Communication method and related apparatus

Abstract

Embodiments of the present application relate to the technical field of communications, and disclose a communication method and a related apparatus. In the embodiments of the present application, a core network side and a radio access network side can realize path switching and / or context release of a plurality of UEs by means of only a round of signaling exchange, thereby reducing signaling exchange between the core network side and the radio access network side in a switching process, and improving the switching efficiency.

Description

Communication method and related apparatus

[0001] The present application claims priority from the Chinese patent application No. 202410666132.1 filed on May 23, 2024, and entitled "Communication method and related apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

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

[0003] In the field of communication, handover is an important concept, which aims to ensure seamless mobile communication services. It involves the user equipment migrating from the wireless link connection of the source cell to the target cell under the control of the network side (including the access network and the core network), so as to ensure that the ongoing call will not be interrupted. The reasons for triggering handover include various, for example, the user equipment moves from one cell area to another cell area, or the service area of the base station changes, resulting in the area where the user equipment is located changes from the service area of base station A to the service area of base station B.

[0004] The existing handover process is usually carried out at a specific user equipment (UE) level. However, in actual scenarios (especially satellite communication scenarios), there are a large number of UE handover scenarios; if a large number of UEs simultaneously perform handover, but the network side is still based on a specific user equipment level, it will bring a large signaling overhead, affecting the efficiency of handover. SUMMARY

[0005] The present application provides a communication method and related apparatus, which realizes the path switching and / or context release of multiple UEs through single interaction of the radio access network side and the core network side, so as to reduce the signaling overhead in the handover process and improve the efficiency of handover.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, a communication method is provided, applied to a first radio access network node RAN, the method comprising:

[0008] sending first information to the core network, the first information comprising a first group identifier, the first group identifier being associated with at least one UE, the first group identifier being determined based on a service area identifier of the first RAN, a coverage area of the first RAN comprising at least one service area, the service area identifier being used to identify a service area in the coverage area of the first RAN and the first group identifier being associated with UEs located in the service area, the first information being used to request the core network side to perform path switching for the UEs associated with the first group identifier;

[0009] receiving second information sent by the core network, the second information comprising a second group identifier, the second group identifier being associated with at least one UE, so that the first RAN determines the UEs for which path switching is completed according to the second information.

[0010] Thus, in the handover process, the radio access network side sends first information to the core network side, and requests the core network side to complete path switching for at least one UE associated with the first group identifier in the first information; and then the core network side sends second information to the radio access network side, so that the radio access network side determines the UEs for which path switching is completed according to the second group identifier in the second information. The radio access network side and the core network side can realize path switching for at least one UE switched to the target RAN through one information interaction, reduce signaling overhead, and improve the efficiency of handover.

[0011] In particular, in a satellite communication system, because the satellite is always in a fast moving process (the speed can reach about 7.5 km / s), the probability of handover of multiple UEs in the satellite service area is relatively frequent, and the propagation delay between the satellite and the core network is relatively long. Through the communication method provided in the present application, signaling interaction between the core network and the radio access network side can be reduced, and the efficiency of handover can be improved.

[0012] In some possible implementation manners of the first aspect, the method further includes:

[0013] sending third information to the second RAN, the third information comprising a third group identifier, the third group identifier being associated with at least one UE, the third information being used to request the second RAN to release the context of the at least one UE associated with the third group identifier. Thus, the embodiments of the present application realize release of the context of multiple UEs switched from the source RAN to the target RAN through one signaling, so as to reduce signaling overhead between networks and improve the efficiency of context release, wherein the first RAN is the target RAN, and the second RAN is the source RAN.

[0014] In some possible implementation manners of the first aspect, the service area identifier comprises at least one of a cell identifier, a geographical area, a tracking area identifier, and a beam identifier. In this way, the cell identifier, the geographical area, the tracking area identifier, and the beam identifier are all identifiers of the service area of the radio access network node, and the UE to be switched is grouped (that is, the UE associated with the first group identifier) by the service area of the radio access network node, and the group-associated UE is simultaneously subjected to path switching or context release, that is, the characteristics of the coverage area of the radio access node are combined, and at least one UE meeting the group condition is switched, which improves the switching efficiency and reduces the signaling overhead.

[0015] In some possible implementation manners of the first aspect, the first information further comprises time information corresponding to the service area identifier, and the time information is used to indicate a time period of path switching of the UE associated with the service area identifier. In this way, after the core network side receives the first information, the time period of path switching of the UE associated with the service area identifier is determined according to the time information, so as to perform path switching on the UE according to the time period.

[0016] In some possible implementation manners of the first aspect, the method further comprises:

[0017] sending sixth information to the core network, the sixth information comprising identifiers of at least two UEs, and the sixth information being used to request path switching of the UEs corresponding to the sixth information;

[0018] receiving seventh information sent by the core network, the seventh information comprising an identifier of at least one UE, and the seventh information being used to confirm, to the first RAN, the UE that completes path switching. In this way, in the switching process, if at least two UEs are switched to the target RAN, the target RAN can send multiple UE identifiers to the core network side through one information, multiple UEs are subjected to path switching through a single signaling, the signaling interaction between the radio access network side and the core network side is reduced, and the switching efficiency is improved.

[0019] In some possible implementation manners of the first aspect, the method further comprises: sending eighth information to the second RAN, the eighth information comprising an identifier of at least one UE, and the eighth information being used to request the second RAN to release the context of the UE corresponding to the eighth information. In this way, the context release of multiple UEs is implemented through one information exchanged by the radio access network side, the signaling interaction between radio access network nodes is reduced, and the overall switching efficiency is improved.

[0020] In some possible implementation manners of the first aspect, the method further comprises:

[0021] In response to receiving the downlink data sent to the UE, the third information is sent to the second RAN, the third information comprising a third group identifier, the third group identifier being associated with at least one UE, the third information being used to request the second RAN to release a context of the at least one UE associated with the third group identifier. In this way, in response to receiving the downlink data sent to the UE, the target RAN determines that the path of the UE is switched to the current radio access node (i.e. the target RAN), and the target RAN can request the source RAN to release the context of the UE in the source RAN by sending the third information to the source RAN.

[0022] In a second aspect, a communication method is provided, applied to a core network side node, the method comprising:

[0023] receiving first information sent by a first RAN, the first information comprising a first group identifier, the first group identifier being associated with at least one UE, the first group identifier being determined based on a service area identifier of the first RAN, a coverage area of the first RAN comprising at least one service area, the service area identifier being used to identify a service area in the coverage area of the first RAN and the UE associated with the first group identifier being located in the service area, the first information being used to request path switching of the UE associated with the first group identifier;

[0024] sending second information to the first RAN, the second information comprising a second group identifier, the second group identifier being associated with at least one UE, so that the first RAN determines the UE completing path switching according to the second group identifier.

