is a schematic flow chart of a method of determining an LTM handover condition according to an embodiment of the application;

fig. 3 is a schematic flow chart of a method of determining an LTM handover condition according to an embodiment of the application;

Fig. 4 is a schematic flow chart of a method of determining an LTM handover condition according to an embodiment of the application;

FIG. 5 is a schematic diagram of a downlink measurement followed by an uplink measurement according to an embodiment of the present application;

FIG. 6 is a schematic diagram of upstream measurement followed by downstream measurement according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a determination device of LTM switching conditions according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a determination device of LTM switching conditions according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a determination device of LTM switching conditions according to an embodiment of the present application;

Fig. 10 is a schematic structural view of a communication device according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a network side device according to an embodiment of the present application.

Detailed Description

The technical solutions of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the application, fall within the scope of protection of the application.

The terms "first," "second," and the like, herein, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application are capable of operation in sequences other than those illustrated or otherwise described herein, and that the "first" and "second" distinguishing between objects generally are not limited in number to the extent that the first object may, for example, be one or more. Furthermore, the "or" in the present application means at least one of the connected objects. For example, "a or B" encompasses three schemes, scheme one: including a and excluding B; scheme II: including B and excluding a; scheme III: both a and B. The character "/" generally indicates that the context-dependent object is an "or" relationship.

The term "indication" according to the application may be either a direct indication (or an explicit indication) or an indirect indication (or an implicit indication). The direct indication may be understood that the sender explicitly informs the specific information of the receiver, the operation to be executed, the request result, and other contents in the sent indication; the indirect indication may be understood as that the receiving side determines corresponding information according to the indication sent by the sending side, or determines and determines an operation or a request result to be executed according to a determination result.

It should be noted that the techniques described in the embodiments of the present application are not limited to long term evolution (Long Term Evolution, LTE)/LTE evolution (LTE-Advanced, LTE-a) systems, but may also be used in other wireless communication systems, such as code division multiple access (Code Division Multiple Access, CDMA), time division multiple access (Time Division Multiple Access, TDMA), frequency division multiple access (Frequency Division Multiple Access, FDMA), orthogonal frequency division multiple access (Orthogonal Frequency Division Multiple Access, OFDMA), single carrier frequency division multiple access (Single-carrier Frequency Division Multiple Access, SC-FDMA), or other systems. The terms "system" and "network" in embodiments of the application are often used interchangeably, and the techniques described may be used for both the above-mentioned systems and radio technologies, as well as other systems and radio technologies. The following description describes a New Radio (NR) system for exemplary purposes and NR terminology is used in much of the following description, but the techniques may also be applied to systems other than NR systems, such as the 6 th Generation (6G) communication system.

Fig. 1 shows a block diagram of a wireless communication system to which an embodiment of the present application is applicable. The wireless communication system includes a terminal 11 and a network device 12. The terminal 11 may be a Mobile phone, a tablet Computer (Tablet Personal Computer), a Laptop (Laptop Computer), a notebook (Personal DIGITAL ASSISTANT, PDA), a palm Computer, a netbook, an Ultra-Mobile Personal Computer (Ultra-Mobile Personal Computer, UMPC), a Mobile internet device (Mobile INTERNET DEVICE, MID), a Personal Digital Assistant (PDA), Augmented Reality (Augmented Reality, AR), virtual Reality (VR) devices, robots, wearable devices (Wearable Device), aircraft (FLIGHT VEHICLE), in-vehicle devices (Vehicle User Equipment, VUE), on-board equipment, pedestrian terminals (PEDESTRIAN USER EQUIPMENT, PUE), smart home (home appliances having wireless communication function, such as refrigerator, television, Washing machine or furniture, etc.), game machine, personal computer (Personal Computer, PC), teller machine or self-service machine, etc. The wearable device includes: intelligent wrist-watch, intelligent bracelet, intelligent earphone, intelligent glasses, intelligent ornament (intelligent bracelet, intelligent ring, intelligent necklace, intelligent anklet, intelligent foot chain etc.), intelligent wrist strap, intelligent clothing etc.. The in-vehicle apparatus may also be referred to as an in-vehicle terminal, an in-vehicle controller, an in-vehicle module, an in-vehicle component, an in-vehicle chip, an in-vehicle unit, or the like. It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application. The network-side device 12 may include an access network device or core network device, where the access network device may also be referred to as a radio access network (Radio Access Network, RAN) device, a radio access network function, or a radio access network element. The Access network device may include a base station, a wireless local area network (Wireless Local Area Network, WLAN) Access Point (AS), or a wireless fidelity (WIRELESS FIDELITY, WIFI) node, etc. among them, the base station may be called a Node B (NB), an Evolved Node B (eNB), a next generation Node B (the next generation Node B, gNB), a New air interface Node B (New Radio Node B, NR Node B), an access point, a relay station (Relay Base Station, RBS), a serving base station (Serving Base Station, SBS), a base transceiver station (Base Transceiver Station, BTS), a radio base station, a radio transceiver, a Basic service set (Basic SERVICE SET, BSS), an Extended service set (Extended SERVICE SET, ESS), a Home Node B (HNB), a home evolved Node B (home evolved Node B), a transmission and reception point (Transmission Reception Point, TRP) or some other suitable terminology in the field, the base station is not limited to a specific technical vocabulary as long as the same technical effect is achieved, In the embodiment of the present application, only the base station in the NR system is described as an example, and the specific type of the base station is not limited.

The core network device may include, but is not limited to, at least one of: a core network node, a core network function, a Mobility management entity (Mobility MANAGEMENT ENTITY, MME), an access Mobility management function (ACCESS AND Mobility Management Function, AMF), a session management function (Session Management Function, SMF), a user plane function (User Plane Function, UPF), a policy control function (Policy Control Function, PCF), policy AND CHARGING Rules Function (PCRF), edge application service discovery Function (Edge Application Server Discovery Function, EASDF), unified data management (Unified DATA MANAGEMENT, UDM), unified data repository (Unified Data Repository, UDR), home subscriber server (Home Subscriber Server, HSS), centralized network configuration (Centralized network configuration, CNC), network storage functions (Network Repository Function, NRF), network open functions (Network Exposure Function, NEF), local NEF (or L-NEF), binding support functions (Binding Support Function, BSF), application functions (Application Function, AF), and the like. it should be noted that, in the embodiment of the present application, only the core network device in the NR system is described as an example, and the specific type of the core network device is not limited. But are not limited to, at least one of: a core network node, a core network function, a Mobility management entity (Mobility MANAGEMENT ENTITY, MME), an access Mobility management function (ACCESS AND Mobility Management Function, AMF), a session management function (Session Management Function, SMF), a user plane function (User Plane Function, UPF), a policy control function (Policy Control Function, PCF), policy AND CHARGING Rules Function (PCRF), edge application service discovery Function (Edge Application Server Discovery Function, EASDF), unified data management (Unified DATA MANAGEMENT, UDM), unified data repository (Unified Data Repository, UDR), home subscriber server (Home Subscriber Server, HSS), centralized network configuration (Centralized network configuration, CNC), network storage functions (Network Repository Function, NRF), network open functions (Network Exposure Function, NEF), local NEF (or L-NEF), binding support functions (Binding Support Function, BSF), application functions (Application Function, AF), and the like. it should be noted that, in the embodiment of the present application, only the core network device in the NR system is described as an example, and the specific type of the core network device is not limited.

The method for determining the LTM switching condition provided by the embodiment of the application is described in detail below through some embodiments and application scenarios thereof with reference to the accompanying drawings.

As shown in fig. 2, an embodiment of the present application provides a method 200 for determining an LTM switching condition, which may be performed by a CU, in other words, by software or hardware installed in the CU, the method including the following steps.

S202: the CU sends a first message to the first DU, or the CU receives a second message sent by a second DU, and the CU sends the first message to the first DU based on the second message; the first message is used for determining a first LTM switching condition, the first LTM switching condition is configured by the CU for the first DU, the second message includes a second LTM switching condition, and the second LTM switching condition includes a LTM switching condition of the second DU.

In one example, in a CU-DU network, a CU uniformly decides LTM switching conditions of respective DUs (including a first DU), e.g., the CU configures the LTM switching conditions to the DUs through a first message, and performs the LTM switching by the DUs.

In this example, for CUs and DUs belonging to different vendors, the procedure of configuring LTM switching conditions to DUs by a CU may be standardized; meanwhile, the LTM switching conditions of the DUs are uniformly determined and configured by the CU, so that the ping-pong switching problem among the DUs can be reduced. For example, if the DU1 and the DU2 are connected to the same CU, if the DU1 and the DU2 determine the LTM switching conditions by themselves, the ping-pong switching is easily caused due to lack of a coordination mechanism of the LTM switching conditions, and the example uniformly determines and configures the LTM switching conditions of each DU through the CU, so that the problem of ping-pong switching can be avoided, and the service continuity and stability of the terminal are improved.

In this example, optionally, the first LTM switch condition is that the CU is configured for at least two of the first DUs; wherein, the CU is configured for at least two first LTM switching conditions of the first DU, where the at least two first LTM switching conditions are different; or, the first LTM switching conditions configured by the CU for at least two of the first DUs are the same.

In this example, the CU may configure the first LTM switch condition for the first DUs according to at least one of the following for each first DU: 1) A time-domain or frequency-domain resource amount of the first DU, such as a total or free resource amount; 2) Hardware configuration of the first DU, such as the number of antenna units; 3) The number of users currently connected to the first DU. The method is beneficial to configuring reasonable LTM switching conditions for the first DU and improving service performance of a network side.

