WO2022022082A1 - 通信方法和通信装置 - Google Patents

通信方法和通信装置 Download PDF

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Publication number
WO2022022082A1
WO2022022082A1 PCT/CN2021/099031 CN2021099031W WO2022022082A1 WO 2022022082 A1 WO2022022082 A1 WO 2022022082A1 CN 2021099031 W CN2021099031 W CN 2021099031W WO 2022022082 A1 WO2022022082 A1 WO 2022022082A1
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WIPO (PCT)
Prior art keywords
cell
access network
terminal device
network slice
session
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PCT/CN2021/099031
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English (en)
French (fr)
Inventor
李卓明
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华为技术有限公司
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Publication of WO2022022082A1 publication Critical patent/WO2022022082A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/08—Reselecting an access point
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/0005—Control or signalling for completing the hand-off
    • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
    • H04W36/0085—Hand-off measurements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/24—Reselection being triggered by specific parameters
    • H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
    • H04W36/302—Reselection being triggered by specific parameters by measured or perceived connection quality data due to low signal strength

Definitions

  • the present application relates to the field of wireless communication, and more particularly, to a communication method and a communication apparatus.
  • a terminal device can perform cell or frequency reselection based on a radio access technology frequency selection priority (radio access technology frequency selection priority, RFSP) index allocated by the core network.
  • RFSP index value can be associated with a set of parameters for cell/band camping or reselection.
  • the access network device may query the terminal device-specific cell/frequency camping or reselection parameters according to the authorized RFSP index, and then deliver the parameters to the terminal device. After the terminal device enters the idle state, it can select the frequency band with high priority to access according to these parameters.
  • the terminal device needs to wait until the current service is completed and enter the idle state, and then perform cell/frequency band reselection according to the radio parameters corresponding to the RFSP index.
  • the terminal device cannot switch to the appropriate cell in time, which may cause the terminal device to fail.
  • the communication quality of the current session of the device is degraded, or the session requested by the terminal device for establishment or activation cannot be responded in time, and the user experience is not good.
  • the present application provides a communication method and a communication device, in order to control the terminal equipment to switch to a suitable cell in a timely manner, thereby helping to improve the communication quality of the terminal equipment in a short time, or to respond to the terminal equipment request to establish or activate the session in time, Improve user experience.
  • the methods of the first to third aspects provided below may be performed by, for example, a first access network device, or may also be performed by a component (such as a circuit, a chip, or a chip system, etc.) configured in the first access network device. .
  • a component such as a circuit, a chip, or a chip system, etc.
  • This application does not limit this.
  • the method provided in the present application is described below by taking the first access network device as the execution body for ease of understanding and description.
  • a first aspect provides a communication method, the method comprising: determining, by a first access network device, that a signal quality of a terminal device in a source cell is lower than a preset threshold, and the source cell is a cell served by the first access network device; The first access network device determines from the at least one neighboring cell according to the first network slice corresponding to the first session activated by the terminal device in the source cell and the network slices respectively supported by the at least one neighboring cell of the source cell A target cell, the target cell supports the first network slice; the first access network device controls the terminal device to switch to the target cell.
  • the first access network device serving the source cell can support the network slice corresponding to the session activated by the terminal device in the source cell, and at least one adjacent cell, respectively.
  • the network slice and the corresponding frequency range of each network slice determine the target cell for the terminal equipment, and control the terminal equipment to switch to the target cell. Therefore, the terminal device can switch to the target cell with better signal quality in a timely manner when the signal quality is poor and there is a switchable target cell, so that measures can be taken in a timely manner in the case of poor communication quality without having to After the terminal equipment completes the current service, it enters the idle state to perform cell reselection. Therefore, the communication quality of the terminal device can be improved in a short time, which is beneficial to improve the user experience.
  • the target cell determined by the first access network device for the terminal device supports the first network slice, and on the other hand, the signal quality meets a preset threshold.
  • the target cell is another cell except the source cell among the multiple cells served by the first access network device.
  • the terminal device performs intra-site handover, it can be handed over to the target cell with better signal quality.
  • the target cell is a cell served by the second access network device.
  • the second access network device and the first access network device are different access network devices. That is, the source cell and the target cell are different stations. Terminal equipment needs to switch access network equipment. That is, the terminal device needs to perform cross-site handover.
  • the cell served by the first access network device only includes the source cell of the terminal device, or if the first access network device does not find a suitable cell in the adjacent cells in the station that can be used as the target cell, the adjacent cell outside the station can be used as the target cell. to find the target cell. It should be understood that if there are multiple off-site neighboring cells, the multiple off-site neighboring cells may be cells served by one or more access network devices.
  • the one or more access network devices include a second access network device.
  • the first access network device may first search for the target cell in the adjacent cells served by the first access network device, and secondly search for the target cell in the adjacent cells served by other access network devices, so as to Avoid the complicated process of switching access network equipment.
  • the method further includes: the first access network device determines the wireless measurement parameter according to the first network slice, the network slices supported by the at least one adjacent cell respectively, and the wireless resources corresponding to the supported network slices; the The first access network device sends a wireless measurement parameter to the terminal device, where the wireless measurement parameter is used for the terminal device to measure the signal quality of the adjacent cell; wherein the measurement of the signal quality of the adjacent cell by the terminal device is used for the target cell Sure.
  • the first access network wants to find a target cell from adjacent cells served by other access network equipment, the target cell may be further selected in combination with the signal quality of the adjacent cells outside each station. Therefore, the first access network device can determine the wireless measurement parameters according to the first network slice, the network slices supported by the adjacent cells, and the wireless resources corresponding to each network slice. The terminal device can measure the signal quality of the adjacent cell based on the wireless measurement parameter, so that the first access network device can determine the target cell according to the measurement result.
  • the method further includes: the first access network device sends a request message to the second access network device, where the request message carries the identification information of the first session and the identification information of the first network slice; the first access network device The network device receives radio resource control (radio resource control, RRC) parameters for handover from the second access network device; the first access network device sends the RRC parameters to the terminal device.
  • radio resource control radio resource control
  • the first access network device may send a request message to the second access network device serving the target cell, so as to request to acquire RRC parameters for handover.
  • the request message is a handover request message.
  • the second access network device may send the RRC parameter to the first access network device through a handover request acknowledgement (handover request knowledgement, handover request ACK) message.
  • the RRC parameter may be carried in the RRC message container in the handover request confirmation message, so that the first access network device can transparently transmit the RRC parameter to the terminal device.
  • a communication method including: a first access network device determining that a first radio resource accessed by a terminal device in a source cell does not support a first radio resource corresponding to a first session requested by the terminal device to establish or activate network slice, the source cell is the cell served by the first access network device; the first access network device determines the target cell, and the second radio resource of the target cell supports the first network slice; the first access network device controls the terminal The device switches to the target cell.
  • the first access network device serving the source cell can A network slice, network slices supported by at least one adjacent cell, and radio resources corresponding to each network slice determine a target cell for the terminal device, and control the terminal device to switch to the target cell. Therefore, the terminal device can switch the terminal device to the target cell in a timely manner, without waiting for the terminal device to complete, in the case that the first session requesting to establish or request to activate is not supported by the radio resources of the source cell and there is a switchable target cell After the current service, it enters the idle state for cell reselection. Therefore, the session request of the terminal device can be responded to in a timely manner, and the first session can be activated in a short time, which is beneficial to improve user experience.
  • the target cell determined by the first access network device for the terminal device supports the first network slice, and on the other hand, the signal quality meets a preset threshold.
  • the second radio resource further supports a network slice corresponding to a second session of the terminal device, where the second session includes an activated session or a deactivated session.
  • the target cell not only supports the first network slice, but also supports other network slices, for example, the network slice corresponding to the activated session or the deactivated session, so as to prevent the activated or deactivated session from generating traffic due to switching cells Interrupted, or need to switch cells again because the target cell does not support it.
  • determining the target cell by the first access network device includes: determining the target frequency range by the first access network device, and determining the target cell based on the target frequency range.
  • the target frequency range is a frequency range that supports the first network slice.
  • the target frequency range indicated by the first radio resource may be selected first, and other frequency ranges may be selected secondly.
  • the first access network device determines the target frequency range, including: the first access network device determines the target according to the network slice that the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice. Frequency Range.
  • the network slice that the terminal device is allowed to access may be determined according to the network slice requested by the terminal device, the network slice subscribed by the terminal device, and the network slice supported by the tracking area or registration area where the terminal device is located.
  • the network slice subscribed by the terminal equipment may be obtained by the access and mobility management network element from the unified data management network element. Therefore, the network slice that the terminal device is allowed to access can be determined by the access and mobility management network element and notified to the first access network device, so that the first access network device can determine the target frequency range.
  • the first access network device determines the target frequency range, including the network slice requested by the first access network device according to the terminal device, the network slice that the terminal device can use according to the subscription, and the support of the tracking area or registration area where the terminal device is located.
  • the network slice, the first network slice and the frequency range of the first network slice determine the target frequency range.
  • the network slices that the terminal device can use according to the subscription may be notified to the first access network device by the core network device such as the access and mobility management network element, for example.
  • the network slice that the terminal device can use according to the subscription may refer to the network slice subscribed by the terminal device; when the terminal device is visiting the network, the network slice that the terminal device can use according to the subscription may refer to the network slice that the terminal device can use according to the subscription.
  • the network slice of the visited network corresponding to the network slice subscribed by the device.
  • the determining, by the first access network device, the target cell includes: determining, by the first access network device, from neighboring cells within the site that support the target frequency range The target cell, the neighboring cells in the station are other cells except the source cell among the multiple cells served by the first access network device.
  • the first access network device controlling the terminal device to switch to the target cell includes: the first access network device sends a radio resource management (radio resource management, RRM) configuration message to the terminal device, the RRM The configuration message is used to control the terminal equipment to switch to the target cell.
  • RRM radio resource management
  • the first access network device may search for the target cell in the neighboring cells in the station served by the first access network device based on the predetermined target frequency range. If the first access network device finds the target cell in the adjacent cells in the site, the terminal device can switch to the target cell supporting the first network slice as long as the intra-site handover is performed.
  • the determining, by the first access network device, the target cell includes: the first access network device selects the target cell from an off-site adjacent cell that supports the target frequency range.
  • the target cell is determined, and the off-site adjacent cell is a cell other than the cell served by the first access network device among the adjacent cells of the source cell.
  • the first access network device determining the target cell from the off-site neighboring cells supporting the target frequency range specifically includes: the first access network device determining whether there is a support target in the off-site neighboring cells of the source cell The first cell in the frequency range; when the first cell exists, the first access network device determines whether the first cell supports the first network slice; the first access network device supports the first network slice in the first cell In the case of , determine the first cell as the target cell.
  • the first access network device may Find the target cell directly in the neighboring cells outside the station. It should be understood that if there are multiple off-site neighboring cells, the multiple off-site neighboring cells may be cells served by one or more access network devices.
  • the one or more access network devices include a second access network device.
  • the first access network device may first search for the target cell in the adjacent cells served by the first access network device, and secondly in the adjacent cells served by other access network devices Find the target cell to avoid the complicated process of switching access network equipment.
  • the target frequency range may preferentially select the frequency range indicated by the first radio resource. That is, the first access network device may first search for the target cell in the adjacent cells served by the first access network device based on the first frequency range, and then search for the target cell in the adjacent cells served by other access network devices The target cell; secondly, based on the second frequency range, first search for the target cell in the adjacent cells served by the first access network equipment, and then search for the target cell in the adjacent cells served by other access network equipment. In any step of the above process, as long as the first access network device finds the target cell, the subsequent steps of finding the target cell may not be performed.
  • the method further includes: the first access network device determines the wireless measurement parameter according to the target frequency range; the first access network device sends the wireless measurement parameter to the terminal device, and the wireless measurement parameter is used by the terminal device to measure the adjacent neighbors.
  • the measurement of the signal quality of the cell; the measurement of the signal quality of the adjacent cells by the terminal equipment is used for the determination of the target cell.
  • the first access network wants to find a target cell from adjacent cells served by other access network equipment, the target cell may be further selected in combination with the signal quality of the adjacent cells outside each station. Therefore, the first access network device can determine the wireless measurement parameters according to the first network slice, the target frequency range, the network slices supported by at least one adjacent cell, and the wireless resources corresponding to each network slice. The terminal device can measure the signal quality of the adjacent cell based on the wireless measurement parameter, so that the first access network device can determine the target cell according to the measurement result.
  • the method further includes: the first access network device sends a request message to the second access network device serving the target cell, where the request message carries the identification information of the first session and the identification information of the first network slice;
  • the first access network device receives RRC parameters for handover from the second access network device; the first access network device sends the RRC parameters to the terminal device.
  • the first access network device may send a request message to the second access network device serving the target cell, so as to request to acquire RRC parameters for handover.
  • the request message is a handover request message.
  • the second access network device may send the RRC parameter to the first access network device through the handover request confirmation message.
  • the RRC parameter may be carried in the RRC message container in the handover request confirmation message, so that the first access network device can transparently transmit the RRC parameter to the terminal device.
  • the RRC parameter is associated with the first network slice, the network slice supported by the second access network device, and the radio resources corresponding to the network slice supported by the second access network device.
  • the network slice supported by the second access network device refers to a network slice supported by at least one cell served by the second access network device.
  • the RRC parameter may be determined by the second access network device according to the first network slice corresponding to the first session to be handed in, and the radio resources corresponding to the first network slice in the cell served by the second access network device, so as to facilitate The second access network device determines which cell to hand over to.
  • a communication method including: a first access network device determining that a first radio resource accessed by a terminal device in a source cell does not support a first network slice of a first session requested by the terminal device to establish or activate , the source cell is a cell served by the first access network device; the first access network device sends an RRC connection release message to the terminal device to release the RRC connection with the terminal device. The first access network device releases the RRC connection with the terminal device, and the currently activated session is also deactivated accordingly.
  • the first access network device may actively release the communication with the terminal device in the case that the first radio resource accessed by the terminal device does not support the first network slice of the first session that requests establishment or activation.
  • RRC connection so that the terminal equipment can quickly enter the idle state and initiate cell reselection. It is not necessary to wait until the current business is completed before entering the idle state. Therefore, the terminal device can perform cell reselection in a timely manner when the first session requested to be established or activated is not supported by the radio resources of the source cell, without having to wait for the terminal device to complete the current service and then enter the idle state to perform cell reselection. reselection. Therefore, the session request of the terminal device can be responded to in a timely manner, and the first session can be activated in a short time, which is beneficial to improve user experience.
  • the method further includes: the first access network device determines the target frequency according to the network slice that is allowed to be accessed and the frequency range corresponding to the first network slice or, the network slice requested by the first access network device according to the terminal device, the network slice that the terminal device can use according to the subscription, the network slice supported by the tracking area or support area where the terminal device is located, the first network slice and the first network slice the corresponding frequency range, determine the target frequency range; the first access network device determines the radio parameters according to the target frequency range, the network slices supported by at least one adjacent cell respectively, and the radio resources corresponding to the supported network slices, The radio parameter is used for cell reselection of the terminal device; and the first access network device sends the radio parameter to the terminal device.
  • the first access network device can send radio parameters to the terminal device, so that the terminal device can perform cell reselection based on the radio parameters, so that the terminal device can quickly select a cell re-accessed cell.
  • the method further includes: the first access network device receives a message from the terminal device for requesting to establish or request to activate the first session.
  • the request by the terminal device to establish or activate the first session in the source cell may occur in different scenarios.
  • the first possible situation is that the terminal device may be a terminal device that accesses the network after being powered on, or it may be a terminal device that initiates a registration request because it moves to a new tracking area that does not belong to the original registration area, or, It can also be the terminal device when it periodically updates the registration with the network.
  • the first access network device receives a message from the terminal device requesting to establish or request to activate the first session, including: the first access network device receives a registration request message from the terminal device, and the registration request message carries a request Identification information of the first session established or requested to be activated.
  • the second possible situation is that the terminal device has established one or more sessions in the source cell served by the first access network device, but the one or more sessions are in a deactivated state, and the terminal device and the first access network device have established one or more sessions.
  • the network access devices each retain the context of the one or more sessions, and the user plane connections of the one or more sessions are not activated.
  • the terminal device desires to establish one or more new sessions in the source cell.
  • the first access network device receives a message from the terminal device requesting to establish or request to activate the first session, including: the first access network device receives a session request message from the terminal device, where the session request message carries a request Identification information of the first session established or requested to be activated.
  • the third possible situation is that the terminal device is in an RRC connection state with the first access network device.
  • the terminal device in the source cell wishes to establish one or more new sessions, or to activate one or more sessions.
  • the first access network device receives a message from the terminal device requesting to establish or request to activate the first session, including: the first access network device receives a session establishment request message from the terminal device, where the session establishment request message contains Carrying the identification information of the first session that is requested to be established, or, the session establishment request message carries the identification information of the first network slice corresponding to the first session; or, the first access network device receives the session activation request message from the terminal device , the session activation request message carries the identification information of the first session requested to be activated, or the session activation request message carries the identification information of the first network slice corresponding to the first session.
  • a communication apparatus including each module or unit for executing the method in any possible implementation manner of the first aspect to the third aspect.
  • a communication apparatus including a processor.
  • the processor is coupled with the memory, and can be used to execute the instructions or data in the memory, so as to implement the method in any possible implementation manner of the first aspect to the third aspect.
  • the communication device further includes a memory.
  • the communication device further includes a communication interface, and the processor is coupled to the communication interface.
  • the communication apparatus is an access network device, such as the first access network device in the first to third aspects.
  • the communication interface may be a transceiver, or an input/output interface.
  • the communication apparatus is a chip configured in an access network device.
  • the access network device may be, for example, the first access network device in the first to third aspects.
  • the communication interface may be an input/output interface.
  • the transceiver may be a transceiver circuit.
  • the input/output interface may be an input/output circuit.
  • a processor including: an input circuit, an output circuit, and a processing circuit.
  • the processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor performs the method of any one of the possible implementations of the first aspect to the third aspect.
  • the above-mentioned processor may be one or more chips
  • the input circuit may be input pins
  • the output circuit may be output pins
  • the processing circuit may be transistors, gate circuits, flip-flops and various logic circuits, etc. .
  • the input signal received by the input circuit may be received and input by, for example, but not limited to, a receiver
  • the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by a transmitter
  • the circuit can be the same circuit that acts as an input circuit and an output circuit at different times.
  • the embodiments of the present application do not limit the specific implementation manners of the processor and various circuits.
  • a processing apparatus including a processor and a memory.
  • the processor is configured to read the instructions stored in the memory, and can receive signals through the receiver and transmit signals through the transmitter, so as to execute the method in any possible implementation manner of the first aspect to the third aspect.
  • processors there are one or more processors and one or more memories.
  • the memory may be integrated with the processor, or the memory may be provided separately from the processor.
  • the memory can be a non-transitory memory, such as a read only memory (ROM), which can be integrated with the processor on the same chip, or can be separately set in different On the chip, the embodiment of the present application does not limit the type of the memory and the setting manner of the memory and the processor.
  • ROM read only memory
  • the relevant data interaction process such as sending indication information, may be a process of outputting indication information from the processor, and receiving capability information may be a process of receiving input capability information by the processor.
  • the data output by the processor can be output to the transmitter, and the input data received by the processor can be from the receiver.
  • the transmitter and the receiver may be collectively referred to as a transceiver.
  • the processing device in the above seventh aspect may be one or more chips.
  • the processor in the processing device may be implemented by hardware or by software.
  • the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor, implemented by reading software codes stored in a memory, which can Integrated in the processor, can be located outside the processor, independent existence.
  • a computer program product comprising: a computer program (also referred to as code, or instructions), which, when the computer program is executed, causes a computer to execute the above-mentioned first to sixth aspects The method in any of the three possible implementations.
  • a computer-readable storage medium stores a computer program (also referred to as code, or instruction) when it runs on a computer, causing the computer to execute the above-mentioned first aspect To the method in any possible implementation manner of the third aspect.
  • a computer program also referred to as code, or instruction
  • a communication system including the aforementioned first access network device and a terminal device.
  • the communication system further includes the aforementioned second access network device.
  • FIG. 1 is a schematic diagram of a network architecture suitable for the method provided by the embodiment of the present application
  • FIGS. 2 to 10 are schematic flowcharts of a communication method provided by an embodiment of the present application.
  • FIG. 11 and FIG. 12 are schematic block diagrams of a communication apparatus provided by an embodiment of the present application.
  • FIG. 13 is a schematic structural diagram of an access network device provided by an embodiment of the present application.
  • the technical solutions provided in this application can be applied to various communication systems, for example, a fifth generation (5th Generation, 5G) mobile communication system or a new radio access technology (NR).
  • the 5G mobile communication system may include a non-standalone (NSA, NSA) and/or an independent network (standalone, SA).
  • NSA non-standalone
  • SA independent network
  • the technical solutions provided in this application can also be applied to machine type communication (MTC), Long Term Evolution-machine (LTE-M), and device to device (D2D) networks.
  • M2M Machine to Machine
  • IoT Internet of Things
  • the IoT network may include, for example, the Internet of Vehicles.
  • vehicle to X vehicle to X
  • V2X vehicle and vehicle Infrastructure
  • V2I vehicle to pedestrian
  • V2N vehicle to network
  • FIG. 1 is a schematic diagram of a network architecture suitable for the method provided by the embodiment of the present application.
  • the network architecture is, for example, the 5G system (the 5h generation system, 5GS) defined in the 3rd Generation Partnership Project (3GPP) technical specification (TS) 23.501.
  • the network architecture can be divided into two parts: access network (AN) and core network (CN).
  • the access network can be used to implement functions related to wireless access, and the core network mainly includes the following key logical network elements: access and mobility management network elements, session management network elements, user plane network elements, and policy control network elements and unified data management network elements.
  • User equipment can be called terminal equipment, access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile equipment, user terminal, terminal, wireless communication equipment, User Agent or User Device.
  • the terminal device may be a device that provides voice/data connectivity to the user, such as a handheld device with a wireless connection function, a vehicle-mounted device, and the like.
  • some examples of terminals can be: mobile phone (mobile phone), tablet computer (pad), computer with wireless transceiver function (such as notebook computer, palmtop computer, etc.), mobile internet device (mobile internet device, MID), virtual reality (virtual reality, VR) equipment, augmented reality (augmented reality, AR) equipment, wireless terminals in industrial control (industrial control), wireless terminals in unmanned driving (self driving), wireless terminals in remote medical (remote medical) Terminal, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, cellular phone, cordless Telephone, session initiation protocol (SIP) telephone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device, computing device or connection with wireless communication capabilities
  • the terminal device may also be a terminal device in an Internet of things (Internet of things, IoT) system.
  • IoT Internet of things
  • IoT is an important part of the development of information technology in the future. Its main technical feature is to connect items to the network through communication technology, so as to realize the intelligent network of human-machine interconnection and interconnection of things.
  • IoT technology can achieve massive connections, deep coverage, and terminal power saving through, for example, narrow band (NB) technology.
  • NB narrow band
  • terminal equipment can also include sensors such as smart printers, train detectors, and gas stations.
  • the main functions include collecting data (part of terminal equipment), receiving control information and downlink data of network equipment, and sending electromagnetic waves to transmit uplink data to network equipment. .
  • Access network The access network can provide network access functions for authorized users in a specific area, and can use different quality transmission tunnels according to the user's level and service requirements.
  • the access network may be an access network using different access technologies.
  • 3GPP access technologies such as those employed in 3G, 4G or 5G systems
  • non-3GPP (non-3GPP) access technologies 3GPP access technology refers to the access technology that conforms to the 3GPP standard specifications.
  • the access network equipment in the 5G system is called the next generation Node Base station (gNB).
  • gNB next generation Node Base station
  • a non-3GPP access technology refers to an access technology that does not conform to 3GPP standard specifications, for example, an air interface technology represented by an access point (AP) in wireless fidelity (WiFi).
  • AP access point
  • WiFi wireless fidelity
  • An access network that implements access network functions based on wireless communication technology can be called a radio access network (RAN).
  • the radio access network can manage radio resources, provide access services for terminal equipment, and then complete the forwarding of control signals and user data between the terminal and the core network.
  • a radio access network may include, but is not limited to, a radio network controller (RNC), a Node B (Node B, NB), a base station controller (BSC), a base transceiver station (base transceiver station) , BTS), home base station (for example, home evolved NodeB, or home Node B, HNB), baseband unit (baseband unit, BBU), AP in WiFi system, wireless relay node, wireless backhaul node, transmission point (transmission point) point, TP) or transmission and reception point (transmission and reception point, TRP), etc., it can also be a gNB or a transmission point (TRP or TP) in a 5G (eg, NR) system, one or a group of base stations in a 5G system (Including multiple antenna panels) Antenna panels, or, can also be network nodes that constitute a gNB or transmission point, such as a baseband unit (BBU), or a distributed unit (DU), or in the next generation communication
  • the access network may provide services to the cell.
  • the terminal device may communicate with the cell through transmission resources (eg, frequency domain resources, or spectrum resources) allocated by the access network device.
  • transmission resources eg, frequency domain resources, or spectrum resources
  • Access and mobility management network elements mainly used for terminal registration, mobility management, and tracking area update procedures in the mobile network.
  • the access and mobility management network elements terminate the non-access stratum (non-access stratum, NAS) messages, complete registration management, connection management and reachability management, assign track area list (TA list) and mobility management, etc., and transparently route session management (session management, SM) messages to the session management network Yuan.
  • the access and mobility management network element can be an access and mobility management function (AMF).
  • Session management network element It is mainly used for session management in the mobile network, such as session establishment, modification and release. Specific functions include allocating Internet Protocol (IP) addresses to terminals, and selecting user plane network elements that provide packet forwarding functions.
  • IP Internet Protocol
  • the session management network element may be a session management function (SMF).
  • SMF session management function
  • User plane network element It is mainly responsible for processing user packets, such as forwarding, charging, and legal interception.
  • the user plane network element may also include a protocol data unit (protocol data unit, PDU) session anchor (PDU session anchor, PSA).
  • PDU protocol data unit
  • PSA protocol data unit
  • a user plane network element may be a user plane function (UPF).
  • UPF user plane function
  • Data network It can be used to provide data transmission services for terminal equipment.
  • the data network can be a public data network (PDN) network, such as the Internet, or a local access data network (LADN), such as mobile edge computing (MEC). ) node network; it can also be a third-party service network, an IP multimedia service (IP multi-media service) network, and the like.
  • PDN public data network
  • LADN local access data network
  • MEC mobile edge computing
  • IP multimedia service IP multi-media service
  • Policy control network element a unified policy framework for guiding network behavior, providing policy rule information and the like for control plane functional network elements (such as AMF, SMF network elements, etc.).
  • the policy control network element may be a policy control function (PCF).
  • PCF policy control function
  • the PCF in the actual network may also be divided into multiple entities according to layers or functions, such as the global PCF and the PCF in the slice, or the session management PCF (session management PCF, SM-PCF) and the access management PCF ( access management PCF, AM-PCF).
  • layers or functions such as the global PCF and the PCF in the slice, or the session management PCF (session management PCF, SM-PCF) and the access management PCF ( access management PCF, AM-PCF).
  • Network slice selection network element It is mainly used to select a suitable network slice for the service of the terminal device.
  • the network slice selection network element may be a network slice selection function (NSSF).
  • NSSF network slice selection function
  • Unified data management network element used to store user data, such as subscription information, authentication/authorization information, and the like.
  • the unified data management network element may be unified data management (UDM).
  • each network element can communicate through the interface shown in the figure.
  • terminal equipment and AMF can communicate through N1 interface
  • RAN and AMF can communicate through N2 interface, and N2 interface can be used for sending non-access stratum (NAS) messages
  • RAN and UPF can communicate through N3 interface , the N3 interface can be used to transmit data on the user plane, etc.
  • the interfaces connecting the RAN to the core network ie, the N2 interface and the N3 interface
  • SMF and UPF can communicate with SMF and UPF through the N4 interface, and the N4 interface can be used for transmission.
  • the tunnel identification information of the N3 connection, the data buffer indication information, and the downlink data notification message; the UPF and the DN can communicate through the N6 interface, and the N6 interface can be used to transmit data on the user plane.
  • the above-mentioned communication relationship between each network element and the interface is only an example, and should not constitute any limitation to the present application. This application does not exclude the possibility of defining other interfaces in future protocols for the communication between the above network elements or the communication between other network elements.
  • the above-mentioned network architecture applied to the embodiments of the present application is only a network architecture described from the perspective of a traditional point-to-point architecture and a service-oriented architecture, and the network architecture applicable to the embodiments of the present application is not limited thereto. Any network architecture capable of implementing the functions of the foregoing network elements is applicable to the embodiments of the present application.
  • AMF, SMF, UPF, network slice selection function (NSSF), PCF, and UDM shown in FIG. 1 can be understood as network elements used to implement different functions in the core network, such as Can be combined into network slices on demand.
  • These core network elements may be independent devices, or may be integrated into the same device to implement different functions, and the present application does not limit the specific forms of the foregoing network elements.
  • Session It can realize data transmission between terminal equipment and DN.
  • the session may be, for example, a protocol data unit (protocol data unit, PDU) session (PDU session).
  • the 5G core network (5G corenet, 5GC) supports PDU connection services.
  • the PDU connection service may refer to the service of exchanging PDU data packets between the terminal device and the DN.
  • the PDU connection service is realized through the establishment of a PDU session initiated by the terminal device. After a PDU session is established, a data transmission channel between the terminal device and the DN is established.
  • Each end device can establish one or more PDU sessions.
  • a PDU session can be identified by a PDU session identifier (PDU session identifier, PDU session ID). In other words, one possible form of identification information for a session is a PDU session identification.
  • PDU session is a possible form of the session, which should not constitute any limitation to this application.
  • Network slicing is an end-to-end logical private network that provides specific network capabilities. Through flexible allocation of network resources and on-demand networking, multiple logical subnets with different characteristics and isolated from each other can be virtualized on the same set of physical facilities to provide targeted services to users. This logical subnet is called a network slice. Network slicing can be used by operators, based on the service level agreement (SLA) signed by customers, to provide mutually isolated and customizable network services for different vertical industries, different customers, and different businesses. Different network slices can be identified and distinguished by single network slice selection assistance information (S-NSSAI).
  • S-NSSAI single network slice selection assistance information
  • Each access network device has a certain coverage area, which can be one or more cells (Cell), and each cell has a unique global cell identifier (cell global identifier, CGI).
  • Cell cells
  • CGI cell global identifier
  • the service area of the entire network slice is divided into several areas, that is, one or more tracking areas (TA).
  • a TA can be identified using a tracking area identifier (TAI).
  • TAI tracking area identifier
  • Cell A cell is described by a higher layer from the perspective of resource management, mobility management or serving unit.
  • the coverage of each access network device may be divided into one or more cells, and each cell may correspond to a frequency range. Each cell can work in the corresponding frequency range.
  • the frequency range can be a frequency point or a frequency band. This application does not limit this.
  • the cell may be an area within the coverage of the wireless network of the access network device.
  • different cells may correspond to the same or different access network devices.
  • the access network device serving cell #1 and the access network device serving cell #2 may be different access network devices, such as base stations. That is, cell #1 and cell #2 may be managed by different base stations.
  • the access network device serving cell #1 and the access network device serving cell #2 may be the same access network device, such as a base station. That is to say, cell #1 and cell #2 may be managed by the same base station, and in this case, it may be said that cell #1 and cell #2 are co-sited.
  • a possible situation where cell #1 and cell #2 co-site is that the access network device serving cell #1 and the access network device serving cell #2 are different radio frequency processing units of the same base station,
  • a radio remote unit that is, cell #1 and cell #2 can be managed by the same base station, have the same baseband processing unit and intermediate frequency processing unit, but have different RF processing units.
  • the source cell is the cell where the terminal equipment camps before handover, or the cell where the terminal equipment camps before performing cell reselection.
  • the source cell in the embodiment of the present application is a cell served by the first access network device.
  • the target cell is a cell determined by the first access network device for the terminal device to be handed over.
  • the target cell in this embodiment of the present application may be a cell served by the first access network device, or may be a cell served by the second access network.
  • Cells served by each access network device may work in different frequency ranges, or may work in the same frequency range.
  • radio resources supported by each cell are not limited to the frequency range, but may also include time domain resources, air domain resource resources, etc., which will not be listed and described here.
  • Handover In a wireless communication system, when a terminal device moves/approaches from one cell to another, in order to keep the communication of the terminal device uninterrupted, handover needs to be performed.
  • the source cell represents a cell that provides services for the terminal device before handover
  • the target cell represents a cell that provides services for the terminal device after the handover.
  • Handovers can be intra-station handovers or inter-station handovers.
  • Intra-site handover can refer to the source cell and the target cell belonging to the same access network device (eg gNB);
  • inter-site handover refers to the source cell and the target cell belonging to different access network devices (eg gNB). This application does not limit this.
  • RRC connection Before normal communication, the terminal equipment can establish an RRC connection with the network equipment, or in other words, the RRC connection with the cell. When the RRC connection is disconnected, the terminal device may enter the RRC idle state (also referred to as the idle state) and cannot communicate normally.
  • the terminal device When the terminal device is in the RRC connection state, the terminal device can transmit data through the currently activated session, and can also request to establish a session or request to activate a session.
  • the terminal device When the terminal device is in the RRC idle state, the terminal device cannot establish or activate a session, and the session activated in the RRC connected state is also deactivated.
  • Neighboring cells in the station adjacent cells served by the same access network equipment. For example, cell #1 and cell #2 in the following are adjacent cells within the station.
  • Off-site adjacent cells adjacent cells served by different access network equipment. For example, cell #1 and cell #4 in the following are adjacent cells outside the station.
  • Cell #1 the cell where the terminal equipment camps before handover, or the cell where the terminal equipment camps before performing cell reselection. That is, the above-mentioned source cell.
  • cell #1 is the source cell of the terminal device in the embodiment of the present application, but may also be the target cell of other terminal devices at the same time.
  • Cell #2 A cell co-sited with Cell #1, and Cell #2 is a neighboring cell of Cell #1. Since the cell #1 and the cell #2 share the same site, the cell #2 can be said to be an intra-site adjacent cell of the cell #1. It should be understood that the intra-station neighboring cells of cell #1 may include but are not limited to cell #2, for example, also include cell #3.
  • Cell #3 Another intra-station neighboring cell of Cell #1.
  • Cell #4 A cell not co-sited with Cell #1, and Cell #4 is a neighboring cell of Cell #1. Since cell #1 and cell #4 are not co-sited, cell #4 can be said to be an off-site adjacent cell of cell #1. It should be understood that the off-site neighboring cells of cell #1 may include but are not limited to cell #4.
  • the first access network device an access network device serving cell #1.
  • the cells served by the first access network device may include only cell #1, may also include cell #2, and may also include other cells other than cell #1 and cell #2, such as cell #3.
  • the second access network device an access network device different from the first access network device.
  • the cells served by the second access network device may include only cell #4, or may include other cells except cell #4.
  • the cell served by the second access network device is adjacent to the cell served by the first access network device, for example, one or more cells in the cell served by the second access network are adjacent cells of cell #1 . Therefore, it can be said that the second access network device and the first access network device are access network devices having a relationship of adjacent cells.
  • the access network devices that have the relationship of adjacent cells with the first access network devices are not necessarily limited to the second access network devices. Example to illustrate. However, this should not constitute any limitation to this application.
  • S-NSSAI#1 The identifier of the network slice corresponding to session 1.
  • S-NSSAI#2 The identifier of the network slice corresponding to session 2.
  • S-NSSAI#3 The identifier of the network slice corresponding to session 3.
  • Target frequency range The frequency range supported by the target cell.
  • the first access network device preferentially selects the first frequency range supported by the source cell (eg, cell #1) as the target frequency range.
  • the first frequency range the frequency range supported by the source cell, that is, the frequency range corresponding to the first radio resource of the source cell.
  • the first frequency range is the N41 frequency band.
  • network element A sending a message or data to network element B
  • network element B receiving the message or data from network element A, which is intended to indicate to whom the message or data is to be sent.
  • network elements and does not limit whether they are sent directly or indirectly via other network elements.
  • the first access network device described herein sends a message or a data packet to the second access network device, but it is not limited that the first access network device directly sends a message or data packet to the second access network device.
  • the communication between the first access network device and the second access network device can pass through AMF to forward.
  • the first access network device and the second access network device support Xn interface communication, the first access network device and the second access network device can interact directly, while No need for AMF forwarding.
  • each embodiment is described by taking Xn interface switching as an example. If there is no Xn interface between the first access network device and the second access network device, the Ng interface handover is performed.
  • the OAM can send configuration information for each access network device to indicate the network slices supported by the cells served by each access network device and the frequency range corresponding to each network slice.
  • the network device and the second access network device can no longer exchange the network slices supported by each other and the frequency range corresponding to each network slice with each other through the Xn interface.
  • the interaction between the first access network device and the second access network device can be forwarded through AMF.
  • the other processes are basically similar, and for the sake of brevity, no additional description of the embodiments is provided below.
  • the first, second, and various numeral numbers are only for the convenience of description, and are not used to limit the scope of the embodiments of the present application.
  • different multicast data, different UEs, different PDU sessions, etc. are distinguished.
  • At least one means one or more
  • plural means two or more.
  • And/or which describes the association relationship of the associated objects, indicates that there can be three kinds of relationships, for example, A and/or B, which can indicate: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A, B can be singular or plural.
  • the character “/” generally indicates that the associated objects are an “or” relationship.
  • At least one item(s) below” or similar expressions thereof refer to any combination of these items, including any combination of single item(s) or plural items(s).
  • At least one (a) of a, b and c can represent: a, or, b, or, c, or, a and b, or, a and c, or, b and c, or, a , b and c.
  • a, b and c can be single or multiple respectively.
  • FIG. 2 is a schematic flowchart of a communication method 200 provided by an embodiment of the present application. As shown in FIG. 2 , the method 200 may include steps 210 to 230 . Each step in the method 200 will be described in detail below.
  • step 210 the first access network device determines that the terminal device satisfies the cell handover condition.
  • step 220 the first access network device determines the target cell.
  • step 230 the first access network device controls the terminal device to switch to the target cell.
  • the first access network device may actively search for a target cell for the terminal device under the condition that the terminal device satisfies the cell handover condition, and control the terminal device to switch to the target cell. Instead of relying on the terminal equipment to initiate cell reselection after entering the idle state, it is not necessary to wait until the current service of the terminal equipment is completed before switching cells. Therefore, the terminal device can be switched to a suitable cell in time, so that the communication quality of the terminal device can be improved in a short time, which is beneficial to improve the user experience.
  • the first access network device determines that the terminal device satisfies the cell handover condition, which specifically includes: the first access network device determines that the signal quality of the terminal device in the source cell is lower than a preset threshold.
  • the signal quality can be evaluated by, for example, reference signal receiving power (reference signal receiving power, RSRP) or reference signal receiving quality (reference signal receiving quality, RSRQ).
  • RSRP reference signal receiving power
  • RSRQ reference signal receiving quality
  • the evaluation can be performed according to the RSRP or RSRQ of a reference signal (reference signal, RS) of a certain cell received by the terminal device.
  • RSRP, RSRQ, etc. can be understood as indicators for evaluating signal quality.
  • the preset threshold can be understood as a threshold value used to judge whether the signal quality is good or bad. Different indicators used for evaluation have different corresponding thresholds.
  • the preset threshold may be a predefined threshold value. This application does not limit its specific value. For the convenience of distinguishing from the threshold value described later, the threshold used for judging the signal quality of the terminal device in the source cell is recorded as the first preset threshold.
  • a possible scenario is that the terminal device and the first access network device may be in an RRC connection state.
  • the terminal device may have established and activated one or more sessions in the source cell.
  • the end device can transmit data through one or more active sessions.
  • the first access network device may perform step 220 to determine the target cell, and step 230 to control the terminal device to switch to the target cell.
  • FIG. 3 shows the specific flow of the communication method in this scenario.
  • the first access network device determines that the terminal device satisfies the cell handover condition, which specifically includes: the first access network device determines that the first radio resource of the source cell does not support the terminal device requesting establishment or activation in the source cell.
  • the wireless resources may include, but are not limited to, frequency domain resources, time domain resources, space domain resources, code domain resources, and the like.
  • the frequency domain resource may specifically refer to the frequency range supported by the cell. In other words, the cell can work within the supported frequency domain.
  • the radio resource supported by the source cell is recorded as the first radio resource
  • the session requested by the terminal device to establish or activate in the source cell is recorded as the first session
  • the first session is recorded as the first session.
  • the corresponding network slice is recorded as the first network slice.