[0025] In some possible implementation ways of the second aspect, the service area identifier comprises at least one of a cell identifier, a geographical area, a tracking area identifier, a beam identifier.

[0026] In some possible implementation ways of the second aspect, the first information further comprises time information corresponding to the service area identifier, the time information being used to indicate a switching time period of the UE corresponding to the service area identifier.

[0027] In some possible implementation ways of the second aspect, the method further comprises:

[0028] sending fourth information to a second RAN, the fourth information comprising a third group identifier, the fourth information being used to request the second RAN to release a context of the UE associated with the third group identifier;

[0029] receiving fifth information sent by the second RAN.

[0030] In some possible implementation ways of the second aspect, the method further comprises:

[0031] receiving sixth information sent by the first RAN, the sixth information comprising identities of at least two UEs, the sixth information being used for requesting path switching of the UEs corresponding to the sixth information;

[0032] sending seventh information to the first RAN, the seventh information comprising identities of at least one UE, the seventh information being used for confirming to the first RAN the UEs that complete path switching.

[0033] In some possible implementation ways of the second aspect, the method further includes:

[0034] sending ninth information to the second RAN, the ninth information comprising identities of at least one UE, the ninth information being used for requesting the second RAN to release contexts of the UEs corresponding to the ninth information;

[0035] receiving tenth information sent by the second RAN.

[0036] In some possible implementation ways of the second aspect, the method further includes:

[0037] obtaining location information of the UE;

[0038] judging whether the UE meets a switching condition based on the location information and coverage areas of multiple RANs;

[0039] if the UE meets the switching condition, switching a path of the UE to the first RAN.

[0040] In a third aspect, a communication method is provided, applied to a first RAN, and the method includes:

[0041] sending sixth information to a core network, the sixth information comprising identities of at least two UEs, the sixth information being used for requesting path switching of the UEs corresponding to the sixth information;

[0042] receiving seventh information sent by the core network, the seventh information comprising identities of at least one UE, the seventh information being used for confirming to the first RAN the UEs that complete path switching.

[0043] In some possible implementation ways of the third aspect, the method further includes: sending eighth information to a second RAN, the eighth information comprising identities of at least one UE, the eighth information being used for requesting the second RAN to release contexts of the UEs corresponding to the eighth information.

[0044] In a fourth aspect, a communication method is provided, applied to a core network side node, and the method includes:

[0045] receive sixth information sent by the first RAN, the sixth information comprising identities of at least two UEs, the sixth information being used for requesting path switching of the UEs corresponding to the sixth information;

[0046] send seventh information to the first RAN, the seventh information comprising identities of at least one UE, the seventh information being used for confirming to the first RAN that the UE completing path switching.

[0047] In some possible implementation ways of the fourth aspect, the method further comprises: sending ninth information to the second RAN, the ninth information comprising identities of at least one UE, the ninth information being used for requesting the second RAN to release the context of the UE corresponding to the ninth information;

[0048] receive tenth information sent by the second RAN.

[0049] In a fifth aspect, a communication apparatus is provided, comprising a processor and a memory, the memory being configured to store computer-executed instructions, and the processor being configured to execute the computer-executed instructions stored in the memory, so that the apparatus executes the method in any one of the first aspect, the second aspect, the third aspect and the fourth aspect.

[0050] In a sixth aspect, a chip is provided, comprising at least one processor and a communication interface, the communication interface being coupled with the at least one processor, and the at least one processor being configured to run computer programs or instructions, so as to implement the communication method in any one of the first aspect, the second aspect, the third aspect and the fourth aspect.

[0051] The communication interface is configured to communicate with other modules outside the chip.

[0052] In a seventh aspect, a computer-readable storage medium is provided, and the computer-readable storage medium stores instructions, when the instructions are run, implementing the communication method in any one of the first aspect, the second aspect, the third aspect and the fourth aspect.

[0053] The technical effects obtained by the second aspect, the third aspect, the fourth aspect, the fifth aspect, the sixth aspect and the seventh aspect are similar to the technical effects obtained by the corresponding technical means in the first aspect and the second aspect, and thus are not described herein. BRIEF DESCRIPTION OF DRAWINGS

[0054] FIG. 1 is a schematic diagram of a 5G network architecture;

[0055] FIG. 2 is a schematic diagram of a satellite communication system;

[0056] FIG. 3 is a schematic diagram of a switching process provided by an embodiment of the present application;

[0057] FIG. 4 is a schematic diagram of a switching process according to an embodiment of the present application;

[0058] FIG. 5A is a schematic diagram of a switching scenario according to an embodiment of the present application;

[0059] FIG. 5B is a schematic diagram of a switching scenario according to an embodiment of the present application;

[0060] FIG. 6 is a flowchart of another communication method according to an embodiment of the present application;

[0061] FIG. 7 is a schematic diagram of a switching scenario according to an embodiment of the present application;

[0062] FIG. 8 is a flowchart of another communication method according to an embodiment of the present application;

[0063] FIG. 9 is a flowchart of another communication method according to an embodiment of the present application;

[0064] FIG. 10 is a flowchart of a communication method according to an embodiment of the present application;

[0065] FIG. 11 is a schematic diagram of a sixth information according to an embodiment of the present application;

[0066] FIG. 12 is a schematic diagram of a communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0067] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0068] Before the embodiments of the present application are explained in detail, an application scenario related to the embodiments of the present application is introduced.

[0069] Next, some nouns related to the embodiments of the present application are introduced.

[0070] 1. Beam

[0071] The service area of a satellite network is divided into multiple small geographical areas according to geographical positions, and each geographical area is called a beam. The beam can be represented in different shapes.

[0072] 2. Satellite ephemeris

[0073] Ephemeris, which can also be referred to as ephemeris table, almanac, almanac, etc., is information used to locate the position of a celestial body at any time. The ephemeris information refers to some information related to the satellite constellation, which can include, in general, the three-dimensional spatial position information of the satellite, the velocity state vector information, the orbital information of the satellite, etc. Specifically, the information can be divided into the position and velocity state vector of the satellite, the orbital plane parameters and the satellite level parameters, etc.

