Communication method and apparatus

Abstract

A communication method and apparatus, which may be applied to the technical field of communications. The method comprises: establishing a first packet data unit (PDU) session in a first region, wherein the first region is a region covered by a first network device; and then, sending information of first slices, wherein the first slices are associated with the first PDU session, the first PDU session is released or deactivated in a second region, and the second region is a region covered by a second network device. The information of the first slices comprises at least one piece of the following information: identifiers of the first slices, the number of the first slices, service types of the first slices, a time when the first PDU session is released or deactivated, a reason why the first PDU session is released or deactivated, or a position where the first PDU session is released or deactivated. The reason why the first PDU session is released or deactivated comprises: the first slices not being supported by the second region, or there being no available resource with respect to the first slices in the second region. The method can improve the continuity of a service that a terminal implements by using network slicing.

Description

Communication method and apparatus

[0001] The present application claims priority to the Chinese Patent Application No. 202410545303.5, filed on April 30, 2024, and entitled “Communication method and apparatus”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a communication method and apparatus. BACKGROUND

[0003] A terminal can access a network through an access network device to implement corresponding services. In order to optimize the network and provide performance support for the terminal to perform services, currently, a communication system can support a self-organization network (SON), and the purpose of this technology is to automatically complete the parameter configuration and optimization of the cellular mobile communication network device, reduce the manual participation in the network operation and management process, and improve the network reliability and reduce the operation cost. The communication system can also support a minimization of drive tests (MDT) to implement mobile network quality evaluation, including identifying coverage strength, coverage holes, and the like.

[0004] In order to meet different service requirements of the terminal, 5G provides customized network services for the terminal through end-to-end network slicing. As a possible implementation manner, through flexible allocation of network resources and on-demand networking, 5G virtually creates multiple logical subnets with different characteristics and mutual isolation on the same physical facility, which can be referred to as network slices. Different logical subnets can be used to provide services for the terminal.

[0005] In some scenarios, as the terminal moves, the terminal using the network slice can be switched from a current source cell to a target cell. During the switching process, if the terminal is in service, it is easy to cause the service of the terminal to be interrupted due to the target cell not supporting the network slice currently used by the terminal or the target cell not having available resources for the network slice currently used by the terminal. Currently, there is an urgent need to propose a solution to improve the service continuity of the terminal as much as possible. SUMMARY

[0006] The present application provides a communication method and apparatus for improving the continuity of services implemented by a terminal using a network slice.

[0007] To achieve the above object, the present application adopts the following technical solutions:

[0008] In a first aspect, a communication method is provided. The method can be applied to a terminal side, for example, a terminal or a communication module in the terminal, or a circuit or chip (such as a modem chip, also known as a baseband chip, or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core) responsible for communication functions in the terminal. Taking the case where the method is applied to a terminal, in the method, a first packet data unit (PDU) session is established in a first area; the first area is an area covered by a first network device; information of a first slice is then sent, the first slice being associated with the first PDU session; the first PDU session is released or deactivated in a second area; the second area is an area covered by a second network device; the information of the first slice includes at least one of the following: an identifier of the first slice; a number of the first slice; a service type of the first slice; a time when the first PDU session is released or deactivated; a reason why the first PDU session is released or deactivated; or a location where the first PDU session is released or deactivated; and the reason why the first PDU session is released or deactivated includes that the first slice is not supported by the second area or that the second area has no available resources for the first slice.

[0009] With the method, the terminal can timely report the information of the first slice associated with the released (or deactivated) first PDU session to the network side, so that the network side (such as a radio access network (RAN)) can optimize the deployment of the boundary of the network slice based on the information of the first slice, thereby improving the service continuity of the service implemented by the terminal using the first slice and improving the service performance. For example, in a service interruption scenario, the network side can adjust or update the deployment of a slice of a specific service type based on the service type of the first slice reported by the terminal, so as to improve the continuity of the service implemented by the terminal using the slice of the specific service type. For another example, the network device can optimize the deployment of a network slice in a specific location based on the location information reported by the terminal, so as to improve the continuity of the service implemented by the terminal using the network slice in the specific location.

[0010] In a possible design, the method further includes:

[0011] The first condition is met, and the information of the first slice is recorded, the first condition including at least one of the following: the number of the first slice reaches a threshold; the service type of the first slice is a preset type; the first slice is a slice with a preset identifier; the time when the first PDU session is released or deactivated is a preset time; the time when the terminal switches to the second area is the preset time; and the location where the first PDU session is released or deactivated is a preset location.

[0012] sending information of the first slice.

[0013] With the method, the terminal records the case that the service is interrupted due to that the second area does not support or has no available resource, and sends to the network device, so that the network device optimizes the boundary deployment of the network slice based on the requirement of service continuity, thereby the service continuity of the terminal using the network slice can be improved.

[0014] In a possible design, the first PDU session is released or deactivated, including:

[0015] receiving a session release command, the session release command indicating that the first PDU session is released or deactivated;

[0016] or determining that data radio bearer (DRB) resources corresponding to the first PDU session are released;

[0017] or determining that the first slice is not supported by the second area or that the second area has no available resource for the first slice.

[0018] In a possible design, the session release command is received, the session release command indicating that the first PDU session is released or deactivated, including:

[0019] the session release command is received through a non-access stratum (NAS);

[0020] or the session release command is received through the NAS; first indication information is sent to an access stratum (AS) through the NAS, the first indication information being used to indicate that the first PDU session is released or deactivated.

[0021] In a possible design, the determination that the DRB resources corresponding to the first PDU session are released includes:

[0022] the determination that the DRB resources corresponding to the first PDU session are released is made through an AS; second indication information is sent to a NAS through the AS, the second indication information indicating that the DRB resources corresponding to the first PDU session are released;

[0023] or the determination that the DRB resources corresponding to the first PDU session are released is made through the AS.

[0024] In a possible design, the determination that the first slice is not supported by the second area or that the second area has no available resource for the first slice includes:

[0025] determining, by the NAS based on the information of the third area and the second area, that the first slice is not supported by the second area or that the second area has no available resource for the first slice;

[0026] or sending, by the NAS, the information of the third area to the AS; determining, by the AS based on the information of the third area and the second area, that the first slice is not supported by the second area or that the second area has no available resource for the first slice;

[0027] The information of the third area comprises at least one of the following: a service area of the first slice; a tracking area (TA) supporting the first slice.

[0028] In a possible design, the method further includes:

[0029] obtaining configuration information, the configuration information being used to configure a terminal to record information of a second slice, the second slice comprising the first slice;

[0030] The information of the second slice comprises one or more of the following: an identifier of the second slice; a number of the second slice; a service type of the second slice; a time when a second PDU session associated with the second slice is released or deactivated; a cause for the second PDU session being released or deactivated; or a location where the second PDU session is released or deactivated.

[0031] In a possible design, the configuration information is further used to configure one or more of the following: a first condition triggering the terminal to record the information of the second slice; a second condition triggering the terminal to send the information of the second slice; or an AS or a NAS of the terminal recording the information of the second slice.

[0032] In a second aspect, a communication method is provided. The method can be applied to a network side, for example, an access network device of the network side, a module (for example, a circuit, a chip or a chip system, etc.) in the access network device, or a logic node, a logic module or software capable of realizing all or part of the function of the access network device. Taking the case where the method is applied to a first network device as an example, in the method, a first packet data unit (PDU) session is established in a first area; the first area is an area covered by the first network device; configuration information is sent, the configuration information being used to configure a terminal to record information of a second slice, the second slice comprising a first slice; the first slice is associated with the first PDU session; the first slice is not supported by a second area or the second area has no available resource for the first slice; the second area is an area covered by a second network device;

[0033] The information of the second slice includes one or more of the following: an identity of the second slice; a number of the second slice; a service type of the second slice; a time when a second PDU session associated with the second slice is released or deactivated; a cause why the second PDU session is released or deactivated; or a location where the second PDU session is released or deactivated.

[0034] In a possible design, the configuration information is further used to configure one or more of the following: a first condition triggering the terminal to record the information of the second slice; a second condition triggering the terminal to send the information of the second slice; and the AS or NAS of the terminal recording the information of the second slice.

[0035] In a possible design, the method further includes: receiving the information of the first slice.

[0036] In a possible design, the receiving the information of the first slice includes:

[0037] receiving a first report, where the first report includes the information of the first slice; the first report includes a minimization of drive test (MDT) or a radio link failure (RLF) report; or the first report is a report dedicated to carrying the information of the first slice.

[0038] In a possible design, the method further includes:

[0039] sending a first request, where the first request is used to request the information of the first slice.

[0040] In a possible design, the sending the first request includes:

[0041] determining that the terminal switches to the second area, and sending the first request.

[0042] In a third aspect, a communication method is provided, which can be applied to a network side, for example, an access network device at the network side, a module (for example, a circuit, a chip or a chip system, etc.) in the access network device, or a logic node, a logic module or software capable of realizing all or part of the functions of the access network device. Taking the case where the method is applied to a first network device, in the method, a first packet data unit (PDU) session is established in a first area; the first area is an area covered by the first network device; information of a first slice is recorded, the first slice being associated with the first PDU session; the first slice is not supported by a second area, or the second area has no available resource for the first slice; the second area is an area covered by a second network device; the information of the first slice includes at least one of the following: an identifier of the first slice; a number of the first slice; a service type of the first slice; a time when the first PDU session is released or deactivated; a reason why the first PDU session is released or deactivated; or a location where the first PDU session is released or deactivated; and the reason why the first PDU session is released or deactivated includes that the first slice is not supported by the second area, or the second area has no available resource for the first slice.

[0043] In a possible design, the method further includes:

[0044] sending the information of the first slice to the second network device.

[0045] In a possible design, before recording the information of the first slice, the method further includes:

[0046] receiving network slice information; the network slice information includes information of network slices supported by the second area, and / or information of available resources of the first slice for the second area;

[0047] determining, according to the network slice information, that the first slice is not supported by the second area, or the second area has no available resource for the first slice.

[0048] In a possible design, the method further includes:

[0049] sending a first message, the first message including an instruction indicating that the terminal is switched from the first area to the second area.

[0050] For example, the first message is an RRC reconfiguration message.

[0051] In a fourth aspect, a communication method is provided, which can be applied to a network side, for example, an access network device of the network side, a module (for example, a circuit, a chip or a chip system, etc.) in the access network device, or a logic node, a logic module or software capable of realizing all or part of the functions of the access network device. Taking the case where the method is applied to a second network device, in the method, it is determined that a second area does not support a first slice associated with a first packet data unit (PDU) session or that the second area has no available resource for the first slice; the second area is an area covered by the second network device; the first PDU session is a PDU session established by a terminal in a first area; the first area is an area covered by a first network device; information of the first slice is recorded; the information of the first slice includes at least one of the following: an identifier of the first slice; a number of the first slice; a service type of the first slice; a time when the first PDU session is released or deactivated; a reason why the first PDU session is released or deactivated; or a location where the first PDU session is released or deactivated; and the reason why the first PDU session is released or deactivated includes that the first slice is not supported by the second area or that the second area has no available resource for the first slice.