  • the first radio resource does not support the first network slice corresponding to the first session requested by the terminal device to establish or activate, which may specifically refer to that the frequency range corresponding to the first radio resource does not support the first network slice, or in other words, the source cell
  • the first network slice is not supported. Therefore, the frequency range provided by the source cell cannot provide access services for the first network slice corresponding to the first session that the terminal device requests to establish or request to activate.
  • each cell can work in the corresponding frequency range, or in other words, each cell can provide the access service of the supported network slice in its corresponding frequency range, therefore, the first wireless network of the source cell
  • the frequency range corresponding to the resource does not support the first network slice, that is, the source cell does not support the first network slice.
  • a possible scenario is that the terminal device accesses the network after being powered on, or initiates a registration request to the network because it moves to a new TA that does not belong to the original registration area.
  • the terminal device when the terminal device periodically updates and registers with the network, it initiates a registration request to the network.
  • the terminal device may carry a list of sessions requested to be established or activated in the registration request.
  • the session list includes identification information of sessions requested by the terminal device to be established and/or activated.
  • the session requested by the terminal device to be established or activated may include, but is not limited to, the first session.
  • FIG. 4 shows the specific flow of the communication method in this scenario.
  • the terminal device when the terminal device changes from the RRC idle state to the RRC connected state, it is expected to activate the user plane connection for the session deactivated in the RRC idle state.
  • the terminal device When initiating an RRC connection request to the first access network device, the terminal device may carry a list of sessions requested to be activated.
  • the session list may include identification information of the session requested by the terminal device to be activated.
  • the session for which activation is requested may include, but is not limited to, the first session, for example.
  • the embodiment described below in conjunction with FIG. 5 shows the specific flow of the communication method in this scenario.
  • the terminal device may send a session establishment request message to the first access network device to request the establishment of one or more sessions.
  • the one or more sessions requested to be established by the terminal device may include, for example, but not limited to, the first session.
  • the embodiments described below with reference to FIG. 6 and FIG. 7 show the specific flow of the communication method in this scenario.
  • the first access network device may determine that the terminal device The cell handover conditions are met.
  • the first access network device may perform step 220 to determine the target cell, and step 230 to control the terminal device to switch to the target cell.
  • the target cell determined by the first access network device for the terminal device may be an in-site adjacent cell of the source cell or an off-site adjacent cell of the source cell, which is not limited in this application.
  • the first access network device may preferentially search for the target cell in the neighboring cells in the station. If the target cell can be found in the neighboring cells in the site, the terminal equipment can perform the cell handover in the site without switching the access network equipment. If the first access network device cannot find a suitable cell as the target cell in the adjacent cells in the station, it can search for the target cell in the adjacent cells outside the station. If the first access network device finds the target cell in the adjacent cells outside the station, the terminal device can perform cross-site cell handover, and the terminal device needs to switch the access network device at this time. It is assumed here that the terminal device switches to the second access network device, and the second access network device is the access network device serving the target cell.
  • the first access network device determines that the cell it serves only includes cell #1, and the first access network device directly searches for the target cell from neighboring cells outside the site. If the first access network device finds the target cell in an off-site adjacent cell, the terminal device can perform cross-site cell handover, and the terminal device needs to be handed over to the second access network device at this time.
  • FIG. 3 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 300 shown in FIG. 3 may include steps 301 to 307 .
  • the terminal device and the first access network device are in an RRC connection state.
  • the terminal device is in cell #1 served by the first access network device, and the terminal device has an active session 1 in cell #1, and the network slice corresponding to session 1 is the network slice identified as S-NSSAI#1.
  • the cells served by the first access network device may further include cell #2, which is a neighboring cell of cell #1. It should be understood that session 1 is an example of the first session, and the network slice identified as S-NSSAI#1 is an example of the first network slice.
  • step 303 may correspond to step 210 in method 200, which shows a possible implementation manner in which the first access network device determines that the terminal device satisfies the cell handover condition in step 210.
  • Step 304 may correspond to step 220 in the method 200, and shows a possible implementation manner in which the first access network device determines the target cell in step 220.
  • a possible situation is that the target cell is another cell except the source cell among the multiple cells served by the first access network device. That is, the first access network device can determine the target cell from the neighboring cells in the station.
  • the target cell is a cell served by the second access network device. That is, the first access network device may determine the target cell from neighboring cells outside the station.
  • the method may further include: the first access network device according to the first network slice, the network slices respectively supported by at least one adjacent cell, and the supported network The wireless resource corresponding to the slice is determined, and the wireless measurement parameter is determined; the first access network device sends the wireless measurement parameter to the terminal device, and the wireless measurement parameter is used for the terminal device to measure the signal quality of the adjacent cell. Measurement of signal quality is used for target cell determination.
  • Step 305 may correspond to step 230 in the method 200, and shows a possible implementation manner in which the first access network device controls the terminal device to switch to the target cell in step 230.
  • a possible implementation manner of step 305 is that the first access network device controls the terminal device to perform intra-site handover.
  • Another possible implementation manner of step 305 is that the first access network device controls the terminal device to perform cross-site handover.
  • the method may further include: Step 3051, the first access network device sends a request message to the second access network device, where the request message carries the identification information of the first session and the first network Identification information of the slice; Step 3052, the second access network device determines RRC parameters according to the information of the session to be handed in; Step 3053, the first access network device receives the RRC parameters for handover from the second access network device; Step 3054, the first access network device sends the RRC parameter to the terminal device; and step 3055, the terminal device accesses the radio resources of the second access network device according to the RRC parameter.
  • the RRC parameter is associated with the first network slice, the network slice supported by the second access network device, and the radio resources corresponding to the network slice supported by the second access network device.
  • the method 300 will be described in detail below with reference to specific processes.
  • the first access network device receives first configuration information from the OAM, where the first configuration information is used to indicate network slices supported by the first access network device and radio resources corresponding to each network slice.
  • an management plane (operation, administration and maintenance, OAM) entity may send configuration information to each access network device.
  • the configuration information sent by the OAM to each access network device may be used to respectively indicate network slices supported by each access network device and radio resources corresponding to the supported network slices.
  • the configuration information sent by the OAM to the first access network device may be recorded as the first configuration information. Since the radio resources include frequency domain resources, the radio resources corresponding to the network slice include the frequency range corresponding to the network slice.
  • the first access network device may configure network slices and frequency ranges that are respectively supported for each cell. Thereby, the network slice supported by each cell and the frequency range corresponding to each network slice can be determined. It should also be understood that when there are multiple cells served by the first access network device, network slices supported by each cell and frequency ranges corresponding to each network slice are not necessarily the same. As previously mentioned, each cell may correspond to a frequency range. In other words, each cell operates in the frequency range it supports.
  • the first configuration information may include: ⁇ S-NSSAI#1, (N41) ⁇ and ⁇ S-NSSAI#2, (N41) ⁇ , indicating that the first access network device supports providing the identifier S in the N41 frequency band - Access services for network slices of NSSAI#1 and S-NSSAI#2.
  • the first access network device can configure the supported network slices and frequency ranges for each cell as follows:
  • the network slices supported by cell #1 may include, for example, the network slice identified as S-NSSAI#1, and the frequency range corresponding to the network slice is N41 frequency band.
  • the network slices supported by cell #2 may include, for example, network slices identified as S-NSSAI#1 and S-NSSAI#2, and the frequency range corresponding to the two network slices is the N41 frequency band.
  • the first configuration information may include: ⁇ S-NSSAI#1, (N41) ⁇ and ⁇ S-NSSAI#2, (N41, N79) ⁇ , indicating that the first access network device supports provisioning in the N41 frequency band Access services for network slices identified as S-NSSAI#1 and S-NSSAI#2, and support access services for network slices identified as S-NSSAI#2 in the N79 frequency band.
  • the cells served by the first access network device include cell #1 and cell #2.
  • the first access network device may configure supported network slices and frequency ranges for each cell as follows: the network slices supported by cell #1 may include, for example, network slices identified as S-NSSAI#1 and S-NSSAI#2, and the network slices The corresponding frequency range is the N41 band.
  • the network slice supported by cell #2 may include, for example, a network slice identified as S-NSSAI#2, and the frequency range corresponding to this network slice is the N79 frequency band.
  • the first configuration information may include: ⁇ S-NSSAI#1, (N41, N79) ⁇ and ⁇ S-NSSAI#2, (N41) ⁇ , indicating that the first access network device supports provisioning in the N41 frequency band Access services for network slices identified as S-NSSAI#1 and S-NSSAI#2, and support to provide access services for network slices identified as S-NSSAI#1 in the N79 frequency band.
  • the first access network device can configure the supported network slices and frequency ranges for each cell as follows:
  • the network slices supported by cell #1 may include, for example, the network slice identified as S-NSSAI#1, and the frequency range corresponding to the network slice is N41 frequency band.
  • the network slices supported by cell #2 may include, for example, network slices identified as S-NSSAI#1 and S-NSSAI#2, and the frequency range corresponding to the two network slices is the N41 frequency band.
  • the network slice supported by cell #3 may include, for example, the network slice identified as S-NSSAI #1, and the frequency range supported by cell #3 is the N79 frequency band.
  • the network slices supported by each cell, the frequency range corresponding to each network slice, and the frequency range supported by each cell listed above are only examples, and should not constitute any limitation to this application. This application does not limit the network slice supported by each cell, the frequency range corresponding to each network slice, and the frequency range supported by each cell.
  • both cell #1 and cell #2 support working in the N41 frequency band
  • both cell #1 and cell #2 support the network slice identified as S-NSSAI#1.
  • the first configuration information may include: ⁇ S-NSSAI#1, (N41, N79) ⁇ and ⁇ S-NSSAI#2, (N41) ⁇ .
  • the cells served by the first access network device include cell #1, cell #2 and cell #3.
  • the first access network device can configure the supported network slices and frequency ranges for each cell as follows:
  • the network slices supported by cell #1 may include, for example, the network slice identified as S-NSSAI#1, and the frequency range corresponding to the network slice is N41 frequency band.
  • the network slices supported by cell #2 may include, for example, network slices identified as S-NSSAI#1 and S-NSSAI#2, and the frequency range corresponding to the two network slices is the N41 frequency band.
  • the network slice supported by cell #3 may include, for example, the network slice identified as S-NSSAI #1, and the frequency range supported by cell #3 is the N79 frequency band.
  • the first access network device acquires second configuration information of the second access network device, where the second configuration information is used to indicate network slices supported by the second access network device and radio resources corresponding to each network slice .
  • the first access network device may receive the second configuration information from the second access network device.
  • the first access network device may acquire the second configuration information through the Xn interface.
  • the first access network device can obtain the second configuration information through the Xn interface.
  • the second access network device may also receive the second configuration information from the OAM by using the method described in step 301 above.
  • the second configuration information sent by the OAM to the second access network device may include: ⁇ S-NSSAI#1, (N41, N79) ⁇ , ⁇ S-NSSAI#2, (N79) ⁇ and ⁇ S-NSSAI#1 #3, (N79) ⁇ , indicating that the second access network device supports providing the access service of the network slice identified as S-NSSAI#1 in the N41 frequency band, and supports the provision of S-NSSAI#1, S-NSSAI#1, Access services for network slices of S-NSSAI#2 and S-NSSAI#3.
  • Step 302 in FIG. 3 shows an implementation manner in which the second access network device receives the second configuration information from the OAM, and the first access network device receives the second configuration information from the second access network device.
  • the second configuration information received by the first access network device from the second access network device may be the same as or different from the second configuration information received by the second access network device from the OAM. It is sent to the first access network device after being processed by the second access network device.
  • the first access network device may receive the second configuration information from the OAM.
  • the OAM may send the first configuration information and the second configuration information to the first access network device through the same signaling.
  • the OAM may also send the configuration information of other access network devices to the first access network device through the same signaling, and the other access network devices may refer to the connection that has a relationship with the first access network device in a neighboring cell. access equipment.
  • step 302 is an optional step.
  • the target cell determined by the first access network device in the subsequent steps is an intra-site neighboring cell, the first access network device does not actually use the information acquired in step 302 .
  • step 303 the first access network device determines that the signal quality of the terminal device in cell #1 is lower than the first preset threshold.
  • the terminal device has established a first session in cell #1, and the user plane connection of the first session has been activated.
  • the identifier of the first network slice corresponding to the first session is S-NSSAI#1.
  • the context (context) of the terminal device saved by the first access network device includes information of the first session.
  • the session that the terminal device has established and activated in cell #1 is not necessarily limited to the first session, and may have established and activated multiple sessions.
  • the first session is taken as an example to describe the method flow provided in this application.
  • the first access network device may determine whether the signal quality of the terminal device in the cell #1 is lower than the first preset threshold according to the measurement of the signal quality of the cell #1 by the terminal device. If the signal quality of the terminal equipment in cell #1 is lower than the first preset threshold, that is, the signal quality of the terminal equipment in cell #1 is not good. The first access network device can thus determine that the terminal device is not suitable to continue to camp in the cell #1, and the terminal device satisfies the cell handover condition.
  • the terminal device may measure the signal quality of the source cell, and report the measurement result (eg, the above-mentioned parameters such as RSRP and RSRQ) to the first access network device.
  • the first access network device may determine whether the signal quality meets the first preset threshold according to the measurement result.
  • the first access network device may further determine that the terminal device satisfies the cell handover condition when the signal quality is lower than the first preset threshold.
  • the terminal device may, according to the measurement of the signal quality of the source cell, report the event that the signal quality is lower than the first preset threshold to the first an access network device. Accordingly, the first access network device determines that the terminal device satisfies the cell handover condition.
  • the measurement of the signal quality of the cell #1 by the terminal device may refer to the prior art, which is not described in detail here for the sake of brevity.
  • the first access network device determines the target cell according to the first network slice corresponding to the first session and the network slices respectively supported by at least one adjacent cell.
  • the first access network device may consider the first network slice corresponding to the first session when determining the target cell for the terminal device. That is, the target cell determined by the first access network device for the terminal device supports the first network slice to avoid interruption of the first session.
  • the first access network device may select a cell supporting the first network slice from the at least one adjacent cell as the target cell according to the first network slice and the network slices respectively supported by the at least one adjacent cell obtained in advance.
  • the first access network device may preferentially search for the target cell in the neighboring cells in the station. If the first access network device finds the target cell in the adjacent cells in the station, the target cell is another cell except the source cell among the multiple cells served by the first access network device.
  • the neighboring cells in the cell of cell #1 include cell #2, and cell #2 also supports the first network slice, the first access network device can determine whether cell #2 can be used as the signal quality of cell #2 according to the signal quality of cell #2. target cell. If the signal quality of cell #2 meets the preset threshold (for the convenience of distinction and description, the preset threshold is recorded as the second preset threshold), it can be used as the target cell.
  • the preset threshold for the convenience of distinction and description, the preset threshold is recorded as the second preset threshold
  • the identifier of the first network slice is S-NSSAI#1
  • the network slices supported by cell #2 include network slices marked as S-NSSAI#1 and S-NSSAI#2, then cell #2 also supports the first network slice.
  • the first access network device may further determine whether it can be used as the target cell according to the signal quality of cell #2.
  • the first access network device may search for neighboring cells of cell #1 from cells whose signal quality meets the second preset threshold according to the signal quality of each cell in the station. If a neighboring cell of cell #1 can be found from the cells whose signal quality meets the second preset threshold, the cell can be determined as the target cell.
  • the identifier of the first network slice is S-NSSAI#1.
  • the first access network device determines that there are cells in the station that meet the second preset threshold, including cell #2.
  • cell #2 also supports the network slice identified as S-NSSAI #1, so cell #2 can be used as the target cell.
  • the first access network device may preferentially Find the target cell within the cell range with the same frequency as cell #1.
  • co-frequency may specifically refer to the same frequency range supported by two cells, such as operating in the same frequency range; on the other hand, inter-frequency may specifically refer to two cells supporting different frequency ranges, such as operating at different frequencies Scope.
  • the identifier of the first network slice is S-NSSAI #1, and the frequency range supported by cell #1 is the N41 frequency band.
  • Neighboring cells within the station of cell #1 include cell #2 and cell #3. Assume that the network slices supported by cell #2 include network slices marked S-NSSAI#1 and S-NSSAI#2, the frequency range supported by cell #2 is the N41 frequency band; the network slices supported by cell #3 include network slices marked S-NSSAI For the network slice of #1, the frequency range supported by cell #3 is the N79 band. Then, the first access network device may give priority to whether the signal quality of cell #2 reaches the second preset threshold. If the signal quality of cell #2 meets the second preset threshold, cell #2 may be used as the target cell.
  • the first access network device can simultaneously obtain measurement results of the signal quality of each cell from other terminal devices in multiple cells it serves.
  • the measurement result of the signal quality of the neighboring cells is used to determine whether the neighboring cells in the site supporting the first network slice meet the second preset threshold.
  • the second preset threshold can be understood as another threshold value used to judge whether the signal quality is good or bad. Different indicators used for evaluation have different corresponding thresholds.
  • the second preset threshold may be a predefined threshold value. This application does not limit its specific value.
  • first preset threshold and the second preset threshold are different preset thresholds. Different indexes may be used for the two; alternatively, the same index and different threshold values may also be used; or, the same index and the same threshold value may also be used. This application does not limit this.
  • the first access network device may also search for the target cell from neighboring cells outside the station. If the first access network device finds the target cell from neighboring cells outside the station, the target cell may be, for example, a cell served by the second access network device.
  • the first access network device searches for the target cell from neighboring cells outside the site, and also searches based on the cells supporting the first network slice.
  • the specific implementation process is similar to the process of searching for the target cell in the adjacent cells in the station described above, and is not repeated here for brevity.
  • a possible implementation manner of step 304 is that the first access network device may use the first network slice, the network slices supported by at least one off-site adjacent cell respectively, and the corresponding network slices. Radio resources, determine the target frequency range, and then search for the target cell based on the target frequency range.
  • this step 304 may specifically include:
  • Step 3041 the first access network device determines the target frequency range according to the first network slice, the network slices supported by at least one adjacent cell, and the frequency range corresponding to each network slice;
  • Step 3042 the first access network device determines the target cell according to the target frequency range.
  • the target frequency range is a frequency range that can be supported by the target cell determined by the first access network device for the terminal device.
  • the first access network device may search for a cell supporting the first network slice from at least one adjacent cell according to the first network slice, and determine the target frequency range according to the frequency range corresponding to each cell of the first network slice.
  • the frequency ranges supported by each cell are different, although there may be multiple cells that support the first network slice, the frequency ranges corresponding to each cell are not necessarily the same. Therefore, the target frequency range may be the same frequency range as cell #1, or may be a different frequency range from cell #1, which is not limited in this application.
  • the frequency range supported by cell #1 is denoted as the first frequency range.
  • the first access network device may preferentially select the same frequency range as cell #1 as the target frequency range. If there is a cell that supports the first network slice and the corresponding frequency range is the first frequency range in the adjacent cell, the first frequency range is preferentially selected as the target frequency range; otherwise, the first network supported by the adjacent cell is selected The other frequency range corresponding to the slice is used as the target frequency range.
  • a frequency range different from the first frequency range corresponding to the first network slice supported by the adjacent cell is denoted as the second frequency range. In other words, the target frequency range is given priority to the first frequency range, followed by the second frequency range.
  • the first frequency range is the N41 band.
  • the frequency range corresponding to the network slice includes the N41 and N79 frequency bands.
  • the target frequency range should be the N41 band first. It can be understood that if the neighboring cells of cell #1 do not support the N41 frequency band, the target frequency range may be the N79 frequency band.
  • the N79 band is an example of the second frequency range.
  • step 3042 specifically includes: the first access network device determines the target cell from neighboring cells within the station that support the target frequency range.
  • the first access network device may first determine whether there is a cell that supports the first frequency range in the neighboring cells in the cell #1, for example Recorded as the first district. In the case that the first cell exists, the first access network device may determine whether to determine the first cell as the target cell according to the signal quality of the first cell. For example, if the signal quality of the first cell satisfies the second preset threshold, the first cell is determined as the target cell.
  • the first access network The device may determine the target cell in the off-site neighbor cells.
  • step 3042 specifically includes: the first access network device determines the target cell from neighboring cells outside the station that support the target frequency range. If the first access network device determines that the target frequency range is the first frequency range, the wireless measurement parameter may be determined based on the first frequency range. For the convenience of distinction and description, the wireless measurement parameter determined based on the first frequency range is denoted as the first wireless measurement parameter.
  • the first access network device may send the first wireless measurement parameter to the terminal device.
  • the terminal device may measure the signal quality of the neighboring cell based on the first wireless measurement parameter.
  • the first wireless measurement parameter triggers the terminal device to perform intra-frequency measurement.
  • the measurement of the signal quality of the adjacent cell by the terminal device based on the first wireless measurement parameter is the measurement in the first frequency range, that is, the measurement of the adjacent cell that supports the first frequency range and supports the first network slice. Measurement of signal quality.
  • the terminal device reports the measurement result to the first access network device.
  • the measurement result reported by the terminal device is a measurement result obtained by measuring the signal quality of the adjacent cell in the first frequency range based on the first wireless measurement parameter.
  • the measurement result may include cell identifiers of one or more neighboring cells and signal quality corresponding to each neighboring cell.
  • the cells reported in the measurement result can basically provide the access service of the first network slice in the first frequency range.
  • the first access network device may determine the target cell according to the measurement result. As mentioned above, the first access network device may determine the cell whose signal quality meets the preset threshold as the target cell. If the first access network device can find the target cell based on the measurement result reported by the terminal device, the first access network device does not need to determine wireless measurement parameters based on other frequency ranges, and the terminal device does not need to perform inter-frequency measurement.
  • the first access network device can use the second frequency range As the target frequency range, try to find the target cell based on the second frequency range in the in-station neighbor cells and the out-station neighbor cells. It can be understood that if the first access network device can find the target cell in the adjacent cells in the station based on the second frequency range, it is not necessary to search for the target cell in the adjacent cells outside the station.
  • the specific process for the first access network device to search for the target cell in the adjacent cells in the station based on the second frequency range is the same as the specific process for the first access network device to search for the target cell in the adjacent cells in the station based on the first frequency range described above.
  • the process is the same, and is not repeated here for brevity.
  • the specific process that the first access network device searches for the target cell in the adjacent cells outside the station based on the second frequency range can be implemented by performing the above steps of determining wireless measurement parameters, delivering wireless measurement parameters, and determining the target cell according to the measurement results.
  • the first access network device may use the second frequency range as the target frequency range, and determine the wireless measurement parameter based on the second frequency range.
  • the wireless measurement parameter determined based on the second frequency range is denoted as the second measurement parameter.
  • the first access network device may deliver the second wireless measurement parameter to the terminal device.
  • the terminal device may measure the signal quality of the neighboring cell based on the second wireless measurement parameter.
  • the second wireless measurement parameter can trigger the terminal device to perform inter-frequency measurement.
  • the measurement of the signal quality of the adjacent cell by the terminal device based on the second wireless measurement parameter is the measurement in the second frequency range, that is, the signal of the adjacent cell that supports the second frequency range and supports the first network slice. measurement of quality.
  • the terminal device may report the measurement result to the first access network device. It can be understood that the measurement result reported by the terminal device this time is a measurement result obtained by measuring the signal quality of the adjacent cell in the second frequency range based on the second wireless measurement parameter.
  • the cells reported in the measurement result can basically provide the access service of the first network slice in the second frequency range.
  • the first access network device may determine the target cell according to the measurement result. As mentioned above, the first access network device may determine the cell whose signal quality meets the preset threshold as the target cell.
  • the first access network device may perform subsequent step 305 to control the terminal device to switch to the target cell; otherwise, the terminal device may continue to camp in the cell in #1.
  • the above process shows the process of searching for the target cell in the neighboring cells in the station and the neighboring cells outside the station.
  • the first access network device does not necessarily need to perform all the steps listed above.
  • the above step 3042 may only need to be performed once. For example, if the target cell is found by performing intra-frequency measurement, it is not necessary to perform inter-frequency measurement; or, if a cell in the same frequency range as cell #1 is not found in the adjacent cells, it is directly performed.
  • Inter-frequency measurement; step 3042 may also need to be performed two or more times, such as performing intra-frequency measurement and then performing inter-frequency measurement; in step 3042, the first access network device supports the target frequency range from an off-site adjacent cell
  • the steps of determining the target cell may not need to be performed.
  • the first access network device A cell in the same frequency range may be found in the neighboring cells in the station and can be used as the target cell. This application does not limit this.
  • the process of determining the target cell by the first access network device is described in detail by taking the first session as an example.
  • the session activated by the terminal device in the source cell may not necessarily be limited to the first session.
  • the session activated by the terminal device in the source cell may also be multiple sessions.
  • the target cell determined by the first access network device for the terminal device should comprehensively consider the multiple sessions, so as to ensure that the multiple sessions can be performed normally without being interrupted. Therefore, when the first access network device determines the target cell, it should try to make the network slices corresponding to the multiple sessions activated by the terminal device in the source cell can be respectively supported by the target cell and can be accessed by the target cell. Radio resources supported by the target cell.
  • the network slice supported by the cell includes the above-mentioned multiple sessions, and the multiple network slices can access the same radio resource in the cell, the cell is preferentially selected as the target cell.
  • step 305 the first access network device controls the terminal device to switch to the target cell.
  • the target cell may be a cell served by the first access network device, or may not be a cell served by the first access network device.
  • the terminal equipment may perform the intra-site handover procedure or the cross-site handover procedure. The following is a detailed description of the intra-site handover process and the cross-site handover process.
  • the terminal device may perform an intra-site handover procedure.
  • the first access network device may determine the handover parameter according to the radio resources supported by the target cell.
  • the handover parameters may include, but are not limited to, the identity of the target cell, the wireless temporary identity of the terminal device in the target cell, carrier frequency, antenna information, beam information, dedicated random access channel (RACH) resources, and RACH resources are associated with synchronization signals and physical broadcast channel (PBCH) blocks, quality of service flow (quality of service flow, QoS Flow) and mapping rules for radio bearers.
  • the handover parameters may include, but are not limited to, the identity of the target cell, the wireless temporary identity of the terminal device in the target cell, carrier frequency, antenna information, beam information, dedicated random access channel (RACH) resources, and RACH resources are associated with synchronization signals and physical broadcast channel (PBCH) blocks, quality of service flow (quality of service flow, QoS Flow) and mapping rules for radio bearers.
  • PBCH physical broadcast channel
  • the first access network device may deliver the handover parameter to the terminal device.
  • the first access network device may issue the handover parameter to the terminal device through a radio resource management (radio resource management, RRM) configuration (RRM configuration) message.
  • RRM radio resource management
  • the handover parameter can be used to allocate a data radio bearer (DRB) for the frequency range of the first session, so as to complete the intra-site handover of the terminal device.
  • DRB data radio bearer
  • the terminal device may perform an inter-site handover procedure.
  • the terminal device can be switched from the first access network device to the second access network device.
  • Step 305 in Figure 3 shows the cross-site handover process.
  • step 305 may specifically include the following steps 3051 to 3055 .
  • step 3051 the first access network device sends a request message to the second access network device, where the request message carries information about the session to be handed over to the second access network device.
  • the first access network device sends a request message to the second access network device, where the request message is used to request handover of the terminal device to the second access network device.
  • the request message may carry the information of the session to be handed over to the second access network device, for example, including but not limited to the identification information of the session and the identification information of the corresponding network slice.
  • the session to be handed over to the second access network device includes the first session, and the network slice corresponding to the first session is the first network slice.
  • the identification information of the session to be handed over to the second access network device carried in the above request message may include, for example, the identification of the first session or other information that can be used to identify the first session;
  • the identification information of the network slice corresponding to the session can be, for example, the identifier of the first network slice or other information that can be used to identify the first network slice. This application does not limit the specific forms of the identification information of the first session and the first network slice.
  • the second access network device determines RRC parameters for handover according to the information of the session to be handed in.
  • the second access network device may, according to the information about the session to be handed in carried in the request message, combine the network slices that it supports, the radio resources corresponding to each network slice, and the network slice corresponding to the session to be handed in, for example, the above-mentioned first Network slicing to determine RRC parameters for handover.
  • the RRC parameter may include, for example, the handover parameters listed in the intra-site handover procedure above. For brevity, they are not listed here.
  • the second access network device may also, after receiving the request message, detect whether the network slice corresponding to the session to be handed in is a network slice supported by itself, and then determine the session that is allowed to be handed in. For example, if the second access network device does not support network slicing of a certain session, it may refuse to switch into the session.
  • the second access network device determines that it supports the first network slice corresponding to the first session, that is, the network slice identified as S-NSSAI#1, and is ready to accept the cut-in to the first session.
  • the second access network device determines that it can support both the N41 frequency band and the N79 frequency band
  • the first session to be switched to.
  • the frequency range of the first radio resource accessed by the first session in the source cell is the N41 frequency band, and the second access network device will preferentially allocate and allocate data radio bearers (data radio bearers) for the first session to be handed over in the N41 frequency band.
  • bearer, DRB determine the corresponding RRC parameters.
  • step 3053 the second access network device sends RRC parameters to the first access network device.
  • the RRC parameter may be encapsulated in an RRC message container, and sent to the terminal device through the first access network device. That is, the first access network device can transparently transmit the RRC parameters from the second access network device to the terminal device.
  • the request message may be a handover request message.
  • the RRC parameter is carried in a handover request acknowledgement (handover request acknowledgement, handover request ACK) message.
  • step 3054 the first access network device forwards the RRC parameter to the terminal device.
  • step 3055 the terminal device accesses the radio resource of the second access network device according to the RRC parameter.
  • the method may further include step 306, the second access network device and the terminal device establish a DRB over the air interface for the successfully switched first session, and activate the user plane of the switched session.
  • step 307 the AMF switches the user plane path of the first session to the second access network device.
  • the second access network device may send a message to the AMF to notify the terminal device to switch to the second access network device and notify the core network to switch the session of the terminal device to the second access network device
  • the user plane path is switched to the second access network device.
  • the core network then performs path switching.
  • the terminal device can switch to the session of the second access network device (for example, including the above-mentioned first session), and can send and receive service data normally.
  • the session of the second access network device for example, including the above-mentioned first session
  • FIG. 3 describes steps 305 to 307 by taking the terminal device performing cross-site handover as an example. However, this should not constitute any limitation to this application. In the intra-site handover process, the process involving cross-site handover in step 305 and steps 306 and 307 do not necessarily need to be executed.
  • the first access network device serving the source cell can support the network slice corresponding to the session activated by the terminal device in the source cell, and at least one adjacent cell, respectively.
  • the network slice and the corresponding frequency range of each network slice determine the target cell for the terminal equipment, and control the terminal equipment to switch to the target cell. Therefore, the terminal device can switch to the target cell with better signal quality in a timely manner when the signal quality is poor and there is a switchable target cell, so that measures can be taken in a timely manner in the case of poor communication quality without having to After the terminal equipment completes the current service, it enters the idle state to perform cell reselection. Therefore, the communication quality of the terminal device can be improved in a short time, which is beneficial to improve the user experience.
  • FIG. 4 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 400 shown in FIG. 4 may include steps 401 to 419 .
  • the terminal device in method 400 can access the terminal device of the network after powering on, or it can also be because of moving to a new tracker that does not belong to the original registration area.
  • the terminal device that initiates the registration request after the zone or it can also be the terminal device that periodically updates the registration to the network.
  • the cell that the terminal device requests to access is cell #1 served by the first access network device, and the terminal device requests to establish one or more sessions and/or request to activate one or more sessions in cell #1.
  • a request to establish or activate a session 1 is used as an example, and then a request to establish or request to activate multiple sessions including session 1 is used as an example to describe the method provided by the embodiment of the present application. It should be understood that session 1 is an example of the first session, and the network slice identified as S-NSSAI#1 is an example of the first network slice.
  • steps performed for requesting session establishment in the following steps are substantially similar to the steps performed for requesting session activation. When there is a difference, the steps are separately explained for the request to establish a session and the request to activate the session.
  • the network slice supported by the first access network device and the frequency range corresponding to each network slice include: ⁇ S-NSSAI#2, (N41) ⁇ , the cell #1 served by the first access network device
  • the supported frequency range is the N41 frequency band
  • the network slice supported by the second access network device and the frequency range corresponding to each network slice include: ⁇ S-NSSAI#1, (N41, N79) ⁇ , ⁇ S-NSSAI#2, ( N79) ⁇ and ⁇ S-NSSAI #3, (N79) ⁇ .
  • the step 412 may correspond to the step 210 in the method 200, which shows a possible implementation manner in which the first access network device determines that the terminal device satisfies the cell handover condition in the step 210.
  • Steps 413 to 414 may correspond to step 220 in the method 200, and illustrate a possible implementation manner in which the first access network device determines the target cell in step 220.
  • the first access network device may determine the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • the first access network device determines the target cell according to the target frequency range.
  • a possible implementation manner of step 414 is that the first access network device determines the target cell from neighboring cells within the station that support the target frequency range.
  • Another possible implementation of step 414 is to determine the target cell from neighboring cells outside the station that support the target frequency range.
  • the method may further include: the first access network device determines the wireless measurement parameter according to the target frequency range; the first access network device sends the terminal to the terminal The device sends wireless measurement parameters, where the wireless measurement parameters are used by the terminal device to measure the signal quality of the adjacent cells, and the measurement of the signal quality of the adjacent cells by the terminal device is used to determine the target cell.
  • Step 415 may correspond to step 230 in method 200 .
  • a possible implementation manner in which the first access network device controls the terminal device to switch to the target cell in step 230 is shown.
  • a possible implementation manner of step 415 is that the first access network device controls the terminal device to perform intra-site handover.
  • Another possible implementation manner of step 415 is that the first access network device controls the terminal device to perform cross-site handover.
  • the method may further include: the first access network device sends a request message to the second access network device, where the request message carries the identification information of the first session and the identifier of the first network slice.
  • the first access network device receives the RRC parameter for handover from the second access network device; and the first access network device sends the RRC parameter to the terminal device.
  • the RRC parameter is associated with the first network slice, the network slice supported by the second access network device, and the radio resources corresponding to the network slice supported by the second access network device.
  • the method 400 will be described in detail below with reference to specific processes.
  • the first access network device obtains configuration information of multiple access network devices from the OAM, where the configuration information of the multiple access network devices is used to indicate network slices and each network supported by the first access network device The radio resources corresponding to the slices, as well as the network slices supported by the access network equipment with the relationship of the adjacent cells and the radio resources corresponding to each network slice.
  • the first access network device may receive first configuration information from the OAM, where the first configuration information may be used to indicate network slices supported by the first access network device and radio resources corresponding to each network slice.
  • This process can be implemented, for example, by performing step 301 above.
  • the first access network device may also receive other configuration information from the OAM or through the Xn interface from other access network devices with adjacent cell relationships, for example, receive second configuration information, where the second configuration information may be used to indicate the second configuration information.
  • step 401 can be implemented by executing steps 301 and 302 in the above method 300.
  • steps 301 and 302 please refer to the relevant descriptions of steps 301 and 302 above, which are not repeated here for brevity.
  • step 402 the AMF acquires configuration information of each access network device.
  • each access network device After each access network device establishes the N2 interface connection with the AMF, it can report the network slices that are supported by the device obtained in the above step 401 to the AMF.
  • each access network device may also report to the AMF the network slices supported by the access network device of the adjacent cell.
  • the first access network device may send the first configuration information to the AMF.
  • each access network device can also obtain the configuration item information of other access network devices from the OAM or from other access network devices through the Xn interface
  • the AMF can also obtain the configuration item information of multiple access network devices from an access network device. configuration information.
  • the first access network device may also report configuration information of other access network devices to the AMF.
  • the first access network device may send the second configuration information to the AMF.
  • the AMF can determine the network slices that can be accessed by the current tracking area or registration area of the terminal device according to the network slice information supported by each access network device and the network slices supported by the access network devices in adjacent cells.
  • the network slice that can be accessed by the tracking area or registration area where the terminal device is currently located may specifically refer to the network slice supported by the access network device in the tracking area or registration area where the terminal device is currently located.
  • the network slice supported by the first access network device indicated by the first configuration information and the radio resources corresponding to each network slice include: ⁇ S-NSSAI#2, (N41) ⁇ ;
  • the network slices supported by the access network equipment and the radio resources corresponding to each network slice include: ⁇ S-NSSAI#1, (N41, N79) ⁇ , ⁇ S-NSSAI#2, (N79) ⁇ and ⁇ S-NSSAI#3 , (N79) ⁇ .
  • the network slice supported by the first access network device includes the network slice identified as S-NSSAI#2
  • the network slice supported by the second access network device includes the network slice identified as S-NSSAI#1, S-NSSAI# 2 and network slices of S-NSSAI#3.
  • the AMF can determine that the network slices that the TA where the terminal device currently resides can support is the first access network device and the second access network device.
  • step 403 the terminal device sends to the AMF via the first access network device a message requesting to establish or request to activate the first session, where the message carries the identification information of the first session.
  • the identification information of the first session may be, for example, an identification of the first session or other information that can be used to identify the first session. This application does not limit this.
  • the identification information of the first session may be session 1, for example.
  • the message sent by the terminal device to the AMF for requesting to establish or request to activate the first session may be, for example, a registration request message.
  • the terminal device may request to establish an RRC connection with the first access network device, for example, send an RRC connection establishment request to the first access network device.
  • the terminal device may carry a registration request message to be forwarded to the AMF in the RRC connection establishment request.
  • the registration request message may further carry the identification information of the session requested by the terminal device to be established or activated.
  • the first access network device then forwards the registration request message to the AMF.
  • the registration request message also carries the identification information of the network slice (requested NSSAI) that the terminal device requests to access. #2, S-NSSAI#3, S-NSSAI#4, S-NSSAI#5 ⁇ network slice.
  • the registration request message also carries the identification information and status information of the session that the terminal device has established. That is to say, the terminal device may have established one or more sessions before initiating the above-mentioned RRC connection establishment, or in other words, before entering the RRC idle state last time, and the one or more sessions may be caused by the terminal device entering the RRC idle state is deactivated.
  • the session established by the terminal device is recorded as the second session.
  • the registration request message may also carry the identifier of the second session or other information that can be used to identify the second session.
  • the registration request message may further carry information used to indicate the state of the second session, so as to indicate that the second session is currently in a deactivated state.
  • step 404 the AMF obtains the identification information of the subscribed network slice of the terminal device from the UDM.
  • UDM can be used to store user data, such as subscription information, authentication/authorization information, and so on.
  • the AMF may acquire the subscription information of the terminal device from the UDM, where the subscription information includes the identification information of the network slice subscribed by the terminal device.
  • a possible situation is that the network slice requested by the terminal device belongs to the subscribed network slice, or in other words, the network slice requested by the terminal device is a subset of the subscribed network slice. Another possible situation is that some network slices previously subscribed by the terminal device may have expired, and the network slices requested by the terminal device do not belong to the subscribed network slices.
  • the network slices subscribed by the terminal device included in the subscription information include those identified as ⁇ S-NSSAI#1, S-NSSAI#2, S-NSSAI#3, S-NSSAI#4 ⁇ Network Slicing. That is, the network slice identified as S-NSSAI#5 may have expired and not belong to the subscribed network slice.
  • step 405 the AMF determines the network slice (allowed NSSAI) that the terminal device is allowed to access.
  • the AMF can determine the network slice that the terminal device is allowed to access according to the network slice requested by the terminal device, the network slice subscribed by the terminal device, and the network slice supported by the tracking area or registration area where the terminal device is located.
  • the network slice requested by the terminal device may be carried in the registration request message, the network slice subscribed by the terminal device may be obtained from UDM, and the network slice supported by the tracking area or registration area where the terminal device is located may be determined based on step 402 above.
  • the AMF can determine the network slice that the terminal device is allowed to access based on the above three items. In an implementation manner, the network slice that the terminal device is allowed to access may be determined by the intersection of the network slice requested by the terminal device, the network slice subscribed by the terminal device, and the network slice supported by the tracking area where the terminal device is located or registered.
  • the network slice requested by the terminal device includes the network slice identified by ⁇ S-NSSAI#1, S-NSSAI#2, S-NSSAI#3, S-NSSAI#4, S-NSSAI#5 ⁇
  • the network slices subscribed by the terminal equipment include the network slices identified as ⁇ S-NSSAI#1, S-NSSAI#2, S-NSSAI#3, S-NSSAI#4 ⁇ , and network slices supported by the tracking area or registration area where the terminal equipment is located Include network slices identified as ⁇ S-NSSAI#1, S-NSSAI#2, S-NSSAI#3 ⁇ . From this, it can be determined that the network slices that the terminal device is allowed to access include the network slices identified as ⁇ S-NSSAI#1, S-NSSAI#2, S-NSSAI#3 ⁇ .