In this example, the CU may configure the same first LTM switching condition for at least two first DUs, which is beneficial to save the configuration overhead of the CU.

In another example, in a CU-DU network, a CU centrally coordinates LTM switching conditions of respective DUs, the CU may communicate second LTM switching conditions of a second DU to a first DU through a first message, the first DU setting or adjusting the first LTM switching conditions of the first DU based on the second LTM switching conditions of the second DU; the first LTM handover condition of the first DU may refer to a handover trigger condition from the first cell (cell 1) to the second cell (cell 2); the second LTM handover condition of the second DU may refer to a handover trigger condition of the second cell to the first cell; the first cell includes a cell under the first DU and the second cell includes a cell under the second DU. Alternatively, the first DU may be a source DU for the terminal connection and the second DU may be a target DU for the terminal.

This example coordinates the LTM handoff conditions for each DU centrally by the CU, enabling a reduction in ping-pong handoff between subordinate cells of different DUs. For example, when DU1 and DU2 are connected to the same CU, the terminal needs to switch from DU1-cell1 to DU2-cell2, and if DU1 and DU2 determine LTM switching conditions by themselves, it may cause the DU2 to switch the UE from DU1 to DU2, and then the DU2 switches the UE back to D1 quickly. Through CU centering coordination, LTM switching conditions of DUs are transferred between DU1 and DU2, so that the ping-pong switching problem can be avoided, and service continuity and stability of the terminal are improved.

In this example, the first DU may set or adjust its own first LTM switch condition based on the first message and at least one of: 1) A time-domain or frequency-domain resource amount of the first DU, such as a total or free resource amount; 2) Hardware configuration of the first DU, such as the number of antenna units; 3) The number of users currently connected to the first DU. The method is beneficial to the first DU to determine reasonable LTM switching conditions and improves service performance of a network side.

In this example, the first message may include some or all of the information of the second message; or the first message includes: the CU determines a first LTM switching condition applicable to the first DU based on a second LTM switching condition of the second DU in the second message.

According to the method for determining the LTM switching conditions, the CU sends the first message to the first DU, the first message can be used for configuring the first LTM switching conditions for the first DU, the LTM switching conditions of all DUs are uniformly determined and configured through the CU, the problem of ping-pong switching can be avoided, and the service continuity and stability of the terminal are improved; or, the first message is generated based on the second message from the second DU, the second message is used for indicating the LTM switching condition of the second DU, and in this embodiment, the CU can coordinate the LTM switching condition of each DU centrally, so that the ping-pong switching problem can be avoided, and the service continuity and stability of the terminal are improved.

In the CU-DU architecture, the CU can acquire global information, the DU is closer to the terminal user, the CU and the DU can belong to different manufacturers, the CU configures the LTM switching condition to the lower node DU, so that the switching time delay can be reduced, the backhaul (backhaul) overhead is reduced, and the interruption time of terminal switching is reduced. Or the CU coordinates the switching conditions between DUs centrally, so that meaningless ping-pong switching caused by non-uniform switching conditions can be reduced, and the continuity and stability of the UE service are enhanced.

Based on the uplink and downlink combined measurement, the network can obtain the uplink and downlink comprehensive channel information, avoid the situation that uplink or downlink channel interference caused by single-side measurement (namely simple downlink or uplink measurement) is overlarge due to the asymmetry of uplink and downlink interference environments (such as in a frequency division duplex (Frequency Division Duplexing, FDD) network or in a high-speed mobile scene), avoid the service quality reduction or UE switching failure caused by poor uplink or downlink single-side link quality, and improve the robustness and the reliability of data service in the user switching process.

Optionally, in various embodiments of the present application, the first message may include at least one of:

1) And the first threshold comprises an offset value threshold with higher transmission quality of the first signal from the second cell received by the terminal than the transmission quality of the first signal from the first cell.

2) And the second threshold comprises a transmission quality threshold of the first signal received by the terminal from the first cell.

3) And a third threshold, wherein the third threshold comprises a transmission quality threshold of the first signal received by the terminal from the second cell.

4) And the first time length comprises a duration time length threshold that the transmission quality of the first signal from the second cell received by the terminal is higher than that of the first signal from the first cell by a first threshold.

5) And a fourth threshold, where the fourth threshold includes a transmission quality threshold of a second signal received by the second cell from the terminal.

6) And a fifth threshold, wherein the fifth threshold comprises a transmission quality threshold of a second signal received by the first cell from the terminal.

7) And a sixth threshold, wherein the sixth threshold comprises an offset value threshold that the transmission quality of the second signal from the terminal received by the second cell is higher than the transmission quality of the second signal from the terminal received by the first cell.

8) And the second duration comprises a duration threshold that the transmission quality of the second signal from the terminal received by the second cell is higher than that of the second signal from the terminal received by the first cell by a sixth threshold.

The first cell comprises a serving cell of the terminal, and the second cell comprises a neighbor cell of the terminal; or, the first cell includes a cell of the first DU, and the second cell includes a cell of the second DU.

The transmission Quality of the first signal or the second signal mentioned in the embodiments of the present application may include reference signal received Power (REFERENCE SIGNAL RECEIVING Power, RSRP), reference signal received Quality (REFERENCE SIGNAL RECEIVING Quality, RSRQ), signal-to-interference-and-noise ratio (Signal to Interference plus Noise Ratio, SINR), received signal strength Indication (RECEIVED SIGNAL STRENGTH Indication, RSSI), and the like. The first signal may refer to a downlink reference signal sent by the network side to the terminal, for example, a Synchronization signal and a physical broadcast channel block (SSB), a channel state Information reference signal (CHANNEL STATE Information-REFERENCE SIGNAL, CSI-RS), etc.; the second signal may refer to an uplink reference signal sent by the terminal to the network side, for example, a Sounding reference signal (Sounding REFERENCE SIGNAL, SRS) and the like.

According to the embodiment, through the related arrangement of the first signal and the second signal, layer 1 (L1) measurement based on uplink and downlink combination can be realized, the network can obtain uplink and downlink comprehensive channel information, and the situation that uplink or downlink channel interference is overlarge and transmission quality is influenced due to single-side measurement (namely simple downlink or uplink measurement) caused by asymmetry of uplink and downlink interference environments is avoided. Optionally, when the quality of the uplink or downlink signal is poor, an event triggering mode may be adopted to trigger downlink or uplink measurement, and switch to a cell with better uplink or downlink signal quality.

Optionally, in the above various embodiments, the first LTM switching condition determined by the first DU includes at least one of:

1) The offset value, which is received by the terminal and is higher than the transmission quality of the first signal from the second cell, reaches a first threshold.

2) The transmission quality of the first signal received by the terminal from the first cell is lower than a second threshold.

3) The transmission quality of the first signal received by the terminal from the second cell is higher than a third threshold.

4) And the duration that the transmission quality of the first signal from the second cell received by the terminal is higher than that of the first signal from the first cell by a first threshold reaches a first time length.

5) The transmission quality of the second signal received by the second cell from the terminal is higher than a fourth threshold.

6) The transmission quality of the second signal received by the first cell from the terminal is below a fifth threshold.

7) The transmission quality of the second signal from the terminal received by the second cell is higher than the transmission quality of the second signal from the terminal received by the first cell by an offset value reaching a sixth threshold.

8) The transmission quality of the second signal from the terminal received by the second cell is higher than the transmission quality of the second signal from the terminal received by the first cell by a duration of a sixth threshold for a second duration.

Optionally, in each of the above embodiments, after the CU sends the first message to the first DU, the method further includes: the CU receives a third message from the first DU, the third message including at least one of:

1) An acknowledgement message (ACKNOWLEDGE, ACK) indicating that the first DU agrees to use the first LTM handover condition.

2) A FAILURE message (FAILURE) indicating that the first DU is not able to accept the first LTM handover condition. This example is mainly applicable to the case where the CU configures the first LTM switching condition to the first DU, and at this time, the CU may reconfigure the LTM switching condition for the first DU based on the failure reason carried in the failure message, or the like.

The method of determining the LTM switching condition according to the embodiment of the application is described in detail above in connection with fig. 2. A method of determining an LTM switching condition according to another embodiment of the present application will be described in detail with reference to fig. 3. It is to be understood that the interaction of the first DU with the CU described from the first DU side is the same as or corresponds to the description of the CU side in the method shown in fig. 2, and the related description is omitted as appropriate to avoid repetition.

Fig. 3 is a schematic flow chart of an implementation of a method for determining an LTM switching condition according to an embodiment of the present application, which may be applied to a first DU side. As shown in fig. 3, the method 300 includes the following steps.

S302: the method comprises the steps that a first DU receives a first message from a CU, wherein the first message is used for determining a first LTM switching condition; the first LTM switch condition is that the CU is configured for the first DU; or, the first message is generated based on a second message sent by a second DU, where the second message is used to indicate an LTM switching condition of the second DU.

Optionally, the first message includes part or all of the information of the second message.

According to the method for determining the LTM switching conditions, the first DU receives the first message from the CU, the first message can be used for configuring the first LTM switching conditions for the first DU, the LTM switching conditions of all DUs are uniformly determined and configured through the CU, the ping-pong switching problem can be avoided, and the service continuity and stability of the terminal are improved; or, the first message is generated based on the second message from the second DU, the second message is used for indicating the LTM switching condition of the second DU, the embodiment can coordinate the LTM switching condition of each DU centrally by the CU, the first DU sets or adjusts the first LTM switching condition of the first DU, the problem of ping-pong switching can be avoided, and the service continuity and stability of the terminal are improved.