[0074] Embodiments of the present application can be applied to various communication systems, such as a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD), a universal mobile telecommunication system (UMTS), a world wide interoperability for microwave access (WiMAX) communication system, a 5th generation (5G) system or a new radio (NR) or a subsequent evolution communication system, etc., and embodiments of the present application are not limited thereto.

[0075] Referring to FIG. 1, it is a schematic diagram of a 5G network architecture based on a service-oriented architecture provided by the 3rd generation partnership project (3GPP). The 5G network architecture can include an access network device and a core network device. The terminal accesses a data network (DN) through the access network device and the core network device.

[0076] In FIG. 1, a terminal can include various hand-held devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem having a wireless communication function. The terminal can also be referred to as a terminal device. The terminal can also refer to a user equipment (UE), an access terminal, a subscriber unit, a user agent, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a wireless modem, a handset, a laptop computer, a point of sale (POS) machine, a customer-premises equipment (CPE), a machine type communication (MTC) terminal, a communication device mounted on an airship, a wearable device, a drone, a robot, a terminal in D2D, a terminal in vehicle to everything (V2X), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a terminal device in a 5G network or a future communication network, etc.

[0077] In FIG. 1, the access network device can be a radio access network (RAN). The RAN can manage radio resources, provide access services for terminals, and complete forwarding of user data between terminals and a core network. The RAN can also be understood as a base station or at least one cell carried by the base station in the network. Exemplarily, the access network device in the embodiments of the present application can be any kind of communication device with wireless transceiving function for communication with terminals. The access network device includes but is not limited to: an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home evolved Node B (HeNB) or a home Node B (HNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (Wi-Fi) system, a wireless relay node, a wireless backhaul node, a transmission point (TP), or a transmission and reception point (TRP), and the like. The access network device can also be a gNB or a transmission point (TRP or TP) in a 5G mobile communication system such as a next radio (NR) system, one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G mobile communication system, or a network node constituting a gNB or a transmission point such as a baseband unit (BBU) or a distributed unit (DU).

[0078] In some deployments, a gNB can include a centralized unit (CU) and a DU. A gNB can also include an active antenna unit (AAU). The CU implements part of the functions of the gNB, and the DU implements part of the functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, implements the radio resource control (RRC), and the functions of the packet data convergence protocol (PDCP) layer. The DU is responsible for processing the physical layer protocol and real-time services, and implements the functions of the radio link control (RLC) layer, the media access control (MAC) layer, and the physical (PHY) layer. The AAU implements part of the physical layer processing functions, radio frequency processing, and related functions of the active antenna. The information of the RRC layer is generated by the CU, and finally becomes the PHY layer information through the encapsulation of the PHY layer of the DU, or is converted from the information of the PHY layer. Therefore, under this architecture, high-layer signaling such as RRC layer signaling can also be considered as being sent by the DU, or by the DU+AAU. It can be understood that the access network device can be a device including one or more of the CU node, the DU node, and the AAU node. In addition, the CU can be divided into an access network device in the access network, or can be divided into an access network device in the core network (CN), which is not limited in the present application.

[0079] The access network device and the terminal can be fixed in position or movable. The access network device and the terminal can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water surface; and can also be deployed on aircraft, balloons, and artificial satellites in the air.

[0080] In FIG. 1, the core network device can include a unified data management (UDM) network element, an access and mobility function (AMF) network element, a session management function (SMF) network element, a policy control function (PCF) network element, an application function (AF) network element, a user plane function (UPF) network element, a network exposure function (NEF) network element, a network repository function (NRF) network element, a network slice selection function (NSSF) network element, an authentication server function (AUSF) network element, and the like.

[0081] These function units can work independently or be combined to realize certain control functions. For example, the AMF, the SMF, and the PCF can be combined to form a management device for performing access authentication, security encryption, location registration, access control, mobility management, session management, and the like.

[0082] UPF: as an interface with a data network, performing functions such as user plane data forwarding, session / stream level-based charging statistics, bandwidth limitation, packet routing and forwarding, quality of service (QoS) processing of user plane data, and the like.

[0083] AMF: mainly performing functions such as mobility management, access authentication / authorization, and the like. In addition, the AMF is also responsible for transferring user policies between a terminal and a policy control function (PCF) network element.

[0084] SMF: mainly used for session management after user access, including PDU session establishment, modification, activation, deactivation, release, etc., as well as UE IP address allocation, dynamic host configuration protocol (DHCP) v4 / v6 function, address resolution protocol (ARP) proxy, IPv6 Neighbour Solicitation Proxying for Ethernet PDU, selectable and controlled user plane, decision of session SSC mode and roaming, etc.

[0085] PCF: mainly used for managing network behavior with a unified policy framework, providing policy rules to control plane network elements (such as AMF, SMF), and access subscription information related to policy decision in unified data repository (UDR).

[0086] UDM: mainly used for generating 3GPP AKA authentication credentials, User ID processing, access authorization based on subscription information, unified management of service NF registration management, subscription information management, etc.

[0087] Data network (DN): provides, for example, operator services, Internet access or third-party services, contains servers, server-side implementation of video source encoding, rendering, etc. DN is a combination of data terminal equipment, data processing equipment and data communication equipment (including communication channels), providing data transmission functions for communication stations and users distributed in different places and resource sharing functions including data and data processing capabilities.

[0088] The 5G core network can also include a controller, which can also be referred to as a management server or a network management server. The controller is used to manage and control the on-board devices on the satellite or the ground network elements, including but not limited to configuration delivery, table entry delivery, etc.

[0089] In FIG. 1, N1, N2, N3, N4 and N6 are interface serial numbers, and the meanings of these interface serial numbers are as follows:

[0090] 1) N1 interface: interface between AMF and UE, which can be used to deliver non-access stratum (NAS) signaling (such as including QoS rules from AMF) to UE, etc.

[0091] 2) N2 interface: the interface between the AMF and the RAN, which can be used to deliver the radio bearer control information from the core network side to the RAN, etc.

[0092] 3) N3 interface: the interface between the RAN and the UPF, which is mainly used to deliver the uplink and downlink user plane data between the RAN and the UPF.

[0093] 4) N4 interface: the interface between the SMF and the UPF, which can be used to deliver information between the control plane and the user plane, including the delivery of the forwarding rules, QoS rules, traffic statistics rules, etc. from the control plane to the user plane, and the information reporting of the user plane.

[0094] 5) N6 interface: the interface between the UPF and the DN, which is used to deliver the uplink and downlink user data flow between the UPF and the DN.