[0052] In a possible design, the method further includes:

[0053] The information of the first slice is sent to the first network device.

[0054] In a possible design, the information of the first slice is recorded, including:

[0055] The information of the first slice is recorded when it is determined that the terminal switches to the second network device.

[0056] In a possible design, the determination that the terminal switches to the second network device includes:

[0057] A second message is received, and the second message includes a radio resource control (RRC) reconfiguration complete message.

[0058] In a fifth aspect, a communication method is provided. After a first network device establishes a third PDU session in a first area, the first network device can determine whether there is a cell that supports the third PDU session and meets a handover condition, based on a measurement report of a terminal and an identifier of a third slice associated with the third PDU session.

[0059] In some examples, if there is a target cell that supports the third PDU session and meets the handover condition, the first network device can hand over the terminal to the target cell of the second network device.

[0060] The cell that supports the third PDU session is a cell that supports the third slice and has available resource for the third slice.

[0061] The cell meeting the handover condition can be, for example, a cell whose signal strength is higher than a threshold in the related art.

[0062] In some other examples, if the target cell of the second network device meets the handover condition but does not support the third PDU session, the above method can be used to record the information of the third slice by the terminal or the first network device or the second network device.

[0063] Alternatively, if the target cell of the second network device meets the handover condition but does not support the third PDU session, the first network device can carry the identifier of the third slice in the handover request sent to the second network device to indicate that the third PDU session is currently associated with the third slice. The second network device can accordingly adjust the slice deployment, such as deploying the target cell to support the third slice. Subsequently, when the terminal accesses the target cell, the third PDU session established by the terminal in the source cell will not be released or deactivated in the target cell since the target cell is timely deployed to support the third slice, and the continuity of the service is ensured.

[0064] The above takes the first network device determining handover to the target cell as an example, and in some other embodiments, the terminal can also determine handover to the target cell by itself.

[0065] In some examples, the source station successfully hands over the UE to the target cell, the target cell is capable of supporting the third slice and has allocated available resources for the third slice, but the signal quality of the target cell is general, such as the signal quality of the target cell is not the strongest among the candidate cells, or the signal quality of the target cell is low. According to the MRO mechanism of the SON in the related art, the UE can feed back a successful handover report (SHR) to the target cell to help the network side optimize the handover decision. In this case, the target cell can not perform handover decision optimization after receiving the SHR, because the UE can consider that the handover to the suboptimal target cell is due to the support of the network for the slice. Alternatively, the target cell can perform handover decision optimization for the third slice after receiving the SHR.

[0066] In a sixth aspect, the present application provides a device comprising a function module for executing the method in any possible design of any of the aspects of the present application, which can be realized by software or hardware, or a combination of software and hardware. For example, the device comprises a processing unit and a communication unit.

[0067] In a seventh aspect, the technical solution of the present application provides a communication apparatus, comprising a processor configured to execute the method in any design of any of the aspects.

[0068] Optionally, the apparatus further comprises the memory and / or the communication interface.

[0069] The communication interface is coupled with the processor, and the communication interface is configured to input and / or output information.

[0070] The memory is configured to store a computer program, and the processor is configured to execute the method according to any one of the above aspects and any one of the possible designs.

[0071] Alternatively, the processor can also be a hardware-implemented circuit, such as an artificial intelligence (AI) processor, to improve the running speed. The present application does not limit the specific implementation manner of the processor.

[0072] Optionally, the communication apparatus can be a whole device or a module in the device, such as a chip.

[0073] In an eighth aspect, a computer readable storage medium is provided, which includes computer instructions. When the computer instructions are run on a device, the device executes the method according to any one of the above aspects and any one of the possible designs.

[0074] In a ninth aspect, a computer program product is provided. When the computer program product is run on a device, the device executes the method according to any one of the above aspects and any one of the possible designs.

[0075] In a tenth aspect, a circuit system is provided, which includes a processing circuit configured to execute the method according to any one of the above aspects and any one of the possible designs. The processing circuit can be implemented as a corresponding circuit component, such as one or more processors. For example, the processing circuit can be implemented as a processor and a memory. For example, the processing circuit can be implemented as a processor and a transceiver. BRIEF DESCRIPTION OF DRAWINGS

[0076] FIG. 1A, FIG. 1B, and FIG. 1C are schematic diagrams of a mobile scenario in the related art;

[0077] FIG. 2A and FIG. 2B are schematic diagrams of an architecture of a system according to an embodiment of the present application;

[0078] FIG. 3 is a flow diagram of a communication method according to an embodiment of the present application;

[0079] FIG. 4 and FIG. 5 are schematic diagrams of scenarios according to an embodiment of the present application;

[0080] FIG. 6-FIG. 10 are flow diagrams of communication methods according to embodiments of the present application;

[0081] FIG. 11 and FIG. 12 are schematic diagrams of structures of communication apparatuses according to embodiments of the present application. DETAILED DESCRIPTION

[0082] Firstly, technical terms involved in the present application are introduced:

[0083] 1、SON

[0084] The 4th generation mobile communication system and the 5th generation mobile communication system can both support the SON mechanism. Optionally, the SON can include self-configuration, self-optimization and self-healing.

[0085] The self-configuration refers to that the base station has the functions of plug and play, automatic downloading and installation of software, automatic configuration of wireless and transmission parameters and self-management of neighbor relation. Optionally, the self-configuration includes the functions of physical cell identifier (PCI) self-configuration and automatic neighbor relation (ANR). Through the self-configuration, the base station can autonomously select the PCI and establish and maintain the neighbor relation within the allowed range.

[0086] The self-optimization refers to that the network device adjusts the wireless parameters such as the transmission power, the handover threshold and the cell individual offset according to the running status, so as to optimize the network performance. Optionally, the self-optimization can include the functions of mobility load balancing (MLB), random access channel (RACH) optimization and mobility robustness optimization (MRO). The MRO technology is used for automatically detecting the problem of handover parameter setting, analyzing and counting a large number of connection failure phenomena, determining the cause of the problem and adjusting the corresponding parameters. Specifically, when the UE detects that the radio link failure (RLF) or the handover failure occurs in the handover process, the UE can send the related RLF report to the base station, so as to help the base station to adjust the parameter configuration.

[0087] Through the self-optimization, the base station can adjust the parameters according to the current load and performance statistics, so as to optimize the system performance. Optionally, the self-optimization of the base station is controlled by the operation, administration and maintenance (OAM) network element. Based on the network performance measurement and data collection, the OAM can start or terminate the network self-optimization operation when necessary. Optionally, the adjustment of the parameters by the base station is within the value range allowed by the OAM.

[0088] Self-healing refers to the network autonomously discovering faults and isolating and recovering in time through monitoring and analyzing error data and alarm information.

[0089] 2、MDT

[0090] Previously, the manual drive test method is used to first determine the test area and design the test route. Then, the measurement data is collected, including the location information and the physical layer, medium access control layer, signaling information and system information, etc. Finally, the post-processing of the collected data is performed, mainly including data analysis and problem positioning analysis. The data analysis mainly refers to the analysis of the network performance indicators, such as the drop rate, the connection rate and the traffic performance. The problem positioning mainly refers to the judgment of whether the fault is located in the terminal or the network according to the measurement parameters (such as signal strength, etc.) and the signaling message, and the possible reasons, etc.

[0091] The manual drive test method is time-consuming and laborious. Therefore, the MDT is introduced in the 4G system, so as to realize the automatic collection and analysis of the UE measurement report containing the location information by the communication system, so as to reduce the workload of the manual drive test to the greatest extent, reduce the network maintenance cost, and also solve the real-time and universality problems in the mobile network quality evaluation.

[0092] The MDT can select the terminal to participate in the MDT report according to certain specific conditions when the operator has the drive test demand. The content of the MDT report involves the radio access network and the quality of service (QoS). The MDT can provide the real-time network quality evaluation data for the operator, which is very helpful for timely discovering the network problems and performing the network optimization.

[0093] The MDT report reported by the UE can be real-time or non-real-time. The MDT includes the logged MDT and the immediate MDT. The logged MDT can be that the terminal records the log (such as the measurement of the signal strength) periodically according to the network configuration in the idle state or the inactive state, or records the preset event (such as the RLF) when the event occurs. Then, the terminal accesses the network and reports the recorded content to the network. Optionally, the recorded content of the terminal includes the event type, the occurrence time, the location, the signal quality when the event occurs, etc. Optionally, the terminal can report multiple events and / or multiple records at a time. The immediate MDT can be that the network configures the measurement parameters of the connected terminal, and the terminal detects and reports the recorded content immediately. The network configuration of the measurement parameters of the terminal can reuse the related technology of the RRC measurement process.

[0094] 3、Network slice (which can be referred to as slice)

[0095] With the development of mobile communication technology, various new services and application scenarios of terminals are emerging, and these services have great differences in the demand for network functions, connection performance, and security. If a single network is used to carry these services, it will be difficult to meet the requirements of high bandwidth, low latency, high reliability, etc. at the same time. In addition, building a new network for each service will bring huge costs. This requires 5G to be flexible and scalable while meeting different service requirements. The industry proposes to provide services for terminals through network slicing.

[0096] Optionally, different network slices can be identified and distinguished by single network slice selection assistance information (S-NSSAI). Optionally, each S-NSSAI can include a slice / service type (SST) indicating the characteristics and service type corresponding to the slice. Optionally, the S-NSSAI can also include a slice differentiator (SD). The SD can be used to distinguish multiple network slice instances of the same SST as a supplement to the SST.

[0097] The NSSAI includes one or more S-NSSAI(s), and the NSSAI can be understood as S-NSSAI List. The NSSAI includes the following:

[0098] - Configured NSSAI: The network configures the NSSAI for the UE to use. After receiving the configured NSSAI, the UE can know the available S-NSSAI(s) under the network. Optionally, the network can indicate the configured NSSAI to the UE through the "configured NSSAI" information element of the registration acceptance message (registration accept). Optionally, if the configuration of the UE changes after registration, the network can notify the UE to update the configured NSSAI through the UE configuration update message (configuration update).

[0099] - Requested NSSAI: The UE can carry the requested NSSAI in the registration request message (registration request). Exemplarily, the requested NSSAI can include the allowed NSSAI or the configured NSSAI.