According to the embodiment, through the related arrangement of the first signal and the second signal, the L1 measurement based on uplink and downlink combination can be realized, the network can obtain the uplink and downlink comprehensive channel information, and the situation that the uplink or downlink channel interference is overlarge and the transmission quality is influenced due to the asymmetry of the uplink and downlink interference environment and the situation that the uplink or downlink channel interference is overlarge due to single-side measurement (namely, simple downlink or uplink measurement) is avoided. Optionally, when the quality of the uplink or downlink signal is poor, an event triggering mode may be adopted to trigger downlink or uplink measurement, and switch to a cell with better uplink or downlink signal quality.

Optionally, in each embodiment above, the first LTM switching condition includes at least one of:

Optionally, in each of the above embodiments, after the first DU receives the first message from the CU, the method further includes: the first DU sends a third message to the CU, the third message including at least one of:

1) An acknowledgement message indicating that the first DU agrees to use the first LTM handover condition.

2) A failure message indicating that the first DU is unable to accept the first LTM handover condition.

Optionally, in each of the above embodiments, after the first DU receives the first message from the CU, the method further includes: the first DU determines whether to perform an LTM handoff based on the first LTM handoff condition and at least one of: 1) A measurement of the second signal upstream, 2) a measurement of the first signal downstream; in case it is determined to perform an LTM handover, the first DU transmits a layer 1 or layer 2 handover command (or referred to as an LTM handover command) informing the terminal to perform handover using pre-configured candidate cell configuration information.

In this embodiment, before the first DU determines whether to perform LTM handover, the method further includes the steps of: 1) The first DU sends the candidate cell configuration information, measurement reporting configuration of a first signal and second signal parameter configuration to a terminal; the measurement reporting of the first signal is configured to report a measurement result of the first signal by the terminal, and the second signal parameter is configured to send a second signal by the terminal; 2) The first DU transmits a first signal, wherein the first signal is used for downlink measurement; 3) The first DU acquires a measurement result of a first signal; 4) The first DU obtains a measurement result of the second signal based on the second signal transmitted by the terminal.

Optionally, the serving cell of the terminal is a first cell, where the first cell includes a cell of the first DU, and the first DU obtains a measurement result of the first signal includes: the first DU receives a measurement result of a first signal from a terminal.

Optionally, the method further comprises at least one of: 1) The first DU receives a second signal on a resource associated with the first signal; 2) The first DU receives a measurement of a second signal from a second DU or core network device.

Fig. 4 is a schematic flow chart of an implementation of a method for determining an LTM switching condition according to an embodiment of the present application, which may be applied to a second DU. As shown in fig. 4, the method 400 includes the following steps.

S402: the second DU sends a second message to the CU, where the second message is used to indicate a second LTM switching condition of the second DU, and part or all of information of the second message is included in the first message, and the first message is used to determine a first LTM switching condition of the first DU.

According to the method for determining the LTM switching conditions, the second DU sends the second message to the CU, the second message is used for indicating the second LTM switching conditions of the second DU, part or all of information of the second message is contained in the first message, and the first message is used for determining the first LTM switching conditions of the first DU.

Optionally, as an embodiment, the second message includes at least one of:

1) And the first threshold comprises an offset value threshold that the transmission quality of the first signal from the first cell received by the terminal is higher than that of the first signal from the second cell.

4) And the first time length comprises a duration time length threshold that the transmission quality of the first signal from the first cell received by the terminal is higher than that of the first signal from the second cell by a first threshold.

7) And a sixth threshold, wherein the sixth threshold comprises an offset value threshold that the transmission quality of the second signal from the terminal received by the first cell is higher than the transmission quality of the second signal from the terminal received by the second cell.

8) And a second duration, where the second duration includes a duration threshold that a transmission quality of the second signal received by the first cell from the terminal is higher than a transmission quality of the second signal received by the second cell from the terminal by a sixth threshold.

Wherein the first cell comprises a cell of the first DU and the second cell comprises a cell of the second DU.

In order to describe the determination method of the LTM switching condition provided in the embodiment of the present application in detail, several specific embodiments will be described below.

Example 1

In this embodiment, in a CU-DU network, a CU uniformly decides LTM switching conditions of respective DUs, configures the LTM switching conditions to corresponding DUs, and performs LTM switching by the DUs, and the embodiment includes the following steps.

Step 1: the CU sends a first message to the first DU for configuring a first LTM switching condition of the first DU. Wherein the first message includes at least one of:

The first cell comprises a serving cell of the terminal, and the second cell comprises a neighbor cell of the terminal; or, the first cell includes a cell of the first DU.

In this embodiment, the first LTM switching condition may be that the switching decision is made only according to the measurement result of the downlink first signal, or only according to the measurement result of the uplink second signal, or by combining the uplink and downlink measurement results.

Step 2: the first DU sends a third message to the CU for feeding back whether the first LTM switching condition is successfully received. Wherein the third message comprises one of:

1) An acknowledgement message (ACKNOWLEDGE, ACK) indicating that the first DU was successfully received and agrees to a first LTM switching condition configured by the CU.

2) A FAILURE message (FAILURE) indicating that the first DU is not able to accept the first LTM handover condition.

Step 3: the DU judges whether to execute LTM switching based on the first LTM switching condition according to the measurement result of the uplink second signal and/or the measurement result of the downlink first signal reported by the UE; if handover is required, the DU sends an L1/2 handover command (HO cmd) informing the terminal to perform handover using the pre-configured candidate cell configuration information.

Optionally, the first LTM switch condition includes at least one of:

The method for determining the LTM switching condition provided by the embodiment of the application standardizes the process of configuring the LTM switching condition to the DU by the CU and the DU belonging to different manufacturers.

According to the method for determining the LTM switching conditions, provided by the embodiment of the application, the CU uniformly determines and configures the LTM switching conditions of all DUs, so that the ping-pong switching problem between DUs can be reduced. For example, if DU1 and DU2 are connected to the same CU, if DU1 and DU2 determine the LTM switching condition by themselves, the coordination mechanism of the LTM switching triggering condition is lacking, which results in ping-pong switching, that is, after the UE switches from DU1 to DU2, DU2 switches the UE back to D1 quickly. The above ping-pong handover problem can be solved by the CU uniformly determining and configuring LTM handover conditions of each DU.

Example two

In this embodiment, the CU coordinates the LTM switching conditions centrally (because there is no direct interface between DUs): the DU2 sends a second LTM switching condition (switching from cell2 to cell1, cell1 belonging to DU1, cell2 belonging to DU 2) to the CU; the CU sends a second LTM switching condition of the DU2 to the DU1 for reference; DU1 sets or adjusts the first LTM switch condition from cell1 to cell2 according to the second LTM switch condition of DU 2. There may also be a similar mechanism for DU1 to initiate coordination with DU 2. The difference from the first embodiment is that: the CU does not decide the handover trigger condition.

In this embodiment, in a CU-DU network, a CU centrally coordinates LTM switching conditions of respective DUs, e.g. passes LTM switching conditions of a source DU to a target DU, the embodiment comprising the following steps.

Step 1: the second DU sends a second message to the CU informing the first DU of the second LTM switch condition of the second DU by the CU. Wherein the first DU and the second DU are two different DUs connected to the same CU.

Wherein the second message may include at least one of:

This embodiment may include two cases: 1. the first DU is a source DU, and the subordinate first cell is a serving cell; the second DU is a target DU, and the subordinate second cell is a handover target cell; the source DU coordinates LTM handoff conditions to the target DU. 2. The first DU is a target DU, and the subordinate first cell is a handover target cell; the second DU is a source DU, the subordinate second cell is the current serving cell, and the target DU coordinates LTM handover conditions to the source DU.

Optionally, the LTM switching condition of the source DU includes at least one of:

1) The offset value, which is received by the terminal and is higher than the transmission quality of the first signal from the first cell, reaches a first threshold.

4) And the duration that the transmission quality of the first signal from the first cell received by the terminal is higher than that of the first signal from the second cell by a first threshold reaches a first time length.

7) The transmission quality of the second signal from the terminal received by the first cell is higher than the transmission quality of the second signal from the terminal received by the second cell by an offset value reaching a sixth threshold.

8) The transmission quality of the second signal from the terminal received by the first cell is higher than the transmission quality of the second signal from the terminal received by the second cell by a duration of a sixth threshold for a second duration.

Step 2: generating a first message by the CU according to the second message, and sending the first message to the first DU, wherein the first message is used for coordinating the LTM switching condition between the first DU and the second DU; wherein the first message carries all or part of information in the second message; for example, the first message may include a first threshold and a first duration of the second DU.

Step 3: the first DU receives the first message from the CU and sets or adjusts the first LTM switching condition from the first cell to the second cell according to the second LTM switching condition of the second DU.

According to the embodiment, the LTM switching conditions of all DUs can be coordinated centrally by the CU, the problem of ping-pong switching can be avoided, and the service continuity and stability of the terminal are improved. For example, when DU1 and DU2 are connected to the same CU, the terminal needs to switch from DU1-cell1 to DU2-cell2, and if DU1 and DU2 determine LTM switching conditions by themselves, it may cause the DU2 to switch the UE from DU1 to DU2, and then the DU2 switches the UE back to D1 quickly. Through CU centering coordination, LTM switching conditions of DUs are transferred between DU1 and DU2, so that the ping-pong switching problem can be avoided, and service continuity and stability of the terminal are improved.