[0095] It should be noted that the part shown in FIG. 1 is only an example architecture diagram, and in addition to the network elements or functional entities shown in FIG. 1, the network architecture can also include other network elements or functional entities, which are not limited by the embodiments of the present application. It should be understood that the interface names between the network elements in the present application are only exemplary, and the interfaces between the network elements can also be other names, and the name of the interface is not limited by the embodiments of the present application.

[0096] The technical solutions of the present application can be applied to satellite communication systems, high-altitude platform (HAPS) communication, unmanned aerial vehicles, and other non-terrestrial network (NTN) systems, such as integrated communication and navigation (IcaN) systems, global navigation satellite systems (GNSS), and ultra-dense low-orbit satellite communication systems. The satellite communication system can be integrated with the traditional mobile communication system. For example, the mobile communication system can be a fourth generation (4G) communication system (for example, a long term evolution (LTE) system), a worldwide interoperability for microwave access (WiMAX) communication system, a fifth generation (5G) communication system (for example, a new radio (NR) system), and a future mobile communication system, etc.

[0097] A satellite communication system includes user equipment (UE) and network equipment. The user equipment can also be referred to as user terminal, mobile station, etc. The network equipment can include one or more satellites and ground station equipment. The satellite can be a low earth orbit (LEO) satellite, a non-geostationary earth orbit (NGEO) satellite, etc.

[0098] FIG. 2 is a schematic diagram of a satellite communication system provided by the present application. The satellite communication system in FIG. 2 includes a satellite 101, a satellite 102, and a satellite 103. Each satellite can provide communication services, navigation services, positioning services, etc. to terminal equipment through multiple beams. The satellite in this scenario is a LEO satellite, and the satellite 103 is connected to ground station equipment. The satellite covers a service area using multiple beams, and different beams can communicate through one or more of time division, frequency division, and space division. The satellite communicates with terminal equipment through broadcast communication signals, navigation signals, etc. The satellite can communicate with ground station equipment. The satellite mentioned in the embodiments of the present application can be a satellite base station (i.e., a satellite with a wireless access node function), can include an orbit receiver or repeater for relaying information, or can be a network side device carried on a satellite.

[0099] The satellite communication system includes a transparent satellite architecture and a non-transparent satellite architecture. Transparent is also referred to as pipe-through forwarding transmission: that is, the signal only performs frequency conversion on the satellite, and the signal amplification process, the satellite is transparent to the signal, as if it does not exist. Non-transparent is also referred to as regenerative (onboard access / processing) transmission: that is, the satellite has partial or full base station functions. For example, the satellite 101 and the satellite 102 in the figure are non-transparent satellite architectures, and the satellite 103 is a transparent satellite architecture. In addition, the satellite can work in an earth-fixed, quasi earth-fixed mode or an earth-moving mode.

[0100] The ground station equipment can be equipment in a core network (CN) of a mobile communication architecture (such as a 3GPP access architecture of a 5G network) in FIG. 1 or equipment in a core network of a future mobile communication architecture. The core network provides an interface to a data network as a bearer network, provides communication connection, authentication, management, policy control, and completion of bearer for data services for user equipment (UE).

[0101] The network device can further include, but is not limited to, an access network device, which can be an evolved node B (eNB), a baseband unit (BBU), an access point (AP) in a wireless fidelity (WIFI) system, a wireless relay node, a wireless backhaul node, an integrated access and backhaul (IAB) node, a transmission point (TP) or a transmission reception point (TRP), a network controlled repeater (NCR), and the like. The network device can also be a gNB or a TRP or a TP in a 5G system, or one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system. In addition, the network device can also be a network node constituting a gNB or a TP, such as a BBU, a distributed unit (DU), and the like. Alternatively, the network device can also be a device assuming a network side function in a device-to-device (D2D) communication system, a machine to machine (M2M) communication system, an Internet of Things (IoT), a vehicle-to-vehicle communication system, or other communication systems.

[0102] The satellite communication system provided by the present application is shown in the above figure, which includes satellites 101, 102, and 103. Each satellite can provide communication and positioning services to mobile stations through multiple beams. Satellite 103 is connected to a core network device. The satellites can be LEO satellites, MEO satellites, GEO satellites, and the like. The mobile stations involved in the present application can include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to wireless modems with wireless communication functions. They can also be user units, cellular phones, smart phones, wireless data cards, personal digital assistants, tablet computers, wireless modems, handheld devices, laptop computers, machine type communication terminals, and the like.

[0103] Please refer to FIG. 3, which is a switching flowchart. In FIG. 3, the switching process has an Xn interface between the source RAN and the target RAN.

[0104] S301, the source RAN sends a radio resource control (RRC) reconfiguration message to a UE in a connected state, the RRC reconfiguration message being used to control the UE to measure the signal strength of a current serving cell and other cells, the RRC reconfiguration message including a measurement object, a report configuration, a measurement identity, and the like.

[0105] S302, the UE receives the RRC reconfiguration message from the source RAN, and sends an RRC reconfiguration complete to the source RAN.

[0106] S303, the UE performs measurement according to the received measurement control message. After the UE measures and determines that an event condition is reached, the UE reports a measurement report to the source RAN.

[0107] S304, after the source RAN receives the measurement report sent by the UE, the source RAN performs handover strategy and target cell / frequency point decision according to the measurement result.

[0108] S305, the source RAN sends a handover request (HANDOVER REQUEST) message to the target RAN through an Xn link, for initiating a handover request; the target RAN is the RAN where the selected target cell is located.

[0109] S306, after the target RAN receives the handover request, the target RAN performs admission control, and allocates UE instances and transmission resources after allowing admission.

[0110] S307, the target RAN sends a handover request acknowledgement (HANDOVER REQUEST ACKNOWLEDGE) to the source RAN, allowing the UE to access the target RAN. If part of the PDU Session fails to switch in, the message needs to carry a list of failed PDU Sessions.

[0111] S308, the source RAN sends an RRC reconfiguration (RRC Reconfiguration) to the UE, requiring the UE to perform handover to the target cell.

[0112] S309, the source RAN sends packet data convergence protocol uplink and downlink sequence numbers (PDCP SNs) to the target RAN through a sequence number status transfer (SN STATUS TRANSFER).

[0113] S310, the UE initiates a non-contention random access MSG1 in the target cell of the target RAN, carrying a dedicated preamble.

[0114] S311, the target RAN side replies to the MSG2 message, i.e., a random access response;

[0115] S312, the UE sends an RRC reconfiguration complete to the target RAN, and the UE performs air interface switching to the target cell.