[0100] - Allowed NSSAI: indicates the S-NSSAI(s) in the requested NSSAI that are allowed by the network. As one possible implementation, the network indicates the allowed NSSAI to the UE via the "allowed NSSAI" information element in the registration accept. The allowed NSSAI is supported by the network in the registration area (RA) of the UE.

[0101] - Rejected NSSAI: indicates the S-NSSAI(s) in the requested NSSAI that are rejected by the network. For example, the core network or the access network side does not support these S-NSSAI(s).

[0102] - Partially allowed NSSAI: similar to the concept of allowed NSSAI, the difference is that the partially allowed NSSAI can only be supported in part of the tracking areas (TAs) in the UE RA.

[0103] - Partially rejected NSSAI: similar to the concept of rejected NSSAI, the difference is that the partially rejected NSSAI can only be supported in part of the TAs in the UE RA.

[0104] 4. UE obtains the service of the network slice

[0105] Taking the UE initial access in 3GPP R15 / R16 as an example, the flow can include:

[0106] 1) The slice list supported by the base station is pre-configured by OAM according to TA granularity, and all cells in a specific TA support the same slice. The base station can report the above slice list to the access and mobility management function (AMF) when establishing an NG interface with the core network. Optionally, if the base station supports central unit (CU) / distributed unit (DU) separation, the DU can first send the per TA supported slice list to the CU, and then the CU reports it to the AMF. After receiving the TA granularity supported slice list from the base station, the AMF can feed back the supported slice list in the public land mobile network (PLMN) to the base station through the NG establishment response. In this way, after the UE accesses the base station, the base station can select the corresponding AMF based on the slice service requested by the UE.

[0107] 2) After the UE accesses the base station, the UE indicates the requested NSSAI to the base station through the radio resource control establishment completion (RRC setup complete) message. Optionally, the RRC setup complete message can also carry the registration request message sent by the UE to the AMF. Based on the requested NSSAI from the terminal and the AMF supported slice list from the AMF, the base station can select a suitable AMF (such as one that can support all or most of the slices in the requested NSSAI) to serve the UE.

[0108] 3) After the base station determines the AMF to serve the UE, it can transparently transmit the UE's registration request to the AMF through the initial UE message, which can include the requested NSSAI.

[0109] 4.) The AMF can determine the slices in the requested NSSAI that belong to the UE's subscription and can be supported by the base station and the AMF at the same time, as the allowed NSSAI, and the remaining slices as the rejected NSSAI, based on the UE's subscription information, the slice list supported by the base station, and the slice list supported by the AMF. The AMF can send the allowed NSSAI to the base station via an initial context setup request message. The base station can determine the radio resource management (RRM) policy and handover decision for the UE based on the allowed NSSAI. Optionally, the initial context setup request message can also include a registration accept message sent by the AMF to the UE. The base station can then transparently forward the registration accept to the UE, which can include the allowed NSSAI and the rejected NSSAI. Within the RA, the UE can initiate a packet data unit (PDU) session establishment request based on the allowed NSSAI, and the UE can not initiate a registration request for the rejected NSSAI within the RA.

[0110] 5.) The UE sends a non-access stratum (NAS) message to the AMF, which can include a PDU session establishment request and information of the PDU session associated slices, to request establishment of a PDU session associated with the allowed S-NSSAI.

[0111] 6.) After receiving the NAS message from the UE, the AMF can forward the PDU session establishment request and the information of the PDU session associated slices to the SMF. After the SMF determines to establish the PDU session, the SMF sends a PDU session establishment accept message to the AMF, which instructs the base station to establish radio resources for the PDU session. The AMF transparently forwards a NAS message to the UE via the base station, which carries the PDU session establishment accept.

[0112] 7.) When UE performs inter-gNB handover, source gNB (or S-gNB) can send the established PDU session and its associated slices to target gNB (or T-gNB). The target gNB can determine whether to accept the PDU session based on its own support for the slices, such as rejecting the PDU session if it does not support it. In this case, the target gNB releases the radio resources corresponding to the PDU session.

[0113] 5、partially Allowed / rejected NSSAI

[0114] According to the protocol of SGPP R15 / R16, as shown in (a-1) of FIG. 1A, the UE sends a registration request carrying a requested NSSAI including slice#1 and slice#2 in TA1 identified by tracking area code (TAC) #1, and TA1 can only support slice#1, wherein TA1 identified by TAC#1 can also be referred to as tracking area 1. As shown in (a-2) of FIG. 1A, TA2 can support slice#1 and slice#2. Since the TA1 where the UE initiates registration does not support slice#2, the core network can return allowed NSSAI including slice#1 and rejected NSSAI including slice#2 to the UE through a registration accept message in combination with the subscription NSSAI of the UE and the slice list supported by the base station side, and the RA includes TAC#1. The UE cannot initiate a registration request again for the rejected slice#2 in the current RA.

[0115] Therefore, one of the key issues of the R18 slice technology research of 3GPP SA2 is how the UE can initiate registration again for the rejected NSSAI in other TAs that can support the rejected NSSAI in the RA. The SA2 introduces partially allowed NSSAI / partially rejected NSSAI. The difference between the two is that when the UE moves in the RA, it does not need to initiate registration again for the partially allowed NSSAI, which is similar to the processing of the allowed NSSAI. However, for the partially rejected NSSAI, the UE needs to initiate registration again in the TA that can support it.

[0116] In the scenario of introducing partially allowed / rejected NSSAI, as shown in (b-1) of FIG. 1A and (b-2) of FIG. 1A, the core network can return, to the UE through the registration accept message, the allowed NSSAI including slice#1, the partially allowed NSSAI including slice#2 (slice#2 can be supported by the TA identified by TAC#2), and the RA including TAC#1 and TAC#2. Or the allowed NSSAI including slice#1, the partially rejected NSSAI including slice#2 (slice#2 can be supported by the TA identified by TAC#2 / supported by the TA not identified by TAC#1), and the RA including TAC#1 and TAC#2. With this method, the UE can re-initiate the registration request for slice#2 in the TA2 in the current RA by expanding the RA range of the UE as much as possible.

[0117] It can be seen that the allowed / rejected NSSAI is valid in the entire RA of the UE, that is, it is applicable to all TAs in the RA of the UE, but the partially allowed NSSAI and the partially rejected NSSAI are valid in part of the TAs in the RA of the UE. The introduction of this feature does not affect the related procedures of network slices (such as the procedure of the UE obtaining the service of the network slice introduced in the 4th part of the terminology), and in the basic procedure of R15 / R16, the definition of the allowed NSSAI and the rejected NSSAI is extended, and the step of containing the allowed NSSAI can also contain the partially allowed NSSAI, and for the same reason, the step of containing the rejected NSSAI can also contain the partially rejected NSSAI. The UE can initiate a PDU session establishment request based on the partially allowed S-NSSAI or request to activate the user plane of the established PDU session to obtain data transmission in the case of being located in the TA supporting the partially allowed S-NSSAI.

[0118] In a TA capable of supporting partially allowed NSSAI, when the UE successfully establishes a PDU session associated with the partially allowed NSSAI, and then moves from the TA to a TA incapable of supporting the partially allowed NSSAI, the radio resources of the PDU session that has been established previously are released by the target station, and the target station informs the core network to perform a deactivation operation on the user plane of the PDU session.

[0119] 6. Network slice area of service (NS-AoS)

[0120] Currently, network slices are deployed in the wireless access network according to the granularity of the TA, and all cells in the TA support the same slice. Considering that the UE and network configuration may be affected when the slice is deployed within a certain time interval and is withdrawn. For example, when the slice is no longer available or becomes available, this may affect the allowed NSSAI and other parameters, and the RA may also need to be changed. Therefore, another key issue of the R18 slice technology research of SA2 is how to support the service of the slice when the service area does not match the slice supported by the TA to which the service area belongs. That is, the granularity of the service area is smaller than the TA, which can be understood as the minimum granularity of the service area being a cell rather than a TA. For example, slice#2 is supported in the TA identified by TAC#1, and there are a total of 4 cells in the TA. Due to deployment and other reasons, the resources allocated by cell#2 for slice#2 are suddenly limited, such as cell#2 not being configured with any resources for slice#2, so cell#2 cannot actually provide services for slice#2 for the UE. In order to avoid affecting the UE and the network side, SA2 newly introduces NS-AoS, which is used to indicate the service area for a specific slice. For example, NS-AoS can be represented by a list of one or more NR cell global identifiers (NCGI) corresponding to the cells, and the feature enhancement points of NS-AoS include:

[0121] -NS-AoS is deployed in the wireless access network, and the AMF can obtain the NS-AoS configured for each slice in the UE RA through OAM.

[0122] - In case the UE indicates support of S-NSSAI location availability information capability, the AMF can send the UE the intra-RA NS-Ao s for the configured NSSAI via the registration accept or UE configuration update message. Exemplarily, the location availability information can be used to indicate the NS-Ao s for a specific slice.

[0123] - The UE can only initiate PDU session establishment request in a cell that has allocated available resources for the allowed NSSAI or partially allowed NSSAI, or request to activate the user plane of an established PDU session for data transmission.

[0124] - When the UE has successfully established a PDU session associated with a (partially) allowed S-NSSAI in a cell that can support the (partially) allowed NSSAI, and moves from the cell to a target cell that has not allocated available resources for the slice, the resources of the established PDU session are released by the target cell, and the target cell informs the core network to perform deactivation of the user plane for the PDU session.

[0125] It can be seen that in the current scenario of deploying network slices, when the terminal is at the boundary of two areas (such as TA or cell), with the movement of the terminal, the PDU session established by the terminal can be easily released or deactivated due to the lack of support for network slices in the TA, resulting in the interruption of the terminal service. As shown in FIG. IB, the serving cell of terminal 1 is in tracking area 1 (denoted as TA#1 or TA1), and TA#1 only supports network slice 1 (denoted as slice#1 or slice1), and TA#2 only supports slice#2. As shown in (a) of FIG. IB, terminal 1 successfully establishes PDU session#1 (or denoted as PDU session1) associated with slice#1 in TA#1. Then, as shown in (b) of FIG. IB, terminal 1 moves to TA#2, and after handover, PDU session#1 of slice#1 is released in the target cell of TA#2 because TA#2 does not support slice#1.

[0126] For another example, service interruption can also occur due to the target cell having no available resources for slice #1. As shown in FIG. 1C, the serving cell cell #1 of terminal 1 supports slice #1 and has allocated available resources for slice #1, and cell #2 supports slice #1 but has not allocated any resources for slice #1. Terminal 1 successfully establishes PDU session #1 associated with slice #1 in cell #1, as shown in (a) of FIG. 1C, and moves to cell #2 after the PDU session is established, as shown in (b) of FIG. 1C. Since cell #2 has not allocated any resources for slice #1, PDU session #1 associated with slice #1 is released in cell #2.