  • step 405 may also be implemented by other network elements, such as implemented by the NSSF.
  • the AMF can send the acquired subscription information of the terminal device, the identification information of the network slice requested by the terminal device, and the identification information of the network slice supported by the tracking area or registration area where the terminal device is located determined in step 402 to the NSSF, and the NSSF to determine the network slices that the terminal device is allowed to access. After the NSSF determines the network slice that the terminal device is allowed to access, it can send the result to the AMF.
  • step 406 the AMF determines a session that is allowed to be established or a session that is allowed to be activated according to the network slice that the terminal device is allowed to access.
  • the session allowed to be established or the session allowed to be activated includes session 1 , session 2 and session 3 .
  • allowing the establishment and allowing the activation are for requesting establishment and requesting activation in step 403 above, respectively.
  • the AMF may determine the session allowed to be established in step 406; if the terminal device requests to activate the first session in step 403, the AMF may determine the session allowed to be activated in step 406.
  • the AMF may determine whether to allow establishment of the first session or whether to allow activation of the first session.
  • the first session is a session permitted to be established or activated, and the following steps may be continued.
  • the first session requested to be established or activated by the terminal device is session 4, the first session does not belong to the session permitted to be established or activated.
  • the AMF may not perform the following steps 407 to 410, but directly perform steps 411 and 412, and send the identification information of the network slice that the terminal device is allowed to access to the first access network device, so that the first access network device can determine this.
  • the first session is a session that is not allowed to be established or is not allowed to be activated.
  • the AMF sends a session management (session management, SM) context update request message or a session management context creation request message to the SMF.
  • session management session management, SM
  • the AMF may send a request message for creating a session management context to the SMF, so as to request the establishment of the first session.
  • the AMF may send a session management context update request message to the SMF, so as to request activation of the first session.
  • step 408 the SMF accepts the first session establishment request, or the SMF accepts the user plane activation request.
  • the SMF accepting the request for establishing the first session may be, for example, a step performed for a session establishment request message requesting to establish the first session.
  • Accepting the request for activation of the user plane by the SMF may be, for example, a step performed in response to a service request message requesting activation of the first session.
  • the SMF may re-select a new UPF because the current location of the terminal device has changed relative to the location when the first session was established.
  • step 409 the SMF establishes the N4 interface session and controls the UPF to establish the user plane connection of the first session; or, the SMF modifies the N4 interface session and controls the UPF to activate the user plane connection of the first session.
  • step 410 the SMF sends to the AMF a response message that the session management context is successfully created or a response message that the session management context is successfully updated.
  • the response message that the session management context is successfully created may be, for example, a response to a session establishment request message for requesting establishment of the first session.
  • the response message that the session management context is successfully updated may be, for example, a response to a service request message requesting to activate the first session.
  • step 411 the AMF sends, to the first access network device, the identification information of the network slice to which the terminal device is allowed to access.
  • the AMF may accept the registration of the terminal device based on the registration request message of the terminal device, and send to the first access network device a message for establishing the context of the terminal device, where the message may carry the identifier of the network slice to which the terminal device is allowed to access. information, session status, and session information to be activated.
  • the session state may include, for example, the states of all established sessions of the terminal device in cell #1.
  • the session of the terminal device in cell #1 may include, for example, a deactivated session and a to-be-activated session.
  • the session information to be activated may specifically refer to the identification information of the session that the terminal device requests to activate and the identification information of the corresponding network slice.
  • the identification information of the first session that the terminal device requests to activate and the identification information of the corresponding first network slice may specifically refer to the identification information of the session that the terminal device requests to activate and the identification information of the corresponding network slice.
  • the first access network device may determine the network slice to which the terminal device is allowed to access according to the identification information of the network slice to which the terminal device is allowed to access.
  • the identification information of the network slice to which the terminal device is allowed to access may be, for example, ⁇ S-NSSAI#1, S-NSSAI#2, S-NSSAI#3 ⁇ or other information that can be used to identify the network slice.
  • the message also carries a registration acceptance message to be sent to the terminal device.
  • the first access network device determines that the first radio resource of cell #1 does not support the first network slice corresponding to the first session.
  • the first access network device may determine the first network slice corresponding to the first session according to the session information to be activated. If the access-allowed network slice does not include the first network slice, the access network device may determine that the first session is a session that is not allowed to be established or a session that is not allowed to be activated. If the access-allowed network slice includes the first network slice, the first access network device may further determine whether the first radio resource supports the first network slice according to the network slice supported by cell #1.
  • the network slice supported by cell #1 does not include the network slice identified as S-NSSAI #1 (that is, the network slice corresponding to session 1, that is, an example of the first network slice), so the first wireless network slice The resource does not support the first network slice.
  • the first access network device determines the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • the frequency range corresponding to the first network slice may specifically refer to the frequency range supported by each adjacent cell supporting the first network slice, in other words, the frequency range corresponding to each adjacent cell of the first network slice.
  • the first access network device may first determine whether the first network slice belongs to a network slice that allows the terminal device to access. In the case that the first network slice belongs to a network slice that allows the terminal device to access, the first access network device may further determine the target frequency range according to the frequency ranges corresponding to the first network slice in each adjacent cell.
  • step 413 can also be replaced by: the first access network device determines the target according to the network slice that the terminal device is allowed to access, the first network slice, the network slice supported by at least one adjacent cell, and the frequency range corresponding to each network slice Frequency Range.
  • the neighboring cells of cell #1 may include cells that are co-sited with cell #1 and cells that are different sites from cell #1.
  • the adjacent cells of cell #1 may include in-site adjacent cells and out-of-station adjacent cells. Therefore, the network slices respectively supported by the at least one adjacent cell may be determined by the network slices supported by the first access network device and the network slices supported by the access network device having a relationship with adjacent cells.
  • the first access network device may preferentially select a cell in the same frequency range (ie, the first frequency range) as cell #1. Therefore, when there is a cell that supports the first network slice and the corresponding frequency range is the first frequency range in the adjacent cells, the first frequency range is preferentially selected as the target frequency range; otherwise, the first frequency range supported by the adjacent cell is selected.
  • the frequency range corresponding to a network slice is used as the target frequency range, for example, denoted as the second frequency range, and the second frequency range and the first frequency range are different frequency ranges. In other words, the target frequency range is given priority to the first frequency range, followed by the second frequency range.
  • the first network slice is a network slice identified as S-NSSAI#1, and the network slice belongs to a network slice that allows terminal equipment to access.
  • the first access network device does not support the network slice identified as S-NSSAI#1
  • the frequency range that the second access network device supports the network slice identified as S-NSSAI#1 includes the N41 frequency band and the N79 frequency band. While the first frequency range supported by cell #1 is the N41 frequency band, the first access network device can preferentially select the N41 frequency band as the target frequency range, and then select the N79 frequency band (ie, an example of the second frequency range) as the target frequency range.
  • the first access network device may use the network slice requested by the terminal device, the network slice that the terminal device can use according to the subscription, and the network slice supported by the tracking area or registration area where the terminal device is located. and the frequency range corresponding to the first network slice to determine the target frequency range.
  • the network slice that can be used according to the subscription of the terminal device may be sent by the core network device (eg, AMF) to the first access network device, for example.
  • the core network device eg, AMF
  • the network slice that the terminal device can use according to the subscription may refer to the network slice subscribed by the terminal device; when the terminal device is visiting the network, the network slice that the terminal device can use according to the subscription may refer to the network slice that the terminal device can use according to the subscription.
  • the network slice of the visited network corresponding to the subscribed network slice.
  • the above-mentioned network slices that allow terminal equipment to access are determined according to the network slices subscribed by the terminal equipment, the network slices requested by the terminal equipment, and the network slices supported by the tracking area or registration area where the terminal equipment is located, the above two implementations can be considered as is replaceable.
  • the first access network device determines the target cell according to the target frequency range.
  • the target frequency range may be the first frequency range or the second frequency range.
  • the first access network device may preferentially search for the target cell from neighboring cells in the station.
  • step 414 specifically includes: the first access network device determines the target cell from neighboring cells within the site that support the target frequency range.
  • the first access network device may first determine whether there is a cell that supports the target frequency range in the neighboring cells in the station, for example, denoted as the first cell. In the presence of the first cell, the first access network device may further determine whether the first cell supports the first network slice. If the first cell supports the first network slice, the first access network device may determine whether to determine the first cell as the target cell according to the signal quality of the first cell. For example, if the signal quality of the first cell satisfies the second preset threshold, the first cell is determined as the target cell.
  • the first access network device can determine the target cell in the neighboring cells outside the station.
  • step 414 specifically includes: the first access network device determines the target cell from neighboring cells outside the station that support the target frequency range.
  • step 414 may further include:
  • Step 4141 the first access network device determines wireless measurement parameters according to the target frequency range
  • Step 4142 the first access network device sends the wireless measurement parameter to the terminal device, where the wireless measurement parameter is used for the terminal device to measure the signal quality of the adjacent cell;
  • Step 4143 the terminal device reports the measurement result of the signal quality of the adjacent cell to the first access network device
  • Step 4144 the first access network device determines the target cell according to the measurement result of the signal quality of the adjacent cells.
  • the first access network device may first determine whether there is a first cell supporting the first frequency range in the adjacent cells outside the station. In the presence of the first cell, the first access network device may determine the wireless measurement parameter (ie, the first wireless measurement parameter) according to the first frequency range, and send the first wireless measurement parameter to the terminal device, so as to facilitate The terminal device measures the signal quality of the first cell based on the first frequency range. The first access network device may further determine whether the first cell can be used as the target cell based on the measurement result reported by the terminal device. For example, in the case that the signal quality of the first cell satisfies the second preset threshold, the first cell is determined as the target cell.
  • the wireless measurement parameter ie, the first wireless measurement parameter
  • the first access network device can further determine whether there are other optional frequency ranges, and continue to search for the target if there are other optional frequency ranges community.
  • the first access network device can search for the target cell based on the second frequency range.
  • the first access network device may first search for the target cell in the adjacent cells in the station, and secondly search for the target cell in the adjacent cells outside the station.
  • the specific process for the first access network device to search for the target cell in the adjacent cells in the station based on the second frequency range is the same as the specific process for the first access network device to search for the target cell in the adjacent cells in the station based on the first frequency range described above.
  • the process is the same. For the sake of brevity, details are not repeated here.
  • the specific process that the first access network device searches for the target cell in the neighboring cells outside the station based on the second frequency range can be implemented by executing steps 4141 to 4144.
  • steps 4141 to 4144 please refer to the above related steps about steps 4141 to 4144. describe.
  • the difference is that the first access network device can determine the wireless measurement parameter (ie, the second wireless measurement parameter) according to the second frequency range, and send the second wireless measurement parameter to the terminal device, so that the terminal device can determine the wireless measurement parameter based on the second frequency range.
  • the second frequency range measures the signal quality of neighboring cells.
  • the first access network device may further determine the target cell based on the measurement result reported by the terminal device.
  • the first access network device may When the target cell is determined among the neighboring cells, the above steps 4141 to 4144 are executed.
  • the wireless measurement parameter (the first wireless measurement parameter or the second wireless measurement parameter) sent by the first access network device to the terminal device may carry, for example, the forwarding mentioned in step 411 by the first access network device to the terminal device. in the Registration Accept message, or can be sent separately. This application does not limit this.
  • the first wireless measurement parameter and the second wireless measurement parameter may be sent separately based on different values of the target frequency range, or may be sent to the terminal device at the same time. This application does not limit this.
  • the process of determining the target cell by the first access network device is described in detail by taking the first session as an example.
  • the session that the terminal device requests to establish or activate from the first access network device is not necessarily limited to the first session.
  • the terminal device may request the first access network device to establish and/or request activation of multiple sessions in parallel.
  • the target cell determined by the first access network device for the terminal device should comprehensively consider the multiple sessions, so as to activate the multiple sessions. Therefore, when determining the target cell, the first access network device should, as far as possible, enable the network slices corresponding to the multiple sessions requested by the terminal device to be established and/or activated to be supported by the target cell, and all of them can be accessed respectively. Radio resources supported by the target cell.
  • the network slices supported by the above-mentioned terminal equipment include multiple sessions requested to be established and/or activated, and the multiple network slices can access the same radio resource in the cell, the priority is given to Select this cell as the target cell.
  • the session requested by the terminal device to be established and/or activated includes session 1 and session 3, it corresponds to the network slices identified as S-NSSAI#1 and S-NSSAI#3, respectively.
  • the network slices supported by the first access network device include S-NSSAI# If the network slice is 2, there is no cell that can support the network slices corresponding to session 1 and session 3 at the same time among the neighboring cells in the cell #1.
  • the network slices supported by the second access network device include network slices identified as S-NSSAI#1, S-NSSAI#2, and S-NSSAI#3, and the target can be found from the neighboring cells outside the cell #1. community.
  • the first access network device may further determine, according to the frequency range corresponding to each network slice supported by the second access network device, that the N79 frequency band can support the two network slices at the same time, so the N79 frequency band is the target frequency range.
  • the first access network device may search for a target cell from neighboring cells outside the cell of cell #1 based on the N79 frequency band.
  • the first access network device cannot find such a cell and can support multiple sessions that the terminal device requests to establish and/or request to activate, the first access network device The priority of the resource, select a cell that supports some sessions as the target cell; or, the first access network device can also select the cell that supports the network slice corresponding to the session with high priority according to the priorities of the multiple sessions as the target cell.
  • the terminal device requests to establish an RRC connection with the first access network device, one or more sessions may have been established, and the one or more sessions are in a deactivated state.
  • the terminal device may carry the one or more established session information when sending the RRC connection establishment request.
  • the first access network device may further combine the one or more established sessions, so as to be able to support the one or more established sessions as much as possible in the selected target cell. established session.
  • the session currently requested to be established or activated by the terminal device includes the first session, and the corresponding network slice is the first network slice; the session currently deactivated by the terminal device includes the second session, and the corresponding network slice is the second network slice.
  • the first access network device determines the target cell for the terminal device, a cell that can support the first network slice and the second network slice should be selected as the target cell as much as possible.
  • the first network slice corresponding to the first session currently requested to be established or activated may be prioritized, and the first network slice that can support the A cell of a network slice is used as the target cell.
  • step 415 the first access network device controls the terminal device to switch to the target cell.
  • the target cell determined by the first access network device for the terminal device may be a cell served by the first access network device, or may not be a cell served by the first access network device.
  • the terminal equipment may perform the intra-site handover procedure or the cross-site handover procedure. Since the intra-site handover process and the cross-site handover process have been described in detail in step 305 of the above method 300, for brevity, they are not repeated here.
  • step 416 the second access network device and the terminal device establish a DRB over the air interface for the successfully handed over session.
  • the successfully switched session may include, for example, the aforementioned first session, or may also include the aforementioned first session and second session. This application does not limit this.
  • step 417 the AMF switches the user plane path of the first session to the second access network device.
  • step 418 the AMF sends the N3 interface endpoint information to the second access network device.
  • step 419 the second access network device establishes a user plane connection with the core network, and activates the first session.
  • the user plane connection is the N3 interface connection between the second access network device and the UPF. Based on the establishment of the N3 interface connection between the second access network device and the UPF, the user plane of the first session is activated. Thereafter, the terminal device can send and receive service data through the activated first session.
  • FIG. 4 describes steps 415 to 419 by taking the terminal device performing cross-site handover as an example. However, this should not constitute any limitation to this application. In the intra-site handover process, the process involving cross-site handover in step 415 and steps 416 to 419 do not necessarily need to be executed.
  • the first access network device serving the source cell can A network slice, network slices supported by at least one adjacent cell, and radio resources corresponding to each network slice determine a target cell for the terminal device, and control the terminal device to switch to the target cell. Therefore, the terminal device can switch the terminal device to the target cell in a timely manner when the first session requesting to establish or request to activate is not supported by the radio resources of the source cell and there is a switchable target cell, so that the terminal device can respond in a timely manner
  • the session request of the device activates the first session in a short time, which is beneficial to improve the user experience.
  • FIG. 5 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 500 shown in FIG. 5 may include steps 501 to 515 .
  • the scenario of method 500 is first described as follows: the terminal device in method 500 has established one or more sessions in cell #1 served by the first access network device, but the one or more Part of the session may be in a deactivated state.
  • the terminal device and the first access network device each retain the context of these sessions and do not activate the user plane connection.
  • the present embodiment is described by taking the first session as an example of a session requesting activation or requesting establishment.
  • the network slice supported by the first access network device and the frequency range corresponding to each network slice include: ⁇ S-NSSAI#2, (N41) ⁇ , the cell #1 served by the first access network device
  • the supported frequency range is the N41 band.
  • the step 507 may correspond to the step 210 in the method 200, which shows a possible implementation manner in which the first access network device determines that the terminal device satisfies the cell handover condition in the step 210.
  • Steps 509 and 510 may correspond to step 220 in the method 200, and illustrate a possible implementation manner in which the first access network device determines the target cell in step 220.
  • the first access network device may determine the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • the first access network device may determine the target cell according to the target frequency range.
  • a possible implementation manner of step 510 is that the first access network device determines the target cell from neighboring cells within the station that support the target frequency range.
  • Another possible implementation of step 510 is to determine the target cell from neighboring cells outside the station that support the target frequency range.
  • the method further includes: the first access network device determines the wireless measurement parameter according to the target frequency range; A wireless measurement parameter is sent, where the wireless measurement parameter is used by the terminal device to measure the signal quality of the adjacent cell, and the measurement of the signal quality of the adjacent cell by the terminal device is used to determine the target cell.
  • Step 511 may correspond to step 230 in the method 200, and shows a possible implementation manner in which the first access network device controls the terminal device to switch to the target cell in step 230.
  • a possible implementation manner of step 511 is that the first access network device controls the terminal device to perform intra-site handover.
  • Another possible implementation manner of step 511 is that the first access network device controls the terminal device to perform cross-site handover.
  • the method further includes: the first access network device sends a request message to the second access network device, where the request message carries the identification information of the first session and the identification of the first network slice information; the first access network device receives the RRC parameter for handover from the second access network device; and the first access network device sends the RRC parameter to the terminal device.
  • the RRC parameter is associated with the first network slice, the network slice supported by the second access network device, and the radio resources corresponding to the network slice supported by the second access network device.
  • the method 500 will be described in detail below with reference to specific processes.
  • step 501 the terminal device sends a message requesting activation or requesting establishment of a first session to the AMF via the first access network device, where the message carries identification information of the first session requesting activation or requesting establishment.
  • the message is a service request message to request activation of the first session.
  • the terminal device may send an RRC connection establishment request message to the first access network device, where the RRC connection establishment request message carries a service request message to be sent to the AMF, and the service request message is used to request activation of the first session .
  • the service request message may carry the identification information of the first session.
  • the first access network device then forwards the service request message to the AMF.
  • the message is a session establishment request message to request the establishment of the first session.
  • the session establishment request message may also be carried in the RRC connection establishment request message to request establishment of the first session.
  • the session establishment request may also carry identification information of the first session.
  • the first access network device then forwards the session request message to the AMF.
  • step 502 the AMF sends a session management context update request message or a session management context creation request message to the SMF.
  • the session management context update request message sent by the AMF to the SMF is used to request activation of the first session.
  • the create session management context request message sent by the AMF to the SMF is used to request establishment of the first session.
  • step 503 the SMF accepts the user plane activation request or accepts the first session establishment request.
  • the SMF accepting the request for activation of the user plane may be, for example, a step performed in response to a service request message requesting to activate the first session.
  • Accepting the session establishment request by the SMF may be, for example, a step performed for a session establishment request message requesting establishment of the first session.
  • the SMF may re-select a new UPF because the current location of the terminal device has changed relative to the location when the first session was established.
  • step 504 the SMF modifies the N4 interface session and controls the UPF to activate the user plane connection of the first session; or, the SMF establishes the N4 interface session and controls the UPF to establish the user plane connection of the first session.
  • step 505 the SMF sends to the AMF a response message that the session management context is successfully updated or a response message that the session management context is successfully created.
  • the response message that the session management context is successfully updated may be, for example, a response to a service request message requesting to activate the first session.
  • the response message that the session management context is successfully created may be, for example, a response to the session establishment request message requesting establishment of the first session.
  • the AMF sends an N2 interface request message to the first access network device, where the N2 interface request message carries the identification information of the first network slice corresponding to the first session requested to be activated or requested to be established.
  • the first session requested to be activated by the terminal device is session 1, and its corresponding first network slice is the network slice identified as S-NSSAI#1; the first session requested by the terminal device to be established is session 2, and its corresponding first network slice is The network slice is the network slice identified as S-NSSAI#2.
  • the first access network device determines that the first radio resource of cell #1 does not support the first network slice corresponding to the first session.
  • the terminal device may continue to activate or establish the first session in the source cell according to the procedures of the prior art. Since this embodiment does not involve this process, it will not be described in detail here.
  • the first radio resource of cell #1 does not support the first network slice.
  • cell #1 is the source cell of the terminal device, and the first access network device needs to determine the target cell for the terminal device.
  • step 508 the first access network device suspends activating or establishing a user plane connection for the first session.
  • the terminal device Since the first access network device determines that the first radio resource of cell #1 does not support the first network slice corresponding to the first session, the terminal device needs to perform cell handover. Therefore, the first access network device may send indication information to the AMF for instructing the processing handover procedure, and suspend the activation or establishment of the user plane connection for the first session. After the AMF receives the indication information sent by the first access network device, it may retry to send the N2 interface request message in step 506 later to continue to activate or establish the user plane connection.
  • the first access network device determines the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • the neighboring cells of cell #1 may include cells that are co-sited with cell #1 and cells that are different sites from cell #1.
  • the adjacent cells of cell #1 may include in-site adjacent cells and out-of-station adjacent cells. Therefore, the network slices respectively supported by the at least one adjacent cell may be determined by the network slices supported by the first access network device and the network slices supported by the access network device having a relationship with adjacent cells. Therefore, the frequency range corresponding to the first network slice may specifically refer to the frequency range respectively supported by each adjacent cell supporting the first network slice.
  • step 509 can also be replaced with: the first access network device determines the target according to the network slice that the terminal device is allowed to access, the first network slice, the network slice supported by at least one adjacent cell, and the frequency range corresponding to each network slice Frequency Range.
  • step 509 can also be implemented by the following steps: the first access network device can use the network slice requested by the terminal device, the network slice that the terminal device can use according to the subscription, and the network slice supported by the tracking area or registration area where the terminal device is located, The first network slice and the frequency range corresponding to the first network slice determine the target frequency range. Since the network slices that can be used by the terminal device according to the subscription have been described in detail above, for brevity, they are not repeated here.
  • the first access network device may preferentially select a cell in the same frequency range (ie, the first frequency range) as cell #1. Therefore, when there is a cell that supports the first network slice and the corresponding frequency range is the first frequency range in the adjacent cells, the first frequency range is preferentially selected as the target frequency range; otherwise, the first frequency range supported by the adjacent cell is selected.
  • Other frequency ranges corresponding to a network slice are used as target frequency ranges, for example, denoted as a second frequency range, and the second frequency range and the first frequency range are different frequency ranges. In other words, the target frequency range is given priority to the first frequency range, followed by the second frequency range.
  • step 509 reference may be made to the relevant description of step 413 in the above method 400, which is not repeated here for brevity.
  • step 510 the first access network device determines the target cell according to the target frequency range.
  • step 511 the first access network device controls the terminal device to switch to the target cell.
  • step 512 the second access network device and the terminal device establish a DRB over the air interface for the successfully handed over session.
  • step 513 the AMF switches the user plane path of the first session to the second access network device.
  • step 514 the AMF sends N3 interface endpoint information to the second access network device.
  • the AMF may send the second request message that has not been sent in step 506 to the second access network device, and carry the N3 interface endpoint information in the second request message.
  • step 515 the second access network device establishes a user plane connection with the core network, and activates the user plane of the first session.
  • steps 510 to 515 are similar to the specific processes of steps 414 to 419 in the above method 400, and are not repeated here for brevity.
  • FIG. 5 describes steps 511 to 515 by taking the terminal device performing cross-site handover as an example. However, this should not constitute any limitation to this application. In the intra-site handover process, the process involving cross-site handover in step 511 and steps 512 to 515 do not necessarily need to be executed.
  • the process of determining the target cell by the first access network device is described in detail by taking the first session as an example.
  • the session that the terminal device requests to establish or activate from the first access network device is not necessarily limited to the first session.
  • the terminal device may request the first access network device to establish and/or request activation of multiple sessions in parallel.
  • the target cell determined by the first access network device for the terminal device should comprehensively consider the multiple sessions in order to activate the multiple sessions. Therefore, when determining the target cell, the first access network device should, as far as possible, enable the network slices corresponding to the multiple sessions requested by the terminal device to be established and/or activated to be supported by the target cell, and all of them can be accessed respectively. Radio resources supported by the target cell.
  • the network slices supported by the above-mentioned terminal equipment include multiple sessions requested to be established and/or activated, and the multiple network slices can access the same radio resource in the cell, the priority is given to Select this cell as the target cell.
  • the terminal device may have established one or more sessions, and the one or more sessions may include activated sessions and/or deactivated sessions.
  • the first access network device may further combine one or more established sessions, so as to be able to support as many sessions as possible in the selected target cell. the one or more established sessions.
  • the session currently requested to be established or activated by the terminal device includes the first session, and the corresponding network slice is the first network slice;
  • the session currently activated by the terminal device includes session #3 (an example of the second session), and the corresponding network slice is network slice #3;
  • the session currently deactivated by the terminal device includes session #4 (another example of the second session), and the corresponding network slice is network slice #4.
  • the first access network device determines the target cell for the terminal device, a cell that can support the first network slice, network slice #3 and network slice #4 should be selected as the target cell as much as possible.
  • the target cell may be selected according to the priority of the session, so that the selected target cell Able to support as many higher priority sessions as possible.
  • the first access network device serving the source cell can slice the first network according to the first session corresponding to the first session.
  • Network slices supported by at least one adjacent cell and radio resources corresponding to each network slice determine a target cell for the terminal device, and control the terminal device to switch to the target cell. Therefore, the terminal device can switch the terminal device to the target cell in time when the first session requesting to establish or request to activate is not supported by the radio resources of the source cell and there is a switchable target cell, so that the first session can be successfully activated. Session, timely response to the session request of the terminal device is beneficial to improve user experience.
  • FIG. 6 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 600 shown in FIG. 6 may include steps 601 to 612.
  • the terminal device and the first access network device are in an RRC connection state.
  • the terminal device is located in cell #1 served by the first access network device, and has established a session, for example, denoted as session 1, and its corresponding network slice is the network slice identified by S-NSSAI #1.
  • the terminal device wishes to establish a new session, or wishes to activate a session, for example denoted as session 3.
  • the network slice corresponding to session 3 is the network slice identified as S-NSSAI#3. It can be understood that session 3 is an example of the first session, and the network slice identified as S-NSSAI#3 is an example of the first network slice.
  • the step 602 may correspond to the step 210 in the method 200, which shows a possible implementation manner in which the first access network device determines that the terminal device satisfies the cell handover condition in the step 210.
  • Steps 603 and 609 may correspond to step 220 in the method 200, and illustrate a possible implementation manner in which the first access network device determines the target cell in step 220.
  • the first access network device may determine the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • the first access network device determines the target cell from neighboring cells within the site that support the target frequency range.
  • steps 606 to 609 the first access network device determines the target cell from neighboring cells outside the station that support the target frequency range.
  • Determining the target cell from the neighboring cells outside the station that supports the target frequency range may specifically include: Step 606, the first access network device determines the wireless measurement parameter according to the target frequency range; Step 607, the first access network device sends to the terminal device. wireless measurement parameters; step 608, the terminal device reports the measurement result of the signal quality of at least one adjacent cell to the first access network device; and step 609, the first access network device according to the signal quality of the at least one adjacent cell The measurement results determine the target cell.
  • Step 610 may correspond to step 230 in the method 200, and shows a possible implementation manner in which the first access network device controls the terminal device to switch to the target cell in step 230.
  • the first access network device controls the terminal device to perform intra-site handover.
  • the first access network device controls the terminal device to perform cross-site handover.
  • the method further includes: the first access network device sends a request message to the second access network device, where the request message carries the identification information of the first session and the identification of the first network slice information; the first access network device receives the RRC parameter for handover from the second access network device; and the first access network device sends the RRC parameter to the terminal device.
  • the RRC parameter is associated with the first network slice, the network slice supported by the second access network device, and the radio resources corresponding to the network slice supported by the second access network device.
  • the method 600 will be described in detail below with reference to specific processes.
  • step 601 the terminal device sends a message requesting to establish or request to activate the first session to the first access network device, and the message carries the identification information of the first network slice.
  • the message is a session establishment request message to request the establishment of the first session.
  • the terminal device may send a session establishment request message to the first access network device, where the session establishment request message may carry identification information of the first network slice.
  • the RRC layer of the request message carries the identification information of the first network slice.
  • the identification information of the first network slice may be S-NSSAI#3. Since the first network slice corresponds to the first session, the request message carries the identifier of the first network slice, that is, requests to establish a session or activate a session in the first network slice by accessing the first network slice.
  • the message is a session activation request message to request activation of the first session.
  • the terminal device may send a session activation request message to the first access network device, where the session activation request message may carry identification information of the first network slice.
  • the first access network device determines that the first radio resource of cell #1 does not support the first network slice corresponding to the first session.
  • the first access network device may determine whether the first radio resource supported by the cell #1 supports the first network slice according to the identification information of the first network slice.
  • the first access network device determines the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • the frequency range corresponding to the first network slice may specifically refer to the frequency range supported by each adjacent cell supporting the first network slice, in other words, the frequency range corresponding to each adjacent cell of the first network slice. Therefore, step 602 can be replaced by: the first access network device determines the target frequency according to the network slice that the terminal device is allowed to access, the first network slice, the network slice supported by at least one adjacent cell, and the frequency range corresponding to each network slice Scope.
  • the first access network device may receive, from the AMF, identification information of a network slice that the terminal device is allowed to access, and determine whether the first network slice belongs to a network slice that the terminal device is allowed to access. In the case that the first network slice belongs to a network slice that allows the terminal device to access, the first access network device may further determine the target frequency range according to the frequency ranges corresponding to the first network slice in each adjacent cell.
  • step 603 can also be replaced with: the network slice requested by the first access network device according to the terminal device, the network slice that the terminal device can use according to the subscription, and the network supported by the tracking area or registration area where the terminal device is located
  • the slice, the first network slice and the frequency range corresponding to the first network slice determine the target frequency range.
  • the first access network device determines the target cell from the neighboring cells in the site according to the target frequency range.
  • the first access network device may perform step 604 to determine whether there is a cell that can be used as the target cell in the neighboring cells in the station.
  • the first access network device may first determine whether there is a first cell supporting the target frequency range in the neighboring cells within the cell #1. In the presence of the first cell, the first access network device may further determine whether the first cell supports the first network slice. In the case that the first cell supports the first network slice, the first access network device may determine whether it can be used as the target cell according to the signal quality of the first cell. In the case that the signal quality of the first cell satisfies the second preset threshold, the first access network device determines that the first cell is the target cell. Thereafter, the intra-site handover process in step 610 may be performed.
  • the first access network device may determine that there is no cell that can be used as the target cell in the neighboring cells in the station.
  • the first access network device may send a reject message to the terminal device to suspend the establishment or activation of the first session.
  • the first access network device may send a rejection message to the terminal device to notify the terminal device that the first access network device refuses to establish or activate the first session.
  • the first access network device may send a rejection message for the service establishment request message to the terminal device, so as to reject the establishment of the first session.
  • the first access network device may send a rejection message for the session activation response message to know not to activate the first session.
  • step 606 the first access network device determines wireless measurement parameters according to the target frequency range.
  • step 607 the first access network device sends the wireless measurement parameter to the terminal device.
  • the wireless measurement parameter may be carried in the above rejection message to trigger the terminal device to measure the signal quality of at least one neighboring cell.
  • step 608 the terminal device measures the signal quality of the at least one adjacent cell based on the wireless measurement parameter, and reports the measurement result of the signal quality of the at least one adjacent cell to the first access network device.
  • the first access network device determines the target cell according to the measurement result of the signal quality of at least one neighboring cell.
  • the target cell thus determined by the first access network device is the target cell determined from the neighboring cells outside the station. Terminal equipment needs to switch access network equipment.
  • the first session requested by the terminal device to be established is session 3, and the first network slice is the network slice identified as S-NSSAI#3.
  • the network slice supported by the first access network device and the frequency range corresponding to each network slice include: ⁇ S-NSSAI#1, (N41) ⁇ and ⁇ S-NSSAI#2, (N41, N79) ⁇
  • the second access network The network slices supported by the network access device and the frequency ranges corresponding to each network slice include: ⁇ S-NSSAI#1, (N41, N79) ⁇ , ⁇ S-NSSAI#2, (N79) ⁇ and ⁇ S-NSSAI#3, (N79) ⁇ .
  • the identifier of the network slice supported by the first access network device does not include S-NSSAI#3, there is no cell that can support the network slice of session 3 in the neighboring cells of the cell #1.
  • the identifier of the network slice supported by the second access network device includes S-NSSAI#3, and a cell that can support the network slice of session 3 exists in the off-site adjacent cells of the cell #1.
  • the first access network device may search for the target cell from neighboring cells outside the cell #1.
  • the first access network device may further determine, according to the frequency range corresponding to the network slice, that the frequency range corresponding to the network slice identified as S-NSSAI#3 in the second access network device is the N79 frequency band, so the target frequency range is N79 frequency band. Thereafter, the first access network device may search for the target cell from neighboring cells outside the cell of cell #1 based on the N79 frequency band.
  • the target cell can provide the access service of the network slice identified as S-NSSAI#3 in the N79 frequency band.
  • the first access network device may determine the target frequency range in combination with the network slices corresponding to session 1 and session 3 respectively. For example, session 1 corresponds to the network slice identified as S-NSSAI#1, session 3 corresponds to the network slice identified as S-NSSAI#3, and the common frequency range corresponding to the second access network equipment is the N79 frequency band, then the target The frequency range is the N79 band. Thereafter, the first access network device may search for the target cell from neighboring cells outside the cell of cell #1 based on the N79 frequency band. The target cell can provide access services for network slices identified as S-NSSAI#1 and S-NSSAI#3 in the N79 frequency band.
  • the first access network device determines for the terminal device that the relevant content of the target cell is in The above method 400 and method 500 have also been described in detail, and for brevity, they will not be repeated here.
  • step 610 the first access network device controls the terminal device to switch to the target cell.
  • the first access network device may control the terminal device to perform an intra-site handover procedure, or may control the terminal device to perform an inter-site handover procedure, depending on whether the target cell is a cell served by the first access network device. It should be understood that since step 305 in the above method 300 has been described in detail in conjunction with the intra-site handover process and the cross-site handover process, and the specific process of the terminal device performing intra-site handover and cross-site handover can refer to the prior art, in order to Concise, not detailed here.
  • step 611 the terminal device sends a message requesting to establish or request to activate the first session to the second access network device, where the message carries the identification information of the first network slice corresponding to the first session.
  • the message sent by the terminal device to the second access network device is similar to the message sent by the terminal device to the first access network device in step 601 for requesting to establish or request to activate the first session, wherein the RRC layer carries the message of the first network slice. identification information.
  • the request message is used to request establishment or activation of the first session.
  • step 612 the terminal device initiates a session establishment process through the second access network device.
  • the terminal device can normally transmit service data through the first session.
  • step 612 does not necessarily need to be performed. For example, in the case of requesting to activate the first session, step 612 may be omitted. After the terminal device switches to the second access network device, the activation of the first session is completed.
  • the first access network device serving the source cell can slice the first network according to the first session corresponding to the first session. , Network slices supported by at least one adjacent cell and radio resources corresponding to each network slice, determine a target cell for the terminal device, and control the terminal device to switch to the target cell. Therefore, when the first session requested to be established is not supported by the radio resources of the source cell and there is a switchable target cell, the terminal device can switch the terminal device to the target cell in time, so that the first session can be successfully established and activated , to respond to the session request of the terminal device in time, which is beneficial to improve the user experience.
  • FIG. 7 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 700 shown in FIG. 7 may include steps 701 to 713 .
  • the applicable scenario of the method 700 is the same as the applicable scenario of the method 600, and the scenario introduced in the above method 600 can be referred to. For brevity, it will not be repeated here.
  • the difference is that in method 700, the terminal device requests to establish a first session.
  • the step 706 may correspond to the step 210 in the method 200, which shows a possible implementation manner in which the first access network device determines that the terminal device satisfies the cell handover condition in the step 210.
  • Steps 707 and 709 may correspond to step 220 in the method 200, and illustrate a possible implementation manner in which the first access network device determines the target cell in step 220.
  • the first access network device may determine the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • the first access network device determines the target cell according to the target frequency range.
  • a possible implementation manner of step 709 is that the first access network device determines the target cell from neighboring cells within the station that support the target frequency range.
  • Another possible implementation of step 709 is to determine the target cell from neighboring cells outside the station that support the target frequency range.
  • the method further includes: the first access network device determines the wireless measurement parameter according to the target frequency range; A wireless measurement parameter is sent, where the wireless measurement parameter is used by the terminal device to measure the signal quality of the adjacent cell, and the measurement of the signal quality of the adjacent cell by the terminal device is used to determine the target cell.
  • Step 710 may correspond to step 230 in the method 200, and shows a possible implementation manner in which the first access network device controls the terminal device to switch to the target cell in step 230.
  • a possible implementation manner of step 710 is that the first access network device controls the terminal device to perform intra-site handover.
  • Another possible implementation manner of step 710 is that the first access network device controls the terminal device to perform cross-site handover.
  • the method further includes: the first access network device sends a request message to the second access network device, where the request message carries the identification information of the first session and the identification of the first network slice information; the first access network device receives the RRC parameter for handover from the second access network device; and the first access network device sends the RRC parameter to the terminal device.
  • the RRC parameter is associated with the first network slice, the network slice supported by the second access network device, and the radio resources corresponding to the network slice supported by the second access network device.
  • the method 700 will be described in detail below with reference to specific processes.
  • step 701 the terminal device sends a message requesting establishment of the first session to the AMF via the first access network device, where the message carries the identification information of the first session.
  • the terminal device may carry the identification information of the first session, but not the identification information of the first network slice, in the message sent to the first access network device.
  • the first access network device may forward the session establishment request message to the AMF.
  • the identification information of the first session may be session 3, for example.
  • the message is a session establishment request message.
  • step 702 the AMF and the SMF create a session management context (SM context) for the first session that is requested to be established.
  • SM context session management context
  • the AMF may select the SMF and create a session management context for the first session with the selected SMF.
  • step 703 the SFM and the UPF establish an N4 interface session.
  • the SMF may select a UPF and send an N4 session establishment request to the selected UPF to request establishment of an N4 session.
  • step 704 the SMF sends the identification information of the first network slice to the AMF.
  • the SMF can send an N1N2 transfer message (N1N2 message transfer) to the AMF, which carries N2 session management information (N2 SM information).
  • N2 session management information includes the information of the newly created session, including the identification information of the first network slice corresponding to the first session.
  • the identification information of the first network slice may be S-NSSAI#3.
  • step 705 the AMF sends the identification information of the first network slice to the first access network device.
  • the AMF may forward the N2 session management information to the first access network device based on the received N2 session management information.
  • the N2 session management information carries the identification information of the first network slice.
  • the first access network device can determine the first network slice corresponding to the first session requested by the terminal device to be established.
  • the N2 session management information is carried in the N2 interface request message.
  • step 706 the first access network device determines that the first radio resource of the cell #1 where the terminal is currently located does not support the first network slice corresponding to the first session.
  • the first access network device may determine whether the first radio resource supported by the cell #1 supports the first network slice according to the identification information of the first network slice.
  • the first access network device determines the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the operating frequency corresponding to the first network slice.
  • step 707 can also be replaced with: the network slice requested by the first access network device according to the terminal device, the network slice that the terminal device can use according to the subscription, and the network supported by the tracking area or registration area where the terminal device is located
  • the slice, the first network slice and the frequency range corresponding to the first network slice determine the target frequency range. It should be understood that the specific process of determining the target frequency range by the first access network device has been described in detail in step 413 of the above method 400, and for the sake of brevity, it will not be repeated here.
  • the first access network device determines that the current operating frequency range of the terminal device is different from the target frequency range, and sends indication information for instructing the handover process to be processed to the AMF.