[0116] S313, the target RAN sends a path switch request (PATH SWITCH REQUEST) message to the AMF, the path switch request message is used to inform that the UE has changed the cell, and the message contains the target cell identifier and the converted PDU Session list. After the core network receives the message, the downlink GTPU data plane is updated, and the GTPU address of the RAN side is modified to the target RAN;

[0117] S314, the AMF sends a path switch request acknowledgment (PATH SWITCH REQUEST ACKNOWLEDGE) message to the target RAN. If the AMF indicates in the path switch request acknowledgment message that the core network fails to establish a PDU Session, the RAN deletes the PDU Session that fails to be established.

[0118] S315, the target RAN sends a user context release (UE CONTEXT RELEASE) message to the source RAN, and the source RAN releases the context of the user that has been switched.

[0119] S316, after switching to the target cell, the target RAN sends an RRC reconfiguration message to the UE, so that the UE performs measurement on the target cell.

[0120] S317, the UE sends an RRC reconfiguration complete to the target RAN.

[0121] Please refer to FIG. 4, which is a schematic diagram of a switching process. In the switching process in FIG. 4, the source RAN and the target RAN do not have an Xn interface.

[0122] S401, the source RAN sends a radio resource control (RRC) reconfiguration message to a UE in a connected state, the RRC reconfiguration message is used to control the UE to perform signal strength measurement on a currently served cell and other cells, and the RRC reconfiguration message includes a measurement object, a report configuration, a measurement identifier, and the like.

[0123] S402, the UE receives the RRC reconfiguration message from the source RAN, and the UE sends an RRC reconfiguration complete (RRC Reconfiguration Complete) to the source RAN.

[0124] S403, the UE performs measurement according to the received measurement control message. After the UE measures and determines that the event condition is reached, the UE reports a measurement report to the source RAN;

[0125] S404, after the source RAN receives the measurement report, the source RAN makes a handover strategy and target cell / frequency decision according to the measurement report;

[0126] S405, the source RAN sends a handover request (HANDOVER REQUIRED) message to the AMF, the handover request message is used to request handover, and the handover request message contains a target RAN Id, a list of PDU sessions for which data forwarding is performed, etc.;

[0127] S406, the AMF initiates a handover request to the target RAN where the specified target cell is located;

[0128] S407, after the target RAN receives the handover request, admission control is performed, and after admission is allowed, UE instances and transmission resources are allocated;

[0129] S408, the target RAN replies to the AMF with a handover request acknowledgement (HANDOVER REQUEST ACKNOWLEDGE) to allow handover. If some PDU sessions fail to be handed in, the list of failed PDU sessions needs to be carried in the message;

[0130] S409, the AMF sends a handover command (HANDOVER COMMAND) message to the source RAN, which contains an address and a list of TEIDs for forwarding, and a list of bearers that need to be released;

[0131] S410, the source RAN sends an RRC reconfiguration to the UE, requiring the UE to perform handover to the target cell;

[0132] S411, the source RAN sends the PDCP SN number to the AMF through uplink RAN status transfer (UPLINK RAN STATUS TRANSFER);

[0133] S412, the AMF sends the PDCP SN number to the target RAN through a downlink RAN status transfer (DOWNLINK RAN STATUS TRANSFER) message;

[0134] S413, the UE sends an RRC reconfiguration completion to the target RAN, and the UE air interface handover to the target cell is completed;

[0135] S414, the target RAN sends a handover notification (HANDOVER NOTIFY) to the AMF, notifying that the UE has accessed the target cell and the N2 handover has been completed;

[0136] S415, after switching to the target cell, the target RAN issues the measurement control information of the new cell to the UE;

[0137] S416, after receiving the new measurement control information issued by the target RAN, the UE replies to the RRC reconfiguration completion.

[0138] S417, the AMF sends a UE CONTEXT RELEASE COMMAND message to the source RAN, and the source RAN releases the user for switching;

[0139] S418, the source RAN replies to the AMF with a UE CONTEXT RELEASE COMPLETE message.

[0140] The switching processes shown in FIG. 3 and FIG. 4 are both at the level of a specific UE for the network side device, and for the scenario of switching multiple UEs at the same time, the signaling overhead is large and the switching efficiency is low.

[0141] Especially for satellite communication systems, since the satellite and the ground are in relative motion, that is, the coverage area of each satellite on the ground is changing, when a certain area is transformed from the coverage area of one satellite to the coverage area of another satellite, the UEs in the area will undergo group switching. Please refer to FIG. 5A and FIG. 5B, the satellite communication system of FIG. 5A and FIG. 5B is a non-geosynchronous satellite communication system, FIG. 5A includes three areas: area 1, area 2 and area 3, and area 2 has a UE cluster, which includes multiple UEs. At time T1, area 2 is in the service area of satellite 2, and the UE cluster is served by one or more beams of satellite 2; since the satellite is in the process of moving, as shown in FIG. 5B, at time T2, area 2 is in the service area of satellite 1, that is, the UE cluster in area 2 is served by one or more beams of satellite 1. Therefore, the UE cluster in area 2 all undergoes switching. And since the satellite moves at a high speed, for a satellite mobile communication system, the scenario of multiple UEs switching at the same time is common, for example, if the speed of the satellite is 7.5 km / s, the frequency of group switching of UEs in the service area of the satellite is about once every few seconds to tens of seconds.

[0142] Further, in the regenerative LEO scenario, the propagation delay between satellites or between satellites and the core network is long, the switching process introduces large signaling overhead and mobile interruption time, and the switching process is at the level of a specific UE, so the switching efficiency is low.

[0143] Based on the above problems, the communication method provided in the embodiments of the present application is as follows: in the switching process, the target RAN sends first information to the AMF, the first information includes a first group identifier, the first group identifier is associated with at least one UE, and the first information is used to request the at least one UE associated with the first group identifier to perform path switching; then the AMF sends second information to the target RAN, the second information includes a second group identifier, so that the target RAN determines the UE that completes the path switching according to the second information. In this way, the access network side and the core network side realize the path switching of the at least one UE switched to the target RAN through one signaling interaction, the path switching efficiency in the switching process is improved, and thus the switching efficiency is improved.

[0144] In the embodiments of the present application, the communication method can be applied to Xn interface, NG interface, F1 interface and the like switching, and the present application does not make specific limitation on this.

[0145] For ease of understanding, in the following embodiments, the network element AMF on the core network side and the RAN on the wireless access network side are taken as examples to illustrate the interaction.