[0127] Therefore, embodiments of the present disclosure provide a communication method. FIG. 2A shows a possible, non-limiting system schematic diagram. As shown in FIG. 2A, a communication system 10 includes a radio access network (RAN) 100 and a core network (CN) 200. The RAN 100 includes at least one RAN node (e.g., 110a and 110b in FIG. 2A, collectively referred to as 110) and at least one terminal (e.g., 120a-120j in FIG. 2A, collectively referred to as 120). The RAN 100 can further include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in FIG. 2A), etc. The terminal 120 is connected to the RAN node 110 in a wireless manner. The RAN node 110 is connected to the core network 200 in a wireless or wired manner. For example, the RAN node is connected to the core network 200 through a transport network.

[0128] Optionally, the core network device in the core network 200 and the RAN node 110 in the RAN 100 can be different physical devices respectively, or can be the same physical device integrated with the logical functions of the core network and the logical functions of the radio access network.

[0129] The communication system 10 can be a 3rd generation partnership project (3GPP) related cellular system, which can apply network slicing technology. For example, a 5G mobile communication system, or a future-oriented evolved system (e.g., a 6G mobile communication system). The communication system 10 can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. The communication system 10 can also be a communication system that combines two or more of the above systems.

[0130] The RAN node 110, which can also be referred to as an access network device, a RAN entity, or an access node, etc., forms part of the communication system, and is configured to facilitate the wireless access by the terminals. The RAN nodes 110 in the communication system 10 can be of the same type or different types. In some scenarios, the roles of the RAN node 110 and the terminal 120 are relative, e.g., the network element 120i in Figure 2A can be a helicopter or a drone, which can be configured to move as a mobile base station, to the terminal 120j accessing the RAN 100 via the network element 120i, the network element 120i is a base station; but to the base station 110a, the network element 120i is a terminal. Both the RAN node 110 and the terminal 120 are sometimes referred to as communication apparatuses, e.g., the network elements 110a and 110b in Figure 2A can be understood as communication apparatuses with base station functionalities, and the network elements 120a-120j can be understood as communication apparatuses with terminal functionalities.

[0131] In a possible scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next generation NodeB (gNB), a next generation base station in a 6th generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system, etc. The RAN node can be a macro base station (e.g., 110a in Figure 2A), a micro base station or an indoor station (e.g., 110b in Figure 2A), a relay node or a donor node, or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, a wearable device, a vehicle or a vehicle-mounted device, etc. For example, the access network device in a vehicle to everything (V2X) technology can be a road side unit (RSU). All or part of the functions of the RAN node in this application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (e.g., a cloud platform). The RAN node can also be provided with a communication module, circuit or chip for performing corresponding communication functions, and program instructions for performing corresponding communication functions. The RAN node in this application can also be a logical node, a logical module or software that can implement all or part of the functions of the RAN node.

[0132] In another possible scenario, multiple RAN nodes cooperate to assist a terminal to implement wireless access, and different RAN nodes respectively implement part of functions of a base station. For example, a RAN node can be a CU, a DU, a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and the DU can be separately configured, or can be included in the same network element, for example, in a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, for example, in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0133] In different systems, the CU (or CU-CP and CU-UP), the DU, or the RU can also have different names, but those skilled in the art can understand their meanings. For example, in an ORAN system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. For the convenience of description, the CU, the CU-CP, the CU-UP, the DU, and the RU are taken as examples for description in this application. Any one of the CU (or the CU-CP, the CU-UP), the DU, and the RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0134] FIG. 2B shows an example of an O-RAN-based architecture. An O-RAN intelligence controller (O-RIC) can be used to collect network information and perform necessary optimization tasks. A gNB-CU can be a gNB-CU supporting O-RAN functions. A gNB-DU can be a gNB-DU supporting O-RAN functions. Optionally, the RIC communicates with the gNB-CU and the gNB-DU through an E2 interface. The O-RIC can directly control the gNB-DU, or control the gNB-DU through the gNB-CU.

[0135] The cells covered by the RAN nodes can include a cell with a frequency f1 and / or a cell with a frequency f2, which are merely examples.

[0136] A terminal can be a device or module with corresponding communication functions and can access the above communication system. The terminal can also be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. The terminal can be widely applied to various scenarios, such as device-to-device (D2D), vehicle to everything (V2X) communication, machine-type communication (MTC), internet of things (IOT), virtual reality, augmented reality, industrial control, automatic driving, remote medical treatment, smart power grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, unmanned aerial vehicle, helicopter, airplane, ship, robot, mechanical arm, smart home device, transport vehicle with wireless communication function, communication module, etc. Embodiments of the present application do not limit the device form of the terminal. The terminal is usually provided with a communication module, circuit or chip for performing corresponding communication functions. The terminal is also configured with program instructions for performing corresponding communication functions.

[0137] In the present application, "sending information" can be understood as a device sending information to another device, or can also be understood as a logical module in a device sending information to another logical module. For example, "the access network device sending information" can be understood as the access network device sending information to another device (such as a terminal), or can be understood as a logical module 1 in the access network device sending information to a logical module 2 in the access network device.

[0138] In the present application, "receiving information" can be understood as a device receiving information from another device, or can also be understood as a logical module in a device receiving information from another logical module. For example, "the access network device receiving information" can be understood as the access network device receiving information from another device (such as a terminal), or can be understood as a logical module 1 in the access network device receiving information from a logical module 2 in the access network device.

[0139] In this application, "sending information to (for example, a terminal)" or related illustrations in the drawings can be understood as the destination of the information is the terminal. It can include direct or indirect sending information to the terminal. "Receiving information from (for example, a terminal)" or "receiving information from (for example, a terminal)" or "receiving information sent by (for example, a terminal)", or related illustrations in the drawings can be understood as the source of the information is the terminal, which can include direct or indirect receiving information from the terminal. The information between the source and the destination of the information transmission may be processed as necessary, such as format change, etc., but the destination can understand the effective information from the source. Similar expressions in this application can be similarly understood, and will not be repeated here.

[0140] The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "At least one" means one or more, and "multiple" means two or more. The "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, A and B together, and B alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, "at least one of A, B or C" includes A, B, C, AB, AC, BC or ABC, and "at least one of A, B and C" can also be understood to include A, B, C, AB, AC, BC or ABC. In addition, unless otherwise specified, the ordinal numbers "first", "second", etc. mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the order, time sequence, priority or importance of multiple objects. In addition, the numbering of steps in each embodiment introduced in the present application is only to distinguish different steps, and is not used to limit the sequence of the steps. For example, S201 can occur before S101, or it can occur after S101, or it can occur simultaneously with S101.

[0141] In the technical solutions of the embodiments of the present application, the collection, storage, use, processing, transmission, provision and disclosure of information involved in the technical solutions comply with the relevant legal regulations and do not violate public order and good customs. It is uniformly stated here that the following will not be repeated.

[0142] The communication method and device of the embodiments of the present application are further described below with reference to the drawings. It can be understood that the network device (such as a base station) and the terminal are taken as an example of the interactive execution subject in the present application, but the present application is not limited to the interactive execution subject. For example, the method executed by the network device in the present application can also be implemented by a module (such as a circuit, a chip or a chip system, etc.) in the network device, or a logic node, a logic module or software capable of implementing all or part of the network device functions; the method executed by the terminal in the present application can also be implemented by a communication module in the terminal or a circuit or chip (such as a modem chip (also known as a baseband chip), or a SoC chip containing a modem core, or a SIP chip) responsible for communication functions in the terminal.

[0143] FIG. 3 shows an example flow of a communication method, which can include:

[0144] S101, the terminal establishes a first packet data unit (PDU) session in a first area.

[0145] The first area is an area covered by a first network device.

[0146] Optionally, the first area can be a TA granularity area or a cell granularity area, and the embodiments of the present application do not limit this. Similarly, the second area in the present application can be a TA or a cell. For example, the first area and the second area are both TAs. For another example, the first area and the second area are both cells.

[0147] One TA can include one or more cells. An area covered by one network device can include part or all of the areas of one or more TAs. For example, the area covered by a base station includes part of the area of TA1 and part of the area of TA2.

[0148] For example, as shown in FIG. 4(a), the area covered by the source base station includes part of the cells of TA1 (an example of the first area), and TA1 supports slice 1. The terminal establishes PDU session 1 in the cell of the source base station, and the PDU session 1 is associated with slice 1.

[0149] S102, the terminal sends information of a first slice, the first slice being associated with a first PDU session. The first PDU session is released or deactivated in a second area.

[0150] The second area is an area covered by a second network device.

[0151] The first PDU session being released or deactivated means that the terminal has released or deactivated the first PDU session. Or it means that the terminal determines to release or deactivate the first PDU session, but has not actually released or deactivated the first PDU session.

[0152] The information of the first slice includes at least one of the following: an identifier of the first slice; a number of the first slice; a service type of the first slice; a time when the first PDU session is released or deactivated; a cause for which the first PDU session is released or deactivated; or a location where the first PDU session is released or deactivated; the cause for which the first PDU session is released or deactivated includes that the first slice is not supported by the second area, or that the second area has no available resource for the first slice.

[0153] The time when the first PDU session is released or deactivated can also be understood as a time when the service interruption occurs.

[0154] The location where the first PDU session is released or deactivated can also be understood as a location where the service interruption occurs.

[0155] The second area has no available resource for the first slice can mean that the second area has not allocated any resource for the first slice. Alternatively, the second area has allocated insufficient resource for the first slice to support establishing or maintaining the first PDU session in the second area.

[0156] The sending of the information of the first slice can be implemented as: sending a first report, the first report including the information of the first slice; the first report including a minimization of drive tests (MDT) or RLF report; or the first report being a report dedicated to carrying the information of the first slice.

[0157] The handover of the terminal from the first area covered by the first network device to the second area covered by the second network device, and the release or deactivation of the first PDU session in the second area, means that the service corresponding to the first session of the terminal is interrupted, which can be referred to as a service interruption scenario. In the service interruption scenario, the terminal can report the information of the first slice associated with the first PDU session to the network device, so that the network device adjusts or optimizes the boundary deployment of the network slice based on the information of the first slice, to improve the service continuity of the terminal using the network slice.

[0158] For example, as shown in (b) of FIG. 4, the area covered by the target base station includes part of the cells of TA2. TA2 supports slice 2, but does not support slice 1 (an example of the first slice). The terminal is handed over from a source cell of a source base station shown in (a) of FIG. 4 to a target cell of a target base station shown in (b) of FIG. 4. Since TA2 does not support slice 1, the PDU session 1 (an example of the first session) associated with slice 1 is released or deactivated in the target cell (an example of the second area).