  • the frequency range in which the terminal device currently works refers to the frequency range corresponding to the first radio resource of the cell #1 where the terminal device is currently located, that is, the frequency range supported by the cell #1. If the current operating frequency range of the terminal device is inconsistent with the target frequency range, it can be determined that the terminal device needs to perform cell handover. Therefore, the first access network device may suspend allocating the DRB for the first session, and send the indication information for instructing the process of handover to the AMF. After receiving the indication information sent by the first access network device, the AMF may retry to send the N2 interface request message in step 705 later to continue establishing the user plane connection.
  • step 709 the first access network device determines the target cell according to the target frequency range.
  • step 709 specifically includes: the first access network device determines the target cell from neighboring cells within the site that support the target frequency range.
  • the first access network device may first determine whether there is a first cell supporting the target frequency range in the neighboring cells within the cell #1. In the presence of the first cell, the first access network device may further determine whether the first cell supports the first network slice. In the case that the first cell supports the first network slice, the first access network device may determine whether it can be used as the target cell according to the signal quality of the first cell. In the case that the signal quality of the first cell satisfies the second preset threshold, the first access network device determines that the first cell is the target cell. Thereafter, the intra-site handover process in step 714 may be performed.
  • step 709 specifically includes: the first access network device determines the target cell from neighboring cells outside the station that support the target frequency range.
  • the first access network device may determine that there is no cell that can be used as the target cell among the neighboring cells in the station. Accordingly, the first access network device can determine the target cell in the neighboring cells outside the station.
  • the first access network device determines for the terminal device that the relevant content of the target cell is in The above method 400 and method 500 have also been described in detail, and for brevity, they will not be repeated here.
  • step 710 the first access network device controls the terminal device to switch to the target cell.
  • the first access network device may control the terminal device to perform an intra-site handover procedure, or may control the terminal device to perform an inter-site handover procedure, depending on whether the target cell is a cell served by the first access network device. It should be understood that since step 305 in the above method 300 has been described in detail in conjunction with the intra-site handover process and the cross-site handover process, and the specific process of the terminal device performing intra-site handover and cross-site handover can refer to the prior art, in order to Concise, not detailed here.
  • step 711 the AMF performs path switching to switch the terminal device to the second access network device.
  • the second access network device may send a handover complete message to the AMF based on the completion of the air interface handover with the terminal device, or send a path switch message to the AMF.
  • the AMF may perform path switching based on a message from the second access network device.
  • step 712 the AMF resends the N2 interface request message in the step to the second access network device, and continues to establish a user plane connection for the newly created first session.
  • step 713 the second access network device allocates a DRB for the newly created first session in the frequency range supported by the target cell.
  • the frequency range supported by the target cell is the above-mentioned target frequency range.
  • the second access network device may allocate a DRB for the first session in the target frequency range. And can send a session establishment accept message to the terminal device.
  • the session establishment accept message may be carried in an access network specific resource setup (AN-specific resource setup) message.
  • AN-specific resource setup access network specific resource setup
  • the terminal device can transmit service data through the first session.
  • step 710 the steps involved in the cross-site handover process
  • steps 711 to 713 do not have to be performed.
  • the first access network device serving the source cell can slice the first network according to the first session corresponding to the first session. , Network slices supported by at least one adjacent cell and radio resources corresponding to each network slice, determine a target cell for the terminal device, and control the terminal device to switch to the target cell. Therefore, when the first session requested to be established is not supported by the radio resources of the source cell and there is a switchable target cell, the terminal device can switch the terminal device to the target cell in time, so that the first session can be successfully established and the target cell can be switched in time. Responding to the session request of the terminal device in a timely manner is beneficial to improve the user experience.
  • FIG. 8 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 800 shown in FIG. 8 may include steps 810 to 820 .
  • the first access network device determines that the first radio resource accessed by the terminal device in the source cell does not support the first network slice corresponding to the first session that the terminal device requests to establish or request to activate.
  • step 820 the first access network device sends an RRC connection release message to the terminal device to release the RRC connection with the terminal device.
  • step 810 the session that the terminal device requests to establish or activate in the source cell is recorded as the first session, and the network slice corresponding to the first session is recorded as the first network slice.
  • the first radio resource accessed by the terminal device in the source cell does not support the first network slice corresponding to the first session, which may specifically mean that the frequency range provided by the first radio resource does not support the first network slice, or the source The cell does not support the first network slice. Therefore, the frequency range provided by the source cell cannot provide access services for the first network slice corresponding to the first session that the terminal device requests to establish or request to activate.
  • a possible scenario is that the terminal device accesses the network after being powered on, or initiates a registration request to the network because it moves to a new TA that does not belong to the original registration area.
  • the terminal device when the terminal device periodically updates and registers with the network, it initiates a registration request to the network.
  • the terminal device may carry a list of sessions requested to be established or activated in the registration request.
  • the session list includes identification information of sessions requested by the terminal device to be established and/or activated.
  • the session requested by the terminal device to be established or activated may include, but is not limited to, the first session.
  • the terminal device may send a session establishment request message to the first access network device to request the establishment of one or more sessions.
  • the one or more sessions requested to be established by the terminal device may include, for example, but not limited to, the first session.
  • the first access network device determines that the first radio resource does not support the first network slice corresponding to the first session that the terminal device requests to establish or activate, it may determine that the terminal device is not suitable for continuing It is camped on cell #1, so step 220 can be executed to release the RRC connection release with the terminal device.
  • the terminal device enters an idle state based on the release of the RRC connection with the first access network device, and can then perform cell selection again to select an appropriate cell and initiate an RRC connection request.
  • the first access network device may actively release the communication with the terminal device in the case that the first radio resource accessed by the terminal device does not support the first network slice of the first session that requests establishment or activation.
  • RRC connection so that the terminal equipment can quickly enter the idle state and initiate cell reselection. It is not necessary to wait until the current business is completed before entering the idle state. Therefore, the terminal device can perform cell reselection in a timely manner when the first session requested to be established or activated is not supported by the radio resources of the source cell, so that the first session requested by the terminal device to be established or activated can be successfully activated, Therefore, the request of the terminal device can be responded to in time, which is beneficial to improve the user experience.
  • FIG. 9 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 900 shown in FIG. 9 may include steps 901 to 921 .
  • the applicable process of the method 900 is the same as the applicable scenario of the above method 400, and is not repeated here for brevity.
  • step 907 may correspond to step 810 in method 800
  • step 911 may correspond to step 820 in method 800
  • the RRC connection release message sent by the first access network device to the terminal device in step 911 may carry radio parameters used for cell reselection.
  • the method further includes: step 910, the first access network device determines the wireless parameter according to the target frequency range, the network slices supported by at least one adjacent cell, and the frequency range corresponding to each network slice .
  • step 901 the terminal device sends, to the AMF via the first access network device, identification information requesting to establish or request to activate the first session.
  • step 902 the AMF obtains the identification information of the network slice of the subscription information of the terminal device from the UDM.
  • step 903 the AMF determines the network slice that the terminal device is allowed to access.
  • step 904 the AMF determines a session that is allowed to be established or allowed to be activated according to the network slice that the terminal device is allowed to access.
  • step 905 the SMF establishes the N4 interface session and controls the UPF to establish the user plane connection of the first session; or, the SMF modifies the N4 interface session and controls the UPF to activate the user plane connection of the first session.
  • step 906 the AMF sends the identification information of the network slice to which the terminal device is allowed to access to the first access network device.
  • the first access network device determines that the first radio resource of the cell #1 where the terminal is currently located does not support the first network slice corresponding to the first session.
  • the first access network device determines the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the frequency range corresponding to the first network slice.
  • step 908 can also be implemented by the following steps: the first access network device can use the network slice requested by the terminal device, the network slice that the terminal device can use according to the subscription, and the network slice supported by the tracking area or registration area where the terminal device is located. , the first network slice and the frequency range corresponding to the first network slice to determine the target frequency range.
  • step 909 the first access network device determines that the frequency range in which the terminal device is currently working is different from the target frequency range.
  • the frequency range in which the terminal device is currently working is the frequency range supported by the cell #1 where the terminal device is currently located, or in other words, the frequency range corresponding to the first radio resource of the cell #1. If the current working frequency range of the terminal device is different from the target frequency range, it means that the first radio resource of the cell #1 does not support the first network slice.
  • the first access network device determines wireless parameters according to the target frequency range, the network slice of at least one adjacent cell, and the frequency range corresponding to each network slice.
  • the radio parameters can be used for cell reselection of the terminal equipment.
  • the wireless parameter may include an indication of a target frequency range, and the terminal device may preferentially reselect a cell supporting the target frequency range based on the indication.
  • step 911 the first access network device sends an RRC connection release message to the terminal device to release the RRC connection with the terminal device.
  • the first access network device decides to suspend the allocation of DRBs for the first session that the terminal device requests to establish or request to activate, and at the same time decides to release the RRC connection with the terminal device and deactivate the terminal All established sessions of the device.
  • the terminal device thus directly enters the idle state and performs cell reselection without waiting for the completion of the current service before entering the idle state.
  • the radio parameters determined by the first access network device in step 910 may be carried in the above-mentioned RRC connection release message. That is, step 910 may be performed before step 911 .
  • the wireless parameter may be delivered to the terminal device through other signaling. In this case, the order of execution of step 910 and step 911 is not limited.
  • the identification information of the first session that requests establishment or activation in step 901 may be carried in the registration request message sent by the terminal device to the AMF.
  • the identification information of the network slice to which the terminal device is allowed to access in step 906 may be carried in the registration accept message sent by the AMF to the first access network device.
  • the RRC connection release message in step 910 may be carried in the registration accept message forwarded by the first access network device to the terminal device.
  • step 912 the terminal device deactivates all sessions and enters an idle state.
  • the terminal device may access the idle state based on the RRC connection release message received in step 911 .
  • step 913 the terminal device performs cell reselection based on the radio parameters, so as to determine that the re-access network device is the second access network device.
  • the terminal device may perform cell reselection based on the radio parameters delivered by the first access network device.
  • the terminal device can first search for a suitable cell in the target frequency range based on the wireless parameters, and the cell can be understood as the target cell in the above embodiment, that is, the cell can provide the access service of the first network slice in the target frequency range, In other words, the radio resources provided by the cell support the first network slice.
  • the terminal device may determine the re-access network device based on the access network device to which the cell belongs.
  • the terminal device determines that the re-access network device is the second access network device based on the cell reselection.
  • step 914 the terminal device initiates an RRC connection to the second access network device, and sends a message requesting establishment or activation of the first session, where the message carries identification information of the first session requested to be established or activated.
  • the identification information of the first session that the terminal device requests to establish or activate may be carried in a service request (service request) message.
  • the terminal device may send an RRC connection request message to the second access network device, and carry a service request message in the RRC connection request message to request establishment or activation of the first session.
  • step 915 the second access network device sends a message requesting to establish or request to activate the first session to the AMF, where the message carries the identification information of the first session.
  • the second access network device may forward the above-mentioned message for requesting establishment or requesting activation to the AMF through the N2 interface message.
  • the second access network device may forward the service request message to the AMF.
  • step 916 the AMF sends a create session management context request message to the SMF, or the AMF sends a session management context update request message to the SMF.
  • the SMF accepts the first session establishment request, or the SMF accepts the user plane activation request.
  • the SMF may also re-select a new UPF because the terminal device is connected to a new access network device.
  • step 918 the SMF establishes the N4 interface session and controls the UPF to establish the user plane connection of the first session; or, the SMF modifies the N4 interface session and controls the UPF to activate the user plane connection of the first session.
  • step 919 the SMF sends a response message of successfully creating the session management context to the AMF, or the SMF sends a response message of successfully updating the session management context to the AMF.
  • step 920 the AMF sends an N2 interface request message to the second access network device, which carries information of the first session, and includes identification information of the first network slice corresponding to the first session.
  • the second access network device establishes a DRB for the terminal device in the target frequency range according to the first network slice corresponding to the first session, and connects to the user plane of the first session.
  • the terminal device may transmit service data through the first session.
  • the first access network device serving the source cell can directly release the communication between the terminal device and the source cell.
  • the terminal device can perform cell reselection in a timely manner when the first session requested to be established or activated is not supported by the radio resources of the source cell, so that the first session requested by the terminal device to be established or activated can be successfully activated, Therefore, the request of the terminal device can be responded to in time, which is beneficial to improve the user experience.
  • FIG. 10 is another schematic flowchart of a communication method provided by an embodiment of the present application.
  • the method 1000 shown in FIG. 10 may include steps 1001 to 1020 .
  • the applicable process of the method 1000 is the same as the applicable scenario of the above method 600, and is not repeated here for brevity.
  • step 1006 may correspond to step 810 in method 800
  • step 1010 may correspond to step 820 in method 800
  • the RRC connection release message sent by the first access network device to the terminal device in step 1010 may carry radio parameters used for cell reselection.
  • the method further includes: step 1009, the first access network device determines the wireless parameter according to the target frequency range, the network slices supported by at least one adjacent cell and the frequency range corresponding to each network slice .
  • step 1001 the terminal device sends to the AMF via the first access network device a message requesting to establish or request to activate the first session, where the message carries the identification information of the first session.
  • step 1002 the AMF and the SMF create a session management context for the first session that is requested to be established, or update the session management context.
  • step 1003 the SMF and the UPF establish an N4 interface session or modify an N4 interface session.
  • step 1004 the SMF sends the identification information of the first network slice to the AMF.
  • step 1005 the AMF sends the identification information of the first network slice to the first access network device.
  • step 1006 the first access network device determines that the first radio resource of the cell #1 where the terminal is currently located does not support the first network slice corresponding to the first session.
  • the first access network device determines the target frequency range according to the network slice to which the terminal device is allowed to access, the first network slice, and the operating frequency corresponding to the first network slice.
  • step 1007 can also be implemented by the following steps: the first access network device can use the network slice requested by the terminal device, the network slice that the terminal device can use according to the subscription, and the network slice supported by the tracking area or registration area where the terminal device is located. , the first network slice and the frequency range corresponding to the first network slice to determine the target frequency range.
  • step 1001 to step 1007 reference may be made to the relevant description of step 701 to step 707 in the above method 700, which is not repeated here for brevity.
  • step 1008 the first access network device determines that the current operating frequency range of the terminal device is different from the target frequency range.
  • the first access network device determines wireless parameters according to the network slice of at least one adjacent cell at the first frequency and the frequency range corresponding to each network slice.
  • the first access network device sends an RRC connection release message to the terminal device to release the RRC connection with the terminal device.
  • step 1011 the terminal device deactivates all sessions and enters an idle state.
  • step 1012 the terminal device performs cell reselection based on the radio parameters, so as to determine that the re-access network device is the second access network device.
  • step 1013 the terminal device initiates an RRC connection to the second access network device, and sends the identification information of the first session requested to be established.
  • step 1014 the second access network device sends the identification information of the first session to the AMF.
  • step 1015 the AMF sends a create session management context request message to the SMF, or the AMF sends a session management context update request message to the SMF.
  • the SMF accepts the first session establishment request, or the SMF accepts the user plane activation request.
  • the SMF may also re-select a new UPF because the terminal device is connected to a new access network device.
  • step 1017 the SMF establishes the N4 interface session and controls the UPF to establish the user plane connection of the first session; or, the SMF modifies the N4 interface session and controls the UPF to activate the user plane connection of the first session.