Example III

This embodiment mainly describes LTM handover based on uplink and downlink combined measurement. Considering a cell free architecture, the Access Point (AP) switching problem between two central processing units (Central Processing Unit, CPU), i.e. the process of switching from an AP (or AP cluster) connected to CPU1 to an AP (or AP cluster) connected to CPU 2.

As shown in fig. 5 and fig. 6, fig. 5 is a schematic diagram of LTM handover based on uplink and downlink combined measurement, where downlink measurement is performed first and then uplink measurement is performed (for example, where uplink and downlink measurement intervals are different); fig. 6 shows an uplink measurement and then a downlink measurement (for example, the uplink and downlink measurement intervals are the same).

The embodiment can perform uplink measurement firstly or downlink measurement firstly, and the time intervals of the uplink and downlink measurement can be the same or different, and the relationship of the intervals is not limited. The sequence of the steps of the following examples is not limited

The LTM switching process based on uplink and downlink combined measurement specifically comprises the following steps:

Step 1: the network pre-configures the L1 measurement report configuration and the configuration parameters of the candidate cells to the UE.

For example, the reporting configuration may include the number of reported measurement results, the number of reported maximum beam measurements for different APs, the content of the reported measurement, the reporting format, etc.

Step 2: the network side pre-configures the uplink reference signal (second signal) parameters to the UE.

Wherein, the uplink reference signal may be SRS.

Step 3: the network side sends a downlink reference signal (first signal), the UE performs L1 downlink measurement, and after the L1 measurement result meets the condition, the UE performs L1 reporting according to the measurement reporting instruction of the network side.

The downlink reference signal may refer to a synchronization signal, or a CSI-RS signal, etc.

The downlink reference signal may be transmitted with a determined transmission interval τ _DL; the beam direction and channel condition may also be calibrated based on event triggering, for example, based on threshold triggering, i.e. when the value of the measured quantity such as RSRP, SINR or RSRQ of the uplink reference signal is below a predetermined threshold, the downlink measurement may be triggered; and when the threshold trigger is adopted, the serving cell source base station or the serving AP instructs the UE to measure the downlink reference signal.

The embodiment can adopt event triggering to carry out downlink measurement, and can quickly respond and switch to a cell or AP with better uplink and downlink quality when only the uplink channel quality is poor (the situation that one of the uplink or downlink signals is poor can occur because the uplink and downlink interference environments are asymmetric).

Step 4: and the UE transmits an uplink reference signal, and the network side performs L1 uplink reference signal measurement.

Wherein the uplink reference signal may refer to an SRS signal.

The uplink reference signal sending configuration information is configured by the network side and is shared to the candidate target cell, the base station or the candidate target AP, for example, the sending configuration information includes information such as sending frequency, sending number, sending period (that is, uplink reference signal measurement interval) of the uplink reference signal, and the like.

In the network architecture of the traditional base station-UE, the source base station and the candidate target base station measure the L1 uplink reference signal, and the candidate target base station sends the uplink reference signal measurement result to the source base station after the measurement is completed.

In the Cell free network architecture, the uplink reference signal of L1 is measured by the AP, and after the measurement is completed, the service AP and the candidate target AP report the uplink measurement result to the CPU.

Where CPU refers to a central processing unit, which may be deployed alone or at some AP.

Alternatively, the candidate target AP may determine whether to report the measurement result according to the reporting condition, for example, the reporting condition may refer to that the measurement quantity of RSRP, SINR or RSRQ of the uplink reference signal reaches the measurement threshold. If the RSRP, SINR or RSRQ of the UE uplink reference signal measured at the candidate target AP reaches a measurement threshold, reporting an uplink measurement result to the CPU; otherwise, if the RSRP, SINR or RSRQ of the UE uplink reference signal at the candidate target AP is lower than the measurement threshold, the AP will not report the uplink measurement result to the CPU.

Alternatively, the candidate target AP may report the measurement result based on event triggering, for example, when the measurement amount such as RSRP, SINR or RSRQ of the downlink reference signal reported by the UE is lower than the measurement threshold, the CPU instructs the candidate target AP to report the measurement result of the uplink reference signal.

In this embodiment, the event triggers the AP to report the measurement result, so that backhaul (backhaul) overhead between the AP and the CPU can be reduced.

The uplink measurement result reported to the CPU by the AP may include measurement amounts such as RSRP, SINR or RSRQ, and/or UE identification, and/or uplink signal parameters such as uplink beam index information.

The uplink reference signal of the UE may be transmitted with a fixed transmission interval τ _UL, e.g., τ _UL may be less than or equal to τ _DL; the uplink measurement may also be triggered based on an event trigger, for example, based on a threshold trigger, i.e. when the value of the measured quantity such as RSRP, SINR or RSRQ of the downlink reference signal of the serving cell or AP is below a predetermined threshold; the uplink reference signal may be sent by using a resource associated with the downlink reference signal and adopting a preconfigured rule, for example, after a fixed time interval after receiving the downlink reference signal, the uplink reference signal is sent by using the resource associated with the downlink reference signal; or after the UE finishes reporting the measurement result of the downlink reference signal, if the measurement result value is lower than a preset threshold:

Under the base station-UE architecture, a source base station instructs the UE to send uplink reference signals and instructs candidate target base stations to measure and report the uplink reference signal quality.

Under the Cell free architecture, the CPU instructs the UE to send the uplink reference signal, instructs the candidate target AP to measure and report the uplink reference signal quality.

In this embodiment, when the uplink measurement is performed by using event triggering, it is possible to quickly respond to handover to a cell or AP with better uplink and downlink quality when only the downlink channel quality is degraded (because the uplink and downlink interference environments are asymmetric, and thus a situation that one of the uplink or downlink signals is poor may occur).

The UE may determine a transmission direction of the uplink reference signal according to the reported downlink reference signal beam direction, for example, only transmit the uplink reference signal near the downlink beam direction.

In this embodiment, the UE may send the uplink reference signal only in the associated beam direction according to the downlink reference signal measurement, so as to reduce the number and time of uplink reference signal sending and reduce the UE power consumption.

Step 5: and the network side judges whether the downlink measurement result and the uplink measurement result meet the switching conditions according to the downlink measurement result reported by the UE, and notifies the UE to apply the configuration parameters of the candidate cells for switching through the LTM switching command when the downlink reference signal measurement result and the uplink measurement result meet the conditions, wherein the specific switching standard belongs to the base station implementation.

Wherein the handover conditions associated with the downlink measurements include at least one of:

1) The transmission quality of one or more first signals of the serving cell and/or the neighbor cell received by the UE satisfies: the neighbor cell quality is higher than the serving cell by an offset value, set as a seventh threshold.

2) The transmission quality of one or more first signals of the serving cell and/or the neighbor cell received by the UE satisfies: the serving cell quality is below an eighth threshold; the neighbor cell quality is above the ninth threshold.

3) The transmission quality of one or more first signals of a serving cell and/or a neighboring cell received by the UE meets a preset condition; wherein the transmission quality includes at least one of RSRP, SINR, RSRQ, RSSI and the like; for example, the transmission quality of the first signal from the candidate target cell is better than the transmission quality of the serving cell for a preset period of time.

Wherein the handover condition associated with the uplink measurement includes at least one of:

1) The transmission quality of the one or more second signals of the UE received by the neighbor cell is above a tenth threshold.

2) The transmission quality of the one or more second signals of the UE received by the serving cell is below an eleventh threshold.

3) The second signal transmission quality measured by the neighbor cell is higher than the serving cell by an offset value, and is set as a twelfth threshold.

4) The transmission quality of one or more second signals measured by the serving cell and/or the neighbor cell meets a preset condition; for example, the transmission quality of the second signal measured by the neighbor cell is better than the transmission quality of the second signal measured by the serving cell for a preset period of time.

For example, when the first signal transmission quality of the neighboring cell 1 is higher than the serving cell by a seventh threshold, and the second signal transmission quality measured by the neighboring cell 1 is higher than the serving cell by a tenth threshold, the network side notifies the UE to apply the configuration parameter of the neighboring cell 1 to switch to the neighboring cell 1.

Step 5: and the UE automatically switches into the target cell by applying the preconfigured target cell configuration parameters according to the switching command.

In the embodiment, based on the L1 measurement combined by uplink and downlink, the network can obtain the comprehensive uplink and downlink channel information, and the situation that the uplink or downlink channel interference is overlarge and the transmission quality is influenced due to the asymmetry of uplink and downlink interference environments and the occurrence of single-side measurement (namely simple downlink or uplink measurement) is avoided. When the quality of the uplink or downlink signal is poor, an event triggering mode can be adopted to trigger downlink or uplink measurement, and the cell with better uplink and downlink signal quality is switched.

The embodiment can screen the AP set serving the UE and the downlink beams of each AP through downlink measurement, that is, the UE can decide the report content (the range of the serving AP after the handover is determined) and the beam direction of the AP based on the threshold and the UE capability according to the downlink reference signal measurement result of each AP.

Example IV

The embodiment mainly introduces the L3 switching based on uplink and downlink combined measurement, and can be used as the supplement of the above LTM switching.