[0159] In this service interruption scenario, the terminal can report the information of the first slice to the network device (e.g., the source base station or the target base station). The network device can adjust the deployment of the network slice according to the information of the first slice to improve the service continuity as much as possible. For example, as shown in (c) of FIG. 4, the network device deploys the first slice as a slice supported by the target cell of TA2 based on the information of the first slice, and TA2 supports the second slice and the first slice. In some examples, subsequently, when another terminal using the first slice establishes a PDU session is handed over from the source cell to the target cell, since the source cell and the target cell both support the first slice, the probability that the target cell releases or deactivates the current PDU session of the terminal can be reduced, and the service continuity of the terminal is improved.

[0160] For another example, as shown in (a) of FIG. 5, the source cell 1 of the terminal supports the first slice, and the source cell 1 allocates available resources for the first slice. As shown in (b) of FIG. 5, the target cell 2 supports the first slice, and the target cell 2 does not have available resources for the first slice. After the terminal successfully establishes the PDU session 1 associated with the first slice in the source cell 1, the terminal is handed over to the target cell 2. Since the target cell 2 does not have available resources for the first slice, after the handover, the PDU session 1 associated with the first slice is released or deactivated in the target cell 2. In this service interruption scenario, the terminal can report the information of the first slice to the network device (e.g., the source base station or the target base station). The network device can adjust the deployment of the network slice according to the information of the first slice to improve the service continuity as much as possible. As shown in (c) of FIG. 5, the network device configures the cell 2 to allocate available resources for the first slice. Subsequently, the terminal uses the first slice again and is handed over from the cell 1 to the cell 2. Since the cell 1 and the cell 2 both have available resources for the first slice, the PDU session established by the terminal in the cell 1 is maintained in the cell 2, so as to ensure the service continuity of the terminal using the first slice.

[0161] For example, the information of the first slice includes the number of the first slice. The number of the first slice is the number of times that the first PDU session associated with the first slice is released or deactivated. In some examples, the first PDU session associated with the first slice is released or deactivated once, and the number of the first slice is incremented by one. For example, after the terminal establishes a first PDU session using the first slice, the first PDU session associated with the first slice is released for the first time, and the number of the first slice is 1. After the terminal establishes a first PDU session using the first slice again, the first PDU session associated with the first slice is deactivated, and the number of the first slice is 2. After the terminal establishes a first PDU session using the first slice again, the first PDU session associated with the first slice is released, and the number of the first slice is 3, and so on.

[0162] In the service interruption scenario, the terminal reports the number of first slices to the network device, and the network device can learn the number of times that the first PDU session associated with the first slice is released or deactivated and the number of times that the terminal uses the first slice according to the number of first slices. The network device can optimize the configuration parameters accordingly. For example, if it is learned that the terminal uses the first slice a large number of times and the service that the terminal wants to implement using the first slice is frequently rejected or interrupted, the network device can adjust the target cell to allocate sufficient resources for the first slice, so that in the subsequent process, the first PDU session associated with the first slice is not released or deactivated in the target cell due to insufficient resources of the target cell for the first slice.

[0163] Taking the information of the first slice as an example, the information of the first slice includes the identifier of the first slice, the reason for the release or deactivation of the first PDU session, and the service type of the first slice. In the service interruption scenario, the terminal reports the identifier of the first slice associated with the first PDU session and the service type of the first slice to the network device, which enables the network device to learn the reason for the release or deactivation of the first PDU session and which service type of which slice the first PDU session is associated with. For example, the network device can learn that the first PDU session is associated with slice 1 of the ultra-reliable low-latency communication (URLLC) service type. Since the URLLC type of service requires low latency, in order to ensure the continuity of the URLLC service, the network device can adjust the deployment of the network slice associated with the URLLC service. For example, the target cell is deployed to support slice 1, so that in the subsequent process, the PDU session associated with slice 1 is not released or deactivated in the target cell.

[0164] Taking the information of the first slice as an example, the information of the first slice includes the location where the first PDU session is released or deactivated, and the identifier of the first slice associated with the first PDU session is slice 1. In the service interruption scenario, the terminal reports the information of the first slice to the network device, which enables the network device to learn the location where the first PDU session is released or deactivated. For example, the terminal reports to the network device that the location where PDU session 1 is released is cell 2 of the target base station, and PDU session 1 is associated with slice 1, and then the network device can deploy cell 2 to support slice 1. By using this method, the network device can optimize the deployment of the network slice in a specific location based on the location information reported by the terminal, so as to improve the continuity of the service implemented by the terminal using the network slice in the location.

[0165] Optionally, the first network device and the second network device are the same or different devices. When the first network device and the second network device are the same device, the terminal is handed over from a location in the first area to a location in the second area, which can be a handover between different cells covered by one network device. The different cells can be cells under the same TA or cells under different TAs.

[0166] In some embodiments, the method can further include, as shown in FIG. 3, S202, when the first condition is met, the terminal records information of the first slice. Subsequently, when the second condition is met, the terminal sends the information of the first slice.

[0167] Optionally, the first condition includes at least one of the following conditions: the number of the first slice reaches a threshold value; the service type of the first slice is a preset type; the first slice is a slice with a preset identifier; the time when the first PDU session is released or deactivated is a preset time; the time when the terminal is handed over to a location in the second area is a preset time; and the location where the first PDU session is released or deactivated is a preset location.

[0168] As described above, when the number of the first slice reaches a threshold value, it means that the first PDU session associated with the first slice is released or deactivated more frequently. In this case, the terminal records the information of the first slice. Taking the threshold value of 4 as an example, after the terminal establishes a first PDU session using the first slice, the first PDU session associated with the first slice is released for the first time, and the number of the first slice is 1. After the terminal establishes a first PDU session using the first slice again, the first PDU session associated with the first slice is deactivated, and the number of the first slice is 2. When the number of the first slice is 4, it means that the service implemented by the terminal using the first slice is frequently refused or interrupted, and the terminal records the information of the first slice. As described above, the terminal can also report the information of the first slice. The network device can adjust the configuration parameters according to the information of the first slice to ensure the service continuity of the terminal after being handed over from a source cell to a target cell as much as possible.

[0169] With this method, the terminal does not record the information of the first slice every time the first PDU session is released or deactivated, but only when the number of the first slice reaches a threshold value. When the number of the first slice reaches the threshold value, it means that the first service implemented by the terminal using the first slice is frequently refused or interrupted, but the terminal still attempts to implement the first service using the first slice, which means that the terminal urgently expects to implement the first service using the first slice. On the one hand, this method can accurately record the information of the first slice expected to be used by the terminal, which can assist the network device in optimizing the configuration parameters. On the other hand, the terminal does not record the information of all the slices associated with the released PDU sessions, which can reduce the storage overhead of the terminal.

[0170] For example, in the case that the first condition is that the service type of the first slice is a preset type, in the service interruption scenario, the service type of the first slice associated with the first PDU session is the preset type, which means that the specific service that the terminal wants to use is rejected or interrupted, and the terminal can record the information of the first slice. As described above, the terminal can also report the information of the first slice. The network device can learn, according to the information of the first slice reported by the terminal, that the specific type of service of the terminal is rejected or interrupted, and accordingly adjust the configuration parameters to ensure the continuity of the specific type of service as much as possible after the terminal switches from the source cell to the target cell. In this method, the terminal can record the information of the specific type of first slice, and thus ensure the continuity of the specific type of service.

[0171] For example, in the case that the first condition is that the place where the first PDU session is released or deactivated is a preset place, in the service interruption scenario, the place where the first PDU session is released or deactivated is the preset place, which means that the service that the terminal wants to use is rejected or interrupted in the target cell, and if the target cell is located in the preset place, the terminal can record the information of the first slice. As described above, the terminal can also report the information of the first slice. The network device can learn, according to the information of the first slice reported by the terminal, that the service of the terminal is rejected or interrupted in the preset place, and accordingly adjust the configuration parameters to ensure the service continuity of the terminal in the preset place as much as possible.

[0172] In some embodiments, optionally, the first PDU session being released or deactivated can be implemented in any of the following modes 1-3:

[0173] Mode 1: The terminal receives a session release command, and the session release command indicates that the first PDU session is released or deactivated.

[0174] Optionally, the terminal can receive the session release command through a non-access stratum (NAS). The NAS can learn, according to the session release command, that the first PDU session is released or deactivated.

[0175] For example, the NAS determines, according to the cause value of the PDU session release or deactivation carried in the session release command, that the first PDU session is deactivated or released due to that the second area does not have enough slice resources for the first slice or the second area does not support the first slice.

[0176] Or the terminal can receive the session release command through the NAS, and the terminal sends first indication information to the access stratum (AS) through the NAS, and the first indication information is used to indicate that the first PDU session is released or deactivated. In this way, the AS can know that the first PDU session is released or deactivated according to the first indication information.

[0177] For example, after the NAS knows the cause value carried in the session release command, the NAS indicates to the AS that the first PDU session is released or deactivated.

[0178] The terminal can release or deactivate the first PDU session according to the above-mentioned session release command.

[0179] Method 2: The terminal determines that the data radio bearer (DRB) resource corresponding to the first PDU session is released.

[0180] Optionally, the terminal can determine through the AS that the DRB resource corresponding to the first PDU session is released, and send second indication information to the NAS through the AS, and the second indication information indicates that the DRB resource corresponding to the first PDU session is released. The NAS can know that the DRB resource corresponding to the first PDU session is released according to the second indication information, and accordingly know that the first PDU session is released or deactivated.

[0181] Or, the terminal can determine through the AS that the DRB resource corresponding to the first PDU session is released. In this way, the AS can know that the first PDU session is released or deactivated accordingly.

[0182] Method 3: The terminal determines that the first slice is not supported by the second area, or the second area does not have available resources for the first slice. In this case, the second area does not support the first PDU session associated with the first slice, or does not have available resources for the first slice.

[0183] Optionally, the terminal can determine through the NAS based on the information of the third area and the second area that the first slice is not supported by the second area, or the second area does not have available resources for the first slice.

[0184] Optionally, the information of the third area includes at least one of the following: a service area of the first slice; a tracking area (TA) that supports the first slice.

[0185] For example, the service area can be a network slice area of service (NS-AoS), or slice location availability information (S-NSSAI location availability information). For example, the slice supported TA can be a list of TAs obtained by the terminal based on a registration or configuration update procedure, or information of TAs obtained in other procedures. For example, the third area information includes: TA list of (partially) allowed NSSAI. Embodiments of the present application do not limit the form of the third area information, as long as it can be used to determine that the first slice is not supported by the second area, or the second area has no available resources for the first slice.