  • step 1018 the SMF sends a response message of successfully creating the session management context to the AMF, or the SMF sends a response message of successfully updating the session management context to the AMF.
  • step 1019 the AMF sends an N2 interface request message to the second access network device, which carries information of the first session, and includes identification information of the first network slice corresponding to the first session.
  • the second access network device establishes a DRB for the terminal device in the target frequency range according to the first network slice corresponding to the first session, and connects to the user plane of the first session.
  • the terminal device may transmit service data through the first session.
  • step 1008 to step 1020 reference may be made to the relevant description of step 909 to step 921 in the above method 900, and for brevity, it will not be repeated here.
  • the first access network device serving the source cell can directly release the communication between the terminal device and the source cell.
  • the terminal device can perform cell reselection in a timely manner when the first session requested to be established or activated is not supported by the radio resources of the source cell, so that the first session requested by the terminal device to be established can be successfully established and activated, thereby Being able to respond to the request of the terminal device in a timely manner is beneficial to improve the user experience.
  • each network element may perform some or all of the steps in each of the embodiments. These steps or operations are only examples, and the embodiments of the present application may also perform other operations or variations of various operations. In addition, various steps may be performed in different orders presented in various embodiments, and may not be required to perform all operations in the embodiments of the present application. Moreover, the size of the sequence number of each step does not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.
  • FIG. 11 is a schematic block diagram of a communication apparatus provided by an embodiment of the present application.
  • the communication apparatus 2000 may include a determination unit 2100 , a control unit 2200 and a transceiver unit 2300 .
  • the communication apparatus 2000 may correspond to the first access network device in the above method embodiments, for example, may be the first access network device, or a component (such as a first access network device) configured in the first access network device circuit, chip or system of chips, etc.).
  • the communication apparatus 2000 may correspond to the first access network device in the methods 200 to 1000 according to the embodiments of the present application, and the communication apparatus 2000 may include a method for performing the method 200 in FIG. 2 to the method in FIG. 10 Units of the method performed by the first access network device in 1000. Moreover, each unit in the communication apparatus 2000 and the other operations and/or functions mentioned above are respectively for realizing the corresponding processes of the method 200 in FIG. 2 to the method 1000 in FIG. 10 .
  • the transceiver unit 2300 in the communication apparatus 2000 may be implemented by a transceiver, for example, may correspond to the transceiver 3020 in the communication apparatus 3000 shown in FIG. 12 or RRU 4100 in base station 4000 shown in FIG. 13 .
  • the determination unit 2100 and the control unit 2200 in the communication device 2000 may be implemented by at least one processor, for example, may correspond to the processor 3010 in the communication device 3000 shown in FIG. 12 or the base station 4000 shown in FIG. 13 .
  • the transceiver unit 2300 in the communication apparatus 2000 may be implemented by an input/output interface, a circuit, and the like.
  • the determination unit 2100 and the control unit 2200 of the device can be implemented by a processor, a microprocessor or an integrated circuit integrated on the chip or chip system.
  • FIG. 12 is another schematic block diagram of a communication apparatus 3000 provided by an embodiment of the present application.
  • the communication device 3000 includes a processor 3010 , a transceiver 3020 and a memory 3030 .
  • the processor 3010, the transceiver 3020 and the memory 3030 communicate with each other through an internal connection path, the memory 3030 is used to store instructions, and the processor 3010 is used to execute the instructions stored in the memory 3030 to control the transceiver 3020 to send signals and / or receive signals.
  • the communication apparatus 3000 may correspond to the first access network device in the foregoing method embodiments, and may be used to execute various steps and/or processes performed by the first access network device in the foregoing method embodiments.
  • the memory 3030 may include read only memory and random access memory and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory.
  • the memory 3030 may be a separate device or may be integrated in the processor 3010 .
  • the processor 3010 may be configured to execute the instructions stored in the memory 3030, and when the processor 3010 executes the instructions stored in the memory, the processor 3010 is configured to execute the instructions corresponding to the first access network device in the foregoing method embodiments individual steps and/or processes.
  • the communication apparatus 3000 is the first access network device in the foregoing embodiment.
  • the transceiver 3020 may include a transmitter and a receiver.
  • the transceiver 3020 may further include antennas, and the number of the antennas may be one or more.
  • the processor 3010, the memory 3030 and the transceiver 3020 may be devices integrated on different chips.
  • the processor 3010 and the memory 3030 may be integrated in the baseband chip, and the transceiver 3020 may be integrated in the radio frequency chip.
  • the processor 3010, the memory 3030 and the transceiver 3020 may also be devices integrated on the same chip. This application does not limit this.
  • the communication apparatus 3000 is a component configured in the first access network device, such as a circuit, a chip, a chip system, and the like.
  • the transceiver 3020 may also be a communication interface, such as an input/output interface, a circuit, and the like.
  • the transceiver 3020, the processor 3010 and the memory 3030 can all be integrated in the same chip, such as a baseband chip.
  • FIG. 13 is a schematic structural diagram of a network device provided by an embodiment of the present application, which may be, for example, a schematic structural diagram of a base station.
  • the base station 4000 can be applied to the system as shown in FIG. 1 to perform the function of the first access network device in the foregoing method embodiment.
  • the base station 4000 may include one or more radio frequency units, such as a remote radio unit (RRU) 4100 and one or more baseband units (BBUs) (also referred to as distributed units (DUs). )) 4200.
  • the RRU 4100 may be called a transceiver unit, which may correspond to the transceiver unit 2300 in FIG. 11 or the transceiver 3020 in FIG. 12 .
  • the RRU 4100 may also be referred to as a transceiver, a transceiver circuit, or a transceiver, etc., which may include at least one antenna 4101 and a radio frequency unit 4102.
  • the RRU 4100 may include a receiving unit and a sending unit, the receiving unit may correspond to a receiver (or called a receiver, a receiving circuit), and the sending unit may correspond to a transmitter (or called a transmitter, a sending circuit).
  • the RRU 4100 part is mainly used for transmitting and receiving radio frequency signals and conversion of radio frequency signals and baseband signals, for example, for sending wireless measurement parameters and RRC connection release messages to terminal equipment.
  • the part of the BBU 4200 is mainly used to perform baseband processing and control the base station.
  • the RRU 4100 and the BBU 4200 may be physically set together, or may be physically separated, that is, a distributed base station.
  • the BBU 4200 is the control center of the base station, and can also be called a processing unit, which can correspond to the determination unit 2100 and the control unit 2200 in FIG. 11 or the processor 3010 in FIG. 12 , and is mainly used to complete baseband processing functions, such as channel Coding, multiplexing, modulation, spread spectrum, etc.
  • the BBU processing unit
  • the BBU may be used to control the base station to perform the operation procedures of the first access network device in the above method embodiments, such as determining a target frequency range, determining a target cell, and the like.
  • the BBU 4200 may be composed of one or more boards, and the multiple boards may jointly support a wireless access network (such as an LTE network) of a single access standard, or may respectively support a wireless access network of different access standards.
  • Wireless access network (such as LTE network, 5G network or other network).
  • the BBU 4200 also includes a memory 4201 and a processor 4202.
  • the memory 4201 is used to store necessary instructions and data.
  • the processor 4202 is configured to control the base station to perform necessary actions, for example, to control the base station to execute the operation flow of the network device in the foregoing method embodiments.
  • the memory 4201 and the processor 4202 may serve one or more single boards. That is to say, the memory and processor can be provided separately on each single board. It can also be that multiple boards share the same memory and processor. In addition, necessary circuits may also be provided on each single board.
  • the base station 4000 shown in FIG. 13 can implement each process involving the first access network device in the method embodiments shown in FIG. 2 to FIG. 10 .
  • the operations and/or functions of each module in the base station 4000 are respectively to implement the corresponding processes in the foregoing method embodiments.
  • the above-mentioned BBU 4200 may be used to perform the actions described in the foregoing method embodiments that are implemented internally by the first access network device, and the RRU 4100 may be used to perform the first access network equipment described in the foregoing method embodiments to send to the terminal device. or an action received from an end device.
  • the RRU 4100 may be used to perform the first access network equipment described in the foregoing method embodiments to send to the terminal device. or an action received from an end device.
  • the base station 4000 shown in FIG. 13 is only a possible form of the access network device, and should not constitute any limitation to the present application.
  • the method provided in this application may be applicable to other forms of access network equipment.
  • it includes AAU, may also include CU and/or DU, or includes BBU and adaptive radio unit (ARU), or BBU; may also be customer terminal equipment (customer premises equipment, CPE), may also be
  • AAU access network equipment
  • BBU adaptive radio unit
  • CPE customer premises equipment
  • the CU and/or DU may be used to perform the actions implemented by the access network device described in the foregoing method embodiments, and the AAU may be used to execute the access network device described in the foregoing method embodiments to send or Action received from the end device.
  • the AAU may be used to execute the access network device described in the foregoing method embodiments to send or Action received from the end device.
  • the present application further provides a processing apparatus, including at least one processor, where the at least one processor is configured to execute a computer program stored in a memory, so that the processing apparatus executes the first access network in any of the foregoing method embodiments The method performed by the device.
  • the embodiment of the present application also provides a processing apparatus, which includes a processor and a communication interface.
  • the communication interface is coupled to the processor.
  • the communication interface is used to input and/or output information.
  • the information includes at least one of instructions and data.
  • the processor is configured to execute a computer program, so that the processing apparatus executes the method executed by the first access network device in any of the foregoing method embodiments.
  • Embodiments of the present application further provide a processing apparatus, including a processor and a memory.
  • the memory is used to store a computer program
  • the processor is used to call and run the computer program from the memory, so that the processing apparatus executes the method executed by the first access network device in any of the foregoing method embodiments .
  • the above-mentioned processing device may be one or more chips.
  • the processing device may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), or a It is a central processing unit (CPU), a network processor (NP), a digital signal processing circuit (DSP), or a microcontroller (microcontroller unit). , MCU), it can also be a programmable logic device (PLD) or other integrated chips.
  • FPGA field programmable gate array
  • ASIC application specific integrated circuit
  • SoC system on chip
  • MCU microcontroller unit
  • MCU programmable logic device
  • PLD programmable logic device
  • each step of the above-mentioned method can be completed by a hardware integrated logic circuit in a processor or an instruction in the form of software.
  • the steps of the methods disclosed in conjunction with the embodiments of the present application may be directly embodied as executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.
  • the software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art.
  • the storage medium is located in the memory, and the processor reads the information in the memory, and completes the steps of the above method in combination with its hardware. To avoid repetition, detailed description is omitted here.
  • the processor in this embodiment of the present application may be an integrated circuit chip, which has a signal processing capability.
  • each step of the above method embodiments may be completed by a hardware integrated logic circuit in a processor or an instruction in the form of software.
  • the aforementioned processors may be general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components .
  • DSPs digital signal processors
  • ASICs application specific integrated circuits
  • FPGAs field programmable gate arrays
  • the methods, steps, and logic block diagrams disclosed in the embodiments of this application can be implemented or executed.
  • a general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
  • the steps of the method disclosed in conjunction with the embodiments of the present application may be directly embodied as executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor.
  • the software modules may be located in random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, registers and other storage media mature in the art.
  • the storage medium is located in the memory, and the processor reads the information in the memory, and completes the steps of the above method in combination with its hardware.
  • the memory in this embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory.
  • the non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically programmable Erase programmable read-only memory (electrically EPROM, EEPROM) or flash memory.
  • Volatile memory may be random access memory (RAM), which acts as an external cache.
  • RAM random access memory
  • DRAM dynamic random access memory
  • SDRAM synchronous DRAM
  • SDRAM double data rate synchronous dynamic random access memory
  • ESDRAM enhanced synchronous dynamic random access memory
  • SLDRAM synchronous link dynamic random access memory
  • direct rambus RAM direct rambus RAM
  • the present application further provides a computer program product, the computer program product includes: computer program code, when the computer program code is run on a computer, the computer is made to execute the steps shown in FIGS. 2 to 10 .
  • the present application further provides a computer-readable storage medium, where the computer-readable storage medium stores program codes, and when the program codes are run on a computer, the computer is made to execute FIGS. 2 to 2 .
  • the present application further provides a communication system, where the communication system includes, but is not limited to, one or more of the foregoing first access network devices and one or more of the foregoing terminal devices.
  • the communication system further includes one or more of the aforementioned second access network devices.
  • the communication apparatus or base station in each of the above apparatus embodiments completely corresponds to the first access network device in the method embodiments, and corresponding steps are performed by corresponding modules or units. Or the step of sending, other steps except sending and receiving may be performed by a processing unit (processor). For functions of specific units, reference may be made to corresponding method embodiments.
  • the number of processors may be one or more.
  • a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and/or a computer.
  • an application running on a computing device and the computing device may be components.
  • One or more components may reside within a process and/or thread of execution, and a component may be localized on one computer and/or distributed between 2 or more computers.
  • these components can execute from various computer readable media having various data structures stored thereon.
  • a component may, for example, be based on a signal having one or more data packets (eg, data from two components interacting with another component between a local system, a distributed system, and/or a network, such as the Internet interacting with other systems via signals) Communicate through local and/or remote processes.
  • data packets eg, data from two components interacting with another component between a local system, a distributed system, and/or a network, such as the Internet interacting with other systems via signals
  • the disclosed system, apparatus and method may be implemented in other manners.
  • the apparatus embodiments described above are only illustrative.
  • the division of the units is only a logical function division. In actual implementation, there may be other division methods.
  • multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented.
  • the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.
  • the functions, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium.
  • the technical solution of the present application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution.
  • the computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.
  • the aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

Abstract

本申请提供了一种通信方法和通信装置。该方法包括：第一接入网设备确定终端设备在源小区的信号质量低于预设门限；该第一接入网设备确定目标小区，并控制终端设备切换至该目标小区。或，第一接入网设备确定终端设备在源小区接入的第一无线资源不支持该终端设备请求建立或请求激活的第一会话对应的第一网络切片；该第一接入网设备确定目标小区，并控制终端设备切换至该目标小区；该目标小区的第二无线资源支持该第一网络切片。由此，当终端设备在源小区的信号质量不好，或源小区的第一无线资源不支持终端设备请求建立或请求激活的会话对应的网络切片时，第一接入网设备可以及时地为终端设备确定目标小区，提升用户体验。

Description

通信方法和通信装置
本申请要求于2020年7月31日提交中国专利局、申请号为202010762533.9、申请名称为“通信方法和通信装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及无线通信领域，并且更具体地，涉及通信方法和通信装置。
背景技术
目前，已知一种技术，终端设备可以基于核心网分配的无线接入技术频率选择优先权(radio access technology frequency selection priority，RFSP)索引来进行小区或频率重选。一个RFSP索引值可以关联到一组小区/频段驻留或重选的参数。在一种实现方式中，接入网设备可以根据授权的RFSP索引查询终端设备专有的小区/频率驻留或重选参数，然后下发给终端设备。终端设备进入空闲态后，便可以根据这些参数选择优先级高的频段接入。
然而，终端设备需要等到当前的业务进行完毕进入空闲态后，才会根据RFSP索引对应的无线参数进行小区/频段重选。终端设备在当前小区的信号质量不好，或者，请求建立或请求激活的会话相应的网络切片不被当前接入的小区的无线资源支持时，就不能及时切换到合适的小区，因此可能导致终端设备当前会话的通信质量下降，或者终端设备请求建立或请求激活的会话不能得到及时地响应，用户体验不好。
发明内容
本申请提供一种通信方法和通信装置，以期控制终端设备及时地切换到合适的小区，从而有利于短时间内提高终端设备的通信质量，或，及时响应终端设备请求建立或请求激活的会话，提高用户体验。
下文提供的第一方面至第三方面的方法例如可以由第一接入网设备执行，或者，也可以由配置在第一接入网设备中的部件(如电路、芯片或芯片系统等)执行。本申请对此不作限定。下文中仅为便于理解和说明，以第一接入网设备作为执行主体来描述本申请提供的方法。
第一方面，提供了一种通信方法，该方法包括：第一接入网设备确定终端设备在源小区的信号质量低于预设门限，该源小区是第一接入网设备服务的小区；该第一接入网设备根据与终端设备在源小区激活的第一会话对应的第一网络切片，以及源小区的至少一个相邻小区分别支持的网络切片，从该至少一个相邻小区中确定目标小区，该目标小区支持第一网络切片；第一接入网设备控制终端设备切换至目标小区。
基于上述技术方案，终端设备在源小区的信号质量不好时，服务于源小区的第一接入网设备可以根据终端设备在源小区激活的会话对应的网络切片、至少一个相邻小区分别支 持的网络切片以及各网络切片对应的频率范围，为终端设备确定目标小区，并控制终端设备切换至该目标小区。因此终端设备可以在信号质量不好且存在可切换的目标小区的情况下，及时地切换到信号质量较好的目标小区中，从而能够在通信质量不好的情况下及时地采取措施，而不必等到终端设备完成当前的业务后再进入空闲态进行小区重选。因此，终端设备的通信质量能够在短时间内得以提升，有利于提高用户体验。
为了获得较好的信号质量，第一接入网设备为终端设备确定的目标小区一方面支持第一网络切片，另一方面信号质量满足预设门限。
结合第一方面，在第一方面的某些可能的实现方式中，该目标小区是第一接入网设备服务的多个小区中除源小区之外的其他小区。
即，终端设备只要执行站内切换，便可切换到信号质量较好的目标小区。
结合第一方面，在第一方面的某些可能的实现方式中，该目标小区是第二接入网设备服务的小区。
这里，第二接入网设备与第一接入网设备是不同的接入网设备。也就是说，源小区与目标小区不同站。终端设备需要切换接入网设备。即，终端设备需要执行跨站切换。
若第一接入网设备服务的小区仅包括终端设备的源小区，或，第一接入网设备在站内相邻小区中未找到合适的小区可作为目标小区，则可以在站外相邻小区中寻找目标小区。应理解，若站外相邻小区为多个，该多个站外相邻小区可以是一个或多个接入网设备服务的小区。该一个或多个接入网设备包括第二接入网设备。
在一种实现方式中，第一接入网设备可以优先在第一接入网设备服务的相邻小区中寻找目标小区，其次在其他接入网设备服务的相邻小区中寻找目标小区，以避免接入网设备切换的复杂流程。
可选地，该方法还包括：第一接入网设备根据第一网络切片、上述至少一个相邻小区分别支持的网络切片以及所述支持的网络切片对应的无线资源，确定无线测量参数；该第一接入网设备向终端设备发送无线测量参数，该无线测量参数用于终端设备对相邻小区的信号质量的测量；其中，终端设备对相邻小区的信号质量的测量用于目标小区的确定。
若第一接入网要从其他接入网设备服务的相邻小区中寻找目标小区，可以进一步结合各站外相邻小区的信号质量来选择目标小区。故，第一接入网设备可以根据第一网络切片、相邻小区支持的网络切片以及各网络切片对应的无线资源，确定无线测量参数。终端设备可以基于该无线测量参数对相邻小区的信号质量进行测量，以便于第一接入网设备根据测量结果确定目标小区。
可选地，该方法还包括：第一接入网设备向第二接入网设备发送请求消息，该请求消息中携带第一会话的标识信息和第一网络切片的标识信息；第一接入网设备从第二接入网设备接收用于切换的无线资源控制(radio resource control，RRC)参数；第一接入网设备向终端设备发送该RRC参数。
第一接入网设备在为终端设备确定了目标小区之后，便可以向服务于目标小区的第二接入网设备发送请求消息，以请求获取用于切换的RRC参数。在一种可能的设计中，该请求消息是切换请求(handover request)消息。与之相应，第二接入网设备可以通过切换请求确认(handover request knowledgement，handover request ACK)消息向第一接入网设备发送RRC参数。该RRC参数可以携带在该切换请求确认消息中的RRC消息容器中， 以便于第一接入网设备将该RRC参数透传给终端设备。
第二方面，提供了一种通信方法，包括：第一接入网设备确定终端设备在源小区接入的第一无线资源不支持该终端设备请求建立或请求激活的第一会话对应的第一网络切片，源小区是该第一接入网设备服务的小区；第一接入网设备确定目标小区，该目标小区的第二无线资源支持第一网络切片；第一接入网设备控制该终端设备切换至该目标小区。
基于上述技术方案，终端设备在源小区请求建立或请求激活的第一会话不能够被源小区的无线资源支持时，服务于源小区的第一接入网设备可以根据该第一会话对应的第一网络切片、至少一个相邻小区各自支持的网络切片以及各网络切片对应的无线资源，为终端设备确定目标小区，并控制终端设备切换至该目标小区。因此，终端设备可以在请求建立或请求激活的第一会话不被源小区的无线资源支持且存在可切换的目标小区的情况下，及时地将终端设备切换至目标小区，而不必等到终端设备完成当前的业务后再进入空闲态进行小区重选。从而可以及时地响应终端设备的会话请求，在短时间内激活第一会话，有利于提高用户体验。
为了获得较好的信号质量，第一接入网设备为终端设备确定的目标小区一方面支持第一网络切片，另一方面信号质量满足预设门限。
可选地，该第二无线资源还支持该终端设备的第二会话对应的网络切片，该第二会话包括激活的会话或去激活的会话。
也就是说，该目标小区不仅支持第一网络切片，还支持其他网络切片，比如，激活的会话或去激活的会话对应的网络切片，从而避免激活的或去激活的会话因切换小区而发生业务中断，或因目标小区不支持而需要重新切换小区。
结合第二方面，在第二方面的某些可能的实现方式中，第一接入网设备确定目标小区，包括：第一接入网设备确定目标频率范围，并基于目标频率范围确定目标小区。
其中，目标频率范围是支持第一网络切片的频率范围。目标频率范围可以优先选择第一无线资源指示的目标频率范围，其次选择其他频率范围。
可选地，第一接入网设备确定目标频率范围，包括：第一接入网设备根据允许终端设备接入的网络切片、第一网络切片以及该第一网络切片对应的频率范围，确定目标频率范围。
应理解，允许终端设备接入的网络切片可以根据终端设备请求的网络切片、终端设备签约的网络切片以及终端设备所在跟踪区或注册区支持的网络切片来确定。终端设备签约的网络切片可以由接入和移动性管理网元从统一数据管理网元获取。因此，允许终端设备接入的网络切片可以由接入和移动性管理网元来确定，并通知第一接入网设备，以便于第一接入网设备确定目标频率范围。
可选地，第一接入网设备确定目标频率范围，包括，第一接入网设备根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片以及终端设备所在跟踪区或注册区支持的网络切片，第一网络切片以及第一网络切片的频率范围，确定目标频率范围。
其中，终端设备根据签约能够使用的网络切片例如可以是由核心网设备如接入和移动性管理网元通知第一接入网设备的。
当终端设备在归属网络时，终端设备根据签约能够使用的网络切片可以是指该终端设备签约的网络切片；当终端设备在拜访网络时，终端设备根据签约能够使用的网络切片可 以是指与终端设备签约的网络切片所对应的拜访网络的网络切片。
因此，上文列举的两种确定目标频率范围的实现方式是可替换的。
结合第二方面，在第二方面的某些可能的实现方式中，所述第一接入网设备确定目标小区，包括：第一接入网设备从支持目标频率范围的站内相邻小区中确定目标小区，所述站内相邻小区是第一接入网设备服务的多个小区中除源小区之外的其他小区。
可选地，所述第一接入网设备控制该终端设备切换至该目标小区，包括：第一接入网设备向该终端设备发送无线资源管理(radio resource management，RRM)配置消息，该RRM配置消息用于控制该终端设备切换至该目标小区。
即，第一接入网设备可以基于预先确定的目标频率范围在第一接入网设备服务的站内相邻小区中寻找目标小区。若第一接入网设备在站内相邻小区中找到了目标小区，终端设备只要执行站内切换，便可切换到支持第一网络切片的目标小区。