This embodiment may include the steps of:

Step 1: measurement report: the terminal acquires the cell quality by measuring RS (SSB and CSI-RS) of the current service cell and neighbor cells and reports the cell quality; the terminal sends an uplink RS to the network side, the source base station and the adjacent target base station of the network side measure the transmission quality of the uplink RS sent by the terminal, and the target base station can send the measurement result to the source base station.

Step 2: switching preparation: and the network side carries out double judgment according to the reported cell quality and the uplink RS measurement result of the terminal side, and judges whether cell switching is needed.

Step 3: a switching command: if the network side judges that the cell switching is needed, a switching request command is sent to a target cell; the target cell feeds back the RRC reconfiguration signaling to the serving cell.

Step 4: and (3) terminal reconfiguration: the service cell sends the RRC configuration information of the target cell to the terminal, and the terminal performs RRC reconfiguration after receiving the configuration signaling of the target cell.

Step 5: downlink synchronization and AGC adjustment: and the terminal solves the DMRS and the PBCH of the PBCH according to the first SSB of the target cell after RRC reconfiguration, acquires a system frame number, a field indication and an SSB index, performs downlink synchronization of a frame level, a time slot level and a symbol level, and adjusts an Automatic Gain Control (AGC) parameter according to the received power of the SSB.

Step 6: uplink synchronization: after downlink synchronization, the terminal performs uplink synchronization through the RACH until the terminal receives a random reception response (RAR) to acquire TA, and the uplink synchronization is completed.

Step 7: and (3) switching is completed: after the above steps are completed, the target cell sends a cell handover completion instruction to the serving cell.

Example five

This example mainly describes CHO conditional switching based on uplink and downlink combined measurements. The base station decides whether to adopt CHO switching according to the uplink and downlink measurement results, and if so, the actual switching time is determined by the UE according to the downlink measurement results.

The detailed conditional switching flow based on uplink and downlink combined measurement comprises the following steps:

Step 1: the source base station transmits measurement control information to the UE; the measurement control information includes information that the UE or the base station needs to measure (measurement control information sent by the core network device to the base station), and includes at least one of the following:

1) The transmission quality of one or more first signals received by the UE from the serving cell and/or the neighbor cell; wherein the transmission quality includes at least one of RSRP, SINR, RSRQ, RSSI and the like; the first signal may refer to a downlink reference signal, such as SSB, CSI-RS, sent by the network side to the UE.

2) The transmission quality of one or more second signals sent by the UE and received by the serving cell and/or the neighbor cell base station; wherein the second signal may refer to an uplink reference signal, such as SRS, sent by the UE to the network side.

Step 2: and the UE measures the first signals of the serving cell and/or the neighbor cell base stations according to the source base station measurement control information and reports the measurement results.

Step 3: the UE transmits a second signal according to the source base station measurement control information; the service cell and the neighbor cell base station measure the transmission quality of the second signal; and the neighbor cell base station transmits the measurement result to the source base station or core network equipment.

Step 4: and the source base station decides whether to use the conditional switching according to at least one of the measurement result reported by the UE, the measurement result of the source base station of the serving cell and the measurement result of the neighbor base station.

The decision condition of the condition switching is increased by the uplink measurement part, and the decision condition of the traditional CHO switching is based on the downlink measurement quantity, and now, by combining the uplink measurement, the more comprehensive channel condition can be obtained, so as to determine whether to adopt the CHO switching.

The criteria for deciding to use conditional handover by the source base station or the core network device include at least one of:

1) The transmission quality of one or more first signals of the serving cell received by the UE is lower than a thirteenth threshold; for example, the RSRP of the first signal is below the thirteenth threshold.

2) The UE receives a difference in transmission quality of one or more first signals of the neighboring cell and the serving cell above a fourteenth threshold.

3) The transmission quality of the one or more second signals of the UE received by the serving cell source base station is below a fifteenth threshold.

4) The transmission quality of the one or more second signals of the UE received by the neighboring cell base station is above a sixteenth threshold.

5) The transmission quality of one or more second signals of the UE received by the serving cell and the neighbor cell satisfies: the transmission quality measured by the neighbor cell is higher than the transmission quality measured by the serving cell by an offset value defined as a seventeenth threshold.

Step 5: if the source base station decides to use conditional HANDOVER, a HANDOVER REQUEST (HANDOVER REQUEST) signaling is sent to a plurality of candidate target base stations satisfying CHO conditions according to a HANDOVER policy.

Step 6: and after receiving the switching request, the candidate target base station performs access control, and if the candidate target base station agrees with the conditional switching, the candidate target base station feeds back a switching request confirmation to the source base station (HANDOVER REQUEST ACKNOWLEDGE).

Step 7: after receiving the switching request confirmation of the candidate target cell, the source base station downloads a spring switching configuration to the UE through an RRC reconfiguration (RRCReconfiguration) message, wherein the conditional switching configuration comprises switching execution conditions of the candidate target cell and configuration parameters of the candidate target cell; wherein the handover execution condition includes at least one of:

1) The transmission quality of one or more first signals of the serving cell and/or the neighbor cell received by the UE satisfies: the neighbor cell quality is higher than the serving cell by an offset value, wherein the offset value is defined as an eighteenth threshold.

Entry conditions: mn+Ofn+Ocn-Hys ] mp+ Ofp + Ocp +off.

Leaving conditions: mn+Ofn+Ocn+Hys <; mp+ Ofp + Ocp +off.

Wherein, each parameter meaning of entering condition and leaving condition is as follows: mn: neighbor cell measurement results without considering any offset; ofn: a neighbor cell measuring object specific offset; ocn: neighbor cell level specific offset; mp: spCell (primary serving cell) measurements, without considering any offset; ofp: spCell measures the specific offset of the object; ocp: spCell cell level specific offset; hys: hysteresis parameters of the event; off: offset parameters for the event.

2) The transmission quality of one or more first signals of the serving cell and/or the neighbor cell received by the UE satisfies: the serving cell quality is below a nineteenth threshold (Thresh 19); the neighbor cell quality is above the twentieth threshold (Thresh 20).

Entry conditions: mp+hys < Thresh19; mn+Ofn+Ocn-Hys > Thresh20.

Leaving conditions: mp-Hys > Thresh19; mn+Ofn+Ocn+ Hys < Thresh20.

3) The transmission quality of one or more first signals of a serving cell and/or a neighboring cell received by the UE meets a preset condition; for example, the transmission quality of the first signal from the candidate target cell is better than the transmission quality of the serving cell for a preset period of time.

Step 8: after receiving the conditional switching configuration of the source base station, the UE sends an RRC reconfiguration complete (RRCReconfigurationComplete) message to the source base station.

If the source base station decides to forward (EARLY DATA forwarding) the handover using the early data, forwarding the user data and SN status information corresponding to the user data to the candidate target base station through an early state transition (EARLY STATUS TRANSFER) message; wherein the SN status information includes HFN and PDCP-SN of the first PDCP SDU forwarded by the source base station to the target base station.

Step 9: the UE measures one or more synchronous signals/reference signals of the candidate target cells after receiving the condition switching configuration, and starts to execute the switching process when a certain candidate target cell meets the switching condition; if the plurality of candidate target cells meet the switching condition, selecting which cell to switch belongs to the UE implementation.

Step 10: and the UE initiates random access to the target cell meeting the switching condition and successfully accesses the target cell.

Step 11: the UE sends RRCReconfigurationComplete a message to the target cell, and CHO handover is successful.

After receiving the reconfiguration complete (RRCReconfigurationComplete) message of the UE, the target base station sends a HANDOVER SUCCESS (HANDOVER SUCCESS) message to the source base station to inform that the UE has successfully accessed to the target cell;

The source base station feeds back SN state information to the target base station through SN STATUS TRANSFER information; if the source base station forwards the data to select late data forwarding for use, the user data is forwarded to the target base station side after receiving the successful message of the handover of the target base station.

The source base station sends a HANDOVER CANCEL message to the other candidate target base stations informing them to release reserved resources and buffered data for the HANDOVER UE.

In this embodiment, CHO conditional switching reduces the UE reporting process during switching, and can reduce the switching delay.

According to the embodiment, by combining uplink and downlink combined measurement, the network side can obtain uplink and downlink comprehensive channel information, judge whether CHO condition switching is adopted, avoid that when the uplink quality is poor, UE can only obtain downlink reference signal measurement values, so that service quality is reduced or UE switching fails, and improve robustness and reliability in a user switching process.

Example six

This embodiment mainly describes that in a Cell free network, a CPU configures a handover condition to an AP, and the AP performs handover, and includes the steps of:

Step 1: the CPU issues measurement control information to the AP and the UE; the measurement control information comprises information that the UE and/or the AP need to measure, and the measurement control information comprises at least one of the following:

1) Transmission quality of one or more first signals received by the UE from the serving AP and/or other APs; the transmission quality includes at least one item such as RSRP, SINR, RSRQ, RSSI, and the first signal may refer to a downlink reference signal, for example, SSB, CSI-RS, sent by the network side to the UE.

2) The transmission quality of one or more second signals from the UE received by the serving AP and/or other APs; wherein the second signal may refer to an uplink reference signal, such as SRS, sent by the UE to the network side.

Step 2: based on the step 1, the UE measures the first signal transmission quality of the service AP and/or other APs according to the measurement control information and reports the measurement result to the service AP; and the service AP sends the result reported by the UE to the CPU.

Step 3: the UE sends a second signal according to the measurement control information; the service AP and/or other APs measure the transmission quality of the second signal and report the measurement result to the CPU.