[0186] For example, the TAs supporting slice 1 are TA1 and TA3. As shown in (b) of FIG. 4, the terminal switches from a source cell of a source base station to a target cell of a target base station, and the target cell is in TA2. The AS determines the target cell currently accessed by the terminal. The AS sends information of the target cell to the NAS. In some examples, the NAS can determine that the target cell of TA2 is not in the TA supporting slice 1 according to the identity of the target cell (an example of the second area information) and the identity of TA1 and TA3 (an example of the third area information), and further determine that slice 1 (an example of the first slice) is not supported by the target cell. In other examples, the NAS can determine that slice 1 is not supported by the target cell according to the tracking area identity (TAI) of the target cell and the identity of TA1 and TA3.

[0187] Alternatively, the terminal can send the third area information to the AS through the NAS, and determine that the first slice is not supported by the second area or the second area has no available resources for the first slice based on the third area information and the second area through the AS;

[0188] Still following the above example, the NAS sends the information of TA1 and TA3 supporting slice 1 to the AS. The AS determines that slice 1 is not supported by the target cell based on the information of TA1 and TA3 supporting slice 1 and the target cell (the second area) currently accessed by the terminal.

[0189] In mode 3, after the terminal determines that the first slice is not supported by the second area or the second area has no available resources for the first slice, the terminal can not have actually released or deactivated the first PDU session. In some examples, the terminal receives a session release command, and actually releases or deactivates the first PDU session according to the session release command.

[0190] The determining that the terminal switches from being located in the first area to being located in the second area can be implemented in the following manners: determining, by the AS, that the terminal switches from being located in the first area to being located in the second area based on the second area; receiving, by the AS, the handover command; sending, by the AS, the information of the second area to the NAS, and determining, by the NAS based on the information of the second area, that the terminal switches from being located in the first area to being located in the second area; or sending, by the AS, the third indication information to the NAS, where the third indication information indicates that the AS receives the handover command, and the handover command is used to indicate that the terminal switches from being located in the first area to being located in the second area.

[0191] For example, the NAS determines the handover in combination with the identifier of the target cell or the TAI of the target cell provided by the AS. For another example, the AS indicates the NAS that the handover command is received. For example, the AS determines the handover based on the identifier of the target cell or the TAI of the target cell. For another example, the AS determines that the handover command is received.

[0192] In some embodiments, the terminal can further acquire configuration information, and the configuration information is used to configure the terminal to record information of a second slice, and the second slice includes the first slice. The second slice can be understood as a slice associated with the PDU session that is released or deactivated, or a slice associated with the service interruption, or a slice in which the service interruption occurs. In this way, the terminal can record the information of the second slice according to the configuration information, and report the information of the second slice when a certain condition is met, so as to optimize the configuration parameters of the network device.

[0193] The information of the second slice includes one or more of the following: an identifier of the second slice; a number of the second slice; a service type of the second slice; a time when a second PDU session associated with the second slice is released or deactivated; a reason why the second PDU session is released or deactivated; or a location where the second PDU session is released or deactivated.

[0194] For example, the configuration information configures the terminal to record the identifier of the second slice and the service type of the second slice, and when a first condition is met, the terminal records the identifier of the second slice and the service type of the second slice. For example, when the first PDU session is released and the service type of the first slice associated with the first PDU session is a preset type, the terminal records the identifier of the first slice and the service type of the first slice. As described above, the terminal can further report the recorded identifier of the first slice and the service type of the first slice to the network device.

[0195] Optionally, the configuration information is further used to configure one or more of the following: a first condition for triggering the terminal to record the information of the second slice; a second condition for triggering the terminal to send the information of the second slice; and the AS or the NAS of the terminal to record the information of the second slice.

[0196] As a possible implementation, as S201 of FIG. 3, the terminal can obtain configuration information from the network device. For example, the base station sends configuration information to the terminal accessing the base station, and the configuration information includes border slice related config of the terminal recording network slices with border service interruption. For example, the border slice related config can be configured to the base station by OAM or RIC, or configured to the base station by the core network device. For example, the border slice related config includes one or more of the following:

[0197] Whether the terminal records information corresponding to the second slice with border service interruption / failure;

[0198] Whether the terminal records the time of service interruption / failure;

[0199] Whether the terminal records the location type of service interruption / failure; the location type can be at least one of TAI, NGCI, and PCI.

[0200] The first condition for triggering the terminal to record the information of the second slice; for example, the first condition includes at least one of the following: the number of the second slice with border service interruption / failure reaches a threshold; the service type of the second slice with border service interruption / failure is a preset type; the second slice is a specified slice or belongs to a specified slice group, for example, the second slice is a specified S-NSSAI, or the second slice belongs to a specified network slice access layer group (NSAG);

[0201] The object of the terminal recording the information of the second slice is NAS or AS;

[0202] The second condition for triggering the terminal to send the information of the second slice.

[0203] The time of service interruption / failure can be understood as the time when the PDU session is released or deactivated.

[0204] The second slice with border service interruption / failure can be understood as the slice associated with the PDU session that is released or deactivated.

[0205] As another possible implementation, the terminal can be preconfigured with the above configuration information.

[0206] For example, the base station sends MDT related configuration information to the terminal. In the service interruption scenario, when the first condition is met, the terminal records information of the first slice according to the configuration information. The terminal can also return an MDT report to the base station, and the MDT report includes information of the first slice.

[0207] In some embodiments, the second condition for triggering the terminal to report the information of the first slice can be a periodic / event-based condition, such as the terminal reporting the information of the first slice after recording the information of the first slice. Alternatively, the terminal reports the information of the first slice based on the number of the first slice or the service type of the first slice. For another example, the terminal receives a first request for requesting a first report. The terminal reports the information of the first slice to the network device in response to the first request.

[0208] The following is an example of a communication method of an embodiment of the application in combination with a handover process. In this example, the terminal determines that the first PDU session is released or deactivated according to the session release command. As shown in FIG. 6, the method includes:

[0209] S101, the terminal establishes a first packet data unit (PDU) session in a first area.

[0210] S201, the first network device sends configuration information to the terminal.

[0211] As described above, this step is optional.

[0212] S301, the first network device sends a handover request to the second network device.

[0213] For example, the first network device determines to hand over the terminal to a target cell of the second network device based on the measurement report reported by the terminal. The first network device sends the handover request to the second network device.

[0214] Optionally, the handover request includes a list of PDU sessions established by the terminal. For example, the handover request includes information of the first PDU session established by the terminal in the first area, and information of the first slice associated with the first PDU session.

[0215] Optionally, the first network device can send the handover request to the second network device through an Xn interface between the first network device and the second network device. Alternatively, the first network device can send the handover request to the AMF, and the AMF forwards the handover request to the second network device.

[0216] S302, the second network device sends a handover response to the first network device.

[0217] After receiving the handover request, the second network device performs admission control on the first PDU session established by the terminal in the first region according to a slice list supported by the second region. In some examples, if the second region does not support a first slice associated with the first PDU session or does not have available resources for the first slice, the second network device can reject admission of the first PDU session and return a handover response to the first network device.

[0218] Optionally, the second network device sends the handover response to the first network device through an Xn interface. Alternatively, the second network device sends the handover response to the AMF, and the AMF forwards the handover response to the first network device.

[0219] Optionally, the handover response includes a handover command for instructing the terminal to switch to a target cell of the second network device.

[0220] Optionally, the handover response includes a list of PDU sessions to be released or deactivated by the terminal. For example, the second device sends information about the first PDU session that is rejected for admission to the first network device through the handover response.

[0221] Optionally, if S201 exists, the order between S201 and S301-S306 is not limited.

[0222] S303. The first network device sends an RRC reconfiguration message to the terminal.

[0223] After receiving the handover response, the first network device sends an RRC reconfiguration message to the terminal to instruct the terminal to perform cell switching.

[0224] Optionally, the RRC reconfiguration message includes a handover command.

[0225] S304. The terminal performs a synchronization process with the second network device.

[0226] After receiving the RRC reconfiguration message, the terminal synchronizes with a target cell of the second region covered by the second network device based on the RRC reconfiguration message, and switches a radio resource control (RRC) connection from a source cell of the first network device to a target cell of the second network device.

[0227] S305. The terminal sends an RRC reconfiguration complete message.

[0228] After switching to the target cell of the second region, the terminal sends an RRC reconfiguration message to indicate that the RRC reconfiguration is complete.

[0229] S306. The second network device sends a session release command to the terminal.

[0230] The second network device receives the RRC reconfiguration complete message, and learns that the terminal has been switched to the second area of the second network device.

[0231] As a possible implementation, since the second area of the second network device does not support a first slice associated with the first PDU session established by the terminal in the first area, or the second area has no available resource for the first slice, the SMF sends a NAS message carrying a session release command, which can be transparently transmitted to the terminal by the second network device.

[0232] The terminal can determine, according to the session release command, that the first PDU session is released or deactivated.

[0233] S307, the terminal records information of the first slice when the first condition is met.

[0234] Part or all of the implementation of S307 can refer to the related description of S202, and will not be repeated.

[0235] As a possible implementation, the terminal determines that the service interruption scenario is met, and the first condition for triggering recording is met, and then records the information of the first slice. For example, the terminal determines that the service interruption scenario is met, and the first condition for triggering recording is met, and then enables the SON / MDT function to record the information of the first slice.

[0236] For example, the first condition is that the service type of the first slice is a preset type, and the preset type includes URLLC. In the service interruption scenario, the service type of the first slice associated with the first PDU session is URLLC, which means that the URLLC service of the terminal is interrupted. When the first condition is met, the terminal triggers to record the information of the first slice. The recorded information of the first slice can be used for the network device to adjust the configuration parameters.

[0237] S102, the terminal sends information of a first slice, the first slice being associated with a first PDU session. The first PDU session is released or deactivated in a second area.

[0238] For example, the terminal can send part or all of the recorded information of the first slice, which is not limited.

[0239] FIG. 7 shows another flow example of the communication method according to the embodiments of the present application. Different from the flow shown in FIG. 6, in the example shown in FIG. 7, the terminal can perform S307 in S304, or after S304, without performing S307 after S306. For example, the terminal can determine, according to the information of the third area and the second area, that the first slice is not supported by the second area, or the second area has no available resource for the first slice, and determine to release or deactivate the first PDU session associated with the first slice according to the determination. In this case, if the first condition is met, for example, the service type of the first slice is a preset type, the terminal records the information of the first slice.

[0240] The embodiments of the present application do not limit the execution time of S307. For example, in another flow example, the terminal performs S307 after S305.

[0241] In another flow, the terminal can perform S307 after S303. In this case, the terminal can still be connected with the first network device after recording the information of the first slice.

[0242] In some embodiments, after recording the information of the first slice, the terminal can send the information of the first slice to the first network device while the terminal is still connected with the first network device. The first network device can forward the information of the first slice to the second network device.