结合第二方面，在第二方面的某些可能的实现方式中，所述第一接入网设备确定目标小区，包括：第一接入网设备从支持目标频率范围的站外相邻小区中确目标小区，所述站外相邻小区是源小区的相邻小区中除第一接入网设备服务的小区之外的小区。
可选地，第一接入网设备从支持目标频率范围的站外相邻小区中确定目标小区具体包括：第一接入网设备确定所述源小区的站外相邻小区中是否存在支持目标频率范围的第一小区；第一接入网设备在存在第一小区的情况下，确定该第一小区是否支持第一网络切片；第一接入网设备在该第一小区支持第一网络切片的情况下，确定该第一小区为目标小区。
若第一接入网设备服务的小区仅包括终端设备的源小区，或，第一接入网设备在站内相邻小区中未找到合适的小区可作为目标小区，则第一接入网设备可以直接在站外相邻小区中寻找目标小区。应理解，若站外相邻小区为多个，该多个站外相邻小区可能是一个或多个接入网设备服务的小区。该一个或多个接入网设备包括第二接入网设备。
在一种实现方式中，第一接入网设备可以基于目标频率范围，优先在第一接入网设备服务的相邻小区中寻找目标小区，其次在其他接入网设备服务的相邻小区中寻找目标小区，以避免接入网设备切换的复杂流程。
此外，该目标频率范围可优先选择第一无线资源指示的频率范围。即，该第一接入网设备可以优先基于第一频率范围，先在第一接入网设备服务的相邻的小区中寻找目标小区，再在其他接入网设备服务的相邻小区中寻找目标小区；其次基于第二频率范围，先在第一接入网设备服务的相邻的小区中寻找目标小区，再在其他接入网设备服务的相邻小区中寻找目标小区。在上述过程的任意一个步骤中，只要第一接入网设备找到目标小区，便可以不再执行后续的寻找目标小区的步骤。
可选地，该方法还包括：第一接入网设备根据目标频率范围确定无线测量参数；第一接入网设备向终端设备发送该无线测量参数，该无线测量参数用于终端设备对相邻小区的信号质量的测量；终端设备对相邻小区的信号质量的测量用于目标小区的确定。
若第一接入网要从其他接入网设备服务的相邻小区中寻找目标小区，可以进一步结合各站外相邻小区的信号质量来选择目标小区。故，第一接入网设备可以根据第一网络切片、目标频率范围、至少一个相邻小区各自支持的网络切片以及各网络切片对应的无线资源，确定无线测量参数。终端设备可以基于该无线测量参数对相邻小区的信号质量进行测量，以便于第一接入网设备根据测量结果确定目标小区。
可选地，该方法还包括：第一接入网设备向服务目标小区的第二接入网设备发送请求消息，该请求消息中携带第一会话的标识信息和第一网络切片的标识信息；第一接入网设备从第二接入网设备接收用于切换的RRC参数；第一接入网设备向终端设备发送该RRC参数。
第一接入网设备在为终端设备确定了目标小区之后，便可以向服务于目标小区的第二接入网设备发送请求消息，以请求获取用于切换的RRC参数。在一种可能的设计中，该请求消息是切换请求消息。与之相应，第二接入网设备可以通过切换请求确认息向第一接入网设备发送RRC参数。该RRC参数可以携带在该切换请求确认消息中的RRC消息容器中，以便于第一接入网设备将该RRC参数透传给终端设备。
结合第一方面或第二方面，所述RRC参数与第一网络切片，第二接入网设备支持的网络切片及第二接入网设备支持的网络切片对应的无线资源关联。其中，第二接入网设备支持的网络切片指第二接入网设备服务的至少一个小区所支持的网络切片。
该RRC参数可以是由第二接入网设备根据待切入的第一会话对应的第一网络切片，第一网络切片在第二接入网设备服务的小区中对应的无线资源来确定，从而便于第二接入网设备确定将切换到哪个小区。
第三方面，提供了一种通信方法，包括：第一接入网设备确定终端设备在源小区接入的第一无线资源不支持终端设备请求建立或请求激活的第一会话的第一网络切片，源小区是第一接入网设备服务的小区；第一接入网设备向终端设备发送RRC连接释放消息，以释放与该终端设备的RRC连接。第一接入网设备释放与终端设备的RRC连接，当前激活的会话也随之去激活。
基于上述技术方案，第一接入网设备可以在终端设备接入的第一无线资源不支持请求建立或请求激活的第一会话的第一网络切片的情况下，主动释放与终端设备之间的RRC连接，从而使得终端设备可以快速地进入空闲态，发起小区重选。而不必等到当前的业务进行完毕后才进入空闲态。因此，终端设备可以在请求建立或请求激活的第一会话不被源小区的无线资源支持的情况下，及时地进行小区重选，而不必等到终端设备完成当前的业务后再进入空闲态进行小区重选。从而可以及时地响应终端设备的会话请求，在短时间内激活第一会话，有利于提高用户体验。
结合第三方面，在第三方面的某些可能的实现方式中，该方法还包括：第一接入网设备根据允许接入的网络切片，以及第一网络切片对应的频率范围，确定目标频率范围；或，第一接入网设备根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片，终端设备所在跟踪区或支持区支持的网络切片，第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围；第一接入网设备根据所述目标频率范围，以及至少一个相邻小区分别支持的网络切片以及所述支持的网络切片对应的无线资源，确定无线参数，该无线参数用于终端设备的小区重选；以及，第一接入网设备向终端设备发送该无线参数。
为了便于终端设备快速地找到合适的小区接入，第一接入网设备可以向终端设备发送无线参数，以便于终端设备基于该无线参数来进行小区重选，从而有利于终端设备快速地选择出重新接入的小区。
结合第二方面或第三方面，在某些可能的实现方式中，该方法还包括：第一接入网设备接收来自终端设备的请求建立或请求激活第一会话的消息。
其中，终端设备在源小区请求建立或请求激活第一会话可能发生在不同的场景下。
第一种可能的情况是，该终端设备可以是在开机后接入网络的终端设备，或者，也可以是因为移动到一个不属于原来注册区域的新跟踪区发起注册请求的终端设备，或者，还可以是周期性地向网络更新注册时的终端设备。
此情况下，第一接入网设备接收来自终端设备的请求建立或请求激活第一会话的消息，包括：第一接入网设备接收来自终端设备的注册请求消息，该注册请求消息中携带请求建立或请求激活的第一会话的标识信息。
第二种可能的情况是，该终端设备在第一接入网设备服务的源小区中已经建立了一个或多个会话，但该一个或多个会话处于去激活状态，终端设备和第一接入网设备各自保留了该一个或多个会话的上下文，该一个或多个会话的用户面连接未激活。或，终端设备期望在源小区建立一个或多个新的会话。
此情况下，第一接入网设备接收来自终端设备的请求建立或请求激活第一会话的消息，包括：第一接入网设备接收来自终端设备的会话请求消息，该会话请求消息中携带请求建立或请求激活的第一会话的标识信息。
第三种可能的情况是，该终端设备与第一接入网设备处于RRC连接态。终端设备在源小区中期望建立一个或多个新的会话，或激活一个或多个会话。
此情况下，第一接入网设备接收来自终端设备的请求建立或请求激活第一会话的消息，包括：第一接入网设备接收来自终端设备的会话建立请求消息，该会话建立请求消息中携带请求建立的第一会话的标识信息，或，该会话建立请求消息中携带第一会话对应的第一网络切片的标识信息；或者，第一接入网设备接收来自终端设备的会话激活请求消息，该会话激活请求消息中携带请求激活的第一会话的标识信息，或，该会话激活请求消息中携带第一会话对应的第一网络切片的标识信息。
应理解，上文列举的几种可能的情况仅为便于理解本申请实施例提供的方法而示例，不应对本申请构成任何限定。
第四方面，提供了一种通信装置，包括用于执行第一方面至第三方面任一种可能实现方式中的方法的各个模块或单元。
第五方面，提供了一种通信装置，包括处理器。该处理器与存储器耦合，可用于执行存储器中的指令或者数据，以实现上述第一方面至第三方面任一种可能实现方式中的方法。可选地，该通信装置还包括存储器。可选地，该通信装置还包括通信接口，处理器与通信接口耦合。
在一种实现方式中，该通信装置为接入网设备，如第一方面至第三方面中的第一接入网设备。当该通信装置为接入网设备时，所述通信接口可以是收发器，或，输入/输出接口。
在另一种实现方式中，该通信装置为配置于接入网设备中的芯片。该接入网设备例如可以是第一方面至第三方面中的第一接入网设备。当该通信装置为配置于接入网设备中的芯片时，所述通信接口可以是输入/输出接口。
可选地，所述收发器可以为收发电路。可选地，所述输入/输出接口可以为输入/输出电路。
第六方面，提供了一种处理器，包括：输入电路、输出电路和处理电路。所述处理电 路用于通过所述输入电路接收信号，并通过所述输出电路发射信号，使得所述处理器执行第一方面至第三方面中任一种可能实现方式中的方法。
在具体实现过程中，上述处理器可以为一个或多个芯片，输入电路可以为输入管脚，输出电路可以为输出管脚，处理电路可以为晶体管、门电路、触发器和各种逻辑电路等。输入电路所接收的输入的信号可以是由例如但不限于接收器接收并输入的，输出电路所输出的信号可以是例如但不限于输出给发射器并由发射器发射的，且输入电路和输出电路可以是同一电路，该电路在不同的时刻分别用作输入电路和输出电路。本申请实施例对处理器及各种电路的具体实现方式不做限定。
第七方面，提供了一种处理装置，包括处理器和存储器。该处理器用于读取存储器中存储的指令，并可通过接收器接收信号，通过发射器发射信号，以执行第一方面至第三方面任一种可能实现方式中的方法。
可选地，所述处理器为一个或多个，所述存储器为一个或多个。
可选地，所述存储器可以与所述处理器集成在一起，或者所述存储器与处理器分离设置。
在具体实现过程中，存储器可以为非瞬时性(non-transitory)存储器，例如只读存储器(read only memory，ROM)，其可以与处理器集成在同一块芯片上，也可以分别设置在不同的芯片上，本申请实施例对存储器的类型以及存储器与处理器的设置方式不做限定。
应理解，相关的数据交互过程例如发送指示信息可以为从处理器输出指示信息的过程，接收能力信息可以为处理器接收输入能力信息的过程。具体地，处理器输出的数据可以输出给发射器，处理器接收的输入数据可以来自接收器。其中，发射器和接收器可以统称为收发器。
上述第七方面中的处理装置可以是一个或多个芯片。该处理装置中的处理器可以通过硬件来实现也可以通过软件来实现。当通过硬件实现时，该处理器可以是逻辑电路、集成电路等；当通过软件来实现时，该处理器可以是一个通用处理器，通过读取存储器中存储的软件代码来实现，该存储器可以集成在处理器中，可以位于该处理器之外，独立存在。
第八方面，提供了一种计算机程序产品，所述计算机程序产品包括：计算机程序(也可以称为代码，或指令)，当所述计算机程序被运行时，使得计算机执行上述第一方面至第三方面中任一种可能实现方式中的方法。
第九方面，提供了一种计算机可读存储介质，所述计算机可读存储介质存储有计算机程序(也可以称为代码，或指令)当其在计算机上运行时，使得计算机执行上述第一方面至第三方面中任一种可能实现方式中的方法。
第十方面，提供了一种通信系统，包括前述的第一接入网设备和终端设备。可选地，该通信系统还包括前述的第二接入网设备。
附图说明
图1是适用于本申请实施例提供的方法的网络架构的示意图；
图2至图10是本申请实施例提供的通信方法的示意性流程图；
图11和图12是本申请实施例提供的通信装置的示意性框图；
图13是本申请实施例提供的接入网设备的结构示意图。
具体实施方式
下面将结合附图，对本申请中的技术方案进行描述。
本申请提供的技术方案可以应用于各种通信系统，例如：第五代(5th Generation，5G)移动通信系统或新无线接入技术(new radio access technology，NR)。其中，5G移动通信系统可以包括非独立组网(non-standalone，NSA)和/或独立组网(standalone，SA)。
本申请提供的技术方案还可以应用于机器类通信(machine type communication，MTC)、机器间通信长期演进技术(Long Term Evolution-machine，LTE-M)、设备到设备(device to device，D2D)网络、机器到机器(machine to machine，M2M)网络、物联网(internet of things，IoT)网络或者其他网络。其中，IoT网络例如可以包括车联网。其中，车联网系统中的通信方式统称为车到其他设备(vehicle to X，V2X，X可以代表任何事物)，例如，该V2X可以包括：车辆到车辆(vehicle to vehicle，V2V)通信，车辆与基础设施(vehicle to infrastructure，V2I)通信、车辆与行人之间的通信(vehicle to pedestrian，V2P)或车辆与网络(vehicle to network，V2N)通信等。
本申请提供的技术方案还可以应用于未来的通信系统，如第六代移动通信系统等。本申请对此不作限定。
图1是适用于本申请实施例提供的方法的网络架构的示意图。如图1所示，该网络架构例如是第三代合作伙伴计划(3rd Generation Partnership Project，3GPP)技术规范(technical specification，TS)23.501中定义的5G系统(the 5h generation system，5GS)。该网络架构可以分为接入网(access network，AN)和核心网(core network，CN)两部分。其中，接入网可用于实现无线接入有关的功能，核心网主要包括以下几个关键逻辑网元：接入和移动性管理网元、会话管理网元、用户面网元、策略控制网元和统一数据管理网元等。
下面对图1中示出的各网元做简单介绍：
1、用户设备(user equipment，UE)：可以称终端设备、接入终端、用户单元、用户站、移动站、移动台、远方站、远程终端、移动设备、用户终端、终端、无线通信设备、用户代理或用户装置。
终端设备可以是一种向用户提供语音/数据连通性的设备，例如，具有无线连接功能的手持式设备、车载设备等。目前，一些终端的举例可以为：手机(mobile phone)、平板电脑(pad)、带无线收发功能的电脑(如笔记本电脑、掌上电脑等)、移动互联网设备(mobile internet device，MID)、虚拟现实(virtual reality，VR)设备、增强现实(augmented reality，AR)设备、工业控制(industrial control)中的无线终端、无人驾驶(self driving)中的无线终端、远程医疗(remote medical)中的无线终端、智能电网(smart grid)中的无线终端、运输安全(transportation safety)中的无线终端、智慧城市(smart city)中的无线终端、智慧家庭(smart home)中的无线终端、蜂窝电话、无绳电话、会话启动协议(session initiation protocol，SIP)电话、无线本地环路(wireless local loop，WLL)站、个人数字助理(personal digital assistant，PDA)、具有无线通信功能的手持设备、计算设备或连接到无线调制解调器的其它处理设备、车载设备、可穿戴设备，5G网络中的终端设备或者 未来演进的公用陆地移动通信网络(public land mobile network，PLMN)中的终端设备等。
此外，终端设备还可以是物联网(Internet of things，IoT)系统中的终端设备。IoT是未来信息技术发展的重要组成部分，其主要技术特点是将物品通过通信技术与网络连接，从而实现人机互连，物物互连的智能化网络。IoT技术可以通过例如窄带(narrow band，NB)技术，做到海量连接，深度覆盖，终端省电。
此外，终端设备还可以包括智能打印机、火车探测器、加油站等传感器，主要功能包括收集数据(部分终端设备)、接收网络设备的控制信息与下行数据，并发送电磁波，向网络设备传输上行数据。
2、接入网(access network，AN)：接入网可以为特定区域的授权用户提供入网功能，并能够根据用户的级别、业务的需求等使用不同质量的传输隧道。接入网络可以为采用不同接入技术的接入网络。目前的无线接入技术有两种类型：3GPP接入技术(例如3G、4G或5G系统中采用的无线接入技术)和非3GPP(non-3GPP)接入技术。3GPP接入技术是指符合3GPP标准规范的接入技术，例如，5G系统中的接入网设备称为下一代基站节点(next generation Node Base station，gNB)。非3GPP接入技术是指不符合3GPP标准规范的接入技术，例如，以无线保真(wireless fidelity，WiFi)中的接入点(access point，AP)为代表的空口技术。
基于无线通信技术实现接入网络功能的接入网可以称为无线接入网(radio access network，RAN)。无线接入网能够管理无线资源，为终端设备提供接入服务，进而完成控制信号和用户数据在终端和核心网之间的转发。
无线接入网例如可以包括但不限于：无线网络控制器(radio network controller，RNC)、节点B(Node B，NB)、基站控制器(base station controller，BSC)、基站收发台(base transceiver station，BTS)、家庭基站(例如，home evolved NodeB，或home Node B，HNB)、基带单元(baseband unit，BBU)，WiFi系统中的AP、无线中继节点、无线回传节点、传输点(transmission point，TP)或者发送接收点(transmission and reception point，TRP)等，还可以为5G(如，NR)系统中的gNB或传输点(TRP或TP)，5G系统中的基站的一个或一组(包括多个天线面板)天线面板，或者，还可以为构成gNB或传输点的网络节点，如基带单元(BBU)，或，分布式单元(distributed unit，DU)，或者下一代通信6G系统中的基站等。本申请实施例对无线接入网设备所采用的具体技术和具体设备形态不做限定。
接入网可以为小区提供服务。终端设备可以通过接入网设备分配的传输资源(例如，频域资源，或者说，频谱资源)与小区通信。
3、接入和移动性管理网元：主要用于移动网络中的终端的注册、移动性管理、跟踪区更新流程，接入和移动性管理网元终结了非接入层(non access stratum，NAS)消息、完成注册管理、连接管理以及可达性管理、分配跟踪区列表(track area list，TA list)以及移动性管理等，并且透明路由会话管理(session management，SM)消息到会话管理网元。在5G通信系统中，接入和移动性管理网元可以是接入与移动性管理功能(access and mobility management function，AMF)。
4、会话管理网元：主要用于移动网络中的会话管理，如会话建立、修改、释放。具体功能如为终端分配互联网协议(internet protocol，IP)地址、选择提供报文转发功能的 用户面网元等。在5G通信系统中，会话管理网元可以是会话管理功能(session management function，SMF)。
5、用户面网元：主要负责对用户报文进行处理，如转发、计费、合法监听等。用户面网元也可以包括协议数据单元(protocol data unit，PDU)会话锚点(PDU session anchor，PSA)。在5G通信系统中，用户面网元可以是用户面功能(user plane function，UPF)。
6、数据网络(data network，DN)：可用于为终端设备提供数据传输服务。数据网络可以是公用数据网(public data network，PDN)网络，如因特网(Internet)等，也可以是本地接入数据网络(local access data network，LADN)，如移动边缘计算(mobile edge computing，MEC)节点的网络；还可以是第三方的业务网络、IP多媒体服务业务(IP multi-media service)网络等。
7、策略控制网元：用于指导网络行为的统一策略框架，为控制平面功能网元(例如AMF，SMF网元等)提供策略规则信息等。
包含用户签约数据管理功能、策略控制功能、计费策略控制功能、服务质量(quality of service，QoS)控制等。在5G通信系统中，策略控制网元可以是策略控制功能(policy control function，PCF)。
需要指出的是，实际网络中PCF还可能按照层次或按功能分为多个实体，例如全局PCF和切片内的PCF，或者会话管理PCF(session management PCF，SM-PCF)和接入管理PCF(access management PCF，AM-PCF)。
8、网络切片选择网元：主要用于为终端设备的业务选择合适的网络切片。在5G通信系统中，网络切片选择网元可以是网络切片选择功能(network slice selection function，NSSF)。
9、统一数据管理网元：用于存储用户数据，如签约信息、鉴权/授权信息等。在5G通信系统中，统一数据管理网元可以是统一数据管理(unified data management，UDM)。
在图1所示的网络架构中，各网元之间可以通过图中所示的接口通信。例如，终端设备与AMF可通过N1接口通信；RAN和AMF可通过N2接口通信，N2接口可用于非接入层(non-access stratum，NAS)消息的发送等；RAN和UPF可通过N3接口通信，N3接口可用于传输用户面的数据等；其中RAN连接核心网的接口(即N2接口和N3接口)总称为Ng接口；SMF和UPF可通过N4接口为SMF和UPF通信，N4接口可用于传输例如N3连接的隧道标识信息，数据缓存指示信息，以及下行数据通知消息等信息；UPF和DN可通过N6接口通信，N6接口可用于传输用户面的数据等。应理解，上述各网元与接口之间的通信关系仅为示例，不应对本申请构成任何限定。本申请并不排除在未来的协议中定义其他接口用于上述各网元之间的通信或其他网元之间的通信的可能。
应理解，上述应用于本申请实施例的网络架构仅是举例说明的从传统点到点的架构和服务化架构的角度描述的网络架构，适用本申请实施例的网络架构并不局限于此，任何能够实现上述各个网元的功能的网络架构都适用于本申请实施例。
还应理解，图1中所示的AMF、SMF、UPF、网络切片选择功能网元(network slice selection function，NSSF)、PCF、UDM可以理解为核心网中用于实现不同功能的网元，例如可以按需组合成网络切片。这些核心网网元可以是各自独立的设备，也可以集成于同一设备中实现不同的功能，本申请对于上述网元的具体形态不作限定。
还应理解，上述命名仅为便于区分不同的功能而定义，不应对本申请构成任何限定。本申请并不排除在5G网络以及未来其它的网络中采用其他命名的可能。例如，在6G网络中，上述各个网元中的部分或全部可以沿用5G中的术语，也可能采用其他名称等。图1中的各个网元之间的接口名称只是一个示例，具体实现中接口的名称可能为其他的名称，本申请对此不作具体限定。此外，上述各个网元之间的所传输的消息(或信令)的名称也仅仅是一个示例，对消息本身的功能不构成任何限定。
为便于理解本申请实施例，首先对本申请中涉及到的术语做简单说明。
1、会话(session)：可实现终端设备与DN之间的数据传输。在本申请实施例中，会话例如可以是协议数据单元(protocol data unit，PDU)会话(PDU session)。5G核心网(5G corenet，5GC)支持PDU连接业务。PDU连接业务可以是指终端设备与DN之间交换PDU数据包的业务。PDU连接业务通过终端设备发起PDU会话的建立来实现。一个PDU会话建立后，也就是建立了一条终端设备和DN的数据传输通道。每个终端设备可以建立一个或多个PDU会话。一个PDU会话可以通过一个PDU会话标识(PDU session identifier，PDU session ID)来标识。换言之，会话的标识信息的一种可能的形式是PDU会话标识。
应理解，PDU会话为会话的一种可能的形式，不应对本申请构成任何限定。
2、网络切片(network slicing，NS)：网络切片是提供特定网络能力的、端到端的逻辑专用网络。通过对网络资源的灵活分配、按需组网，可以在同一套物理设施上虚拟出多个具有不同特点且相互隔离的逻辑子网，来针对性地为用户提供服务。该逻辑子网即称为网络切片。网络切片可以由运营商使用，基于客户签订的服务等级协议(service level agreement，SLA)，为不同垂直行业、不同客户、不同业务，提供相互隔离、功能可定制的网络服务。不同的网络切片可以通过单网络切片选择辅助信息(single network slice selection assistance information，S-NSSAI)来标识和区分。
在网络切片的整个服务区域内往往有很多个接入网设备，如gNB。每个接入网设备都有一定的覆盖区域，可以是一个或多个小区(Cell)，每个小区有唯一的全球小区标识(cell global identifier，CGI)。整个网络切片的服务区域分成了若干个区域，即，一个或多个跟踪区(tracking area，TA)。TA可以使用跟踪区标识(tracking area identifier，TAI)来标识。TA由一个或多个小区组成。
3、小区(cell)：小区是高层从资源管理、移动性管理或服务单元的角度来描述的。每个接入网设备的覆盖范围可以被划分为一个或多个小区，且每个小区可以对应一个频率范围。每个小区可以在所对应的频率范围工作。频率范围可以是一个频点，也可以是一个频段。本申请对此不作限定。
需要说明的是，小区可以是接入网设备的无线网络的覆盖范围内的区域。在本申请实施例中，不同的小区可以对应相同或者不同的接入网设备。
例如，服务于小区#1的接入网设备和服务于小区#2的接入网设备可以是不同的接入网设备，如，基站。也就是说，小区#1和小区#2可以由不同的基站来管理。
又例如，服务于小区#1的接入网设备和服务于小区#2的接入网设备可以是同一个接入网设备，如，基站。也就是说，小区#1和小区#2可以由相同的基站来管理，这种情况下，可以称小区#1和小区#2共站。
其中，小区#1和小区#2共站的一种可能的情况是，服务于小区#1的接入网设备和服务于小区#2的接入网设备是同一基站的不同的射频处理单元，如，射频拉远单元(radio remote unit，RRU)，也就是说，小区#1和小区#2可以由同一基站管理，具有相同的基带处理单元和中频处理单元，但具有不同的射频处理单元。
源小区是终端设备在切换前驻留的小区，或者，进行小区重选前驻留的小区。本申请实施例中的源小区是第一接入网设备服务的小区。目标小区是第一接入网设备为终端设备确定的希望切换过去的小区。本申请实施例中的目标小区可能是第一接入网设备服务的小区，也可能是第二接入网服务的小区。
各接入网设备服务的小区可以为一个或多个。同一接入网设备服务的小区可以工作在不同的频率范围，也可以工作在相同的频率范围。
应理解，各小区所支持的无线资源并不仅限于频率范围，还可以包括时域资源、空域资源资源等，这里不一一列举说明。
4、切换(handover)：在无线通信系统中，当终端设备从一个小区向另一个小区移动/靠近时，为了保持终端设备的通信不中断，需要进行切换。在本申请实施例中，源小区表示切换前为终端设备提供服务的小区，目标小区表示切换后为终端设备提供服务的小区。
切换可以是站内切换或站间切换。站内切换，可以指源小区与目标小区属于同一个接入网设备(如gNB)；站间切换，指源小区与目标小区属于不同的接入网设备(如gNB)。本申请对此不做限定。
5、RRC连接：终端设备在正常通信之前，可以建立与网络设备之间的RRC连接，或者说，与小区之间的RRC连接。当RRC连接断开时，终端设备可以进入RRC空闲态，(也可简称空闲态)无法正常通信。
终端设备在处于RRC连接态时，终端设备可以通过当前已激活的会话传输数据，还可以请求建立会话、或请求激活会话。终端设备在处于RRC空闲态时，终端设备无法建立或激活会话，在RRC连接态激活的会话也被去激活。
6、站内相邻小区：由同一个接入网设备服务的相邻小区。比如下文中的小区#1和小区#2为站内相邻小区。
7、站外相邻小区：由不同接入网设备服务的相邻小区。比如下文中的小区#1和小区#4为站外相邻小区。
为了更好地理解本申请实施例，首先做出如下几点说明：
第一，为方便理解和说明，做出如下假设和定义：
小区#1：终端设备在切换前驻留的小区，或者，终端设备进行小区重选前驻留的小区。即上述源小区。
应理解，源小区和目标小区都是相对于某个终端设备而言的。比如，小区#1是本申请实施例中的终端设备的源小区，但同时也可能是其他终端设备的目标小区。
小区#2：与小区#1共站的小区，且小区#2是小区#1的相邻小区。由于小区#1和小区#2共站，可以称小区#2是小区#1的站内相邻小区。应理解，小区#1的站内相邻小区可以包括但不限于小区#2，例如还包括小区#3。
小区#3：小区#1的另一站内相邻小区。
小区#4：与小区#1不共站的小区，且小区#4是小区#1的相邻小区。由于小区#1和小区#4不共站，可以称小区#4是小区#1的站外相邻小区。应理解，小区#1的站外相邻小区可以包括但不限于小区#4。
第一接入网设备：服务于小区#1的接入网设备。第一接入网设备服务的小区可以仅包括小区#1，也可以包括小区#2，还可以包括除小区#1和小区#2之外的其他小区，如小区#3。
第二接入网设备：不同于第一接入网设备的接入网设备。第二接入网设备服务的小区可以仅包括小区#4，也可以包括除小区#4之外的其他小区。
应理解，第二接入网设备服务的小区与第一接入网设备服务的小区相邻，比如，第二接入网服务的小区中有一个或多个小区是小区#1的相邻小区。因此可以称第二接入网设备与第一接入网设备是具有相邻小区关系的接入网设备。但应理解，与第一接入网设备具有相邻小区关系的接入网设备并不一定仅限于第二接入网设备，本申请中仅为便于理解和说明，以第二接入网设备为例来说明。但这不应对本申请构成任何限定。
S-NSSAI#1：会话1相应的网络切片的标识。
S-NSSAI#2：会话2相应的网络切片的标识。
S-NSSAI#3：会话3相应的网络切片的标识。
目标频率范围：目标小区支持的频率范围。第一接入网设备优先选择源小区(如小区#1)支持的第一频率范围作为目标频率范围。
第一频率范围：源小区支持的频率范围，也即，源小区的第一无线资源所对应的频率范围。例如在本申请实施例中，第一频率范围为N41频段。
应理解，为便于区分和说明，本申请中通过上述不同的编号来区分不同的接入网设备、不同的小区、不同的网络切片和不同的会话。这些编号仅为示例，不应对本申请构成任何限定。且，本申请也并不限定gNB、小区、网络切片以及会话的标识的具体形式。
第二，在本申请中，涉及网元A向网元B发送消息或数据，以及网元B接收来自网元A的消息或数据的相关描述，旨在说明该消息或数据是要发给哪个网元，而并不限定它们之间是直接发送还是经由其他网元间接发送。
比如，文中所述的第一接入网设备向第二接入网是设备发送消息或数据包，并不限定第一接入网设备是直接向第二接入网设备发送消息或数据包。在Ng切换场景下，由于第一接入网设备与第二接入网设备之间不支持Xn接口的通信，故，第一接入网设备与第二接入网设备之间的通信可以通过AMF来转发。而在Xn切换场景下，由于第一接入网设备与第二接入网设备之间支持Xn接口的通信，故第一接入网设备与第二接入网设备之间可以直接交互，而无需AMF的转发。文中虽未一一罗列，但本领域的技术人员可以理解其含义。
第三，下文示出的多个流程图中，均以Xn接口切换为例来描述了各实施例。如果第一接入网设备和第二接入网设备之间没有Xn接口，就执行Ng接口切换。
此外，在没有Xn接口的情况下，OAM可以为各接入网设备发送配置信息，以指示各接入网设备服务的小区分别支持的网络切片以及各网络切片对应的频率范围，第一接入网设备和第二接入网设备之间可以不再通过Xn接口和对方交换各自支持的网络切片和各网络切片对应的频率范围。
另外，在没有Xn接口的情况下，第一接入网设备与第二接入网设备之间的交互可以通过AMF转发。其他流程基本相似，为了简洁，下文中不另附实施例说明。
第四，在本申请实施例中，“当……时”、“在……的情况下”、“若”以及“如果”等描述均指在某种客观情况下设备(如，终端设备或者网络设备)会做出相应的处理，并非是限定时间，且也不要求设备(如，终端设备或者网络设备)在实现时一定要有判断的动作，也不意味着存在其它限定。
第五，在下文示出的实施例中第一、第二以及各种数字编号仅为描述方便进行的区分，并不用来限制本申请实施例的范围。例如，区分不同的多播数据、不同的UE、不同的PDU会话等。
第六，“至少一个”是指一个或者多个，“多个”是指两个或两个以上。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B的情况，其中A，B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，a、b和c中的至少一项(个)，可以表示：a，或，b，或，c，或，a和b，或，a和c，或，b和c，或，a、b和c。其中a、b和c分别可以是单个，也可以是多个。
第七，下文多个实施例中列举了多个已有信令。应理解，这些信令的名称仅为便于理解而示例，不应对本申请构成任何限定。本申请并不排除在未来的协议中定义其他的信令名称来替代本申请中所列举的信令名称以实现相同或相似功能的可能。比如，“RRC连接释放消息”也可以是“RRC释放消息”等。为了简洁，这里不一一列举。
下面将结合附图详细说明本申请实施例提供的通信方法。
图2是本申请一实施例提供的通信方法200的示意性流程图。如图2所示，该方法200可以包括步骤210至230。下面对方法200中的各步骤做详细说明。
在步骤210中，第一接入网设备确定终端设备满足小区切换条件。
在步骤220中，第一接入网设备确定目标小区。
在步骤230中，第一接入网设备控制终端设备切换至目标小区。
第一接入网设备可以在终端设备满足小区切换条件的情况下，主动为终端设备寻找目标小区，并控制终端设备切换至该目标小区。而不依赖于终端设备进入空闲态后，发起小区重选，因此不必等到终端设备当前的业务进行完毕才切换小区。从而可以及时地将终端设备切换到合适的小区，使得终端设备的通信质量能够在短时间内得以提升，有利于提高用户体验。
可选地，步骤210中第一接入网设备确定终端设备满足小区切换条件，具体包括：第一接入网设备确定终端设备在源小区的信号质量低于预设门限。
其中，信号质量例如可以通过参考信号接收功率(reference signal receiving power，RSRP)或参考信号接收质量(reference signal receiving quality，RSRQ)等来评估。示例性地，可以根据终端设备接收到的某小区的参考信号(reference signal，RS)的RSRP或RSRQ来评估。应理解，RSRP、RSRQ等可以理解为用于评估信号质量的指标。
预设门限可以理解为用来判断信号质量好与差的一个门限值。用于评估的指标不同，所对应的门限值也不同。此外，预设门限可以是预定义的一个门限值。本申请对其具体取 值不作限定。为便于与后文的门限值区分，将用于判断终端设备在源小区的信号质量的门限记为第一预设门限。
一种可能的场景是，终端设备与第一接入网设备可以处于RRC连接态。终端设备在源小区可能已经建立了并激活了一个或多个会话。终端设备可通过激活的一个或多个会话进行数据传输。
若第一该接入网设备确定终端设备在源小区的信号质量低于该第一预设门限，则可确定该终端设备满足小区切换条件。第一接入网设备可以执行步骤220，确定目标小区，以及步骤230，控制终端设备切换至目标小区。
下文中结合图3描述的实施例示出了此场景下的通信方法的具体流程。
可选地，步骤210中第一接入网设备确定终端设备满足小区切换条件，具体包括：第一接入网设备确定源小区的第一无线资源不支持终端设备在源小区请求建立或请求激活的第一会话对应的第一网络切片。
其中，无线资源可以包括但不限于，频域资源、时域资源、空域资源、码域资源等。频域资源具体可以是指小区支持的频率范围。或者说，小区能够在所支持的频域范围内工作。
在本申请实施例中，为便于区分和说明，将源小区支持的无线资源记为第一无线资源，将终端设备在源小区请求建立或请求激活的会话记为第一会话，将第一会话对应的网络切片记为第一网络切片。第一无线资源不支持终端设备请求建立或请求激活的第一会话对应的第一网络切片，具体可以是指，该第一无线资源对应的频率范围不支持第一网络切片，或者说，源小区不支持第一网络切片。因此，源小区提供的频率范围不能为终端设备请求建立或请求激活的第一会话对应的第一网络切片提供接入服务。由于在通常情况下，每个小区可以在所对应的频率范围工作，或者说，每个小区可以在其对应的频率范围提供所支持的网络切片的接入服务，故，源小区的第一无线资源对应的频率范围不支持第一网络切片，也就是源小区不支持第一网络切片。
一种可能的场景是，终端设备在开机后接入网络，或因为移动到一个不属于原来注册区域的新TA，向网络发起注册请求。或者，终端设备周期性地向网络更新注册时，向网络发起注册请求。终端设备可能在注册请求中携带请求建立或请求激活的会话列表。该会话列表中包括终端设备请求建立和/或请求激活的会话的标识信息。该终端设备请求建立或请求激活的会话例如可以包括但不限于第一会话。下文中结合图4描述的实施例示出了此场景下的通信方法的具体流程。
另一种可能的场景是，终端设备由RRC空闲态转为RRC连接态时，期望将RRC空闲态去激活的会话激活用户面连接。终端设备在向第一接入网设备发起RRC连接请求时，可以携带请求激活的会话列表。该会话列表中可以包括终端设备请求激活的会话的标识信息。该请求激活的会话例如可以包括但不限于第一会话。下文中结合图5描述的实施例示出了此场景下的通信方法的具体流程。
还一种可能的场景是，终端设备期望建立新的会话。终端设备可以向第一接入网设备发送会话建立请求消息，以请求建立一个或多个会话。终端设备请求建立的一个或多个会话例如可以包括但不限于第一会话。下文中结合图6和图7描述的实施例示出了此场景下的通信方法的具体流程。
在上述多个可能场景的任一场景中，若第一接入网设备确定第一无线资源不支持终端设备请求建立或请求激活的第一会话对应的第一网络切片，则可确定该终端设备满足小区切换条件。第一接入网设备可以执行步骤220，确定目标小区，以及步骤230，控制终端设备切换至目标小区。
第一接入网设备为终端设备确定的目标小区可能是源小区的站内相邻小区，也可能是源小区的站外相邻小区，本申请对此不作限定。
在一种可能的实现方式中，第一接入网设备可以优先在站内相邻小区中寻找目标小区。若在站内相邻小区中可以找到目标小区，终端设备可以执行站内小区切换，而不需要切换接入网设备。若第一接入网设备在站内相邻小区中找不到合适的小区作为目标小区，则可以在站外相邻小区中寻找目标小区。若第一接入网设备在站外相邻小区中找到目标小区，终端设备可以执行跨站小区切换，终端设备此时需要切换接入网设备。这里假设终端设备切换到第二接入网设备，该第二接入网设备是服务目标小区的接入网设备。
在另一种可能的实现方式中，第一接入网设备确定其服务的小区仅包括小区#1，第一接入网设备直接从站外相邻小区中寻找目标小区。若第一接入网设备在站外相邻小区中找到目标小区，终端设备可以执行跨站小区切换，终端设备此时需要切换至第二接入网设备。
由于下文会结合图3至图7对本申请提供的通信方法应用于上述场景的具体过程展开描述，为了简洁，这里暂且不作详述。
图3是本申请实施例提供的通信方法的另一示意性流程图。图3所示的方法300可以包括步骤301至步骤307。
为便于理解本实施例，首先对方法300所适用的场景做如下说明：终端设备与第一接入网设备处于RRC连接态。终端设备在第一接入网设备服务的小区#1中，且终端设备在小区#1中存在激活的会话1，会话1对应的网络切片是标识为S-NSSAI#1的网络切片。第一接入网设备服务的小区还可包括小区#2，小区#2是小区#1的相邻小区。应理解，会话1是第一会话的一例，标识为S-NSSAI#1的网络切片是第一网络切片的一例。
在方法300中，步骤303可以对应于方法200中的步骤210，示出了步骤210中第一接入网设备确定终端设备满足小区切换条件的一种可能的实现方式。
步骤304可对应于方法200中的步骤220，示出了步骤220中第一接入网设备确定目标小区的可能的实现方式。在步骤304中，一种可能的情况是，目标小区是第一接入网设备服务的多个小区中除源小区之外的其他小区。即，第一接入网设备可以从站内相邻小区中确定目标小区。另一种可能的情况是，目标小区是第二接入网设备服务的小区。即，第一接入网设备可以从站外相邻小区中确定目标小区。在从站外相邻小区中确定目标小区的情况下，该方法还可以进一步包括：第一接入网设备根据第一网络切片、至少一个相邻小区分别支持的网络切片以及所述支持的网络切片对应的无线资源，确定无线测量参数；第一接入网设备向终端设备发送无线测量参数，该无线测量参数用于终端设备对相邻小区的信号质量的测量，终端设备对相邻小区的信号质量的测量用于目标小区的确定。
步骤305可对应于方法200中的步骤230，示出了步骤230中第一接入网设备控制终端设备切换至目标小区的可能的实现方式。与步骤304对应，步骤305的一种可能的实现方式是，第一接入网设备控制终端设备进行站内切换。步骤305的另一种可能的实现方式是，第一接入网设备控制终端设备进行跨站切换。在跨站切换的情况下，该方法还可以进 一步包括：步骤3051，第一接入网设备向第二接入网设备发送请求消息，该请求消息中携带第一会话的标识信息和第一网络切片的标识信息；步骤3052，第二接入网设备根据待切入的会话的信息，确定RRC参数；步骤3053，第一接入网设备从第二接入网设备接收用于切换的RRC参数；步骤3054，第一接入网设备向终端设备发送该RRC参数；以及步骤3055，终端设备根据RRC参数，接入第二接入网设备的无线资源。可选地，该RRC参数与第一网络切片、第二接入网设备支持的网络切片以及第二接入网设备支持的网络切片对应的无线资源关联。
下面结合具体的流程来对方法300做详细说明。
在步骤301中，第一接入网设备从OAM接收第一配置信息，该第一配置信息用于指示第一接入网设备支持的网络切片以及各网络切片对应的无线资源。
示例性地，在网络切片规划和部署过程中，管理面(operation，administration and maintenance，OAM)实体(以下简称OAM)可以向各接入网设备发送配置信息。OAM向各接入网设备发送的配置信息可分别用于指示各接入网设备各自支持的网络切片以及所述支持的网络切片对应的无线资源。OAM向第一接入网设备发送的配置信息可以记为第一配置信息。由于无线资源包括频域资源，故，网络切片对应的无线资源包括网络切片对应的频率范围。
应理解，第一接入网设备基于第一配置信息可以为各小区配置分别支持的网络切片以及频率范围。由此可以确定各小区支持的网络切片以及各网络切片对应的频率范围。还应理解，第一接入网设备服务的小区为多个时，各小区支持的网络切片以及各网络切片对应的频率范围并不一定是相同的。如前所述，每个小区可对应于一个频率范围。或者说，每个小区在它所支持的频率范围工作。
一示例，第一配置信息可以包括：{S-NSSAI#1，(N41)}和{S-NSSAI#2，(N41)}，表示该第一接入网设备支持在N41频段提供标识为S-NSSAI#1和S-NSSAI#2的网络切片的接入服务。
假设第一接入网设备服务的小区包括小区#1和小区#2。第一接入网设备可以为各小区配置支持的网络切片和频率范围如下：小区#1支持的网络切片例如可以包括标识为S-NSSAI#1的网络切片，该网络切片对应的频率范围为N41频段。小区#2支持的网络切片例如可以包括标识为S-NSSAI#1和S-NSSAI#2的网络切片，该两个网络切片对应的频率范围为N41频段。
另一示例，第一配置信息可以包括：{S-NSSAI#1，(N41)}和{S-NSSAI#2，(N41，N79)}，表示该第一接入网设备支持在N41频段提供标识为S-NSSAI#1和S-NSSAI#2的网络切片的接入服务，并支持在N79频段提供标识为S-NSSAI#2的网络切片的接入服务。
假设第一接入网设备服务的小区包括小区#1和小区#2。第一接入网设备可以为各小区配置支持的网络切片和频率范围如下：小区#1支持的网络切片例如可以包括标识为S-NSSAI#1和S-NSSAI#2的网络切片，该网络切片对应的频率范围为N41频段。小区#2支持的网络切片例如可以包括标识为S-NSSAI#2的网络切片，该网络切片对应的频率范围为N79频段。
再一示例，第一配置信息可以包括：{S-NSSAI#1，(N41，N79)}和{S-NSSAI#2，(N41)}，表示该第一接入网设备支持在N41频段提供标识为S-NSSAI#1和S-NSSAI#2 的网络切片的接入服务，并支持在N79频段提供标识为S-NSSAI#1的网络切片的接入服务。
假设第一接入网设备服务的小区包括小区#1、小区#2和小区#3。第一接入网设备可以为各小区配置支持的网络切片和频率范围如下：小区#1支持的网络切片例如可以包括标识为S-NSSAI#1的网络切片，该网络切片对应的频率范围为N41频段。小区#2支持的网络切片例如可以包括标识为S-NSSAI#1和S-NSSAI#2的网络切片，该两个网络切片对应的频率范围为N41频段。小区#3支持的网络切片例如可以包括标识为S-NSSAI#1的网络切片，小区#3支持的频率范围为N79频段。
应理解，网络切片在不同小区对应的频率范围不一定相同，这与各小区支持的频率范围有关。
还应理解，上文列举的各小区支持的网络切片以及各网络切片对应的频率范围、各小区支持的频率范围仅为示例，不应对本申请构成任何限定。本申请对于各小区支持的网络切片、各网络切片对应的频率范围以及各小区支持的频率范围均不作限定。
需要说明的是，运营商在进行网络规划时，为了尽可能地保证终端设备的切换是同频切换，工作在同一个频率范围的多个小区往往都可以支持相同的网络切片。比如，小区#1和小区#2都支持在N41频段工作，小区#1和小区#2都支持标识为S-NSSAI#1的网络切片。
下文中为方便理解和说明，假设第一配置信息可以包括：{S-NSSAI#1，(N41，N79)}和{S-NSSAI#2，(N41)}。第一接入网设备服务的小区包括小区#1、小区#2和小区#3。第一接入网设备可以为各小区配置支持的网络切片和频率范围如下：小区#1支持的网络切片例如可以包括标识为S-NSSAI#1的网络切片，该网络切片对应的频率范围为N41频段。小区#2支持的网络切片例如可以包括标识为S-NSSAI#1和S-NSSAI#2的网络切片，该两个网络切片对应的频率范围为N41频段。小区#3支持的网络切片例如可以包括标识为S-NSSAI#1的网络切片，小区#3支持的频率范围为N79频段。
在步骤302中，第一接入网设备获取第二接入网设备的第二配置信息，该第二配置信息用于指示第二接入网设备支持的网络切片以及各网络切片对应的无线资源。
在一种实现方式中，第一接入网设备可以从第二接入网设备接收第二配置信息。例如，第一接入网设备可以通过Xn接口获取第二配置信息。例如，若上述第一接入网设备和第二接入网设备可通过Xn接口通信，则第一接入网设备可以通过Xn接口获取该第二配置信息。或者，该第二接入网设备也可以通过上文步骤301中所述的方法，从OAM接收第二配置信息。
一示例，OAM向第二接入网设备发送的第二配置信息可以包括：{S-NSSAI#1，(N41，N79)}、{S-NSSAI#2，(N79)}和{S-NSSAI#3，(N79)}，表示该第二接入网设备支持在N41频段提供标识为S-NSSAI#1的网络切片的接入服务，并支持在N79频段提供标识为S-NSSAI#1、S-NSSAI#2和S-NSSAI#3的网络切片的接入服务。
图3中的步骤302示出了第二接入网设备从OAM接收第二配置信息，第一接入网设备从第二接入网设备接收第二配置信息的实现方式。
应理解，第一接入网设备从第二接入网设备接收到的第二配置信息可以与第二接入网设备从OAM接收到的第二配置信息相同，也可以不同，例如可以是经第二接入网设备的 处理后发送给第一接入网设备的。
在另一种实现方式中，第一接入网设备可以从OAM接收第二配置信息。例如，OAM可以通过同一信令向第一接入网设备发送第一配置信息和第二配置信息。当然，OAM还可以通过同一信令向第一接入网设备发送其他接入网设备的配置信息，所述其他接入网设备可以是指与第一接入网设备具有相邻小区关系的接入网设备。
需要说明的是，步骤302是可选步骤。当第一接入网设备在后续步骤中确定的目标小区为站内相邻小区时，第一接入网设备实际上没有使用到通过步骤302获取到的信息。
在步骤303中，第一接入网设备确定终端设备在小区#1的信号质量低于第一预设门限。
终端设备在小区#1已经建立了第一会话，且该第一会话的用户面连接已激活。该第一会话对应的第一网络切片的标识为S-NSSAI#1。第一接入网设备保存的该终端设备的上下文(context)中包括该第一会话的信息。
应理解，终端设备在小区#1中已经建立并激活的会话并不一定仅限于第一会话，也可能已经建立并激活了多个会话。为便于理解和说明，这里以第一会话为例来说明本申请提供的方法流程。
第一接入网设备可以根据终端设备对小区#1的信号质量的测量，确定终端设备在小区#1的信号质量是否低于第一预设门限。若终端设备在小区#1的信号质量低于第一预设门限，也即，终端设备在小区#1的信号质量不好。第一接入网设备由此可以确定，终端设备不适合继续驻留在小区#1中，终端设备满足小区切换条件。
在一种实现方式中，终端设备可以对源小区的信号质量进行测量，并将测量结果(如，上述RSRP、RSRQ等参数)上报给第一接入网设备。第一接入网设备可以根据该测量结果，判断信号质量是否满足第一预设门限。第一接入网设备进而可以在信号质量低于第一预设门限的情况下，确定该终端设备满足小区切换条件。
在另一种实现方式中，终端设备可以根据对源小区的信号质量的测量，在信号质量低于第一预设门限的情况下，将信号质量低于第一预设门限的事件上报给第一接入网设备。第一接入网设备据此确定该终端设备满足小区切换条件。
应理解，终端设备对小区#1的信号质量的测量可以参考现有技术，为了简洁，这里不做详述。
在步骤304中，第一接入网设备根据第一会话对应的第一网络切片，以及至少一个相邻小区分别支持的网络切片，确定目标小区。
为了保持第一会话的正常通信，第一接入网设备在为该终端设备确定目标小区时，可以结合该第一会话对应的第一网络切片来考虑。也就是说，第一接入网设备为终端设备所确定的目标小区支持第一网络切片，以避免第一会话的中断。
第一接入网设备可以根据第一网络切片，以及预先获取到的至少一个相邻小区分别支持的网络切片，从至少一个相邻小区中选择一个支持第一网络切片的小区作为目标小区。
第一接入网设备可以优先在站内相邻小区中寻找目标小区。若第一接入网设备在站内相邻小区中找到目标小区，该目标小区是第一接入网设备服务的多个小区中除源小区之外的其他小区。
例如，小区#1的站内相邻小区包括小区#2，且小区#2也支持第一网络切片，则第一 接入网设备可以根据小区#2的信号质量，确定是否可以将小区#2作为目标小区。若小区#2的信号质量满足预设门限(为便于区分和说明，将该预设门限记为第二预设门限)，则可作为目标小区。
一示例，第一网络切片的标识为S-NSSAI#1，小区#2支持的网络切片包括标识为S-NSSAI#1和S-NSSAI#2的网络切片，则小区#2也支持第一网络切片。第一接入网设备可进一步根据小区#2的信号质量来判断是否可作为目标小区。
又例如，第一接入网设备可以根据站内各小区的信号质量，从信号质量满足第二预设门限的小区中寻找小区#1的相邻小区。若从信号质量满足第二预设门限的小区中能找到小区#1的相邻小区，则可将该小区确定为目标小区。
一示例，第一网络切片的标识为S-NSSAI#1。第一接入网设备确定站内存在满足第二预设门限的小区包括小区#2。如前所述，小区#2也支持标识为S-NSSAI#1的网络切片，因此可将小区#2作为目标小区。
又例如，小区#1的站内相邻小区中包括多个支持第一网络切片的小区，且该多个支持第一网络切片的小区支持的频率范围不同，则第一接入网设备可以优先在与小区#1同频的小区范围内寻找目标小区。
这里，同频具体可以是指两个小区支持的频率范围相同，比如工作在相同的频率范围；与之相对，异频具体可以是指两个小区支持的频率范围不同，比如工作在不同的频率范围。
一示例，第一网络切片的标识为S-NSSAI#1，小区#1支持的频率范围为N41频段。在小区#1的站内相邻小区包括小区#2和小区#3。假设小区#2支持的网络切片包括标识为S-NSSAI#1和S-NSSAI#2的网络切片，小区#2支持的频率范围为N41频段；小区#3支持的网络切片包括标识为S-NSSAI#1的网络切片，小区#3支持的频率范围为N79频段。则第一接入网设备可优先考虑小区#2的信号质量是否达到第二预设门限。若小区#2的信号质量满足第二预设门限，则可将小区#2作为目标小区。
需要说明的是，第一接入网设备可以同时从其服务的多个小区中的其他终端设备获取到对各小区的信号质量的测量结果，因此，第一接入网设备可以根据对站内相邻小区的信号质量的测量结果来判断支持第一网络切片的站内相邻小区是否满足第二预设门限。
应理解，第二预设门限可以理解为是用来判断信号质量好与差的另一个门限值。用于评估的指标不同，所对应的门限值也不同。此外，第二预设门限可以是预定义的一个门限值。本申请对其具体取值不作限定。
还应理解，第一预设门限和第二预设门限为不同的预设门限。二者可以采用不同的指标；或者，也可以采用相同的指标，不同的门限值；或者，还可以采用相同的指标，相同的门限值。本申请对此不作限定。
第一接入网设备也可以从站外相邻小区中寻找目标小区。若第一接入网设备从站外相邻小区中找到目标小区，该目标小区例如可以是第二接入网设备服务的小区。
第一接入网设备从站外相邻小区中寻找目标小区，同样也基于支持第一网络切片的小区来寻找。其具体实现过程与上文所述的在站内相邻小区中寻找目标小区的过程相似，为了简洁，这里不再赘述。
在本申请实施例中，步骤304的一种可能的实现方式是，第一接入网设备可以根据第一网络切片，以及至少一个站外相邻小区分别支持的网络切片以及各网络切片对应的无线 资源，确定目标频率范围，然后基于目标频率范围来寻找目标小区。
示例性地，该步骤304具体可以包括：
步骤3041，第一接入网设备根据第一网络切片，至少一个相邻小区各自支持的网络切片以及各网络切片对应的频率范围，确定目标频率范围；
步骤3042，第一接入网设备根据目标频率范围确定目标小区。
在步骤3041中，目标频率范围是第一接入网设备为终端设备确定的目标小区能够支持的频率范围。
第一接入网设备可以根据第一网络切片，从至少一个相邻小区中寻找支持第一网络切片的小区，并根据该第一网络切片在各小区对应的频率范围，确定目标频率范围。
由于各小区支持的频率范围不同，虽然可能存在多个小区都支持第一网络切片，但在各小区对应的频率范围不一定相同。因此，目标频率范围可以是与小区#1相同的频率范围，也可以是与小区#1不同的频率范围，本申请对此不作限定。为方便区分和说明，将小区#1支持的频率范围记为第一频率范围。
在一种实现方式中，第一接入网设备可以优先选择与小区#1相同的频率范围作为目标频率范围。在相邻小区中存在支持第一网络切片，且对应的频率范围为第一频率范围的小区的情况下，优先选择第一频率范围作为目标频率范围；否则，选择相邻小区支持的第一网络切片对应的其他频率范围作为目标频率范围。为便于区分和说明，将相邻小区支持的第一网络切片对应的不同于第一频率范围的频率范围记为第二频率范围。换言之，目标频率范围优先为第一频率范围，其次为第二频率范围。
如上例所示，第一频率范围为N41频段。小区#1的相邻小区中，支持标识为S-NSSAI#1的网络切片的小区中，该网络切片对应的频率范围包括N41和N79频段。则目标频率范围优先选择N41频段。可以理解，若小区#1的相邻小区不支持N41频段，则目标频率范围可能为N79频段。N79频段即为第二频率范围的一例。
可选地，步骤3042具体包括：第一接入网设备从支持目标频率范围的站内相邻小区中确定目标小区。