[0146] Please refer to FIG. 6, which is a schematic diagram of a communication method provided in the embodiments of the present application, and the method shown in FIG. 6 includes S601-S602.

[0147] S601, the first RAN sends first information to the AMF, the first information includes a first group identifier, and the first group identifier is associated with at least one UE.

[0148] The first information is used to request the core network side to perform path switching on the at least one UE associated with the first group identifier, that is, to switch the path to the first RAN.

[0149] Optionally, the first information is used to modify the address of the downlink user plane tunneling protocol (GPRS Tunneling Protocol User Plane, GTPU) data plane of the at least one UE associated with the first group identifier to the address of the first RAN.

[0150] Optionally, the first information is used to request the core network side to perform downlink data path switching on the at least one UE associated with the first group identifier.

[0151] The first RAN is the target RAN in the UE switching process, that is, the UE is switched from being served by other RAN to being served by the first RAN. For example, the UE moves from the coverage area of other RAN to the coverage area of the first RAN due to the movement of the UE.

[0152] Optionally, the first group identity is determined based on a service area identity of the first RAN, the coverage area of the first RAN comprises at least one service area, the service area identity is used to identify a service area in the coverage area of the first RAN and the UE associated with the first group identity is located in the service area. For example, in FIG. 5A, the coverage area of satellite 1 is area 1 and the coverage area of satellite 2 is area 2. Area 1 comprises a plurality of squares, each of which corresponds to a service area. The UE associated with the first group identity is located in the service area corresponding to the service area identity.

[0153] Optionally, the service area identity comprises at least one of a cell identity, a geographical area, and a tracking area identity.

[0154] Optionally, if the communication method in FIG. 6 is applied to a satellite communication system, the service area identity comprises at least one of a cell identity, a geographical area, a tracking area identity (TAC ID), and a beam identity (Beam ID).

[0155] Optionally, if the service area identity is a cell identity, the first group identity can be a cell identity, and the UE associated with the first group identity is located in the cell corresponding to the cell identity. The first group identity can also be a cell group list comprising at least one cell, and the first group identity can also be another identity generated based on the cell identity.

[0156] Optionally, if the service area is a geographical area, the first group identity can be an identity of the geographical area, and the UE associated with the first group identity is located in the geographical area. The first group identity can also be another identity generated based on the identity of the geographical area or the geographical area.

[0157] Optionally, if the service area is a tracking area identity, the first group identity can be a tracking area identity, and the UE associated with the first group identity is located in the tracking area. The first group identity can also be another identity generated based on the tracking area identity.

[0158] Optionally, if the service area is a beam identity, the first group identity can be a beam identity, and the UE associated with the first group identity is located in the beam area corresponding to the beam identity. The first group identity can also be another identity generated based on the beam identity.

[0159] Optionally, the service area identity comprises a cell identity and a beam identity, and the first group identity comprises a cell identity and a beam identity list comprising at least one beam. The UE associated with the first group identity is located in the cell corresponding to the cell identity and in the beam area corresponding to at least one beam in the beam identity list. The first group identity can also be another identity generated based on the cell identity and the beam identity.

[0160] Optionally, the service area comprises a cell ID and a geographical area, and the first group identification comprises a cell ID and a geographical area list, the geographical area list comprising at least one geographical area, and the associated UE of the first group identification is a UE in the cell corresponding to the cell ID and in at least one geographical area in the geographical area list. The first group identification can also be other identification generated based on the cell ID and the geographical area.

[0161] Optionally, the service area comprises a tracking area ID and a cell ID, and the first group identification comprises a tracking area ID and a cell ID list, the cell ID list comprising at least one cell ID, and the associated UE of the first group identification is a UE in the tracking area corresponding to the tracking area ID and in at least one cell in the cell ID list. The first group identification can also be other identification generated based on the cell ID and the tracking area ID.

[0162] Optionally, the service area comprises a tracking area ID and a geographical area, and the first group identification comprises a tracking area ID and a geographical area list, the geographical area list comprising at least one geographical area, and the associated UE of the first group identification is a UE in the tracking area corresponding to the tracking area ID and in at least one geographical area in the geographical area list. The first group identification can also be other identification generated based on the geographical area and the tracking area ID.

[0163] It is easy to understand that the first group identification can also be generated based on at least two, at least three, or four of the cell ID (cell ID), the geographical area, the tracking area ID (TAC ID), and the beam ID (Beam ID).

[0164] Optionally, before the first RAN sends the path switching request to the AMF, the UE has been synchronized to the target cell of the first RAN and completed the RRC switching process by sending an RRC Reconfiguration Complete message to the RAN.

[0165] The first group identification is used to identify the first group, and the first group comprises at least one UE. The RAN requests the target cell identification and the PDU Session list of the converted at least one UE associated with the first group identification from the core network side through the first group identification.

[0166] S602, after the AMF receives the first information sent by the first RAN, the AMF sends second information to the first RAN, the second information comprising a second group identification.

[0167] Optionally, the second group identification is associated with at least one UE.

[0168] Optionally, the RAN determines the UE that completes the path switching according to the second information.

[0169] Optionally, the second information is generated by the core network side based on the first information, that is, after receiving the first information, the core network side determines the UE requesting path switching according to the first information, and after performing path switching, the core network side notifies the radio access network side of the path switching result through the second information.

[0170] Optionally, if the UE associated with the second group identifier is the UE completing path switching, the first RAN sends the first information to the AMF to request the core network side to switch the path of the UE associated with the first group identifier to the first RAN, and if the core network side completes path switching of all UEs associated with the first group identifier, the first group identifier and the second group identifier are associated with the same UE.

[0171] Optionally, if the UE associated with the second group identifier is the UE completing path switching, the first RAN sends the first information to the AMF to request the core network side to switch the path of the UE associated with the first group identifier to the first RAN, and if the core network side completes path switching of part of the UEs associated with the first group identifier, that is, there is a UE associated with the first group identifier that does not complete path switching, the UE associated with the first group identifier and the UE associated with the second group identifier are different, and the UE associated with the second group identifier is a subset of all UEs associated with the first group identifier, that is, the UE associated with the second group identifier is part of the UEs associated with the first group identifier that complete downlink data path switching.

[0172] Optionally, the second group identifier includes indication information for indicating that the core network side completes path switching of all or part of the UEs associated with the first group identifier. For example, if the indication information is "true", the first RAN can determine that the core network side completes path switching of all UEs associated with the first group identifier, and if the indication information is "false", the first RAN can determine that the core network side does not complete path switching of all UEs associated with the first group identifier, and the second group identifier further includes identifier information for identifying the UE that does not complete path switching.