[0243] In some embodiments, after receiving the information of the first slice, the second network device can also send the information of the first slice to the first network device. For example, the terminal sends the information of the first slice to the second network device after being connected with the second network device. The second network device sends the information of the first slice to the first network device. In this way, the first network device can optimize the handover strategy according to the information of the first slice. For example, if the first PDU session is determined to be released or deactivated in the area covered by the second network device, the terminal is avoided to be handed over to the area covered by the second network device as much as possible.

[0244] The embodiments of the present application also provide a communication method, which comprises:

[0245] S401, establishing a first packet data unit (PDU) session in a first area.

[0246] The first area is an area covered by the first network device.

[0247] S402, recording information of a first slice, the first slice being associated with the first PDU session.

[0248] The second area is an area covered by the second network device. The first slice is not supported by the second area, or the second area has no available resource for the first slice.

[0249] As a possible implementation, the first network device can obtain the information of the second network device from the second network device based on the Xn interface interaction, and determine whether the target cell of the second network device can support the first PDU session established by the terminal based on the information of the second network device. For example, the first network device obtains a list of slices supported by the target cell of the second network device, and / or a list of cells without available resources for the first slice, and determines whether the target cell can support the first PDU session based on the above information. In some examples, if the target cell does not support the first slice, or the target cell does not have available resources for the first slice, the first network device determines that the target cell does not support the first PDU session associated with the first slice. In this case, the first network device records the information of the first slice for optimizing the deployment of the border network slice.

[0250] In some embodiments, the first network device further determines the timing of triggering the recording of the information of the first slice in combination with a third condition. As a possible implementation, when the first slice is not supported by the second area and the third condition is met, the first network device triggers the recording of the information of the first slice. Alternatively, when the second area does not have available resources for the first slice and the third condition is met, the first network device triggers the recording of the information of the first slice.

[0251] Optionally, the third condition includes at least one of the following conditions: the number of the first slices reaches a threshold; the traffic type of the first slice is a preset type; the first slice is a slice with a preset identifier; the time when the first PDU session is released or deactivated is a preset time; the time when the terminal switches to the second area is a preset time; and the location where the first PDU session is released or deactivated is a preset location.

[0252] For example, the first network device determines that the first slice is not supported by the second area, and the number of the first slices reaches a threshold, which means that the terminal uses the first slice more frequently, and the business implemented by the terminal using the first slice is frequently rejected or interrupted. In this case, the third condition is met, and the first network device triggers the recording of the information of the first slice.

[0253] Optionally, as shown in FIG. 8, the method can further include:

[0254] S403, the first network device sends the information of the first slice to the second network device.

[0255] For example, the first network device sends the information of the first slice to the second network device through the Xn interface or the E2 interface.

[0256] The following gives a flowchart example of the method of the first network device recording the information of the first slice in combination with the handover process. As shown in FIG. 9, the method includes:

[0257] S401, the first network device establishes a first packet data unit (PDU) session in a first area.

[0258] S501, the first network device sends a handover request to a second network device.

[0259] S502, the second network device sends a handover response to the first network device.

[0260] S503, the first network device sends an RRC reconfiguration message to the terminal.

[0261] S501-S503 can refer to S301-S303, and will not be described here.

[0262] S402, the first network device records information of the first slice.

[0263] As a possible implementation, after S502, the first network device can learn that the second area of the second network device does not support the first PDU session according to a list of slices supported by a target cell of the second network device. Then, the first network device can perform S402.

[0264] Alternatively, the first network device performs S402 after S503. The embodiments of the present application do not limit the specific execution time of S402. The first network device can perform S402 as soon as it learns that the terminal has experienced service interruption or will experience service interruption.

[0265] S403, the first network device sends the information of the first slice to the second network device.

[0266] After receiving the information of the first slice, the second network device can optimize the deployment of the border network slice to ensure the continuity of the terminal service as much as possible.

[0267] The embodiments of the present application also provide a communication method, which records information of a first slice by a second network device. As shown in FIG. 10, after S401, the method can include:

[0268] S601, the second network device determines that a second area does not support a first slice associated with a first packet data unit (PDU) session or that the second area has no available resource for the first slice.

[0269] The first area is an area covered by the first network device. The second area is an area covered by the second network device.

[0270] The first PDU session is a PDU session established by a terminal in the first area.

[0271] For example, the second network device determines whether the target cell can support the first slice based on a list of slices supported by the target cell. For another example, the second network device determines whether the target cell has available resources for the first slice based on a list of cells that have no available resources for the first slice.

[0272] As a possible implementation, as shown in FIG. 10, the method can further include S501-S504. After S504, the second network device can perform S601. Alternatively, after S501 or S502 or S503, the second network device performs S601, without limitation.

[0273] S602, the second network device records information of the first slice.

[0274] In some examples, if the target cell does not support the first slice or the target cell has no available resources for the first slice, the second network device determines that the target cell does not support a first PDU session associated with the first slice. In this case, the second network device records information of the first slice for optimizing deployment of a border network slice.

[0275] With this method, after the second network device records information of the first slice, the second network device can optimize deployment of a border network slice based on the recorded information of the first slice, thereby reducing signaling interaction overhead between devices.

[0276] Optionally, the second network device can further determine whether to trigger recording of the information of the first slice in combination with a fourth condition. As a possible implementation, when the first slice is not supported by the second area and the fourth condition is met, the second network device triggers recording of the information of the first slice. Alternatively, when the second area has no available resources for the first slice and the fourth condition is met, the second network device triggers recording of the information of the first slice.

[0277] Optionally, the fourth condition includes at least one of the following conditions: the number of the first slices reaches a threshold; the service type of the first slice is a preset type; the first slice is a slice with a preset identifier; the time when the first PDU session is released or deactivated is a preset time; the time when the terminal switches to a location in the second area is a preset time; and the location where the first PDU session is released or deactivated is a preset location.

[0278] Optionally, as shown in FIG. 10, the method can further include:

[0279] S603, the second network device sends the information of the first slice to the first network device.

[0280] Optionally, in one or more embodiments of the present application, the second network device can send the information of the first slice to the first network device through an Xn interface or an E2 interface, without limitation.

[0281] After receiving the information of the first slice, the first network device can optimize the handover decision behavior of the first network device, such as trying not to hand over to the second network device.

[0282] The embodiment of the application further provides a communication method. After the first network device establishes a third PDU session in the first area, the first network device can determine whether there is a cell that supports the third PDU session and meets a handover condition based on a measurement report of the terminal and an identifier of a third slice associated with the third PDU session.

[0283] In some examples, if there is a target cell that supports the third PDU session and meets the handover condition, the first network device can hand over the terminal to the target cell of the second network device.

[0284] The cell that supports the third PDU session is a cell that supports the third slice and has available resources for the third slice.

[0285] The cell that meets the handover condition may, for example, be a cell with a signal strength higher than a threshold in the related art.

[0286] In other examples, if the target cell of the second network device meets the handover condition but does not support the third PDU session, the above method can be used to record the information of the third slice by the terminal or the first network device or the second network device. For example, as shown in FIG. 6, S301-S307 are performed, so that the terminal can record the information of the third slice in the current service interruption scenario to assist the network device in adjusting the deployment of the border network slice and improving the continuity of subsequent services of the terminal. In this example, the third slice can be the first slice mentioned in this document, and some methods related to the first slice can be referred to the related solutions of the first slice.

[0287] Alternatively, if the target cell of the second network device meets the handover condition but does not support the third PDU session, the first network device can carry the identifier of the third slice in the handover request sent to the second network device to indicate to the second network device that the current third PDU session is associated with the third slice. The second network device can adjust the slice deployment accordingly, such as deploying the target cell to support the third slice. Subsequently, when the terminal accesses the target cell, since the target cell is timely deployed to support the third slice, the third PDU session established by the terminal in the source cell will not be released or deactivated in the target cell, and the continuity of the service is guaranteed.

[0288] In the foregoing example of determining the handover to the target cell by the first network device, in some other embodiments, the terminal device can determine the handover to the target cell by itself. For example, in conditional handover (CHO), the first network device (e.g., a source base station) configures a plurality of CHO candidate cells for the terminal device, and configures a trigger condition for each CHO candidate cell. When the trigger condition is met, the terminal device can initiate the handover to the CHO candidate cell that meets the trigger condition.

[0289] In some examples, the first network device successfully hands over the UE to a target cell in the second network device, the target cell is capable of supporting the third slice and is allocated with available resources for the third slice, but the radio condition of the target cell is generally poor, for example, the signal quality of the target cell is not the strongest among the candidate cells, or the signal quality of the target cell is low. According to the MRO mechanism of the SON in the related art, the UE can feed back a successful handover report (SHR) to the target cell to help the network side optimize the handover decision. In this case, the target cell receiving the SHR can not perform the handover decision optimization, because the UE can consider that the handover to the suboptimal target cell is caused by the support of the network for the slice. Alternatively, the target cell receiving the SHR can perform the handover decision optimization for the third slice.

[0290] By way of example, the terminal device and the network device in the embodiments of the present application can be implemented by the communication apparatus in FIG. 11. FIG. 11 shows a hardware structure schematic diagram of the communication apparatus provided by the embodiments of the present application. The communication apparatus 400 includes at least one processor 401, a memory 403, and at least one communication interface 404.

[0291] The processor 401 can be a central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs of the present application.

[0292] Optionally, the communication apparatus can include a communication line, which can include a path for transmitting information between corresponding components of the apparatus.

[0293] The communication interface 404 uses any transceiver-like device for communicating with other devices or communication networks, such as an Ethernet, a RAN, a wireless local area networks (WLAN), etc.

[0294] The memory 403 can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disk storage, a magnetic disk storage or other magnetic storage devices, or any other medium capable of storing desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to this. The memory can exist independently, and be connected to the processor through a communication line. The memory can also be integrated with the processor.

[0295] The memory 403 is configured to store computer-executable instructions for implementing the solutions of the present application, and the processor 401 is configured to execute the computer-executable instructions stored in the memory 403.

[0296] Optionally, the computer-executable instructions in the embodiments of the present application can also be referred to as application program codes, and the embodiments of the present application are not limited in this regard.

[0297] In a specific implementation, as an example, the processor 401 can include one or more CPUs, such as CPU0 and CPU1 in FIG. 11.

[0298] In a specific implementation, as an example, the communication apparatus 400 can include multiple processors, such as the processor 401 and the processor 408 in FIG. 11. Each of these processors can be a single-CPU processor or a multi-CPU processor. The processor herein can refer to one or more devices, circuits, and / or processing cores for processing data (for example, computer program instructions).