示例性地，若第一接入网设备确定目标频率范围为第一频率范围，第一接入网设备可以先确定小区#1的站内相邻小区中是否存在支持第一频率范围的小区，例如记为第一小区。在存在第一小区的情况下，第一接入网设备可以根据该第一小区的信号质量，确定是否将第一小区确定为目标小区。比如，若第一小区的信号质量满足第二预设门限，则将第一小区确定为目标小区。若第一小区的信号质量低于第二预设门限，或者，小区#1不存在站内相邻小区(即，第一接入网设备服务的小区仅包括小区#1)，第一接入网设备可以在站外相邻小区中确定目标小区。
可选地，步骤3042具体包括：第一接入网设备从支持目标频率范围的站外相邻小区中确定目标小区。若第一接入网设备确定目标频率范围为第一频率范围，则可基于第一频率范围确定无线测量参数。为便于区分和说明，将基于第一频率范围所确定的无线测量参数记为第一无线测量参数。
第一接入网设备可以向终端设备发送该第一无线测量参数。终端设备可以基于该第一无线测量参数进行相邻小区的信号质量的测量。换言之，该第一无线测量参数触发终端设备进行同频测量。
如前所述，运营商在进行网络规划时，为了尽可能地保证终端设备的切换是同频切换，工作在同一个频率范围的多个小区往往都可以支持相同的网络切片。因此可以理解，终端设备基于该第一无线测量参数对相邻小区的信号质量的测量是在第一频率范围的测量，也即对支持第一频率范围且支持第一网络切片的相邻小区的信号质量的测量。
此后，终端设备向第一接入网设备上报测量结果。可以理解，终端设备上报的测量结果是基于第一无线测量参数，在第一频率范围对相邻小区的信号质量进行测量所得到的测量结果。示例性地，该测量结果中可以包括一个或多个相邻小区的小区标识以及各相邻小区对应的信号质量。
可以理解，该测量结果中所上报的小区基本上都能够在第一频率范围提供第一网络切片的接入服务。第一接入网设备可以根据该测量结果来确定目标小区。如前所述，第一接入网设备可以将信号质量满足预设门限的小区确定为目标小区。若第一接入网设备基于终端设备上报的测量结果可以找到目标小区，则第一接入网设备不必再基于其他频率范围确定无线测量参数，终端设备也就不必进行异频测量。
若第一接入网设备基于终端设备上报的测量结果没有找到目标小区，比如，各相邻小区的信号质量都低于第二预设门限，则第一接入网设备可以将第二频率范围作为目标频率范围，尝试基于第二频率范围在站内相邻小区和站外相邻小区中寻找目标小区。可以理解，若第一接入网设备基于第二频率范围在站内相邻小区中可以找到目标小区，则不必再去站外相邻小区中寻找目标小区。
第一接入网设备基于第二频率范围在站内相邻小区中寻找目标小区的具体过程与上文中描述的第一接入网设备基于第一频率范围在站内相邻小区中寻找目标小区的具体过程相同，为了简洁，这里不再重复。
第一接入网设备基于第二频率范围在站外相邻小区中寻找目标小区的具体过程可以通过执行上述确定无线测量参数、下发无线测量参数以及根据测量结果确定目标小区的步骤来实现。
所不同的是，第一接入网设备在确定无线测量参数时，可以将第二频率范围作为目标频率范围，基于第二频率范围确定无线测量参数。为便于区分和说明，将基于第二频率范围所确定的无线测量参数记为第二测量参数。
第一接入网设备可以将该第二无线测量参数下发给终端设备。终端设备可以基于该第二无线测量参数进行相邻小区的信号质量的测量。换言之，该第二无线测量参数可以触发终端设备进行异频测量。
可以理解，终端设备基于该第二无线测量参数对相邻小区的信号质量的测量是在第二频率范围的测量，也即对支持第二频率范围且支持第一网络切片的相邻小区的信号质量的测量。
此后，终端设备可以向第一接入网设备上报测量结果。可以理解，此次终端设备上报的测量结果是基于第二无线测量参数，在第二频率范围对相邻小区的信号质量进行测量所得到的测量结果。
可以理解，该测量结果中所上报的小区基本上都能够在第二频率范围提供第一网络切片的接入服务。第一接入网设备可以根据该测量结果来确定目标小区。如前所述，第一接入网设备可以将信号质量满足预设门限的小区确定为目标小区。
若第一接入网设备基于终端设备上报的测量结果可以找到目标小区，则第一接入网设备可以执行后续步骤305，控制终端设备切换至目标小区；否则，终端设备可以继续驻留在小区#1中。
应理解，上文为便于理解，示出了在站内相邻小区和站外相邻小区寻找目标小区的过程。在实际执行过程中，第一接入网设备并不一定要执行上文所列举的全部步骤。比如，上述步骤3042可能只需执行一次，比如执行同频测量就找到了目标小区，则不必再执行异频测量；或者，相邻小区中未找到与小区#1相同频率范围的小区，直接执行异频测量；步骤3042也可能需要执行两次甚至更多次，比如执行了同频测量后又执行异频测量；步骤3042中第一接入网设备从支持目标频率范围的站外相邻小区中确定目标小区的步骤(例如包括确定并向终端设备下发无线测量参数、从终端设备接收测量结果以及根据测量结果确定目标小区等步骤)也可能不需要执行，比如，第一接入网设备可能在站内相邻小区中就找到了相同频率范围的小区可作为目标小区。本申请对此不作限定。
需要说明的是，上文为方便理解和说明，以第一会话为例详细说明了第一接入网设备确定目标小区的过程。事实上，终端设备在源小区激活的会话可能并不一定仅限于第一会话。终端设备在源小区激活的会话还可能为多个会话。此情况下，第一接入网设备为终端设备确定的目标小区应综合考虑该多个会话，以期保证该多个会话都能够正常进行，而不被中断。因此，该第一接入网设备在确定目标小区时，应尽可能地使得该终端设备在源小区激活的多个会话分别对应的网络切片都分别能够被目标小区支持，且都分别能够接入该目标小区支持的无线资源。换言之，若存在这样一个小区，其所支持的网络切片包括上述多个会话，且该多个网络切片都能够在该小区中接入同一无线资源，则优先选择该小区作为目标小区。
在步骤305中，第一接入网设备控制终端设备切换至目标小区。
如前所述，目标小区可能是第一接入网设备服务的小区，也可能不是第一接入网设备服务的小区。终端设备可能执行站内切换流程，也可能执行跨站切换流程。下面分别对站内切换流程和跨站切换流程做详细说明。
若目标小区是第一接入网设备服务的小区，终端设备可以执行站内切换流程。
示例性地，第一接入网设备可以根据目标小区支持的无线资源，确定切换参数。该切换参数例如可以包括但不限于，目标小区的标识、终端设备在目标小区的无线临时标识、载波频率、天线信息、波束信息、专用的随机接入信道(random access channel，RACH)资源、和RACH资源关联的同步信号和物理广播信道(physical broadcast channel，PBCH)块、服务质量流(quanlity of service flow，QoS Flow)和无线承载的映射规则等。
此后，第一接入网设备可以将该切换参数下发给终端设备。在一种可能的设计中，第一接入网设备可以将该切换参数通过无线资源管理(radio resource management，RRM)配置(RRM configuration)消息下发给终端设备。该切换参数可用于为第一会话的频率范围分配数据无线承载(data radio bearer，DRB)，以完成终端设备的站内切换。
应理解，终端设备进行站内切换的具体流程可以参考现有技术，为了简洁，这里不做限定。
若目标小区不是第一接入网设备服务的小区，终端设备可以执行跨站切换流程。终端设备可以从第一接入网设备切换至第二接入网设备。图3中的步骤305示出了跨站切换流 程。
示例性地，步骤305具体可以包括下述步骤3051至3055。
步骤3051中，第一接入网设备向第二接入网设备发送请求消息，该请求消息中携带待切入第二接入网设备的会话的信息。
第一接入网设备向第二接入网设备发送请求消息，该请求消息用于请求将终端设备切换至第二接入网设备。该请求消息中可以携带待切入第二接入网设备的会话的信息，例如包括但不限于会话的标识信息及其对应的网络切片的标识信息。在上文示例中，待切入第二接入网设备的会话包括第一会话，该第一会话对应的网络切片为第一网络切片。以第一会话为例，上述请求消息中携带的待切入第二接入网设备的会话的标识信息例如可以包括该第一会话的标识或其他可用于标识该第一会话的信息；上述待切入的会话对应的网络切片的标识信息例如可以第一网络切片的标识或其他可用于标识该第一网络切片的信息。本申请对于第一会话和第一网络切片的标识信息的具体形式不作限定。
在步骤3052中，第二接入网设备根据待切入的会话的信息，确定用于切换的RRC参数。
第二接入网设备可以根据该请求消息中携带的待切入的会话的信息，结合自身支持的网络切片以及各网络切片对应的无线资源，以及准备切入的会话对应的网络切片，例如上述第一网络切片，从而确定用于切换的RRC参数。应理解，该RRC参数例如可以包括上文站内切换流程中列举的切换参数。为了简洁，这里不一一列举。
第二接入网设备也可以在接收到该请求消息后，检测待切入的会话对应的网络切片是否是自身支持的网络切片，进而确定允许切入的会话。比如，如果第二接入网设备不支持其中某个会话的网络切片，便可以拒绝切入该会话。
例如，第二接入网设备判断自身支持第一会话对应的第一网络切片，即上述标识为S-NSSAI#1的网络切片，则准备接受切入第一会话。第二接入网设备根据该标识为S-NSSAI#1的网络切片，以及第二接入网设备支持的该网络切片对应的工作频段包括N41和N79，确定在N41频段和N79频段都可以支持待切入的第一会话。而第一会话在源小区的接入的第一无线资源的频率范围为N41频段，则第二接入网设备优先将准备在N41频段为待切入的第一会话分配分配数据无线承载(data radio bearer，DRB)资源，确定相应的RRC参数。
在步骤3053中，第二接入网设备向第一接入网设备发送RRC参数。
在一种实现方式中，该RRC参数可以封装在RRC消息容器中，通过第一接入网设备发送给终端设备。也即，第一接入网设备可以将来自第二接入网设备的RRC参数透传给终端设备。
在一种可能的设计中，该请求消息可以是切换请求(handover request)消息。该RRC参数携带在切换请求确认(handover request acknowledgement，handover request ACK)消息中。
在步骤3054中，第一接入网设备向终端设备转发该RRC参数。
在步骤3055中，终端设备根据该RRC参数接入到第二接入网设备的无线资源。
若终端设备切换了接入网设备，该方法还可以包括步骤306，第二接入网设备和终端设备在空口为成功切换的第一会话建立DRB，激活切入的会话的用户面。
在步骤307中，AMF切换第一会话的用户面路径到第二接入网设备。
第二接入网设备在终端设备接入后，可以向AMF发送消息，以通知终端设备切换到第二接入网设备，并通知核心网将终端设备的切换到第二接入网设备的会话的用户面路径切换到第二接入网设备。核心网随后执行路径切换。
此后，终端设备切入到第二接入网设备的会话(如包括上述第一会话)便可以正常收发业务数据。
应理解，终端设备进行跨站切换的具体流程可以参考现有技术，为了简洁，这里不做限定。
还应理解，图3以终端设备进行跨站切换为例描述了步骤305至步骤307。但这不应对本申请构成任何限定。在站内切换流程中，步骤305中涉及跨站切换的流程和步骤306、步骤307并不一定要执行。
基于上述技术方案，终端设备在源小区的信号质量不好时，服务于源小区的第一接入网设备可以根据终端设备在源小区激活的会话对应的网络切片、至少一个相邻小区分别支持的网络切片以及各网络切片对应的频率范围，为终端设备确定目标小区，并控制终端设备切换至该目标小区。因此终端设备可以在信号质量不好且存在可切换的目标小区的情况下，及时地切换到信号质量较好的目标小区中，从而能够在通信质量不好的情况下及时地采取措施，而不必等到终端设备完成当前的业务后再进入空闲态进行小区重选。因此，终端设备的通信质量能够在短时间内得以提升，有利于提高用户体验。
图4是本申请实施例提供的通信方法的又一示意性流程图。图4所示的方法400可以包括步骤401至步骤419。
为便于理解和说明，首先对方法400的场景做如下说明：方法400中的终端设备可以在开机后接入网络的终端设备，或者，也可以是因为移动到一个不属于原来注册区域的新跟踪区后发起注册请求的终端设备，或者，还可以是周期性地向网络更新注册时的终端设备。该终端设备请求接入的小区为第一接入网设备服务的小区#1，且终端设备在小区#1请求建立一个或多个会话和/或请求激活一个或多个会话。下文实施例中先以请求建立或请求激活会话1为例，再以请求建立或请求激活包括会话1在内的多个会话为例来说明本申请实施例提供的方法。应理解，会话1是第一会话的一例，标识为S-NSSAI#1的网络切片是第一网络切片的一例。
还应理解，下文步骤中针对请求建立会话而执行的步骤与针对请求激活会话而执行的步骤是基本相似的。在存在不同时，各步骤中分别针对请求建立会话和请求激活会话做了区分说明。
此外，本实施例中假设第一接入网设备支持的网络切片及各网络切片对应的频率范围包括：{S-NSSAI#2，(N41)}，第一接入网设备服务的小区#1支持的频率范围为N41频段；第二接入网设备支持的网络切片及各网络切片对应的频率范围包括：{S-NSSAI#1，(N41，N79)}、{S-NSSAI#2，(N79)}和{S-NSSAI#3，(N79)}。
在方法400中，步骤412可对应于方法200中的步骤210，示出了步骤210中第一接入网设备确定终端设备满足小区切换条件的一种可能的实现方式。
步骤413至步骤414可对应于方法200中的步骤220，示出了步骤220中第一接入网设备确定目标小区的可能的实现方式。在步骤413中，第一接入网设备可以根据允许终端 设备接入的网络切片、第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。在步骤414中，第一接入网设备根据目标频率范围确定目标小区。步骤414的一种可能的实现方式是，第一接入网设备从支持目标频率范围的站内相邻小区中确定所述目标小区。步骤414的另一种可能的实现方式是，从支持目标频率范围的站外相邻小区中确定所述目标小区。在从支持目标频率范围的站外相邻小区中确定目标小区的情况下，该方法还可以进一步包括：第一接入网设备根据目标频率范围确定无线测量参数；第一接入网设备向终端设备发送无线测量参数，该无线测量参数用于终端设备对相邻小区的信号质量的测量，终端设备对相邻小区的信号质量的测量用于目标小区的确定。
步骤415可对应于方法200中的步骤230。示出了步骤230中第一接入网设备控制终端设备切换至目标小区的可能的实现方式。与步骤414对应，步骤415的一种可能的实现方式是，第一接入网设备控制终端设备进行站内切换。步骤415的另一种可能的实现方式是，第一接入网设备控制终端设备进行跨站切换。在进行跨站切换的情况下，该方法还可以进一步包括：第一接入网设备向第二接入网设备发送请求消息，该请求消息中携带第一会话的标识信息和第一网络切片的标识信息；第一接入网设备从第二接入网设备接收用于切换的RRC参数；以及第一接入网设备向终端设备发送该RRC参数。可选地，该RRC参数与第一网络切片、第二接入网设备支持的网络切片以及第二接入网设备支持的网络切片对应的无线资源关联。
下面结合具体的流程对方法400做详细说明。
在步骤401中，第一接入网设备从OAM获取多个接入网设备的配置信息，该多个接入网设备的配置信息用于指示第一接入网设备支持的网络切片及各网络切片对应的无线资源，以及与具有相邻小区关系的接入网设备支持的网络切片及各网络切片对应的无线资源。
比如，第一接入网设备可以从OAM接收第一配置信息，该第一配置信息可以用于指示第一接入网设备支持的网络切片以及各网络切片对应的无线资源。该过程例如可以通过执行上文步骤301来实现。
第一接入网设备也可以从OAM或通过Xn接口从具有相邻小区关系的其他接入网设备接收其他配置信息，比如，接收第二配置信息，该第二配置信息可以用于指示第二接入网设备支持的网络切片以及各网络切片对应的无线资源。该过程例如可以通过执行上文步骤302来实现。
应理解，步骤401可通过执行上文方法300中的步骤301和步骤302来实现，关于步骤401的具体内容可参看上文步骤301和步骤302的相关描述，为了简洁，这里不再重复。
在步骤402中，AMF获取各接入网设备的配置信息。
各接入网设备在与AMF建立N2接口连接后，便可以将在上述步骤401中获取到的各自所支持的网络切片上报给AMF。可选地，每个接入网设备也可以将相邻小区的接入网设备支持的网络切片上报给AMF。例如，第一接入网设备可以向AMF发送第一配置信息。
由于各接入网设备也可以从OAM或通过Xn接口从其他接入网设备获取其他接入网设备的配置项信息，AMF也可以从某一接入网设备获取到多个接入网设备的配置信息。可选地，第一接入网设备也可以将其他接入网设备的配置信息上报给AMF。例如，第一 接入网设备可以向AMF发送第二配置信息。
应理解，AMF获取各接入网设备的配置信息的具体实现方式不作限定。
AMF可以根据各接入网设备各自支持的网络切片信息，以及相邻小区的接入网设备各自支持的网络切片，确定终端设备当前所在跟踪区或注册区能够接入的网络切片。终端设备当前所在跟踪区或注册区能够接入的网络切片，具体可以是指终端设备当前所在的跟踪区或注册区中的接入网设备支持的网络切片。
比如，第一配置信息所指示的第一接入网设备支持的网络切片和各网络切片对应的无线资源包括：{S-NSSAI#2，(N41)}；第二配置信息所指示的第二接入网设备支持的网络切片和各网络切片对应的无线资源包括：{S-NSSAI#1，(N41，N79)}、{S-NSSAI#2，(N79)}和{S-NSSAI#3，(N79)}。则可以看到，第一接入网设备支持的网络切片包括标识为S-NSSAI#2的网络切片，第二接入网设备支持的网络切片包括标识为S-NSSAI#1、S-NSSAI#2和S-NSSAI#3的网络切片。若第一接入网设备服务的小区和第二接入网设备服务的小区在同一个TA，则AMF可以确定该终端设备当前所在TA能够支持的网络切片为第一接入网设备和第二接入网设备支持的网络切片的并集{S-NSSAI#1、S-NSSAI#2，S-NSSAI#3}，而不仅仅是终端设备当前接入的第一接入网设备所支持的S-NSSAI#2。
在步骤403中，终端设备经由第一接入网设备向AMF发送请求建立或请求激活第一会话的消息，该消息中携带第一会话的标识信息。
其中，第一会话的标识信息例如可以是第一会话的标识或可用于标识第一会话的其他信息。本申请对此不作限定。在本实施例中，该第一会话的标识信息例如可以是会话1。
在一种可能的设计中，终端设备向AMF发送的请求建立或请求激活第一会话的消息例如可以是注册请求消息。示例性地，终端设备可以请求与第一接入网设备建立RRC连接，比如向第一接入网设备发送RRC连接建立请求。该终端设备可以在该RRC连接建立请求中携带待转发给AMF的注册请求消息。该注册请求消息中可以进一步携带终端设备请求建立或请求激活的会话的标识信息。该第一接入网设备继而向AMF转发该注册请求消息。
可选地，该注册请求消息中还携带该终端设备请求接入的网络切片(requested NSSAI)的标识信息，例如，请求接入的网络切片可以包括标识为{S-NSSAI#1，S-NSSAI#2，S-NSSAI#3，S-NSSAI#4，S-NSSAI#5}的网络切片。
可选地，该注册请求消息中还携带该终端设备已经建立的会话的标识信息和状态信息。也就是说，该终端设备在发起上述RRC连接建立之前，或者说，在上一次进入RRC空闲态之前，可能已经建立了一个或多个会话，该一个或多个会话由于终端设备进入RRC空闲态而被去激活。这里为方便区分和说明，将该终端设备已经建立的会话记为第二会话。该注册请求消息中还可以携带该第二会话的标识或可用于标识该第二会话的其他信息。该注册请求消息中还可以进一步携带用于指示该第二会话的状态的信息，以指示该第二会话当前处于去激活状态。
在步骤404中，AMF从UDM获取该终端设备的签约的网络切片的标识信息。
前已述及，UDM可用于存储用户数据，如签约信息、鉴权/授权信息等。AMF可以从UDM获取该终端设备的签约信息，该签约信息中包含了终端设备签约的网络切片的标识信息。
一种可能的情况是，终端设备请求的网络切片属于签约的网络切片，或者说，终端设备请求的网络切片是签约的网络切片的子集。另一种可能的情况是，终端设备此前签约的某些网络切片可能已过期，终端设备请求的网络切片不属于签约的网络切片。
例如，在本实施例中，该签约信息中包含的该终端设备签约的网络切片包括标识为{S-NSSAI#1，S-NSSAI#2，S-NSSAI#3，S-NSSAI#4}的网络切片。即，标识为S-NSSAI#5的网络切片可能已过期，不属于签约的网络切片。
在步骤405中，AMF确定允许终端设备接入的网络切片(allowed NSSAI)。
AMF可以根据上述终端设备请求的网络切片、终端设备签约的网络切片，以及终端设备所在跟踪区或注册区支持的网络切片，确定允许终端设备接入的网络切片。其中，终端设备请求的网络切片可以在上述注册请求消息中携带，终端设备签约的网络切片可以从UDM中获取，终端设备所在跟踪区或注册区支持的网络切片可以基于上文步骤402确定。AMF可以基于上述三项，确定允许终端设备接入的网络切片。在一种实现方式中，允许终端设备接入的网络切片可以由终端设备请求的网络切片、终端设备签约的网络切片以及终端设备所在跟踪区或注册支持的网络切片的交集确定。
比如，上文中已示例，终端设备请求的网络切片包括标识{S-NSSAI#1，S-NSSAI#2，S-NSSAI#3，S-NSSAI#4，S-NSSAI#5}的网络切片，终端设备签约的网络切片包括标识为{S-NSSAI#1，S-NSSAI#2，S-NSSAI#3，S-NSSAI#4}的网络切片，终端设备所在跟踪区或注册区支持的网络切片包括标识为{S-NSSAI#1，S-NSSAI#2，S-NSSAI#3}的网络切片。由此可以确定允许终端设备接入的网络切片包括标识为{S-NSSAI#1，S-NSSAI#2，S-NSSAI#3}的网络切片。
应理解，上述步骤405也可以由其他网元来实现，比如由NSSF实现。AMF可以将获取到的该终端设备的签约信息、终端设备请求的网络切片的标识信息，以及在步骤402中确定的终端设备所在跟踪区或注册区支持的网络切片的标识信息发送给NSSF，由NSSF来确定允许终端设备接入的网络切片。NSSF在确定出允许终端设备接入的网络切片后，可将结果发送给AMF。
在步骤406中，AMF根据允许终端设备接入的网络切片，确定允许建立会话或允许激活的会话。
基于上文示例中允许终端设备接入的网络切片，可以确定允许建立的会话或允许激活的会话包括会话1、会话2和会话3。这里，允许建立和允许激活是分别针对上文步骤403中请求建立和请求激活而言的。若终端设备在步骤403中请求建立第一会话，AMF可以在步骤406中确定允许建立的会话；若终端设备在步骤403中请求激活第一会话，AMF可以在步骤406中确定允许激活的会话。
在步骤406中，AMF可以确定是否允许建立第一会话或是否允许激活第一会话。在本实施例中，若终端设备请求建立或请求激活的第一会话为会话1，则第一会话是允许建立或允许激活的会话，可以继续执行下述步骤。若终端设备请求建立或请求激活的第一会话为会话4，则第一会话不属于允许建立或允许激活的会话。则AMF可以不执行下述步骤407至步骤410，而直接执行步骤411和412，向第一接入网设备发送允许终端设备接入的网络切片的标识信息，以便第一接入网设备确定该第一会话是不允许建立或不允许激活的会话。
在步骤407中，AMF向SMF发送会话管理(session management，SM)上下文更新请求消息或创建会话管理上下文请求消息。
针对步骤403中请求建立第一会话的消息，AMF可以向SMF发送创建会话管理上下文请求消息，以用于请求建立第一会话。针对步骤403中请求激活第一会话的消息，AMF可以向SMF发送会话管理上下文更新请求消息，以用于请求激活第一会话。
在步骤408中，SMF接受第一会话建立的请求，或，SMF接受用户面激活的请求。
其中，SMF接受第一会话建立的请求例如可以是针对请求建立第一会话的会话建立请求消息而执行的步骤。SMF接受用户面激活的请求例如可以是针对请求激活第一会话的业务请求消息而执行的步骤。
在某些情况下，SMF可能会因为终端设备当前位置相对第一会话建立时的位置发生了变化，而重新选择一个新的UPF。
在步骤409中，SMF建立N4接口会话，控制UPF建立第一会话的用户面连接；或，SMF修改N4接口会话，控制UPF激活第一会话的用户面连接。
在步骤410中，SMF向AMF发送创建会话管理上下文成功的响应消息或会话管理上下文更新成功的响应消息。
其中，创建会话管理上下文成功的响应消息例如可以是针对请求建立第一会话的会话建立请求消息的响应。会话管理上下文更新成功的响应消息例如可以针对请求激活第一会话的业务请求消息的响应。
在步骤411中，AMF向第一接入网设备发送允许终端设备接入的网络切片的标识信息。
示例性地，AMF可以基于终端设备的注册请求消息，接受终端设备的注册，向第一接入网设备发送建立终端设备上下文的消息，该消息中可以携带允许终端设备接入的网络切片的标识信息、会话状态以及待激活的会话信息。
其中，会话状态例如可以包括该终端设备在小区#1中的所有已建立的会话的状态。在本实施例的场景下，终端设备在小区#1的会话例如可以包括去激活的会话和待激活的会话。
待激活的会话信息具体可以是指终端设备请求激活的会话的标识信息以及对应的网络切片的标识信息。比如，本实施例中终端设备请求激活的第一会话的标识信息及其对应的第一网络切片的标识信息。
第一接入网设备可以根据允许终端设备接入的网络切片的标识信息确定允许终端设备接入的网络切片。在本实施例中，允许终端设备接入的网络切片的标识信息例如可以是{S-NSSAI#1，S-NSSAI#2，S-NSSAI#3}或可用于标识网络切片的其他信息。
可选地，作为对步骤403中注册请求消息的响应，该消息中还携带了待发送给该终端设备的注册接受消息。
在步骤412中，第一接入网设备确定小区#1的第一无线资源不支持第一会话对应的第一网络切片。
第一接入网设备可以根据待激活的会话信息，确定第一会话对应的第一网络切片。若允许接入的网络切片不包括该第一网络切片，则接入网设备可以确定该第一会话是不允许建立的会话或不允许激活的会话。若允许接入的网络切片包括第一网络切片，第一接入网 设备进而可以根据小区#1支持的网络切片确定第一无线资源是否支持第一网络切片。
在本实施例中，小区#1支持的网络切片不包括标识为S-NSSAI#1的网络切片(即，与会话1对应的网络切片，也即第一网络切片的一例)，故第一无线资源不支持第一网络切片。
在步骤413中，第一接入网设备根据允许终端设备接入的网络切片、第一网络切片及第一网络切片对应的频率范围，确定目标频率范围。
这里，第一网络切片对应的频率范围具体可以是指支持该第一网络切片的各相邻小区分别支持的频率范围，换言之，也就是该第一网络切片在各相邻小区对应的频率范围。第一接入网设备首先可确定该第一网络切片是否属于允许终端设备接入的网络切片。在第一网络切片属于允许终端设备接入的网络切片的情况下，第一接入网设备可以进一步根据该第一网络切片在各相邻小区中分别对应的频率范围，确定目标频率范围。因此，步骤413也可以替换为：第一接入网设备根据允许终端设备接入的网络切片、第一网络切片、至少一个相邻小区支持的网络切片以及各网络切片对应的频率范围，确定目标频率范围。
应理解，小区#1的相邻小区可能包括与小区#1同站的小区和与小区#1异站的小区。换言之，小区#1的相邻小区可能包括了站内相邻小区和站外相邻小区。因此，上述至少一个相邻小区分别支持的网络切片可以由第一接入网设备支持的网络切片以及具有相邻小区关系的接入网设备支持的网络切片来确定。
可以理解，小区#1的相邻小区中可能存在多个小区支持该第一网络切片，但不同的小区中该第一网络切片对应的无线资源可能不同，或者说，对应的频率范围可能不同。第一接入网设备可以优先选择与小区#1相同频率范围(即，第一频率范围)的小区。因此，在相邻小区中存在支持第一网络切片，且对应的频率范围为第一频率范围的小区的情况下，优先选择第一频率范围作为目标频率范围；否则，选择相邻小区支持的第一网络切片对应的频率范围作为目标频率范围，例如记为第二频率范围，第二频率范围与第一频率范围为不同的频率范围。换言之，目标频率范围优先为第一频率范围，其次为第二频率范围。
在本实施例中，第一网络切片是标识为S-NSSAI#1的网络切片，该网络切片属于允许终端设备接入的网络切片。结合上例示出的第一接入网设备和第二接入网设备分别支持的网络切片及各网络切片对应的频率范围，第一接入网设备不支持标识为S-NSSAI#1的网络切片，第二接入网设备支持标识为S-NSSAI#1的网络切片的频率范围包括N41频段和N79频段。而小区#1支持的第一频率范围为N41频段，则第一接入网设备可以优先选择N41频段作为目标频率范围，其次选择N79频段(即，第二频率范围的一例)作为目标频率范围。
在另一种实现方式中，第一接入网设备可以根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片以及终端设备所在跟踪区或注册区支持的网络切片，第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。
这里，终端设备的根据签约能够使用的网络切片例如可以是由核心网设备(如AMF)发送给第一接入网设备的。
当终端设备在归属网络时，终端设备根据签约能够使用的网络切片可以是指该终端设备签约的网络切片；当终端设备在拜访网络时，终端设备根据签约能够使用的网络切片可以是指与终端签约的网络切片所对应的拜访网络的网络切片。
由于上述允许终端设备接入的网络切片是根据终端设备签约的网络切片、终端设备请求的网络切片以及终端设备所在跟踪区或注册区支持的网络切片确定的，故，上述两种实现方式可以认为是可替换的。
在步骤414中，第一接入网设备根据目标频率范围确定目标小区。
可以理解，目标频率范围可能是第一频率范围，也可能是第二频率范围。
在一种实现方式中，第一接入网设备可以优先从站内相邻小区中寻找目标小区。可选地，步骤414具体包括：第一接入网设备从支持目标频率范围的站内相邻小区中确定目标小区。
示例性地，第一接入网设备可以先确定站内相邻小区中是否存在支持目标频率范围的小区，例如记为第一小区。在存在第一小区的情况下，第一接入网设备可以进一步确定该第一小区是否支持第一网络切片。若该第一小区支持第一网络切片，第一接入网设备可以根据该第一小区的信号质量，确定是否将第一小区确定为目标小区。比如，若第一小区的信号质量满足第二预设门限，则将第一小区确定为目标小区。若第一小区的信号质量低于第二预设门限，或者，第一小区不支持第一网络切片，或者，小区#1不存在站内相邻小区(即，第一接入网设备服务的小区仅包括小区#1)，第一接入网设备可以在站外相邻小区中确定目标小区。
可选地，步骤414具体包括：第一接入网设备从支持目标频率范围的站外相邻小区中确定目标小区。
示例性地，步骤414可进一步包括：
步骤4141，第一接入网设备根据目标频率范围确定无线测量参数；
步骤4142，第一接入网设备向终端设备发送该无线测量参数，该无线测量参数用于终端设备对相邻小区的信号质量的测量；
步骤4143，终端设备向第一接入网设备上报对相邻小区的信号质量的测量结果；
步骤4144，第一接入网设备根据对相邻小区的信号质量的测量结果，确定目标小区。
与上文从站内相邻小区中寻找小区的过程相似，第一接入网设备可以先确定站外相邻小区中是否存在支持第一频率范围的第一小区。在存在第一小区的情况下，第一接入网设备可以根据第一频率范围确定无线测量参数(即，第一无线测量参数)，并将该第一无线测量参数发送给终端设备，以便于终端设备基于第一频率范围对第一小区的信号质量进行测量。第一接入网设备进而可以基于终端设备上报的测量结果，确定该第一小区是否可作为目标小区。比如，在第一小区的信号质量满足第二预设门限的情况下，将第一小区确定为目标小区。
若第一小区的信号质量低于第二预设门限，则第一接入网设备可以进一步判断是否有其他可选的频率范围，并在有其他可选的频率范围的情况下，继续寻找目标小区。
比如，若小区#1的相邻小区中还存在支持第一网络切片，且对应的频率范围为第二频率范围的小区，则第一接入网设备可以基于第二频率范围寻找目标小区。第一接入网设备可以优先在站内相邻小区中寻找目标小区，其次在站外相邻小区中寻找目标小区。
第一接入网设备基于第二频率范围在站内相邻小区中寻找目标小区的具体过程与上文中描述的第一接入网设备基于第一频率范围在站内相邻小区中寻找目标小区的具体过程相同。为了简洁，这里不再赘述。
第一接入网设备基于第二频率范围在站外相邻小区中寻找目标小区的具体过程可以通过执行步骤4141至步骤4144来实现，其具体过程可以参考上文关于步骤4141至步骤4144的相关描述。
所不同的是，第一接入网设备可以根据第二频率范围确定无线测量参数(即，第二无线测量参数)，并将该第二无线测量参数发送给终端设备，以便于终端设备基于第二频率范围对相邻小区的信号质量进行测量。第一接入网设备进而可以基于终端设备上报的测量结果确定目标小区。
应理解，在第一接入网设备服务的小区仅包括小区#1的情况下，或者说，小区#1不存在站内相邻小区的情况下，第一接入网设备可以直接从站外相邻小区中确定目标小区，即执行上述步骤4141至步骤4144。
此外，第一接入网设备向终端设备发送的无线测量参数(第一无线测量参数或第二无线测量参数)例如可以携带在步骤411中提及的由第一接入网设备向终端设备转发的注册接受消息中，或者，也可以单独发送。本申请对此不作限定。
第一无线测量参数和第二无线测量参数可以基于目标频率范围的不同取值，分开来单独发送，也可以同时下发给终端设备。本申请对此不作限定。
还应理解，第一接入网设备从站内相邻小区和/或站外相邻小区中确定目标小区的具体过程可以参看上文方法300中的步骤304中的相关描述，为了简洁，这里不再赘述。
需要说明的是，上文为方便理解和说明，以第一会话为例详细说明了第一接入网设备确定目标小区的过程。事实上，终端设备向第一接入网设备请求建立或请求激活的会话并不一定仅限于第一会话。终端设备可能并行地向第一接入网设备请求建立和/或请求激活多个会话。此情况下，第一接入网设备为终端设备确定的目标小区应综合考虑该多个会话，以期激活该多个会话。因此，该第一接入网设备在确定目标小区时，应尽可能地使得该终端设备请求建立和/或请求激活的多个会话对应的网络切片能够被目标小区支持，且都分别能够接入该目标小区支持的无线资源。
换言之，若存在这样一个小区，其所支持的网络切片包括上述终端设备请求建立和/或请求激活的多个会话，且该多个网络切片都能够在该小区中接入同一无线资源，则优先选择该小区作为目标小区。
例如，若终端设备请求建立和/或请求激活的会话包括会话1和会话3，分别对应标识为S-NSSAI#1和S-NSSAI#3的网络切片。
由上文第一接入网设备和第二接入网设备分别支持的网络切片以及各网络切片对应的频率范围可以看到，第一接入网设备支持的网络切片包括标识为S-NSSAI#2的网络切片，则该小区#1的站内相邻小区中不存在能够同时支持会话1和会话3对应的网络切片的小区。而第二接入网设备支持的网络切片包括标识为S-NSSAI#1、S-NSSAI#2和S-NSSAI#3的网络切片，则可以从小区#1的站外相邻小区中寻找目标小区。第一接入网设备可以进一步根据第二接入网设备支持的各网络切片对应的频率范围，可以确定N79频段可以同时支持该两个网络切片，故N79频段为目标频率范围。第一接入网设备可以基于N79频段从小区#1的站外相邻小区中寻找目标小区。
应理解，上文为便于理解，结合具体示例描述了第一接入网设备确定目标频率范围进而确定目标小区的过程。应理解，上文示例的各会话与网络切片的对应关系、各接入网设 备支持的网络切片以及各网络切片对应的频率范围等仅为示例，不应对本申请构成任何限定。
若第一接入网设备无法找到这样一个小区，能够支持终端设备请求建立和/或请求激活的多个会话，则第一接入网设备可以根据各相邻小区的无线资源的负荷、各无线资源的优先级，选择一个支持部分会话的小区作为目标小区；或者，该第一接入网设备也可以根据该多个会话的优先级，将支持高优先级的会话所对应的网络切片的小区作为目标小区。
前已述及，该终端设备在请求与第一接入网设备建立RRC连接之前，可能已经建立了一个或多个会话，该一个或多个会话处于去激活态。终端设备在发送RRC连接建立请求时可以携带该一个或多个已建立的会话信息。第一接入网设备在为该终端设备确定目标小区时，还可以进一步结合该一个或多个已建立的会话，以期在所选择的目标小区中，能够尽可能地支持该一个或多个已建立的会话。
例如，终端设备当前请求建立或请求激活的会话包括第一会话，对应的网络切片为第一网络切片；终端设备当前去激活的会话包括第二会话，对应的网络切片为第二网络切片。第一接入网设备为终端设备确定目标小区时，应尽可能地选择能够支持第一网络切片和第二网络切片的小区作为目标小区。
若第一接入网设备无法找到这样一个小区，能够支持第一网络切片和第二网络切片，则可以优先考虑当前请求建立或请求激活的第一会话对应的第一网络切片，选择能够支持第一网络切片的小区作为目标小区。
应理解，上文列举的各种可能的情况仅为示例，不应对本申请构成任何限定。
在步骤415中，第一接入网设备控制终端设备切换至目标小区。
第一接入网设备为终端设备确定的目标小区可能是第一接入网设备服务的小区，也可能不是第一接入网设备服务的小区。终端设备可能执行站内切换流程，也可能执行跨站切换流程。由于上文方法300中的步骤305中已经对站内切换流程和跨站切换流程做了详细说明，为了简洁，这里不再重复。
应理解，终端设备进行跨站切换的具体流程可以参考现有技术，为了简洁，这里不做详述。
在步骤416中，第二接入网设备和终端设备在空口为成功切换的会话建立DRB。
应理解，成功切换的会话例如可以包括上述第一会话，或者，也可以包括上述第一会话和第二会话。本申请对此不作限定。
在步骤417中，AMF切换第一会话的用户面路径到第二接入网设备。
在步骤418中，AMF向第二接入网设备发送N3接口端点信息。
在步骤419中，第二接入网设备和核心网建立用户面连接，激活第一会话。
在本实施例中，用户面连接也即第二接入网设备与UPF之间的N3接口连接。基于第二接入网设备与UPF之间的N3接口连接的建立，第一会话的用户面得以激活。此后，终端设备便可以通过激活的第一会话收发业务数据。
应理解，图4以终端设备进行跨站切换为例描述了步骤415至步骤419。但这不应对本申请构成任何限定。在站内切换流程中，步骤415中涉及跨站切换的流程和步骤416至步骤419并不一定要执行。
基于上述技术方案，终端设备在源小区请求建立或请求激活的第一会话不能够被源小 区的无线资源支持时，服务于源小区的第一接入网设备可以根据该第一会话对应的第一网络切片、至少一个相邻小区各自支持的网络切片以及各网络切片对应的无线资源，为终端设备确定目标小区，并控制终端设备切换至该目标小区。因此，终端设备可以在请求建立或请求激活的第一会话不被源小区的无线资源支持且存在可切换的目标小区的情况下，及时地将终端设备切换至目标小区，从而可以及时地响应终端设备的会话请求，在短时间内激活第一会话，有利于提高用户体验。
图5是本申请实施例提供的通信方法的另一示意性流程图。图5所示的方法500可以包括步骤501至步骤515。
为便于理解和说明，首先对方法500的场景做如下说明：方法500中的终端设备在第一接入网设备服务的小区#1中已经建立了一个或多个会话，但该一个或多个会话中的部分会话可能处于去激活状态。终端设备和第一接入网设备各自保留了该这些会话的上下文，没有激活用户面连接。
下文中为方便理解和说明，以第一会话作为请求激活或请求建立的会话的一例来说明本实施例。
应理解，下文步骤中针对请求建立会话而执行的步骤与针对请求激活会话而执行的步骤是基本相似的。在存在不同时，各步骤中分别针对请求建立会话和请求激活会话做了区分说明。
此外，本实施例中假设第一接入网设备支持的网络切片及各网络切片对应的频率范围包括：{S-NSSAI#2，(N41)}，第一接入网设备服务的小区#1支持的频率范围为N41频段。
在方法500中，步骤507可对应于方法200中的步骤210，示出了步骤210中第一接入网设备确定终端设备满足小区切换条件的一种可能的实现方式。
步骤509和步骤510可对应于方法200中的步骤220，示出了步骤220中第一接入网设备确定目标小区的可能的实现方式。在步骤509中，第一接入网设备可以根据允许终端设备接入的网络切片、第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。在步骤510中，第一接入网设备可以根据目标频率范围确定目标小区。步骤510的一种可能的实现方式是，第一接入网设备从支持目标频率范围的站内相邻小区中确定所述目标小区。步骤510的另一种可能的实现方式是，从支持目标频率范围的站外相邻小区中确定所述目标小区。在从支持目标频率范围的站外相邻小区中确定目标小区的情况下，该方法还进一步包括：第一接入网设备根据目标频率范围确定无线测量参数；第一接入网设备向终端设备发送无线测量参数，该无线测量参数用于终端设备对相邻小区的信号质量的测量，终端设备对相邻小区的信号质量的测量用于目标小区的确定。
步骤511可对应于方法200中的步骤230，示出了步骤230中第一接入网设备控制终端设备切换至目标小区的可能的实现方式。与步骤510对应，步骤511的一种可能的实现方式是，第一接入网设备控制终端设备进行站内切换。步骤511的另一种可能的实现方式是，第一接入网设备控制终端设备进行跨站切换。在进行跨站切换的情况下，该方法还进一步包括：第一接入网设备向第二接入网设备发送请求消息，该请求消息中携带第一会话的标识信息和第一网络切片的标识信息；第一接入网设备从第二接入网设备接收用于切换的RRC参数；以及第一接入网设备向终端设备发送该RRC参数。可选地，该RRC参数 与第一网络切片、第二接入网设备支持的网络切片以及第二接入网设备支持的网络切片对应的无线资源关联。
下面结合具体的流程对方法500做详细说明。
在步骤501中，终端设备经由第一接入网设备向AMF发送请求激活或请求建立第一会话的消息，该消息中携带请求激活或请求建立的第一会话的标识信息。
在一种可能的设计中，该消息为业务请求(service request)消息，以请求激活第一会话。示例性地，终端设备可以向第一接入网设备发送RRC连接建立请求消息，该RRC连接建立请求消息中携带了待发送给AMF的业务请求消息，该业务请求消息用于请求激活第一会话。例如，该业务请求消息中可以携带第一会话的标识信息。该第一接入网设备继而向AMF转发该业务请求消息。
在另一种可能的设计中，该消息为会话建立请求消息(session establishment request)，以请求建立第一会话。该会话建立请求消息也可以携带在RRC连接建立请求消息中，以请求建立第一会话。该会话建立请求中也可以携带第一会话的标识信息。第一接入网设备继而向AMF转发该会话请求消息。
在步骤502中，AMF向SMF发送会话管理上下文更新请求消息或创建会话管理上下文请求消息。
针对请求激活第一会话的业务请求消息，AMF向SMF发送的会话管理上下文更新请求消息用于请求激活第一会话。针对请求建立第一会话的会话建立请求消息，AMF向SMF发送的创建会话管理上下文请求消息用于请求建立第一会话。
在步骤503中，SMF接受用户面激活的请求或接受第一会话建立的请求。
其中，SMF接受用户面激活的请求例如可以是针对请求激活第一会话的业务请求消息而执行的步骤。SMF接受会话建立请求例如可以是针对请求建立第一会话的会话建立请求消息而执行的步骤。
在某些情况下，SMF可能会因为终端设备当前位置相对第一会话建立时的位置发生了变化，而重新选择一个新的UPF。
在步骤504中，SMF修改N4接口会话，控制UPF激活第一会话的用户面连接；或者，SMF建立N4接口会话，控制UPF建立第一会话的用户面连接。
在步骤505中，SMF向AMF发送会话管理上下文更新成功的响应消息或创建会话管理上下文成功的响应消息。
其中，会话管理上下文更新成功的响应消息例如可以针对请求激活第一会话的业务请求消息的响应。创建会话管理上下文成功的响应消息例如可以是针对请求建立第一会话的会话建立请求消息的响应。
在步骤506中，AMF向第一接入网设备发送N2接口请求消息，该N2接口请求消息中携带请求激活或请求建立的第一会话对应的第一网络切片的标识信息。例如，终端设备请求激活的第一会话为会话1，其对应的第一网络切片是标识为S-NSSAI#1的网络切片；终端设备请求建立的第一会话为会话2，其对应的第一网络切片是标识为S-NSSAI#2的网络切片。
在步骤507中，第一接入网设备确定小区#1的第一无线资源不支持第一会话对应的第一网络切片。
比如，若第一会话对应的第一网络切片是标识为S-NSSAI#2的网络切片，则小区#1的第一无线资源支持第一网络切片。此情况下，终端设备可以继续在源小区中，按照现有技术的流程，激活或建立第一会话。由于本实施例不涉及此过程，这里不作详述。
又比如，若第一会话对应的第一网络切片是标识为S-NSSAI#1的网络切片，则小区#1的第一无线资源不支持第一网络切片。此情况下，小区#1为该终端设备的源小区，第一接入网设备需要为终端设备确定目标小区。
在步骤508中，第一接入网设备暂停为第一会话激活或建立用户面连接。
由于第一接入网设备确定小区#1的第一无线资源不支持第一会话对应的第一网络切片，终端设备需要进行小区切换。因此，第一接入网设备可以向AMF发送用于指示处理切换流程中的指示信息，暂停为该第一会话激活或建立用户面连接。AMF接收到第一接入网设备发送的指示信息后，可以在稍后重新尝试发送步骤506中的N2接口请求消息，继续激活或建立用户面连接。
在步骤509中，第一接入网设备根据允许终端设备接入的网络切片、第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。
应理解，小区#1的相邻小区可能包括与小区#1同站的小区和与小区#1异站的小区。换言之，小区#1的相邻小区可能包括了站内相邻小区和站外相邻小区。因此，上述至少一个相邻小区分别支持的网络切片可以由第一接入网设备支持的网络切片以及具有相邻小区关系的接入网设备支持的网络切片来确定。因此，第一网络切片对应的频率范围具体可以是指支持该第一网络切片的各相邻小区分别支持的频率范围。换言之，步骤509也可以替换为：第一接入网设备根据允许终端设备接入的网络切片、第一网络切片、至少一个相邻小区支持的网络切片以及各网络切片对应的频率范围，确定目标频率范围。
此外，步骤509还可通过如下步骤来实现：第一接入网设备可以根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片以及终端设备所在跟踪区或注册区支持的网络切片，第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。由于上文中已经对终端设备根据签约能够使用的网络切片做了详细说明，为了简洁，这里不再重复。
如前所述，第一接入网设备可以优先选择与小区#1相同频率范围(即，第一频率范围)的小区。因此，在相邻小区中存在支持第一网络切片，且对应的频率范围为第一频率范围的小区的情况下，优先选择第一频率范围作为目标频率范围；否则，选择相邻小区支持的第一网络切片对应的其他频率范围作为目标频率范围，例如记为第二频率范围，第二频率范围与第一频率范围为不同的频率范围。换言之，目标频率范围优先为第一频率范围，其次为第二频率范围。
应理解，关于步骤509的具体过程可参看上文方法400中步骤413的相关描述，为了简洁，这里不再赘述。
在步骤510中，第一接入网设备根据目标频率范围确定目标小区。
在步骤511中，第一接入网设备控制终端设备切换至目标小区。
在步骤512中，第二接入网设备和终端设备在空口为成功切换的会话建立DRB。
在步骤513中，AMF切换第一会话的用户面路径到第二接入网设备。
在步骤514中，AMF向第二接入网设备发送N3接口端点信息。
在一种实现方式中，AMF可以将在步骤506中暂未发送的第二请求消息发送给第二接入网设备，并在该第二请求消息中携带N3接口端点信息。
在步骤515中，第二接入网设备和核心网建立用户面连接，激活第一会话的用户面。
步骤510至步骤515的具体过程与上文方法400中步骤414至步骤419的具体过程相似，为了简洁，这里不再重复。
应理解，图5以终端设备进行跨站切换为例描述了步骤511至步骤515。但这不应对本申请构成任何限定。在站内切换流程中，步骤511中涉及跨站切换的流程和步骤512至步骤515并不一定要执行。
需要说明的是，上文为方便理解和说明，以第一会话为例详细说明了第一接入网设备确定目标小区的过程。事实上，终端设备向第一接入网设备请求建立或请求激活的会话并不一定仅限于第一会话。终端设备可能并行地向第一接入网设备请求建立和/或请求激活多个会话。此情况下，第一接入网设备为终端设备确定的目标小区应综合考虑该多个会话，以期激活该多个会话。因此，该第一接入网设备在确定目标小区时，应尽可能地使得该终端设备请求建立和/或请求激活的多个会话对应的网络切片能够被目标小区支持，且都分别能够接入该目标小区支持的无线资源。
换言之，若存在这样一个小区，其所支持的网络切片包括上述终端设备请求建立和/或请求激活的多个会话，且该多个网络切片都能够在该小区中接入同一无线资源，则优先选择该小区作为目标小区。
还需要说明的是，终端设备在请求建立或请求激活第一会话之前，可能已经建立了一个或多个会话，该一个或多个会话可能包括激活的会话和/或去激活的会话。第一接入网设备在为当前请求建立或请求激活的第一会话确定目标小区时，可以进一步结合一个或多个已建立的会话，以期在所选择的目标小区中，能够尽可能多地支持该一个或多个已建立的会话。
例如，终端设备当前请求建立或请求激活的会话包括第一会话，对应的网络切片为第一网络切片；终端设备当前已激活的会话包括会话#3(第二会话的一例)，对应的网络切片为网络切片#3；终端设备当前去激活的会话包括会话#4(第二会话的又一例)，对应的网络切片为网络切片#4。第一接入网设备为终端设备确定目标小区时，应尽可能地选择能够支持第一网络切片、网络切片#3和网络切片#4的小区作为目标小区。
若第一接入网设备无法找到这样一个小区，能够同时支持第一网络切片、网络切片#3和网络切片#4，则可以根据会话的优先级来选择目标小区，以使得所选择的目标小区能够尽可能多地支持优先级较高的会话。
基于上述技术方案，终端设备在源小区请求激活的第一会话不能够被源小区的无线资源支持时，服务于源小区的第一接入网设备可以根据该第一会话对应的第一网络切片、至少一个相邻小区各自支持的网络切片以及各网络切片对应的无线资源，为终端设备确定目标小区，并控制终端设备切换至该目标小区。因此，终端设备可以在请求建立或请求激活的第一会话不被源小区的无线资源支持且存在可切换的目标小区的情况下，及时地将终端设备切换至目标小区，从而可以成功激活第一会话，及时地响应终端设备的会话请求，有利于提高用户体验。
图6是本申请实施例提供的通信方法的再一示意性流程图。图6所示的方法600可以 包括步骤601至步骤612。
为了便于理解和说明，首先对方法600所适用的场景做出如下说明：终端设备与第一接入网设备处于RRC连接态。终端设备处于第一接入网设备服务的小区#1中，并已经建立了一个会话，例如记作会话1，其对应的网络切片是S-NSSAI#1标识为的网络切片。终端设备希望建立一个新的会话，或希望激活一个会话，例如记作会话3。会话3对应的网络切片是标识为S-NSSAI#3的网络切片。可以理解，会话3是第一会话的一例，标识为S-NSSAI#3的网络切片是第一网络切片的一例。
应理解，下文步骤中针对请求建立会话而执行的步骤与针对请求激活会话而执行的步骤是基本相似的。在存在不同时，各步骤中分别针对请求建立会话和请求激活会话做了区分说明。
在方法600中，步骤602可对应于方法200中的步骤210，示出了步骤210中第一接入网设备确定终端设备满足小区切换条件的一种可能的实现方式。
步骤603和步骤609可对应于方法200中的步骤220，示出了步骤220中第一接入网设备确定目标小区的可能的实现方式。在步骤603中，第一接入网设备可以根据允许终端设备接入的网络切片、第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。在步骤604中，第一接入网设备从支持目标频率范围的站内相邻小区中确定目标小区。在步骤606至步骤609中，第一接入网设备从支持目标频率范围的站外相邻小区中确定目标小区。从支持目标频率范围的站外相邻小区中确定目标小区具体可以包括：步骤606，第一接入网设备根据目标频率范围确定无线测量参数；步骤607，第一接入网设备向终端设备发送无线测量参数；步骤608，终端设备向第一接入网设备上报对至少一个相邻小区的信号质量的测量结果；以及步骤609，第一接入网设备根据至少一个相邻小区的信号质量的测量结果确定目标小区。
步骤610可对应于方法200中的步骤230，示出了步骤230中第一接入网设备控制终端设备切换至目标小区的可能的实现方式。与步骤604对应，第一接入网设备控制终端设备进行站内切换。与步骤609对应，第一接入网设备控制终端设备进行跨站切换。在进行跨站切换的情况下，该方法还进一步包括：第一接入网设备向第二接入网设备发送请求消息，该请求消息中携带第一会话的标识信息和第一网络切片的标识信息；第一接入网设备从第二接入网设备接收用于切换的RRC参数；以及第一接入网设备向终端设备发送该RRC参数。可选地，该RRC参数与第一网络切片、第二接入网设备支持的网络切片以及第二接入网设备支持的网络切片对应的无线资源关联。
下面结合具体的流程对方法600做详细说明。
在步骤601中，终端设备向第一接入网设备发送请求建立或请求激活第一会话的消息，该消息中携带第一网络切片的标识信息。
在一种可能的设计中，该消息为会话建立请求(session establishment request)消息，以请求建立第一会话。示例性地，终端设备可以向第一接入网设备发送会话建立请求消息，该会话建立请求消息中可以携带第一网络切片的标识信息。例如，在该请求消息的RRC层携带该第一网络切片的标识信息。在本实施例中，第一网络切片的标识信息可以为S-NSSAI#3。由于该第一网络切片与第一会话对应，在该请求消息中携带第一网络切片的标识，也即通过接入第一网络切片来请求建立一个会话或激活第一网络切片中的一个会 话。
在另一种可能的设计中，该消息为会话激活请求(session activation request)消息，以请求激活第一会话。示例性地，终端设备可以向第一接入网设备发送会话激活请求消息，该会话激活请求消息中可以携带第一网络切片的标识信息。
在步骤602中，第一接入网设备确定小区#1的第一无线资源不支持第一会话对应的第一网络切片。
第一接入网设备可以根据第一网络切片的标识信息，确定小区#1所支持的第一无线资源是否支持第一网络切片。
在步骤603中，第一接入网设备根据允许终端设备接入的网络切片、第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。
其中，允许终端设备接入的网络切片在上文方法400中的步骤405已经做了详细说明。为了简洁，这里不再重复。
第一网络切片对应的频率范围具体可以是指支持该第一网络切片的各相邻小区分别支持的频率范围，换言之，也就是该第一网络切片在各相邻小区对应的频率范围。因此，步骤602可以替换为：第一接入网设备根据允许终端设备接入的网络切片、第一网络切片、至少一个相邻小区支持的网络切片以及各网络切片对应的频率范围，确定目标频率范围。
第一接入网设备可以从AMF接收允许终端设备接入的网络切片的标识信息，并确定该第一网络切片是否属于允许终端设备接入的网络切片。在第一网络切片属于允许终端设备接入的网络切片的情况下，第一接入网设备可以进一步根据该第一网络切片在各相邻小区中分别对应的频率范围，确定目标频率范围。