[0173] Optionally, the second group identifier and the first group identifier can have the same generation manner, that is, determined based on the service area identifier of the first RAN, and the determination manner of the first group identifier in S601 can be referred to.

[0174] In this way, in the switching process, the radio access network side sends the first information to the core network side, and requests the core network side to complete path switching of at least one UE associated with the first group identifier through the first group identifier in the first information, and then the core network side sends the second information to the radio access network side, so that the radio access network side determines the UE completing path switching according to the second group identifier in the second information. The radio access network side and the core network side can realize path switching of at least one UE switching to the target RAN through one information interaction, reduce signaling overhead, and improve the efficiency of switching.

[0175] Further, the communication method in FIG. 6 is initiated by the target RAN in the handover process, that is, the target RAN determines that at least one UE switching to the target RAN is associated with the first group identifier, and sends the first group identifier to the core network side, requesting path switching of the at least one UE associated with the first group identifier.

[0176] Optionally, the path switching request sent by the radio access network side to the core network side carries the first information, and the path switching request sent by the core network side to the radio access network side carries the second information.

[0177] Optionally, the handover request confirmation sent by the radio access network side to the core network side carries the first information, and the handover notification sent by the core network side to the radio access network side carries the second information.

[0178] Optionally, the radio access network side sends the first information to the core network side, and is further configured to request the core network side to establish a PDU Session list of the at least one UE associated with the first group identifier; and the core network side sends the second information to the radio access network side, and the radio access network side can determine the PDU Session list established according to the second group identifier in the second information.

[0179] Optionally, if the radio access network side determines that the core network side has not completed the PDU Session in the PDU Session list according to the second group identifier, the radio access network side deletes the PDU Session not established by the core network side.

[0180] It is easy to understand that some handover scenarios of the UE are related to time, for example, all UEs in cell A are switched to cell C from time B. Therefore, the handover of the UE associated with the group identifier can be controlled through time information. Please refer to FIG. 5A and FIG. 5B, at time T2, the UE cluster in region 2 is switched from being served by satellite 2 to being served by satellite 1, that is, the UE cluster is switched from satellite 2 to satellite 1 at time T2.

[0181] In some embodiments, the first information further includes service area identifier corresponding time information, and the time information is used to limit the handover time period of the UE in the service area corresponding to the service area identifier; thus, after the AMF receives the first information, the time period of the path switching of the UE associated with the service area identifier is determined according to the time information.

[0182] Optionally, after determining the handover time period, the core network side can perform path switching on the UE in the handover time period, or can perform path switching on the UE in advance before the handover time period.

[0183] Exemplarily, if the service identifier is a cell identifier, the first group identifier includes cell A and cell B, and the time information includes a first time period corresponding to cell A and a second time period corresponding to cell B, after the core network side receives the first information, the core network side determines, according to the time information, that the path switching time period of the UE associated with cell A is the first time period, and the path switching time period of the UE associated with cell B is the second time period.

[0184] Optionally, the time information can be a timer corresponding to the service identifier, that is, the timer indicates the time period of the path switching of the UE in the first group identifier, and the timer can be activated based on switching associated information (such as switching request information or switching notification and the like).

[0185] Optionally, the timer includes a start time and a duration of the timer, for example, the service identifier is a cell identifier, the time information corresponding to cell 1 is timer 1, and the time information corresponding to cell 2 is timer 2, timer 1 is a timer with a start time of 1:10 and a duration of 60 seconds, and timer 2 is a timer with a start time of 1:11 and a duration of 60 seconds, then the UE in cell 1 performs switching within 1:10; and the UE in cell 2 performs switching within 1:11.

[0186] Optionally, the time information can be a time point corresponding to the service identifier, for example, the service identifier is a geographical area, the time information corresponding to geographical area 1 is 1:00, and the time information corresponding to geographical area 2 is 1:10, then the UE in geographical area 1 performs switching at 1:00; and the UE in geographical area 2 performs switching at 1:10.

[0187] Please refer to FIG. 7, which is a schematic diagram of a switching scenario provided by an embodiment of the present application. FIG. 7 is a satellite communication system, and the source RAN and the target RAN are both satellites, or the satellite has part or all of the functions of the RAN. In time period 1, cell x and cell y belong to the coverage area of the source RAN; if the area indicated by the dashed line in FIG. 7; in time period 2, cell x and cell y belong to the coverage area of the target RAN; that is, in time period 2, UE1 to UEM in cell x and cell y are switched from the source RAN to the target RAN.

[0188] Optionally, if the service identifier is any one of a cell identifier (cell ID), a geographical area, a tracking area identifier (TAC ID), and a beam identifier (Beam ID), the time information is a switching time period corresponding to the service identifier, for example, the service identifier is a beam identifier, and the time information is a switching time period corresponding to the beam indicated by the beam identifier, that is, the time period of the switching triggered by the UE in the beam corresponding to the beam identifier.

[0189] Optionally, if the service identifiers are at least two of a cell identifier (cell ID), a geographic area, a tracking area identifier (TAC ID), and a beam identifier (Beam ID), and the time information is a switching time period corresponding to at least one of the at least two service identifiers in the first group identifier.

[0190] For example, the service identifiers include a cell identifier and a beam identifier in the cell, and the time information includes a switching time period corresponding to each beam in the cell, and the time information is a switching time period corresponding to one of the at least two service identifiers in the first group identifier.

[0191] For example, the service identifiers include a cell identifier and a beam identifier in the cell, and the time information includes a first switching time period corresponding to each cell and a second switching time period corresponding to each beam in each cell. That is, if the first group identifier is determined based on at least two service identifiers, each service identifier has a corresponding switching time period.

[0192] It is understood that the path switching at the wireless access network side is completed, the target RAN (the first RAN) sends a UE Context Release to the source RAN, the UE Context Release is used to request to release the context information of the UE at the source RAN side, and the connection between the UE and the source RAN is ended. If multiple UEs are simultaneously switched from the source RAN to the target RAN, the target RAN sends a UE Context Release to the source RAN at a specific UE level to release the context of a single UE at the source RAN side, and multiple UE Context Releases are sent within a specific time period, which increases the signaling overhead between networks and even affects the transmission delay of information between the wireless access networks. In order to improve the release efficiency of multiple user contexts, the embodiments of the present application simultaneously release the contexts of multiple UEs switched from the source RAN to the target RAN through one signaling to reduce the signaling overhead between networks and improve the context release efficiency. After S602, the method further includes: the first RAN sends third information to the second RAN, the third information includes a third group identifier, the third group identifier is associated with at least one UE, and the third information is used to request the second RAN to release the context of the at least one UE associated with the third group identifier. The third group identifier is associated with at least one UE. In this way, by sending the third information to the second RAN, the second RAN deletes the context of the at least one UE associated with the third group identifier according to the third group identifier, so as to reduce the signaling overhead between the wireless access network nodes during the context release in the switching process and improve the switching efficiency.