Step 4: based on step 2 and/or step 3, the cpu decides whether to decide the switching occasion by the AP according to at least one of the UE measurement result, the serving AP measurement result, and the measurement results of other APs.

Wherein the criteria for determining a handoff occasion by the CPU comprises at least one of:

1) The transmission quality of the one or more first signals received by the UE from the serving AP is below a twenty-first threshold.

2) The UE receives one or more first signals from other APs and the serving AP with a difference in transmission quality above a twenty-two threshold.

3) The transmission quality of the one or more second signals received by the serving AP from the UE is below a twenty-third threshold.

4) The transmission quality of the one or more second signals received by the other APs from the UE is above the twenty-four threshold.

5) The transmission quality of the one or more second signals from the UE measured by the other APs is higher than the transmission quality measured by the serving AP by an offset value, wherein the offset value is defined as a twenty-fifth threshold.

The embodiment includes deciding whether to grasp the handover right by the AP based on three cases of downlink measurement, uplink measurement, and uplink-downlink joint measurement.

Step 5: based on step 4, if the CPU determines that the AP decides the switching occasion, the CPU sends a first message to the serving AP and the candidate target AP for configuring the switching condition. Wherein the first message includes at least one of:

1) An offset value, where the transmission quality of the first signal received by the UE from the candidate target AP is higher than the first signal from the serving AP, is defined as a twenty-sixth threshold.

2) The transmission quality threshold of the first signal received by the UE from the serving AP is defined as a twenty-seventh threshold.

3) The transmission quality threshold of the first signal received by the UE from the candidate target AP is defined as the twenty-eighth threshold.

4) The duration (or duration, or the like) that the UE receives the first signal from the candidate target AP with a transmission quality better than the transmission quality of the first signal from the serving AP is defined as the third time.

5) The transmission quality threshold of the second signal received by the candidate target AP from the UE is defined as a twenty-ninth threshold.

6) The transmission quality of the second signal received by the serving AP from the UE is defined as the thirty-first threshold.

7) The offset value, at which the second signal transmission quality from the UE received by the candidate target AP is higher than the serving AP, is set to the thirty-first threshold.

8) The duration of time that the transmission quality of the second signal from the UE received by the candidate target AP is better than the transmission quality of the second signal from the UE received by the serving AP is defined as the fourth time.

Step 6: based on step 5, the serving AP and the candidate target AP send a third message to the CPU for feeding back whether the handover condition is successfully received. Wherein the third message comprises one of:

1) ACKNOWLEDGE (ACK) message: for informing the CPU that the configured handover condition has been successfully received and agreed.

2) FAILURE message: for informing the CPU of the handover condition of disagreement with its configuration.

Step 7: based on step 6, the UE measures the transmission quality of the first signals of the service AP and the candidate target AP according to the configuration information of the service AP, and reports the measurement result to the service AP; and (5) downlink measurement.

Step 8: based on step 6, the ue sends a second signal to the serving AP and/or the candidate target AP according to the configuration information of the serving AP.

Step 9: based on step 8, the serving AP and/or the candidate target AP measure the transmission quality of the second signal transmitted by the one or more UEs; the candidate target AP feeds back the measurement result of the second signal to the service AP; step 8 and step 9 are uplink measurements.

Step 10: based on the step 9 and/or the step 7, the service AP judges whether AP switching is needed or not based on the switching condition configured by the CPU according to the second signal measurement result and/or the first signal measurement result reported by the UE; wherein the handover condition comprises at least one of:

1) The transmission quality of one or more first signals received by the UE from the serving AP and/or the candidate target AP satisfies: the first candidate target AP signal transmission quality is higher than the first serving AP by a twenty-sixth threshold.

2) The transmission quality of one or more first signals received by the UE from the serving AP and/or the candidate target AP satisfies: the first serving AP signal transmission quality is below a twenty-seventh threshold and/or the first candidate target AP signal transmission quality is above a twenty-eighth threshold.

3) The transmission quality of one or more first signals of the serving AP and/or the candidate target AP received by the UE meets the preset condition; for example, the transmission quality of the first signal from the first candidate target AP is better than the transmission quality of the first serving AP in the third time.

4) The transmission quality of the one or more second signals of the UE received by the first candidate target AP is above a twenty-ninth threshold.

5) The transmission quality of the one or more second signals of the UE received by the first serving AP is below a thirty-first threshold.

6) The second signal transmission quality measured by the first candidate target AP is above the first serving AP by a thirty-first threshold.

7) The transmission quality of the one or more second signals measured by the serving AP and/or the candidate target AP satisfies a preset condition. For example, the transmission quality of the second signal measured by the first candidate target AP is better than the transmission quality of the second signal measured by the first serving AP for the fourth time.

Step 11: based on step 10, if the serving AP determines that AP handoff is required: the service AP sends a switching request command to the target AP; the target AP feeds back the RRC reconfiguration signaling to the service AP; the service AP sends RRC configuration information of the target AP to the terminal; after receiving the configuration signaling of the target cell, the terminal performs RRC reconfiguration and initiates random access to the target AP.

Alternatively, the configuration information of the candidate target AP may be preconfigured to the terminal by the CPU through the serving AP.

The service AP sends a switching command to the terminal, and the terminal initiates random access to the target AP according to the pre-configured candidate target cell configuration information.

According to the embodiment, the signaling transmission process of the target AP and the service AP is reduced by pre-configuring the target AP information, so that the switching time delay is further reduced.

Step 12: and after the terminal is successfully accessed into the target AP, the target AP sends a switching completion instruction to the original service AP.

The embodiment reduces the process of reporting the CPU by the AP in the switching process, can reduce the backhaul transmission and signaling overhead and reduce the switching time delay;

by combining uplink and downlink combined measurement, the network side can obtain comprehensive uplink and downlink channel information, avoid UE switching failure caused by poor uplink quality, and improve robustness and service reliability in the user switching process.

According to the method for determining the LTM switching condition provided by the embodiment of the application, the execution main body can be a device for determining the LTM switching condition. In the embodiment of the present application, a method for determining LTM switching conditions by using a determination device for determining LTM switching conditions is taken as an example, and the determination device for determining LTM switching conditions provided in the embodiment of the present application is described.

Fig. 7 is a schematic structural diagram of a determination device of an LTM switching condition according to an embodiment of the present application, which may correspond to a CU in other embodiments. As shown in fig. 7, the apparatus 700 includes the following modules.

A transmitting module 702, configured to transmit a first message to a first DU, or a receiving module 704, configured to receive a second message transmitted by a second DU, and the transmitting module 702 is configured to transmit the first message to the first DU based on the second message; the first message is used for determining a first LTM switching condition, the first LTM switching condition is configured by the device for the first DU, the second message includes a second LTM switching condition, and the second LTM switching condition includes a LTM switching condition of the second DU.

Optionally, the apparatus 700 further comprises a processing module or the like.

According to the determining device for the LTM switching conditions, the sending module sends the first message to the first DU, the first message can be used for configuring the first LTM switching conditions for the first DU, the LTM switching conditions of all DUs are uniformly determined and configured, the problem of ping-pong switching can be avoided, and the service continuity and stability of the terminal are improved; or, the first message is generated based on the second message from the second DU, where the second message is used to indicate the LTM switching condition of the second DU, and this embodiment may coordinate the LTM switching condition of each DU by the apparatus 700 centrally, so that the ping-pong switching problem may be avoided, and service continuity and stability of the terminal may be improved.

Optionally, as an embodiment, the first message includes at least one of:

Optionally, as an embodiment, the first LTM switching condition includes at least one of:

Optionally, as an embodiment, the first message includes part or all of the information of the second message.

Optionally, as an embodiment, the receiving module 704 is further configured to receive a third message from the first DU, where the third message includes at least one of:

Optionally, as an embodiment, the first LTM switch condition is that the apparatus is configured for at least two of the first DUs; wherein, the device is configured for at least two first LTM switching conditions of the first DU, and the at least two first LTM switching conditions are different; or, the first LTM switching conditions configured by the device for at least two first DUs are the same.

The apparatus 700 according to the embodiment of the present application may refer to the flow of the method 200 corresponding to the embodiment of the present application, and each unit/module in the apparatus 700 and the other operations and/or functions described above are respectively for implementing the corresponding flow in the method 200, and may achieve the same or equivalent technical effects, which are not described herein for brevity.

Fig. 8 is a schematic structural diagram of a determination apparatus of an LTM switching condition according to an embodiment of the present application, which may correspond to the first DU in other embodiments. As shown in fig. 8, the apparatus 800 includes the following modules.

A receiving module 802, configured to receive a first message from a CU, where the first message is used to determine a first LTM switching condition; the first LTM switch condition is that the CU is configured for the device; or, the first message is generated based on a second message sent by a second DU, where the second message is used to indicate an LTM switching condition of the second DU.

Optionally, the apparatus 800 further comprises a processing module or the like.

According to the determining device for the LTM switching conditions, the receiving module receives the first message from the CU, the first message can be used for configuring the first LTM switching conditions, the LTM switching conditions of all DUs are uniformly determined and configured through the CU, the ping-pong switching problem can be avoided, and the service continuity and stability of the terminal are improved; or, the first message is generated based on the second message from the second DU, the second message is used for indicating the LTM switching condition of the second DU, the LTM switching condition of each DU can be centrally coordinated by the CU, the processing module sets or adjusts the first LTM switching condition of itself, the ping-pong switching problem can be avoided, and the service continuity and stability of the terminal are improved.