在另一种实现方式中，步骤603也可以替换为：第一接入网设备根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片以及终端设备所在跟踪区或注册区支持的网络切片，第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。
应理解，关于第一接入网设备确定目标频率范围的具体过程在上文方法400中的步骤410已经做了详细说明，为了简洁，这里不再赘述。
在步骤604中，第一接入网设备根据目标频率范围从站内相邻小区中确定目标小区。
第一接入网设备可以通过执行步骤604来确定站内相邻小区中是否存在可作为目标小区的小区。
示例性地，第一接入网设备可以首先确定该小区#1的站内相邻小区中是否存在支持目标频率范围的第一小区。在存在第一小区的情况下，第一接入网设备可以进一步确定第一小区是否支持第一网络切片。在第一小区支持第一网络切片的情况下，第一接入网设备可以根据第一小区的信号质量，确定是否可以作为目标小区。在第一小区的信号质量满足第二预设门限的情况下，第一接入网设备确定该第一小区为目标小区。此后，可以执行步骤610中的站内切换流程。
在小区#1的站内相邻小区不存在支持第一小区的情况下，或，在第一小区不支持第一网络切片的情况下，或，在第一小区的信号质量低于第二预设门限的情况下，第一接入网设备可以确定站内相邻小区中不存在可作为目标小区的小区。
在步骤605中，第一接入网设备可以向终端设备发送拒绝消息，暂停建立或激活该第一会话。
在一种实现方式中，该第一接入网设备可以向终端设备发送拒绝消息，以通知终端设备，该第一接入网设备拒绝建立或激活第一会话。
作为对上文步骤601中的会话建立请求消息的响应，第一接入网设备可以向终端设备发送针对该业务建立请求消息的拒绝消息，以拒绝建立该第一会话。作为对上文步骤601中会话激活请求消息的响应，第一接入网设备可以向知道不发送针对会话激活响应消息的拒绝消息，以拒绝激活该第一会话。
在步骤606中，第一接入网设备根据目标频率范围确定无线测量参数。
在步骤607中，第一接入网设备向终端设备发送该无线测量参数。
在一种实现方式中，该无线测量参数可以携带在上述拒绝消息中，以触发终端设备对至少一个相邻小区的信号质量的测量。
在步骤608中，终端设备基于该无线测量参数对至少一个相邻小区的信号质量进行测量，向第一接入网设备上报对至少一个相邻小区的信号质量的测量结果。
在步骤609中，第一接入网设备根据至少一个相邻小区的信号质量的测量结果，确定目标小区。
第一接入网设备由此而确定的目标小区是从站外相邻小区中确定的目标小区。终端设备需要切换接入网设备。
一示例，终端设备请求建立的第一会话为会话3，第一网络切片是标识为S-NSSAI#3的网络切片。假设第一接入网设备支持的网络切片及各网络切片对应的频率范围包括：{S-NSSAI#1，(N41)}和{S-NSSAI#2，(N41，N79)}，第二接入网设备支持的网络切片及各网络切片对应的频率范围包括：{S-NSSAI#1，(N41，N79)}、{S-NSSAI#2，(N79)}和{S-NSSAI#3，(N79)}。
可以看到，第一接入网设备支持的网络切片的标识不包括S-NSSAI#3，则该小区#1的站内相邻小区不存在能够支持会话3的网络切片的小区。而第二接入网设备支持的网络切片的标识包括S-NSSAI#3，则该小区#1的站外相邻小区存在能够支持会话3的网络切片的小区。第一接入网设备可以从小区#1的站外相邻小区中寻找目标小区。第一接入网设备可以进一步根据该网络切片对应的频率范围，确定标识为S-NSSAI#3的网络切片在第二接入网设备中对应的频率范围是N79频段，故目标频率范围为N79频段。此后，第一接入网设备可以基于N79频段从小区#1的站外相邻小区中寻找目标小区。该目标小区能够在N79频段提供标识为S-NSSAI#3的网络切片的接入服务。
进一步地，若终端设备在小区#1中已经建立了会话1，对应的网络切片是标识为S-NSSAI#1的网络切片。则第一接入网设备可以结合会话1和会话3分别对应的网络切片，确定目标频率范围。如，会话1对应标识为S-NSSAI#1的网络切片，会话3对应标识为S-NSSAI#3的网络切片，在第二接入网设备对应的共同的频率范围是N79频段，则该目标频率范围为N79频段。此后，第一接入网设备可以基于N79频段从小区#1的站外相邻小区中寻找目标小区。该目标小区能够在N79频段提供标识为S-NSSAI#1和S-NSSAI#3的网络切片的接入服务。
应理解，上文为便于理解，结合具体示例描述了第一接入网设备确定目标频率范围进而确定目标小区的过程。文中示例的各会话与网络切片的对应关系、各接入网设备支持的网络切片以及各网络切片对应的频率范围等仅为示例，不应对本申请构成任何限定。
还应理解，在存在多个请求建立和/或请求激活的会话的情况下，第一接入网设备为终端设备确定目标小区的相关内容在上文方法400和方法500中已经做了详细说明，为了简洁，这里不再赘述。
还应理解，在终端设备还存在一个或多个已建立的会话(例如包括激活的和/或去激活的会话)的情况下，第一接入网设备为终端设备确定目标小区的相关内容在上文方法400和方法500中也已经做了详细说明，为了简洁，这里不再赘述。
在步骤610中，第一接入网设备控制终端设备切换至目标小区。
如前所述，第一接入网设备可能控制终端设备执行站内切换流程，也可能控制终端设备执行跨站切换流程，这取决于目标小区是否为第一接入网设备服务的小区。应理解，由于在上文方法300中的步骤305中已经结合站内切换流程和跨站切换流程分别做了详细说明，且终端设备进行站内切换和跨站切换的具体流程可以参考现有技术，为了简洁，这里不做详述。
在步骤611中，终端设备向第二接入网设备发送请求建立或请求激活第一会话的消息，该消息中携带第一会话对应的第一网络切片的标识信息。
终端设备向第二接入网设备发送的消息与终端设备在步骤601中向第一接入网设备发送的请求建立或请求激活第一会话的消息相似，其中在RRC层携带第一网络切片的标识信息。该请求消息用于请求建立或请求激活第一会话。
在步骤612中，终端设备通过第二接入网设备发起会话建立流程。
由此，第一会话得以成功建立。终端设备可以通过第一会话正常传输业务数据。
应理解，基于请求建立或请求激活第一会话的不同场景，步骤612也并不一定要执行。例如，在请求激活第一会话的场景下，步骤612可以省略。终端设备在切换至第二接入网设备之后，便完成了第一会话的激活。
还应理解，上文示出的多个步骤并不是一定要执行的。比如，若目标小区为小区#1的站内相邻小区，上文步骤604至步骤608至步骤611不一定要执行。
基于上述技术方案，终端设备在源小区请求建立的第一会话不能够被源小区的无线资源支持时，服务于源小区的第一接入网设备可以根据该第一会话对应的第一网络切片、至少一个相邻小区各自支持的网络切片以及各网络切片对应的无线资源，为终端设备确定目标小区，并控制终端设备切换至该目标小区。因此，终端设备可以在请求建立的第一会话不被源小区的无线资源支持且存在可切换的目标小区的情况下，及时地将终端设备切换至目标小区，从而可以成功建立并激活第一会话，及时地响应终端设备的会话请求，有利于提高用户体验。
图7是本申请实施例提供的通信方法的再一示意性流程图。图7所示的方法700可以包括步骤701至步骤713。
方法700所适用的的场景与方法600所适用的场景相同，可以参看上文方法600中介绍的场景。为了简洁，这里不再重复。所不同的是，在方法700中，终端设备请求建立第一会话。
在方法700中，步骤706可对应于方法200中的步骤210，示出了步骤210中第一接入网设备确定终端设备满足小区切换条件的一种可能的实现方式。
步骤707和步骤709可对应于方法200中的步骤220，示出了步骤220中第一接入网 设备确定目标小区的可能的实现方式。在步骤707中，第一接入网设备可以根据允许终端设备接入的网络切片、第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。在步骤709中，第一接入网设备根据目标频率范围确定目标小区。步骤709的一种可能的实现方式是，第一接入网设备从支持目标频率范围的站内相邻小区中确定所述目标小区。步骤709的另一种可能的实现方式是，从支持目标频率范围的站外相邻小区中确定所述目标小区。在从支持目标频率范围的站外相邻小区中确定目标小区的情况下，该方法还进一步包括：第一接入网设备根据目标频率范围确定无线测量参数；第一接入网设备向终端设备发送无线测量参数，该无线测量参数用于终端设备对相邻小区的信号质量的测量，终端设备对相邻小区的信号质量的测量用于目标小区的确定。
步骤710可对应于方法200中的步骤230，示出了步骤230中第一接入网设备控制终端设备切换至目标小区的可能的实现方式。与步骤709对应，步骤710的一种可能的实现方式是，第一接入网设备控制终端设备进行站内切换。步骤710的另一种可能的实现方式是，第一接入网设备控制终端设备进行跨站切换。在进行跨站切换的情况下，该方法还进一步包括：第一接入网设备向第二接入网设备发送请求消息，该请求消息中携带第一会话的标识信息和第一网络切片的标识信息；第一接入网设备从第二接入网设备接收用于切换的RRC参数；以及第一接入网设备向终端设备发送该RRC参数。可选地，该RRC参数与第一网络切片、第二接入网设备支持的网络切片以及第二接入网设备支持的网络切片对应的无线资源关联。
下面结合具体的流程对方法700做详细说明。
在步骤701中，终端设备经由第一接入网设备向AMF发送请求建立第一会话的消息，该消息中携带第一会话的标识信息。
在一种实现方式中，终端设备可以在向第一接入网设备发送的消息中携带第一会话的标识信息，而不携带第一网络切片的标识信息。第一接入网设备可以将该会话建立请求消息转发给AMF。在本实施例中，该第一会话的标识信息例如可以是会话3。
如方法600中所述，在一种可能的设计中，该消息为会话建立请求消息。
在步骤702中，AMF和SMF为请求建立的第一会话创建会话管理(session management)上下文(SM context)。
例如，AMF可以选择SMF，并和所选择的SMF为第一会话创建会话管理上下文。
在步骤703中，SFM和UPF建立N4接口会话。
例如，SMF可以选择UPF，并向选择的UPF发送N4会话建立请求，以请求建立N4会话。
在步骤704中，SMF向AMF发送第一网络切片的标识信息。
SMF可以向AMF发送N1N2传输消息(N1N2 message transfer)，其中携带N2会话管理信息(N2 SM information)。该N2会话管理信息中包含新创建的会话的信息，其中包括上述第一会话对应的第一网络切片的标识信息。在本实施例中，该第一网络切片的标识信息可以是S-NSSAI#3。
在步骤705中，AMF向第一接入网设备发送第一网络切片的标识信息。
该AMF可以基于接收到的N2会话管理信息，向第一接入网设备转发该N2会话管理信息。如前所述，该N2会话管理信息中携带第一网络切片的标识信息。由此，第一接入 网设备可以确定终端设备请求建立的第一会话对应的第一网络切片。
在一种可能的设计中，该N2会话管理信息携带在N2接口请求消息中。
在步骤706中，第一接入网设备确定终端当前所在小区#1的第一无线资源不支持第一会话对应的第一网络切片。
第一接入网设备可以根据第一网络切片的标识信息，确定小区#1所支持的第一无线资源是否支持第一网络切片。
在步骤707中，第一接入网设备根据允许终端设备接入的网络切片、第一网络切片以及该第一网络切片对应的工作频率，确定目标频率范围。
在另一种实现方式中，步骤707也可以替换为：第一接入网设备根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片以及终端设备所在跟踪区或注册区支持的网络切片，第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。应理解，关于第一接入网设备确定目标频率范围的具体过程在上文方法400中的步骤413已经做了详细说明，为了简洁，这里不再赘述。
在步骤708中，第一接入网设备确定终端设备当前工作的频率范围与目标频率范围不同，向AMF发送用于指示处理切换流程中的指示信息。
终端设备当前工作的频率范围是指终端设备当前所在的小区#1的第一无线资源所对应的频率范围，也即小区#1支持的频率范围。若终端设备当前工作的频率范围与目标频率范围不一致，则可确定该终端设备需要进行小区切换。因此，第一接入网设备可以暂停为第一会话分配DRB，并向AMF发送用于指示处理切换流程中的指示信息。AMF接收到第一接入网设备发送的指示信息后，可以在稍后重新尝试发送步骤705中的N2接口请求消息，继续建立用户面连接。
在步骤709中，第一接入网设备根据目标频率范围确定目标小区。
可选地，步骤709具体包括：第一接入网设备从支持目标频率范围的站内相邻小区中确定目标小区。
示例性地，第一接入网设备可以首先确定该小区#1的站内相邻小区中是否存在支持目标频率范围的第一小区。在存在第一小区的情况下，第一接入网设备可以进一步确定第一小区是否支持第一网络切片。在第一小区支持第一网络切片的情况下，第一接入网设备可以根据第一小区的信号质量，确定是否可以作为目标小区。在第一小区的信号质量满足第二预设门限的情况下，第一接入网设备确定该第一小区为目标小区。此后，可以执行步骤714中的站内切换流程。
可选地，步骤709具体包括：第一接入网设备从支持目标频率范围的站外相邻小区中确定目标小区。
在小区#1的站内相邻小区不存在支持第一小区的情况下，或，在第一小区不支持第一网络切片的情况下，或，在第一小区的信号质量低于第二预设门限的情况下，或，在第一接入网设备服务的小区仅包括小区#1的情况下，第一接入网设备可以确定站内相邻小区中不存在可作为目标小区的小区。第一接入网设备据此可以在站外相邻小区中确定目标小区。
第一接入网设备在站外相邻小区中确定目标小区的具体过程在上文方法400的步骤411中已经做了详细说明，为了简洁，这里不再赘述。
应理解，在存在多个请求建立的会话的情况下，第一接入网设备为终端设备确定目标小区的相关内容在上文方法400和方法500中已经做了详细说明，为了简洁，这里不再赘述。
还应理解，在终端设备还存在一个或多个已建立的会话(例如包括激活的和/或去激活的会话)的情况下，第一接入网设备为终端设备确定目标小区的相关内容在上文方法400和方法500中也已经做了详细说明，为了简洁，这里不再赘述。
在步骤710中，第一接入网设备控制终端设备切换至目标小区。
如前所述，第一接入网设备可能控制终端设备执行站内切换流程，也可能控制终端设备执行跨站切换流程，这取决于目标小区是否为第一接入网设备服务的小区。应理解，由于在上文方法300中的步骤305中已经结合站内切换流程和跨站切换流程分别做了详细说明，且终端设备进行站内切换和跨站切换的具体流程可以参考现有技术，为了简洁，这里不做详述。
在步骤711中，AMF进行路径切换，将终端设备切换到第二接入网设备。
在一种实现方式中，第二接入网设备可以基于与终端设备之间的空口切换的完成，向AMF发送切换完成消息，或者，向AMF发送路径切换消息。AMF可以基于来自第二接入网设备的消息进行路径切换。
在步骤712中，AMF向第二接入网设备重新发送步骤中的N2接口请求消息，继续为新创建的第一会话建立用户面连接。
在步骤713中，第二接入网设备在目标小区支持的频率范围为新创建的第一会话分配DRB。
目标小区支持的频率范围即上述目标频率范围。第二接入网设备可以在目标频率范围为第一会话分配DRB。并可以向终端设备发送会话建立接受消息。
在一种可能的设计中，该会话建立接受消息可以携带在接入网特定资源建立(AN-specific resource setup)消息中。
第一会话成功建立后，终端设备便可以通过该第一会话传输业务数据。
应理解，上文示出的多个步骤并不是一定都要执行。比如，若目标小区为小区#1的站内相邻小区，上文步骤710中的部分步骤(涉及跨站切换流程的步骤)以及步骤711至步骤713不一定要执行。
基于上述技术方案，终端设备在源小区请求建立的第一会话不能够被源小区的无线资源支持时，服务于源小区的第一接入网设备可以根据该第一会话对应的第一网络切片、至少一个相邻小区各自支持的网络切片以及各网络切片对应的无线资源，为终端设备确定目标小区，并控制终端设备切换至该目标小区。因此，终端设备可以在请求建立的第一会话不被源小区的无线资源支持且存在可切换的目标小区的情况下，及时地将终端设备切换至目标小区，从而可以成功建立第一会话，及时地响应终端设备的会话请求，有利于提高用户体验。
图8是本申请实施例提供的通信方法的再一示意性流程图。图8所示的方法800可以包括步骤810至步骤820。
在步骤810中，第一接入网设备确定终端设备在源小区接入的第一无线资源不支持终端设备请求建立或请求激活的第一会话对应的第一网络切片。
在步骤820中，第一接入网设备向终端设备发送RRC连接释放消息，以释放与终端设备的RRC连接。
在步骤810中，终端设备在源小区请求建立或请求激活的会话记为第一会话，第一会话对应的网络切片记为第一网络切片。终端设备在源小区接入的第一无线资源不支持第一会话对应的第一网络切片，具体可以是指，该第一无线资源所提供的频率范围不支持第一网络切片，或者说，源小区不支持第一网络切片。因此，源小区提供的频率范围不能为终端设备请求建立或请求激活的第一会话对应的第一网络切片提供接入服务。
一种可能的场景是，终端设备在开机后接入网络，或因为移动到一个不属于原来注册区域的新TA，向网络发起注册请求。或者，终端设备周期性地向网络更新注册时，向网络发起注册请求。终端设备可能在注册请求中携带请求建立或请求激活的会话列表。该会话列表中包括终端设备请求建立和/或请求激活的会话的标识信息。该终端设备请求建立或请求激活的会话例如可以包括但不限于第一会话。
另一种可能的场景是，终端设备期望建立新的会话。终端设备可以向第一接入网设备发送会话建立请求消息，以请求建立一个或多个会话。终端设备请求建立的一个或多个会话例如可以包括但不限于第一会话。
在上述多个可能的场景中，若第一接入网设备确定第一无线资源不支持终端设备请求建立或请求激活的第一会话对应的第一网络切片，则可确定该终端设备不适合继续驻留在小区#1中，因此可以执行步骤220，释放与该终端设备之间的RRC连接释放。
终端设备基于与第一接入网设备之间的RRC连接释放，进入空闲态，进而可以重新进行小区选择，以选择合适的小区，发起RRC连接请求。
基于上述技术方案，第一接入网设备可以在终端设备接入的第一无线资源不支持请求建立或请求激活的第一会话的第一网络切片的情况下，主动释放与终端设备之间的RRC连接，从而使得终端设备可以快速地进入空闲态，发起小区重选。而不必等到当前的业务进行完毕后才进入空闲态。因此，终端设备可以在请求建立或请求激活的第一会话不被源小区的无线资源支持的情况下，及时地进行小区重选，使得终端设备请求建立或请求激活的第一会话得以成功激活，从而能够及时地响应终端设备的请求，有利于提高用户体验。
由于下文会结合图9和图10对本申请提供的通信方法800应用于上述场景的具体过程展开描述，为了简洁，这里暂且不作详述。
图9是本申请实施例提供的通信方法的再一示意性流程图。图9所示的方法900可以包括步骤901至步骤921。
方法900所适用的流程与上文方法400中所适用的场景相同，为了简洁，这里不再赘述。
在方法900中，步骤907可对应于方法800中的步骤810，步骤911可对应于方法800中的步骤820。可选地，第一接入网设备在步骤911中向终端设备发送的RRC连接释放消息可以携带用于小区重选的无线参数。可选地，在步骤911之前，该方法还包括：步骤910，第一接入网设备根据目标频率范围、至少一个相邻小区各自支持的网络切片以及各网络切片对应的频率范围，确定无线参数。
应理解，方法900中各步骤中关于建立会话和激活会话的相关说明可以参看上文实施例中的相关描述，为了简洁，这里不再重复。
在步骤901中，终端设备经由第一接入网设备向AMF发送请求建立或请求激活第一会话的标识信息。
在步骤902中，AMF从UDM获取该终端设备的签约信息的网络切片的标识信息。
在步骤903中，AMF确定允许终端设备接入的网络切片。
在步骤904中，AMF根据允许终端设备接入的网络切片，确定允许建立或允许激活的会话。
在步骤905中，SMF建立N4接口会话，控制UPF建立第一会话的用户面连接；或者，SMF修改N4接口会话，控制UPF激活第一会话的用户面连接。
在步骤906中，AMF向第一接入网设备发送允许终端设备接入的网络切片的标识信息。
在步骤907中，第一接入网设备确定终端当前所在小区#1的第一无线资源不支持第一会话对应的第一网络切片。
在步骤908中，第一接入网设备根据允许终端设备接入的网络切片、第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。
可替换地，步骤908也可通过如下步骤实现：第一接入网设备可以根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片以及终端设备所在跟踪区或注册区支持的网络切片，第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。
应理解，步骤901至步骤908的具体过程可参看上文方法400中步骤403至步骤410的相关描述，为了简洁，这里不再重复。
在步骤909中，第一接入网设备确定终端设备当前工作的频率范围与目标频率范围不同。
终端设备当前工作的频率范围也就是终端设备当前所在的小区#1支持的频率范围，或者说，小区#1的第一无线资源所对应的频率范围。若终端设备当前工作的频率范围与目标频率范围不同，则说明该小区#1的第一无线资源不支持第一网络切片。
步骤910中，第一接入网设备根据目标频率范围、至少一个相邻小区的网络切片以及各网络切片对应的频率范围，确定无线参数。
该无线参数可用于终端设备的小区重选。例如，该无线参数中可以包括目标频率范围的指示，终端设备可以基于该指示优先重选支持目标频率范围的小区。
在步骤911中，第一接入网设备向终端设备发送RRC连接释放消息，以释放与终端设备的RRC连接。
第一接入网设备基于小区#1不支持第一网络切片，决定暂停为终端设备请求建立或请求激活的第一会话分配DRB，同时决定释放与终端设备之间的RRC连接，去激活该终端设备所有已经建立的会话。终端设备由此直接进入空闲态，进行小区重选，而不必等到当前业务进行完成后才进入空闲态。
在一种实现方式中，第一接入网设备在步骤910中确定的无线参数可以携带在上述RRC连接释放消息中。即，步骤910可以在步骤911之前执行。在另一种实现方式中，该无线参数可以通过其他信令下发给终端设备。此情况下，对步骤910和步骤911执行的先后顺序不作限定。
在一种可能的设计中，步骤901中的请求建立或请求激活的第一会话的标识信息可以 携带在由终端设备向AMF发送的注册请求消息中。步骤906中允许终端设备接入的网络切片的标识信息可以携带在由AMF向第一接入网设备发送的注册接受消息中。步骤910中的RRC连接释放消息可以携带在由第一接入网设备向终端设备转发的注册接受消息中。
在步骤912中，终端设备去激活所有会话，进入空闲态。
终端设备可以基于在步骤911接收到的RRC连接释放消息，接入空闲态。
在步骤913中，终端设备基于无线参数进行小区重选，以确定重新接入的接入网设备为第二接入网设备。
终端设备在空闲态可以基于第一接入网设备下发的无线参数进行小区重选。终端设备可以首先基于无线参数，在目标频率范围寻找合适的小区，该小区可以理解为上文实施例中的目标小区，即，该小区可以在目标频率范围提供第一网络切片的接入服务，或者说，该小区提供的无线资源支持第一网络切片。终端设备可以基于该小区所属的接入网设备，确定重新接入的接入网设备。
假设该终端设备基于小区重选，确定重新接入的接入网设备为第二接入网设备。
在步骤914中，终端设备向第二接入网设备发起RRC连接，并发送请求建立或请求激活的第一会话的消息，该消息中携带请求建立或请求激活的第一会话的标识信息。
在一种可能的设计中，该终端设备请求建立或请求激活的第一会话的标识信息可以携带在业务请求(service request)消息中。终端设备可以向第二接入网设备发送RRC连接请求消息，并在该RRC连接请求消息中携带业务请求消息，以请求建立或请求激活第一会话。
在步骤915中，第二接入网设备向AMF发送请求建立或请求激活第一会话的消息，该消息中携带该第一会话的标识信息。
步骤915中第二接入网设备可以通过N2接口消息向AMF转发上述请求建立或请求激活的消息。作为步骤914中接收到的业务请求消息的响应，第二接入网设备可以将该业务请求消息转发给AMF。
在步骤916中，AMF向SMF发送创建会话管理上下文请求消息，或，AMF向SMF发送会话管理上下文更新请求消息。
在步骤917中，SMF接受第一会话建立的请求，或，SMF接受用户面激活的请求。SMF还可能会因终端设备接入到新的接入网设备，而重新选择一个新的UPF。
在步骤918中，SMF建立N4接口会话，控制UPF建立第一会话的用户面连接；或者，SMF修改N4接口会话，控制UPF激活第一会话的用户面连接。
在步骤919在，SMF向AMF发送创建会话管理上下文成功的响应消息，或，SMF向AMF发送会话管理上下文更新成功的响应消息。
在步骤920中，AMF向第二接入网设备发送N2接口请求消息，其中携带第一会话的信息，其中包含了第一会话对应的第一网络切片的标识信息。
在步骤921中，第二接入网设备根据第一会话对应的第一网络切片，在目标频率范围为终端设备建立DRB，连接第一会话的用户面。
由此，第一会话得以成功激活。终端设备可以通过第一会话传输业务数据。
基于上述技术方案，终端设备在源小区请求建立或请求激活的第一会话不能够被源小 区的无线资源支持时，服务于源小区的第一接入网设备可以直接释放与该终端设备之间的RRC连接，以便于终端设备进入空闲态，进行小区重选，而不必等到终端设备当前的业务进行完毕后才进入空闲态。因此，终端设备可以在请求建立或请求激活的第一会话不被源小区的无线资源支持的情况下，及时地进行小区重选，使得终端设备请求建立或请求激活的第一会话得以成功激活，从而能够及时地响应终端设备的请求，有利于提高用户体验。
图10是本申请实施例提供的通信方法的再一示意性流程图。图10所示的方法1000可以包括步骤1001至1020。
方法1000所适用的流程与上文方法600中所适用的场景相同，为了简洁，这里不再赘述。
在方法1000中，步骤1006可对应于方法800中的步骤810，步骤1010可对应于方法800中的步骤820。可选地，第一接入网设备在步骤1010中向终端设备发送的RRC连接释放消息可以携带用于小区重选的无线参数。可选地，在步骤1010之前，该方法还包括：步骤1009，第一接入网设备根据目标频率范围、至少一个相邻小区各自支持的网络切片以及各网络切片对应的频率范围，确定无线参数。
应理解，方法1000中各步骤中关于建立会话和激活会话的相关说明可以参看上文实施例中的相关描述，为了简洁，这里不再重复。
在步骤1001中，终端设备经由第一接入网设备向AMF发送请求建立或请求激活第一会话的消息，该消息携带该第一会话的标识信息。
在步骤1002中，AMF和SMF为请求建立的第一会话创建会话管理上下文，或，更新会话管理上下文。
在步骤1003中，SMF和UPF建立N4接口会话或修改N4接口会话。
在步骤1004中，SMF向AMF发送第一网络切片的标识信息。
在步骤1005中，AMF向第一接入网设备发送第一网络切片的标识信息。
在步骤1006中，第一接入网设备确定终端当前所在小区#1的第一无线资源不支持第一会话对应的第一网络切片。
在步骤1007中，第一接入网设备根据允许终端设备接入的网络切片、第一网络切片以及该第一网络切片对应的工作频率，确定目标频率范围。
可替换地，步骤1007也可通过如下步骤实现：第一接入网设备可以根据终端设备请求的网络切片、终端设备根据签约能够使用的网络切片以及终端设备所在跟踪区或注册区支持的网络切片，第一网络切片以及第一网络切片对应的频率范围，确定目标频率范围。
应理解，步骤1001至步骤1007的具体过程可参看上文方法700中步骤701至步骤707的相关描述，为了简洁，这里不再重复。
在步骤1008中，第一接入网设备确定终端设备当前工作的频率范围与目标频率范围不同。
在步骤1009中，第一接入网设备根据第一频率至少一个相邻小区的网络切片以及各网络切片对应的频率范围，确定无线参数。
在步骤1010中，第一接入网设备向终端设备发送RRC连接释放消息，以释放与终端设备的RRC连接。
在步骤1011中，终端设备去激活所有会话，进入空闲态。
在步骤1012中，终端设备基于无线参数进行小区重选，以确定重新接入的接入网设备为第二接入网设备。
在步骤1013中，终端设备向第二接入网设备发起RRC连接，并发送请求建立的第一会话的标识信息。
在步骤1014中，第二接入网设备通过向AMF发送第一会话的标识信息。
在步骤1015中，AMF向SMF发送创建会话管理上下文请求消息，或，AMF向SMF发送会话管理上下文更新请求消息。
在步骤1016中，SMF接受第一会话建立的请求，或，SMF接受用户面激活的请求。SMF还可能会因终端设备接入到新的接入网设备，而重新选择一个新的UPF。
在步骤1017中，SMF建立N4接口会话，控制UPF建立第一会话的用户面连接；或，SMF修改N4接口会话，控制UPF激活第一会话的用户面连接。
在步骤1018在，SMF向AMF发送创建会话管理上下文成功的响应消息，或，SMF向AMF发送会话管理上下文更新成功的响应消息。
在步骤1019中，AMF向第二接入网设备发送N2接口请求消息，其中携带第一会话的信息，其中包含了第一会话对应的第一网络切片的标识信息。
在步骤1020中，第二接入网设备根据第一会话对应的第一网络切片，在目标频率范围为终端设备建立DRB，连接第一会话的用户面。
由此，第一会话得以成功建立并激活。终端设备可以通过第一会话传输业务数据。
应理解，步骤1008至步骤1020的具体过程可参看上文方法900中的步骤909至步骤921的相关描述，为了简洁，这里不再重复。
基于上述技术方案，终端设备在源小区请求建立或请求激活的第一会话不能够被源小区的无线资源支持时，服务于源小区的第一接入网设备可以直接释放与该终端设备之间的RRC连接，以便于终端设备进入空闲态，进行小区重选，而不必等到终端设备当前的业务进行完毕后才进入空闲态。因此，终端设备可以在请求建立或请求激活的第一会话不被源小区的无线资源支持的情况下，及时地进行小区重选，使得终端设备请求建立的第一会话得以成功建立并激活，从而能够及时地响应终端设备的请求，有利于提高用户体验。
应理解，在上文各实施例中，各网元可以执行各实施例中的部分或全部步骤。这些步骤或操作仅是示例，本申请实施例还可以执行其它操作或者各种操作的变形。此外，各个步骤可以按照各实施例呈现的不同的顺序来执行，并且有可能并非要执行本申请实施例中的全部操作。且，各步骤的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
以上，结合图2至图10详细说明了本申请实施例提供的通信方法。以下，结合图11至图13详细说明本申请实施例提供的通信装置。
图11是本申请实施例提供的通信装置的示意性框图。如图11所示，该通信装置2000可以包括确定单元2100、控制单元2200和收发单元2300。
可选地，该通信装置2000可对应于上文方法实施例中的第一接入网设备，例如，可以为第一接入网设备，或者配置于第一接入网设备中的部件(如电路、芯片或芯片系统等)。
应理解，该通信装置2000可对应于根据本申请实施例的方法200至1000中的第一接入网设备，该通信装置2000可以包括用于执行图2中的方法200至图10中的方法1000 中第一接入网设备执行的方法的单元。并且，该通信装置2000中的各单元和上述其他操作和/或功能分别为了实现图2中的方法200至图10中的方法1000的相应流程。
应理解，该通信装置2000为第一接入网设备时，该通信装置2000中的收发单元2300可以通过收发器实现，例如可对应于图12中示出的通信装置3000中的收发器3020或图13中示出的基站4000中的RRU 4100。该通信装置2000中的确定单元2100和控制单元2200可通过至少一个处理器实现，例如可对应于图12中示出的通信装置3000中的处理器3010或图13中示出的基站4000中的处理单元4200或处理器4202。
还应理解，该通信装置2000为配置于第一接入网设备中的芯片或芯片系统时，该通信装置2000中的收发单元2300可以通过输入/输出接口、电路等实现，该通信装置2000中的确定单元2100和控制单元2200可以通过该芯片或芯片系统上集成的处理器、微处理器或集成电路等实现。
图12是本申请实施例提供的通信装置3000的另一示意性框图。如图12所示，该通信装置3000包括处理器3010、收发器3020和存储器3030。其中，处理器3010、收发器3020和存储器3030通过内部连接通路互相通信，该存储器3030用于存储指令，该处理器3010用于执行该存储器3030存储的指令，以控制该收发器3020发送信号和/或接收信号。
应理解，该通信装置3000可以对应于上述方法实施例中的第一接入网设备，并且可以用于执行上述方法实施例中第一接入网设备执行的各个步骤和/或流程。可选地，该存储器3030可以包括只读存储器和随机存取存储器，并向处理器提供指令和数据。存储器的一部分还可以包括非易失性随机存取存储器。存储器3030可以是一个单独的器件，也可以集成在处理器3010中。该处理器3010可以用于执行存储器3030中存储的指令，并且当该处理器3010执行存储器中存储的指令时，该处理器3010用于执行上述方法实施例中与第一接入网设备对应的各个步骤和/或流程。
可选地，该通信装置3000是前文实施例中的第一接入网设备。
其中，收发器3020可以包括发射机和接收机。收发器3020还可以进一步包括天线，天线的数量可以为一个或多个。该处理器3010和存储器3030与收发器3020可以是集成在不同芯片上的器件。如，处理器3010和存储器3030可以集成在基带芯片中，收发器3020可以集成在射频芯片中。该处理器3010和存储器3030与收发器3020也可以是集成在同一个芯片上的器件。本申请对此不作限定。
可选地，该通信装置3000是配置在第一接入网设备中的部件，如电路、芯片、芯片系统等。
其中，收发器3020也可以是通信接口，如输入/输出接口、电路等。该收发器3020与处理器3010和存储器3030都可以集成在同一个芯片中，如集成在基带芯片中。
图13是本申请实施例提供的网络设备的结构示意图，例如可以为基站的结构示意图。该基站4000可应用于如图1所示的系统中，执行上述方法实施例中第一接入网设备的功能。
如图所示，该基站4000可以包括一个或多个射频单元，如远端射频单元(remote radio unit，RRU)4100和一个或多个基带单元(BBU)(也可称为分布式单元(DU))4200。所述RRU 4100可以称为收发单元，可以与图11中的收发单元2300或图12中的收发器 3020对应。可选地，该RRU 4100还可以称为收发机、收发电路、或者收发器等等，其可以包括至少一个天线4101和射频单元4102。可选地，RRU 4100可以包括接收单元和发送单元，接收单元可以对应于接收器(或称接收机、接收电路)，发送单元可以对应于发射器(或称发射机、发射电路)。所述RRU 4100部分主要用于射频信号的收发以及射频信号与基带信号的转换，例如用于向终端设备发送无线测量参数、RRC连接释放消息等。所述BBU 4200部分主要用于进行基带处理，对基站进行控制等。所述RRU 4100与BBU 4200可以是物理上设置在一起，也可以物理上分离设置的，即分布式基站。
所述BBU 4200为基站的控制中心，也可以称为处理单元，可以与图11中的确定单元2100和控制单元2200或图12中的处理器3010对应，主要用于完成基带处理功能，如信道编码，复用，调制，扩频等等。例如所述BBU(处理单元)可以用于控制基站执行上述方法实施例中关于第一接入网设备的操作流程，例如，确定目标频率范围、确定目标小区等。
在一个示例中，所述BBU 4200可以由一个或多个单板构成，多个单板可以共同支持单一接入制式的无线接入网(如LTE网)，也可以分别支持不同接入制式的无线接入网(如LTE网，5G网或其他网)。所述BBU 4200还包括存储器4201和处理器4202。所述存储器4201用以存储必要的指令和数据。所述处理器4202用于控制基站进行必要的动作，例如用于控制基站执行上述方法实施例中关于网络设备的操作流程。所述存储器4201和处理器4202可以服务于一个或多个单板。也就是说，可以每个单板上单独设置存储器和处理器。也可以是多个单板共用相同的存储器和处理器。此外每个单板上还可以设置有必要的电路。
应理解，图13所示的基站4000能够实现图2至图10所示方法实施例中涉及第一接入网设备的各个过程。基站4000中的各个模块的操作和/或功能，分别为了实现上述方法实施例中的相应流程。具体可参见上述方法实施例中的描述，为避免重复，此处适当省略详细描述。
上述BBU 4200可以用于执行前面方法实施例中描述的由第一接入网设备内部实现的动作，而RRU 4100可以用于执行前面方法实施例中描述的第一接入网设备向终端设备发送或从终端设备接收的动作。具体请见前面方法实施例中的描述，此处不再赘述。
应理解，图13所示出的基站4000仅为接入网设备的一种可能的形态，而不应对本申请构成任何限定。本申请所提供的方法可适用于其他形态的接入网设备。例如，包括AAU，还可以包括CU和/或DU，或者包括BBU和自适应无线单元(adaptive radio unit，ARU)，或BBU；也可以为客户终端设备(customer premises equipment，CPE)，还可以为其它形态，本申请对于网络设备的具体形态不做限定。
其中，CU和/或DU可以用于执行前面方法实施例中描述的由接入网设备内部实现的动作，而AAU可以用于执行前面方法实施例中描述的接入网设备向终端设备发送或从终端设备接收的动作。具体请见前面方法实施例中的描述，此处不再赘述。
本申请还提供了一种处理装置，包括至少一个处理器，所述至少一个处理器用于执行存储器中存储的计算机程序，以使得所述处理装置执行上述任一方法实施例中第一接入网设备所执行的方法。
本申请实施例还提供了一种处理装置，包括处理器和通信接口。所述通信接口与所述 处理器耦合。所述通信接口用于输入和/或输出信息。所述信息包括指令和数据中的至少一项。所述处理器用于执行计算机程序，以使得所述处理装置执行上述任一方法实施例中第一接入网设备所执行的方法。
本申请实施例还提供了一种处理装置，包括处理器和存储器。所述存储器用于存储计算机程序，所述处理器用于从所述存储器调用并运行所述计算机程序，以使得所述处理装置执行上述任一方法实施例中第一接入网设备所执行的方法。
应理解，上述处理装置可以是一个或多个芯片。例如，该处理装置可以是现场可编程门阵列(field programmable gate array，FPGA)，可以是专用集成芯片(application specific integrated circuit，ASIC)，还可以是系统芯片(system on chip，SoC)，还可以是中央处理器(central processor unit，CPU)，还可以是网络处理器(network processor，NP)，还可以是数字信号处理电路(digital signal processor，DSP)，还可以是微控制器(micro controller unit，MCU)，还可以是可编程控制器(programmable logic device，PLD)或其他集成芯片。
在实现过程中，上述方法的各步骤可以通过处理器中的硬件的集成逻辑电路或者软件形式的指令完成。结合本申请实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器，处理器读取存储器中的信息，结合其硬件完成上述方法的步骤。为避免重复，这里不再详细描述。
应注意，本申请实施例中的处理器可以是一种集成电路芯片，具有信号的处理能力。在实现过程中，上述方法实施例的各步骤可以通过处理器中的硬件的集成逻辑电路或者软件形式的指令完成。上述的处理器可以是通用处理器、数字信号处理器(DSP)、专用集成电路(ASIC)、现场可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件。可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件译码处理器执行完成，或者用译码处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器，处理器读取存储器中的信息，结合其硬件完成上述方法的步骤。
可以理解，本申请实施例中的存储器可以是易失性存储器或非易失性存储器，或可包括易失性和非易失性存储器两者。其中，非易失性存储器可以是只读存储器(read-only memory，ROM)、可编程只读存储器(programmable ROM，PROM)、可擦除可编程只读存储器(erasable PROM，EPROM)、电可擦除可编程只读存储器(electrically EPROM，EEPROM)或闪存。易失性存储器可以是随机存取存储器(random access memory，RAM)，其用作外部高速缓存。通过示例性但不是限制性说明，许多形式的RAM可用，例如静态随机存取存储器(static RAM，SRAM)、动态随机存取存储器(dynamic RAM，DRAM)、同步动态随机存取存储器(synchronous DRAM，SDRAM)、双倍数据速率同步动态随机存取存储器(double data rate SDRAM，DDR SDRAM)、增强型同步动态随机存取存储器 (enhanced SDRAM，ESDRAM)、同步连接动态随机存取存储器(synchlink DRAM，SLDRAM)和直接内存总线随机存取存储器(direct rambus RAM，DR RAM)。应注意，本文描述的系统和方法的存储器旨在包括但不限于这些和任意其它适合类型的存储器。
根据本申请实施例提供的方法，本申请还提供一种计算机程序产品，该计算机程序产品包括：计算机程序代码，当该计算机程序代码在计算机上运行时，使得该计算机执行图2至图10所示实施例中的第一接入网设备执行的方法。
根据本申请实施例提供的方法，本申请还提供一种计算机可读存储介质，该计算机可读存储介质存储有程序代码，当该程序代码在计算机上运行时，使得该计算机执行图2至图10所示实施例中的第一接入网设备执行的方法。
根据本申请实施例提供的方法，本申请还提供一种通信系统，该通信系统包括但不限于，一个或多个前述的第一接入网设备以及一个或多个前述的终端设备。可选地，该通信系统还包括一个或多个前述的第二接入网设备。
上述各个装置实施例中的通信装置或基站和方法实施例中的第一接入网设备完全对应，由相应的模块或单元执行相应的步骤，例如收发单元(收发器)执行方法实施例中接收或发送的步骤，除发送、接收外的其它步骤可以由处理单元(处理器)执行。具体单元的功能可以参考相应的方法实施例。其中，处理器可以为一个或多个。
在本说明书中使用的术语“部件”、“模块”、“系统”等用于表示计算机相关的实体、硬件、固件、硬件和软件的组合、软件、或执行中的软件。例如，部件可以是但不限于，在处理器上运行的进程、处理器、对象、可执行文件、执行线程、程序和/或计算机。通过图示，在计算设备上运行的应用和计算设备都可以是部件。一个或多个部件可驻留在进程和/或执行线程中，部件可位于一个计算机上和/或分布在2个或更多个计算机之间。此外，这些部件可从在上面存储有各种数据结构的各种计算机可读介质执行。部件可例如根据具有一个或多个数据分组(例如来自与本地系统、分布式系统和/或网络间的另一部件交互的二个部件的数据，例如通过信号与其它系统交互的互联网)的信号通过本地和/或远程进程来通信。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的 部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(read-only memory，ROM)、随机存取存储器(random access memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (33)

  1. 一种通信方法，其特征在于，包括：
    第一接入网设备确定终端设备在源小区的信号质量低于预设门限，所述源小区是所述第一接入网设备服务的小区；
    所述第一接入网设备根据与所述终端设备在所述源小区中激活的第一会话对应的第一网络切片，以及所述源小区的至少一个相邻小区分别支持的网络切片，从所述至少一个相邻小区中确定目标小区，其中，所述目标小区支持所述第一网络切片；
    所述第一接入网设备控制所述终端设备切换至所述目标小区。
  2. 如权利要求1所述的方法，其特征在于，所述目标小区是所述第一接入网设备服务的多个小区中除所述源小区之外的其他小区。
  3. 如权利要求1所述的方法，其特征在于，所述目标小区是第二接入网设备服务的小区。
  4. 如权利要求3所述的方法，其特征在于，所述方法还包括：
    所述第一接入网设备根据所述第一网络切片、所述至少一个相邻小区分别支持的网络切片以及所述支持的网络切片对应的无线资源，确定无线测量参数；
    所述第一接入网设备向所述终端设备发送所述无线测量参数，所述无线测量参数用于所述终端设备对所述相邻小区的信号质量的测量；其中，所述终端设备对所述相邻小区的信号质量的测量用于所述目标小区的确定。
  5. 如权利要求3或4所述的方法，其特征在于，所述方法还包括：
    所述第一接入网设备向所述第二接入网设备发送请求消息，所述请求消息中携带所述第一会话的标识信息和所述第一网络切片的标识信息；
    所述第一接入网设备从所述第二接入网设备接收用于切换的无线资源控制RRC参数；
    所述第一接入网设备向所述终端设备发送所述RRC参数。
  6. 如权利要求5所述的方法，其特征在于，所述RRC参数与所述第一网络切片、所述第二接入网设备支持的网络切片以及所述第二接入网设备支持的网络切片对应的无线资源关联。
  7. 一种通信方法，其特征在于，包括：
    第一接入网设备确定终端设备在源小区接入的第一无线资源不支持所述终端设备请求建立或请求激活的第一会话对应的第一网络切片，所述源小区是所述第一接入网设备服务的小区；
    所述第一接入网设备确定目标小区，所述目标小区的第二无线资源支持所述第一网络切片；
    所述第一接入网设备控制所述终端设备切换至所述目标小区。
  8. 如权利要求7所述的方法，其特征在于，所述第二无线资源还支持所述终端设备的第二会话对应的网络切片，所述第二会话包括激活的会话或去激活的会话。
  9. 如权利要求7或8所述的方法，其特征在于，所述方法还包括：
    所述第一接入网设备根据允许所述终端设备接入的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定目标频率范围；或
    所述第一接入网设备根据所述终端设备请求的网络切片、所述终端设备根据签约能够使用的网络切片、所述终端设备所在跟踪区或注册区支持的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定目标频率范围。
  10. 如权利要求9所述的方法，其特征在于，所述第一接入网设备确定目标小区，包括：
    所述第一接入网设备从支持所述目标频率范围的站内相邻小区中确定所述目标小区，所述站内相邻小区是所述第一接入网设备服务的多个小区中除所述源小区之外的其他小区。
  11. 如权利要求9所述的方法，其特征在于，所述第一接入网设备确定目标小区，包括：
    所述第一接入网设备从支持所述目标频率范围的站外相邻小区中确定所述目标小区，所述站外相邻小区是所述源小区的相邻小区中除所述第一接入网设备服务的小区之外的小区。
  12. 如权利要求11所述的方法，其特征在于，所述方法还包括：
    所述第一接入网设备根据所述目标频率范围确定无线测量参数；
    所述第一接入网设备向所述终端设备发送所述无线测量参数，所述无线测量参数用于所述终端设备对所述相邻小区的信号质量的测量；所述终端设备对所述相邻小区的信号质量的测量用于所述目标小区的确定。
  13. 如权利要求11或12所述的方法，其特征在于，所述方法还包括：
    所述第一接入网设备向服务所述目标小区的第二接入网设备发送请求消息，所述请求消息中携带所述第一会话的标识信息和所述第一网络切片的标识信息；
    所述第一接入网设备从所述第二接入网设备接收用于切换的无线资源控制RRC参数；
    所述第一接入网设备向所述终端设备发送所述RRC参数。
  14. 如权利要求13所述的方法，其特征在于，所述RRC参数与所述第一网络切片、所述第二接入网设备支持的网络切片以及所述第二接入网设备支持的网络切片对应的无线资源关联。
  15. 一种通信方法，其特征在于，包括：
    第一接入网设备确定终端设备在源小区接入的第一无线资源不支持所述终端设备请求建立或请求激活的第一会话的第一网络切片，所述源小区是所述第一接入网设备服务的小区；
    所述第一接入网设备向所述终端设备发送无线资源控制RRC连接释放消息，以释放与所述终端设备的RRC连接。
  16. 如权利要求15所述的方法，其特征在于，所述方法还包括：
    所述第一接入网设备根据允许所述终端设备接入的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定目标频率范围；或，所述第一接入网设备根据所述终端设备请求的网络切片、所述终端设备根据签约能够使用的网络切片以及所述终端设 备所在跟踪区或注册区支持的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定所述目标频率范围；以及
    所述第一接入网设备根据所述目标频率范围、所述至少一个相邻小区分别支持的网络切片以及所述支持的网络切片对应的无线资源，确定所述无线参数，所述无线参数用于所述终端设备的小区重选；
    所述第一接入网设备向所述终端设备发送所述无线参数。
  17. 一种通信装置，其特征在于，包括：
    确定单元，用于确定终端设备在源小区的信号质量低于预设门限，所述源小区是所述装置服务的小区；还用于根据与所述终端设备在所述源小区中激活的第一会话对应的第一网络切片，以及所述源小区的至少一个相邻小区分别支持的网络切片，从所述至少一个相邻小区中确定目标小区，其中，所述目标小区支持所述第一网络切片；
    控制单元，用于控制所述终端设备切换至所述目标小区。
  18. 如权利要求17所述的装置，其特征在于，所述目标小区是所述装置服务的多个小区中除所述源小区之外的其他小区。
  19. 如权利要求17所述的装置，其特征在于，所述目标小区是第二接入网设备服务的小区。
  20. 如权利要求19所述的装置，其特征在于，所述确定单元还用于根据所述第一网络切片、所述至少一个相邻小区分别支持的网络切片以及所述支持的网络切片对应的无线资源，确定无线测量参数；
    所述装置还包括收发单元，用于向所述终端设备发送所述无线测量参数，所述无线测量参数用于所述终端设备对所述相邻小区的信号质量的测量；其中，所述终端设备对所述相邻小区的信号质量的测量用于所述目标小区的确定。
  21. 如权利要求19或20所述的装置，其特征在于，所述装置还包括收发单元，所述收发单元用于：
    向所述第二接入网设备发送请求消息，所述请求消息中携带所述第一会话的标识信息和所述第一网络切片的标识信息；
    从所述第二接入网设备接收用于切换的无线资源控制RRC参数；
    向所述终端设备发送所述RRC参数。
  22. 如权利要求21所述的装置，其特征在于，所述RRC参数与所述第一网络切片、所述第二接入网设备支持的网络切片以及所述第二接入网设备支持的网络切片对应的无线资源关联。
  23. 一种通信装置，其特征在于，包括：
    确定单元，用于确定终端设备在源小区接入的第一无线资源不支持所述终端设备请求建立或请求激活的第一会话对应的第一网络切片，所述源小区是所述装置服务的小区；还用于确定目标小区，所述目标小区的第二无线资源支持所述第一网络切片；
    控制单元，用于控制所述终端设备切换至所述目标小区。
  24. 如权利要求23所述的装置，其特征在于，所述第二无线资源还支持所述终端设备的第二会话对应的网络切片，所述第二会话包括激活的会话或去激活的会话。
  25. 如权利要求23或24所述的装置，其特征在于，所述确定单元还用于根据允许所 述终端设备接入的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定目标频率范围；或
    所述确定单元还用于根据所述终端设备请求的网络切片、所述终端设备根据签约能够使用的网络切片、所述终端设备所在跟踪区或注册区支持的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定目标频率范围。
  26. 如权利要求25所述的装置，其特征在于，所述确定单元具体用于从支持所述目标频率范围的站内相邻小区中确定所述目标小区，所述站内相邻小区是所述装置服务的多个小区中除所述源小区之外的其他小区。
  27. 如权利要求25所述的装置，其特征在于，所述确定单元具体用于从支持所述目标频率范围的站外相邻小区中确定所述目标小区，所述站外相邻小区是所述源小区的相邻小区中除所述装置服务的小区之外的小区。
  28. 如权利要求27所述的装置，其特征在于，所述确定单元还用于根据所述目标频率范围确定无线测量参数；
    所述装置还包括收发单元，用于向所述终端设备发送所述无线测量参数，所述无线测量参数用于所述终端设备对所述相邻小区的信号质量的测量；所述终端设备对所述相邻小区的信号质量的测量用于所述目标小区的确定。
  29. 如权利要求27或28所述的装置，其特征在于，所述装置还包括收发单元，所述收发单元用于：
    向服务目标小区的第二接入网设备发送请求消息，所述请求消息中携带所述第一会话的标识信息和所述第一网络切片的标识信息；
    从所述第二接入网设备接收用于切换的无线资源控制RRC参数；
    向所述终端设备发送所述RRC参数。
  30. 如权利要求29所述的装置，其特征在于，所述RRC参数与所述第一网络切片、所述第二接入网设备支持的网络切片以及所述第二接入网设备支持的网络切片对应的无线资源关联。
  31. 一种通信装置，其特征在于，包括：
    确定单元，用于确定终端设备在源小区接入的第一无线资源不支持所述终端设备请求建立或请求激活的第一会话的第一网络切片，所述源小区是所述装置服务的小区；
    收发单元，用于向所述终端设备发送无线资源控制RRC连接释放消息，以释放与所述终端设备的RRC连接。
  32. 如权利要求31所述的装置，其特征在于，所述确定单元还用于根据允许所述终端设备接入的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定目标频率范围；或，所述确定单元还用于根据所述终端设备请求的网络切片、所述终端设备根据签约能够使用的网络切片、所述终端设备所在跟踪区或注册区支持的网络切片、所述第一网络切片以及所述第一网络切片对应的频率范围，确定所述目标频率范围；
    所述确定单元还用于根据所述目标频率范围、所述至少一个相邻小区分别支持的网络切片以及所述支持的网络切片对应的无线资源，确定所述无线参数，所述无线参数用于所述终端设备的小区重选；
    所述收发单元还用于向所述终端设备发送所述无线参数。
  33. 一种计算机可读存储介质，其特征在于，包括计算机程序，当所述计算机程序在计算机上运行时，使得所述计算机执行如权利要求1至16中任一项所述的方法。
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