[0299] The structure shown in FIG. 11 is only an example, and the communication apparatus can include more or fewer components, or other component layout, which is not limited. For example, the communication apparatus can include a processor implemented in hardware, or the processor implemented in a program calling manner. Or the communication apparatus includes a processor and a memory. Or the communication apparatus includes a processor and a communication interface.

[0300] It can be understood that, in order to implement the above functions, the device in the embodiments of the present application comprises a hardware structure and / or a software module corresponding to the execution of each function. The units and algorithm steps of the examples described in conjunction with the embodiments disclosed in the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is implemented in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the technical solutions of the embodiments of the present application.

[0301] The embodiments of the present application can divide the functional units of the device / apparatus according to the above method examples. For example, each functional unit can be divided according to each function, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in the form of hardware or software functional unit. It should be noted that the division of units in the embodiments of the present application is illustrative, and is only a logical function division. Actual implementation can have another division method.

[0302] The embodiments of the present application provide a device. The device can be the first terminal or other device or corresponding component. The device can include a memory and one or more processors. The memory and the processor are coupled. The memory is configured to store computer program code, and the computer program code includes computer instructions. When the processor executes the computer instructions, the device can perform each function or step corresponding to the execution of the device in the above method embodiments. The structure of the device can refer to the structure of the device shown in FIG. 11.

[0303] The core structure of the device can be represented as the structure shown in FIG. 12. The device includes a processing module 1301 and a storage module 1303.

[0304] The processing module 1301 (also referred to as a processing unit) can include at least one of a central processing unit (CPU), an application processor (AP), or a communication processor (CP), or an AI processor, such as the processor shown in FIG. 11. The processing module 1301 can perform operations or data processing related to control and / or communication of at least one of the other elements of the user communication device.

[0305] The storage module 1303 can include a volatile memory and / or a non-volatile memory. The storage module is configured to store instructions or data related to at least one of the other modules of the device. For example, it can be implemented as the memory shown in FIG. 11.

[0306] Optionally, the communication module 1305 (also referred to as a communication unit) is further included to support the device to communicate with other devices (through a communication network). For example, the communication module can be connected to a network via wireless communication or wired communication to communicate with other devices. The wireless communication can employ at least one of cellular communication protocols, such as Long Term Evolution (LTE), Long Term Evolution-Advanced (LTE-A), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Universal Mobile Telecommunication System (UMTS), Wireless Broadband (WiBro), or Global System for Mobile Communications (GSM). The wireless communication can include, for example, short-range communication. The short-range communication can include at least one of Wireless-Fidelity (Wi-Fi), Bluetooth, Near Field Communication (NFC), Magnetic Stripe Transmission (MST), or GNSS. For example, the communication module can be implemented as the communication interface of FIG. 11.

[0307] The embodiments of the present application further provide a chip system including at least one processor and at least one interface circuit. The processor and the interface circuit can be interconnected by a line. For example, the interface circuit can be used to receive a signal from another device (e.g., a memory of a communication device). For another example, the interface circuit can be used to send a signal to another device (e.g., a processor). For example, the interface circuit can read an instruction stored in a memory and send the instruction to the processor. When the instruction is executed by the processor, the communication device can perform various steps in the above-described embodiments. Of course, the chip system can further include other discrete devices, which are not limited in the embodiments of the present application.

[0308] The embodiments of the present application further provide a computer storage medium including computer instructions, which, when executed on the above-described communication device, cause the communication device to perform various functions or steps performed by a mobile phone in the above-described method embodiments.

[0309] The embodiments of the present application further provide a computer program product, which, when executed on a computer, causes the computer to perform various functions or steps performed by a mobile phone in the above-described method embodiments.

[0310] From the above description of the embodiments, those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-described functional modules is taken as an example for illustration, and in actual applications, the above-described functions can be completed by different functional modules according to needs, i.e., the internal structure of the device is divided into different functional modules to complete all or part of the above-described functions.

[0311] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented in other manners. For example, the division of the apparatus embodiments is merely an example, and the division of the modules or units can be different, for example, multiple modules or units can be combined or integrated into another apparatus, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, apparatuses or units, and can be in electrical, mechanical or other forms.

[0312] The units described as separate components may or may not be physically separate, and the components shown as units may be one physical unit or multiple physical units, i.e., may be located in one place, or may be distributed in multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0313] In addition, each functional unit in the various embodiments of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0314] If the integrated unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application essentially or the parts that make contributions to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product, which is stored in a storage medium, includes several instructions to make a device (which can be a single chip, a chip, etc.) or a processor execute all or part of the steps of the various embodiments of the method of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0315] The above is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any changes or replacements within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method characterized by comprising: The method comprises: establishing a first packet data unit (PDU) session in a first area; the first area is an area covered by a first network device; sending information of a first slice, the first slice being associated with the first PDU session; the first PDU session being released or deactivated in a second area; the second area being an area covered by a second network device; the information of the first slice comprises at least one of the following: an identifier of the first slice; a number of the first slice; a service type of the first slice; a time when the first PDU session is released or deactivated; a reason why the first PDU session is released or deactivated; or a location where the first PDU session is released or deactivated; the reason why the first PDU session is released or deactivated comprises that the first slice is not supported by the second area or that the second area has no available resource for the first slice.

2. The method of claim 1, wherein, The method further comprises: satisfying a first condition to record the information of the first slice, the first condition comprising at least one of the following: the number of the first slice reaches a threshold; the service type of the first slice is a preset type; the first slice is a slice with a preset identifier; the time when the first PDU session is released or deactivated is a preset time; the time when the terminal switches to the second area is the preset time; the location where the first PDU session is released or deactivated is a preset location; sending the information of the first slice.

3. The method of claim 2, wherein, The first PDU session being released or deactivated comprises: receiving a session release command, the session release command indicating that the first PDU session is released or deactivated; or determining that data radio bearer (DRB) resources corresponding to the first PDU session are released; or determining that the first slice is not supported by the second area or that the second area has no available resource for the first slice.

4. The method of claim 3, wherein, Receiving a session release command, the session release command indicating that the first PDU session is released or deactivated, comprises: receiving the session release command through a non-access stratum (NAS); or receiving the session release command through the NAS; sending first indication information through the NAS, the first indication information being used to indicate that the first PDU session is released or deactivated.

5. The method according to claim 3 or 4, characterized in that, Determining that data radio bearer (DRB) resources corresponding to the first PDU session are released, comprises: determining through an access stratum (AS) that the DRB resources corresponding to the first PDU session are released, and sending second indication information through the AS, the second indication information indicating that the DRB resources corresponding to the first PDU session are released; or determining through the AS that the DRB resources corresponding to the first PDU session are released.

6. The method according to claim 3 or 4, characterized in that, Determining that the first slice is not supported by the second area or that the second area has no available resource for the first slice, comprises: determining through a non-access stratum (NAS) based on information of a third area and the second area that the first slice is not supported by the second area or that the second area has no available resource for the first slice; or sending, by the NAS, information of the third area to the AS; determining, by the AS based on the information of the third area and the second area, that the first slice is not supported by the second area or that the second area has no available resource for the first slice; the information of the third area comprises at least one of: a service area of the first slice; a tracking area (TA) supporting the first slice.

7. The method according to any one of claims 1 to 6, characterized in that, Further comprising: obtaining configuration information, the configuration information being used for configuring a terminal to record information of a second slice, the second slice comprising the first slice; the information of the second slice comprises one or more of: an identifier of the second slice; a number of the second slice; a service type of the second slice; a time when a second PDU session associated with the second slice is released or deactivated; a cause of the second PDU session being released or deactivated; or a location where the second PDU session is released or deactivated.

8. The method of claim 7, wherein, the configuration information is further used for configuring one or more of: a first condition triggering the terminal to record the information of the second slice; a second condition triggering the terminal to send the information of the second slice; an AS or a NAS of the terminal recording the information of the second slice.

9. A communication method characterized by comprising: The method comprises: establishing a first packet data unit (PDU) session in a first area; the first area being an area covered by a first network device; recording information of a first slice, the first slice being associated with the first PDU session; the first slice not being supported by a second area or the second area having no available resource for the first slice; the second area being an area covered by a second network device; the information of the first slice comprises at least one of: an identifier of the first slice; a number of the first slice; a service type of the first slice; a time when the first PDU session is released or deactivated; a cause of the first PDU session being released or deactivated; or a location where the first PDU session is released or deactivated; the cause of the first PDU session being released or deactivated comprising that the first slice is not supported by the second area or that the second area has no available resource for the first slice.

10. The method of claim 9, wherein, Further comprising: sending the information of the first slice to the second network device.

11. A communication method, comprising: Comprising: determining that a second area does not support a first slice associated with a first packet data unit (PDU) session or that the second area has no available resource for the first slice; the second area being an area covered by a second network device; the first PDU session being a PDU session established by a terminal in a first area; the first area being an area covered by a first network device; recording information of the first slice; the information of the first slice comprises at least one of: an identifier of the first slice; a number of the first slice; a service type of the first slice; a time when the first PDU session is released or deactivated; a cause of the first PDU session being released or deactivated; or a location where the first PDU session is released or deactivated. The reason that the first PDU session is released or deactivated includes that the first slice is not supported by the second area or the second area has no available resource for the first slice.

12. The method of claim 11, wherein, Further comprising: sending, to the first network device, information of the first slice.

13. A communication device / chip, characterized in that, comprising means or modules for performing the method of any of claims 1-8, or comprising means or modules for performing the method of any of claims 9-10, or comprising means or modules for performing the method of any of claims 11-12.

14. A circuit system, characterized by The circuitry comprises processing circuitry configured to perform the method of any of claims 1-8, or to perform the method of claim 9 or 10, or to perform the method of claim 11 or 12.

15. A communications device, characterized by comprising: at least one processor and a communication interface for receiving and / or sending signals, the processor being configured to enable the method of any of claims 1-8 to be performed, or the processor being configured to enable the method of any of claims 9-10 to be performed, or the processor being configured to enable the method of any of claims 11-12 to be performed.

16. A communications device, characterized by The apparatus comprises a processor configured to enable the apparatus to implement the method of any of claims 1-8; or, the processor configured to enable the apparatus to implement the method of claim 9 or 10, or the processor configured to enable the apparatus to implement the method of claim 11 or 12.

17. A communications device, characterized by comprising a processor and a memory; The memory is configured to store computer-executable instructions, and the processor is configured to execute the computer-executable instructions stored in the memory to cause the apparatus to perform the method of any of claims 1-8, or to perform the method of any of claims 9-10, or to perform the method of any of claims 11-12, when the apparatus is running.

18. A computer-readable storage medium, characterized in that, comprising a program or instructions, which, when executed, cause the method of any of claims 1-8 to be implemented, or the method of any of claims 9-10 to be implemented, or the method of any of claims 11-12 to be implemented.

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