Optionally, as an embodiment, the first message includes at least one of:

The first cell comprises a serving cell of the terminal, and the second cell comprises a neighbor cell of the terminal; or, the first cell includes a cell of the apparatus, and the second cell includes a cell of the second DU.

Optionally, as an embodiment, the apparatus further includes a sending module, configured to send a third message to the CU, where the third message includes at least one of:

1) An acknowledgement message indicating that the device agrees to use the first LTM switch condition.

2) A failure message indicating that the device is unable to accept the first LTM switch condition.

Optionally, as an embodiment, the processing module 804 is further configured to determine whether to perform an LTM handover based on the first LTM handover condition and at least one of: a measurement result of the uplink second signal and a measurement result of the downlink first signal; in the case of determining to perform LTM handover, the device sends a layer 1 or layer 2 handover command informing the terminal to perform handover using the preconfigured candidate cell configuration information.

Optionally, as an embodiment, the apparatus further includes a sending module, configured to send the candidate cell configuration information, a measurement reporting configuration of the first signal, and a second signal parameter configuration to a terminal; the measurement reporting of the first signal is configured to report a measurement result of the first signal by the terminal, and the second signal parameter is configured to send a second signal by the terminal; transmitting a first signal, wherein the first signal is used for downlink measurement; the receiving module 802 is further configured to obtain a measurement result of the first signal; the receiving module 802 is further configured to obtain a measurement result of the second signal based on the second signal sent by the terminal.

Optionally, as an embodiment, the serving cell of the terminal is a first cell, where the first cell includes a cell of the apparatus, and the receiving module 802 is configured to receive a measurement result of the first signal from the terminal.

Optionally, as an embodiment, the receiving module 802 is further configured to at least one of: receiving a second signal on a resource associated with the first signal; a measurement of a second signal from a second DU or core network device is received.

The apparatus 800 according to the embodiment of the present application may refer to the flow of the method 300 corresponding to the embodiment of the present application, and each unit/module in the apparatus 800 and the other operations and/or functions described above are respectively for implementing the corresponding flow in the method 300, and may achieve the same or equivalent technical effects, which are not described herein for brevity.

Fig. 9 is a schematic structural diagram of a determination apparatus of an LTM switching condition according to an embodiment of the present application, which may correspond to the second DU in other embodiments. As shown in fig. 9, the apparatus 900 includes the following modules.

A sending module 902, configured to send a second message to the CU, where the second message is used to indicate a second LTM switching condition of the apparatus, and part or all of information of the second message is included in the first message, where the first message is used to determine a first LTM switching condition of the first DU.

Optionally, the apparatus 900 further comprises a processing module or the like.

The determining device for LTM switching conditions provided in the embodiment of the application sends the second message to the CU, where the second message is used to indicate the second LTM switching condition of the device, and part or all of the information of the second message is included in the first message, and the first message is used to determine the first LTM switching condition of the first DU.

Optionally, as an embodiment, the second message includes at least one of:

Wherein the first cell comprises a cell of the first DU and the second cell comprises a cell of the apparatus.

The apparatus 900 according to the embodiment of the present application may refer to the flow of the method 400 corresponding to the embodiment of the present application, and each unit/module in the apparatus 900 and the other operations and/or functions described above are respectively for implementing the corresponding flow in the method 400, and may achieve the same or equivalent technical effects, which are not described herein for brevity.

The LTM switching condition determining device provided in the embodiment of the present application can implement each process implemented by the method embodiments of fig. 2 to fig. 4, and achieve the same technical effects, and for avoiding repetition, a detailed description is omitted herein.

Optionally, as shown in fig. 10, the embodiment of the present application further provides a communication device 1000, including a processor 1001 and a memory 1002, where the memory 1002 stores a program or an instruction that can be executed on the processor 1001, for example, when the communication device 1000 is a network side device, the program or the instruction is executed by the processor 1001 to implement each step of the above embodiment of the method for determining the LTM switching condition, and the same technical effect can be achieved, so that repetition is avoided and no description is repeated here.

The embodiment of the application also provides network side equipment, which comprises a processor and a communication interface, wherein the communication interface is used for sending a first message to a first DU or receiving a second message sent by a second DU, and sending the first message to the first DU based on the second message; the first message is used for determining a first LTM switching condition, the first LTM switching condition is configured for the first DU by the network side device, the second message includes a second LTM switching condition, and the second LTM switching condition includes an LTM switching condition of the second DU. Or the communication interface is configured to receive a first message from the CU, where the first message is used to determine a first LTM switching condition; the first LTM switching condition is that the CU is configured for the network side equipment; or, the first message is generated based on a second message sent by a second DU, where the second message is used to indicate an LTM switching condition of the second DU. Or the communication interface is configured to send a second message to the CU, where the second message is used to indicate a second LTM switching condition of the network side device, and part or all of information of the second message is included in the first message, and the first message is used to determine a first LTM switching condition of the first DU.

The network side device embodiment corresponds to the network side device method embodiment, and each implementation process and implementation manner of the method embodiment can be applied to the network side device embodiment, and the same technical effects can be achieved.

Specifically, the embodiment of the application also provides network side equipment. As shown in fig. 11, the network side device 1100 includes: an antenna 111, a radio frequency device 112, a baseband device 113, a processor 114 and a memory 115. The antenna 111 is connected to a radio frequency device 112. In the uplink direction, the radio frequency device 112 receives information via the antenna 111, and transmits the received information to the baseband device 113 for processing. In the downlink direction, the baseband device 113 processes information to be transmitted, and transmits the processed information to the radio frequency device 112, and the radio frequency device 112 processes the received information and transmits the processed information through the antenna 111.

The method performed by the network side device in the above embodiment may be implemented in the baseband apparatus 113, where the baseband apparatus 113 includes a baseband processor.

The baseband apparatus 113 may, for example, include at least one baseband board, where a plurality of chips are disposed, as shown in fig. 11, where one chip, for example, a baseband processor, is connected to the memory 115 through a bus interface, so as to call a program in the memory 115 to perform the network device operation shown in the above method embodiment.

The network-side device may also include a network interface 116, such as a common public radio interface (Common Public Radio Interface, CPRI).

Specifically, the network side device 1100 of the embodiment of the present invention further includes: instructions or programs stored in the memory 115 and capable of running on the processor 114, the processor 114 invokes the instructions or programs in the memory 115 to perform the methods performed by the modules shown in fig. 7, 8 or 9, and achieve the same technical effects, and are not repeated here.

The embodiment of the application also provides a readable storage medium, on which a program or an instruction is stored, which when executed by a processor, implements each process of the above embodiment of the method for determining the LTM switching condition, and can achieve the same technical effect, so that repetition is avoided, and no further description is given here.

Wherein the processor is a processor in the terminal described in the above embodiment. The readable storage medium may be non-volatile or non-transitory. Readable storage media include computer readable storage media such as computer readable memory ROM, random access memory RAM, magnetic or optical disks, and the like.

The embodiment of the application further provides a chip, the chip comprises a processor and a communication interface, the communication interface is coupled with the processor, the processor is used for running a program or instructions, the various processes of the embodiment of the method for determining the LTM switching condition can be realized, the same technical effects can be achieved, and the repetition is avoided, and the description is omitted here.

It should be understood that the chips referred to in the embodiments of the present application may also be referred to as system-on-chip chips, or the like.

The embodiment of the present application further provides a computer program/program product, where the computer program/program product is stored in a storage medium, and the computer program/program product is executed by at least one processor to implement each process of the above embodiment of the method for determining an LTM switching condition, and the same technical effects can be achieved, so that repetition is avoided, and details are not repeated herein.

The embodiment of the application also provides a system for determining the LTM switching condition, which comprises the following steps: the terminal and the network side device are used for executing the steps of the method for determining the LTM switching condition.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of the present application is not limited to performing the functions in the order shown or discussed, but may also include performing the functions in a substantially simultaneous manner or in an opposite order depending on the functions involved, e.g., the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

From the description of the embodiments above, it will be apparent to those skilled in the art that the above-described example methods may be implemented by means of a computer software product plus a necessary general purpose hardware platform, but may also be implemented by hardware. The computer software product is stored on a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes instructions for causing a terminal or network side device to perform the methods according to the embodiments of the present application.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms of embodiments may be made by those of ordinary skill in the art without departing from the spirit of the application and the scope of the claims, which fall within the protection of the present application.

Claims

1. A method for determining a layer 1 or layer 2 triggered mobility LTM handover condition, comprising:

the CU sends a first message to the first DU,

Or the CU receives a second message sent by a second DU, and the CU sends a first message to the first DU based on the second message;

The first message is used for determining a first LTM switching condition, the first LTM switching condition is configured by the CU for the first DU, the second message includes a second LTM switching condition, and the second LTM switching condition includes a LTM switching condition of the second DU.

2. The method of claim 1, wherein the first message comprises at least one of:

A first threshold, where the first threshold includes an offset threshold where a transmission quality of a first signal received by the terminal from the second cell is higher than a transmission quality of the first signal from the first cell;

a second threshold, where the second threshold includes a transmission quality threshold of a first signal received by the terminal from the first cell;

a third threshold, where the third threshold includes a transmission quality threshold of the first signal received by the terminal from the second cell;

A first duration, wherein the first duration comprises a duration threshold that the transmission quality of a first signal from a second cell received by a terminal is higher than that of the first signal from the first cell by a first threshold;

A fourth threshold, where the fourth threshold includes a transmission quality threshold of a second signal received by the second cell from the terminal;

A fifth threshold, where the fifth threshold includes a transmission quality threshold of a second signal received by the first cell from the terminal;

A sixth threshold, where the sixth threshold includes an offset threshold where the transmission quality of the second signal received by the second cell from the terminal is higher than the transmission quality of the second signal received by the first cell from the terminal;

A second duration, where the second duration includes a duration threshold that a transmission quality of a second signal received by the second cell from the terminal is higher than a transmission quality of a second signal received by the first cell from the terminal by a sixth threshold;

3. The method according to claim 1 or 2, wherein the first LTM switch condition comprises at least one of:

the offset value, which is received by the terminal and is higher than the transmission quality of the first signal from the second cell, reaches a first threshold;

the transmission quality of a first signal received by the terminal from a first cell is lower than a second threshold;

the transmission quality of the first signal from the second cell received by the terminal is higher than a third threshold;

The transmission quality of the first signal from the second cell received by the terminal is higher than that of the first signal from the first cell by a first threshold, and the duration of the first signal from the second cell is longer than the first duration;

the transmission quality of a second signal received by a second cell from the terminal is higher than a fourth threshold;

The transmission quality of the second signal from the terminal received by the first cell is lower than a fifth threshold;

An offset value, which is received by the second cell and has a higher transmission quality than the transmission quality of the second signal received by the first cell and from the terminal, reaches a sixth threshold;

the transmission quality of the second signal from the terminal received by the second cell is higher than that of the second signal from the terminal received by the first cell by a duration of a sixth threshold for a second duration;

4. The method of claim 1, wherein the first message includes some or all of the information of the second message if the CU receives a second message sent by a second DU and the CU sends a first message to a first DU based on the second message.

5. The method of any of claims 1 to 4, wherein after the CU sends the first message to the first DU, the method further comprises: the CU receives a third message from the first DU, the third message including at least one of:

An acknowledgement message indicating that the first DU agrees to use the first LTM handover condition;

a failure message indicating that the first DU is unable to accept the first LTM handover condition.

6. The method of claim 1, wherein the first LTM switch condition is that the CU is configured for at least two of the first DUs; wherein,

The CU is configured for at least two first LTM switching conditions configured for the first DU, wherein the at least two first LTM switching conditions are different; or alternatively, the first and second heat exchangers may be,

The first LTM switching conditions configured by the CU for at least two of the first DUs are the same.

7. A method for determining an LTM switch condition, comprising:

The method comprises the steps that a first DU receives a first message from a CU, wherein the first message is used for determining a first LTM switching condition;

The first LTM switch condition is that the CU is configured for the first DU; or alternatively, the first and second heat exchangers may be,

The first message is generated based on a second message sent by a second DU, the second message being used to indicate LTM handover conditions of the second DU.

8. The method of claim 7, wherein the first message comprises at least one of:

9. The method of claim 7 or 8, wherein the first LTM switch condition comprises at least one of:

10. The method of claim 7, wherein the first message comprises some or all of the information of the second message.

11. The method according to any one of claims 7 to 10, wherein after the first DU receives the first message from the CU, the method further comprises: the first DU sends a third message to the CU, the third message including at least one of:

12. The method according to any one of claims 7 to 11, wherein after the first DU receives the first message from the CU, the method further comprises:

the first DU determines whether to perform an LTM handoff based on the first LTM handoff condition and at least one of: a measurement result of the uplink second signal and a measurement result of the downlink first signal;

in the case of determining to perform LTM handover, the first DU sends a layer 1 or layer 2 handover command informing the terminal to perform handover using the preconfigured candidate cell configuration information.

13. The method of claim 12, wherein the first DU is before determining whether to perform an LTM handoff, the method further comprising:

The first DU sends the candidate cell configuration information, measurement reporting configuration of a first signal and second signal parameter configuration to a terminal; the measurement reporting of the first signal is configured to report a measurement result of the first signal by the terminal, and the second signal parameter is configured to send a second signal by the terminal;

The first DU transmits a first signal, wherein the first signal is used for downlink measurement;

The first DU acquires a measurement result of a first signal;

The first DU obtains a measurement result of the second signal based on the second signal transmitted by the terminal.

14. The method of claim 13, wherein the serving cell of the terminal is a first cell, the first cell comprising a cell of the first DU, the first DU obtaining the measurement result of the first signal comprising:

The first DU receives a measurement result of a first signal from a terminal.

15. The method of claim 13, further comprising at least one of:

the first DU receives a second signal on a resource associated with the first signal;

the first DU receives a measurement of a second signal from a second DU or core network device.

16. A method for determining an LTM switch condition, comprising:

The second DU sends a second message to the CU, where the second message is used to indicate a second LTM switching condition of the second DU, and part or all of information of the second message is included in the first message, and the first message is used to determine a first LTM switching condition of the first DU.

17. The method of claim 16, wherein the second message comprises at least one of:

A first threshold, where the first threshold includes an offset threshold where a transmission quality of a first signal received by a terminal from a first cell is higher than a transmission quality of a first signal from a second cell;

A first duration, wherein the first duration comprises a duration threshold that the transmission quality of a first signal from a first cell received by a terminal is higher than that of a first signal from a second cell by a first threshold;

A sixth threshold, where the sixth threshold includes an offset threshold where the transmission quality of the second signal received by the first cell from the terminal is higher than the transmission quality of the second signal received by the second cell from the terminal;

a second duration, where the second duration includes a duration threshold that a transmission quality of a second signal received by the first cell from the terminal is higher than a transmission quality of a second signal received by the second cell from the terminal by a sixth threshold;

18. A device for determining an LTM switching condition, comprising:

A transmitting module for transmitting a first message to the first DU,

Or a receiving module, configured to receive a second message sent by a second DU, and a sending module, configured to send a first message to a first DU based on the second message;

The first message is used for determining a first LTM switching condition, the first LTM switching condition is configured by the device for the first DU, the second message includes a second LTM switching condition, and the second LTM switching condition includes a LTM switching condition of the second DU.

19. The apparatus of claim 18, wherein the first message comprises at least one of:

20. The apparatus of claim 18 or 19, wherein the first LTM switch condition comprises at least one of:

21. The apparatus of claim 18, wherein the first message comprises some or all of the information of the second message.

22. The apparatus according to any one of claims 18 to 21, wherein the receiving module is further configured to receive a third message from the first DU, the third message including at least one of:

23. The apparatus of claim 18, wherein the first LTM switch condition is that the apparatus is configured for at least two of the first DUs; wherein,

The device is configured for at least two first LTM switching conditions configured for the first DU, wherein the at least two first LTM switching conditions are different; or alternatively, the first and second heat exchangers may be,

The first LTM switching conditions configured by the apparatus for at least two of the first DUs are the same.

24. A device for determining an LTM switching condition, comprising:

a receiving module, configured to receive a first message from a CU, where the first message is used to determine a first LTM switching condition;

the first LTM switch condition is that the CU is configured for the device; or alternatively, the first and second heat exchangers may be,

25. The apparatus of claim 24, wherein the first message comprises at least one of:

26. The apparatus of claim 24 or 25, wherein the first LTM switch condition comprises at least one of:

27. The apparatus of claim 24, wherein the first message comprises some or all of the information of the second message.

28. The apparatus according to any one of claims 24 to 27, further comprising a sending module configured to send a third message to the CU, the third message comprising at least one of:

An acknowledgement message indicating that the device agrees to use the first LTM handover condition;

a failure message indicating that the device is unable to accept the first LTM switch condition.

29. The method of any of claims 24 to 28, wherein the processing module is further configured to determine whether to perform an LTM switch based on the first LTM switch condition and at least one of: a measurement result of the uplink second signal and a measurement result of the downlink first signal;

in the case of determining to perform LTM handover, the device sends a layer 1 or layer 2 handover command informing the terminal to perform handover using the preconfigured candidate cell configuration information.

30. The apparatus of claim 29, further comprising a transmitting module configured to transmit the candidate cell configuration information, a measurement reporting configuration of the first signal, and a second signal parameter configuration to a terminal; the measurement reporting of the first signal is configured to report a measurement result of the first signal by the terminal, and the second signal parameter is configured to send a second signal by the terminal;

transmitting a first signal, wherein the first signal is used for downlink measurement;

The receiving module is further used for obtaining a measurement result of the first signal;

The receiving module is further configured to obtain a measurement result of the second signal based on the second signal sent by the terminal.

31. The apparatus of claim 30, wherein the serving cell of the terminal is a first cell, the first cell comprising a cell of the apparatus, and wherein the receiving module is configured to receive a measurement of a first signal from the terminal.

32. The apparatus of claim 30, wherein the receiving module is further configured to at least one of:

receiving a second signal on a resource associated with the first signal;

A measurement of a second signal from a second DU or core network device is received.

33. A device for determining an LTM switching condition, comprising:

And a sending module, configured to send a second message to the CU, where the second message is used to indicate a second LTM switching condition of the device, and part or all of information of the second message is included in the first message, where the first message is used to determine a first LTM switching condition of the first DU.

34. The apparatus of claim 33, wherein the second message comprises at least one of:

35. A network side device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the method of any one of claims 1 to 17.

36. A readable storage medium, characterized in that it stores thereon a program or instructions, which when executed by a processor, implement the steps of the method according to any of claims 1 to 17.