[0193] In the third group identifier, the at least one UE is switched from the second RAN to the first RAN, and the first RAN is the target RAN and the second RAN is the source RAN.

[0194] Optionally, there is an Xn interface between the source RAN and the target RAN, and the target RAN sends a UE context release to the source RAN, the UE context release carrying the third information.

[0195] Optionally, the third group identifier has the same generation manner as the first group identifier or the second group identifier, i.e., is determined based on the service area identifier of the first RAN, which can refer to the determination manner of the first group identifier in S601 or the determination manner of the first group identifier in S602.

[0196] It is easy to understand that if there is no Xn interface between the target RAN and the source RAN, the release of the context of the UE on the source RAN side can be triggered by the core network side, please refer to FIG. 8, which is a communication method provided by an embodiment of the present application, the communication method shown in FIG. 8 includes: S801-S802.

[0197] S801, the AMF sends fourth information to the second RAN, the fourth information including the third group identifier, and the fourth information being used to request the second RAN to release the context of the UE associated with the third group identifier.

[0198] S802, the second RAN sends fifth information to the AMF.

[0199] Optionally, the fifth information can be triggered by the fourth information, i.e., after the second RAN receives the fourth information, the second RAN sends the fifth information to the core network side for confirmation of the fourth information.

[0200] In this way, at least one UE context release on the wireless access network side can be realized by the core network side initiating a signaling interaction with the wireless access network side, reducing the signaling interaction between the core network and the wireless access network, and improving the switching efficiency.

[0201] Optionally, the core network side sends a UE CONTEXT RELEASE COMMAND to the wireless access network side, the UE CONTEXT RELEASE COMMAND carrying the fourth information, and the wireless access network side sends a UE CONTEXT RELEASE COMPLETE to the core network side, the UE CONTEXT RELEASE COMPLETE carrying the fifth information.

[0202] It is easy to understand that if the switching of at least two UEs is triggered by the movement of the UEs, and at least two UEs are switched to the target RAN by other RANs, and when at least two UEs are synchronized to the target RAN, the target RAN sends sixth information to the core network side, and requests the core network side to perform path switching on at least two UEs through the sixth information, so as to reduce the signaling interaction between the wireless access network side and the core network, and improve the efficiency of the switching.

[0203] Please refer to FIG. 9, which is a schematic diagram of a communication method provided by an embodiment of the present application. The method shown in FIG. 9 includes S901-S902.

[0204] S901, the first RAN sends sixth information to the AMF, the sixth information including the identities of the at least two UEs, the sixth information being used to request the AMF to perform path switching on the UEs corresponding to the identities of the at least two UEs in the sixth information.

[0205] S902, after the AMF receives the sixth information sent by the first RAN, the AMF sends seventh information to the first RAN, the seventh information including the identity of at least one UE, the seventh information being used to confirm to the first RAN side that the path switching of the UE is completed.

[0206] Optionally, the first RAN sends the sixth information to the AMF, requesting the core network side to switch the paths of the at least two UEs in the sixth information to the first RAN; if the core network side completes the path switching of all the UEs associated with the sixth information, the seventh information carries the identities of the at least two UEs, and the UE identities carried by the sixth information and the seventh information are the same.

[0207] Optionally, the first RAN sends the sixth information to the AMF, requesting the core network side to switch the paths of the at least two UEs in the sixth information to the first RAN; if the core network side completes the path switching of part of the UEs among all the UEs associated with the sixth information, i.e., the path switching of all the UEs is not completed or there is at least one UE whose path switching is not completed, the seventh information carries the identities of the UEs, which are less than the identities of the UEs carried by the sixth information.

[0208] In this way, in the switching process, if the at least two UEs switch to the target RAN, the target RAN can send multiple UE identities to the core network side through one information, implement the path switching of multiple UEs by a single signaling plan, reduce the signaling interaction between the radio access network side and the core network side, and improve the efficiency of switching.

[0209] Optionally, the path switching request sent by the radio access network side to the core network side carries the sixth information, and the path switching request sent by the core network side to the radio access network side carries the seventh information.

[0210] Optionally, the switching request confirmation sent by the radio access network side to the core network side carries the sixth information, and the switching notification sent by the core network side to the radio access network side carries the seventh information.

[0211] As can be appreciated, in the above embodiments, in FIG. 6, the core network side and the radio access network side can realize path switching of at least one UE through the first information and the second information; in FIG. 9, the core network side and the radio access network side can realize path switching of at least one UE through the sixth information and the seventh information. The network side can select a corresponding path switching mode according to the UE switching type. For example, if the UE movement triggers the switching, that is, the switching triggered by the UE moving from the coverage area of one RAN to the coverage area of another RAN, the path switching mode shown in FIG. 9 can be selected; if the switching is triggered by the network side movement, the path switching mode shown in FIG. 6 can be selected, such as the satellite communication system in FIG. 5A and FIG. 5B, due to the movement of the satellite, the UE in the area 2 is switched from the satellite 2 to the satellite 1.

[0212] Optionally, after S902, the method further includes: the first RAN sending eighth information to the second RAN, the eighth information including the identification of the at least one UE, and the eighth information being used to request the second RAN to release the context of the UE corresponding to the eighth information.

[0213] In this way, the release of the context of multiple UEs is realized through one information exchanged by the radio access network side, the signaling interaction between radio access network nodes is reduced, and the overall switching efficiency is improved.

[0214] Optionally, the source RAN and the target RAN have an Xn interface, and the target RAN sends the UE context release to the source RAN, the UE context release carrying the eighth information.

[0215] As can be appreciated, if there is no Xn interface between the target RAN and the source RAN, the release of the context of the UE on the source RAN side can be triggered by the core network side, please refer to FIG. 10, which is a communication method provided by an embodiment of the present application, the communication method shown in FIG. 10 includes: S1001-S1002.

[0216] S1001, the AMF sends ninth information to the second RAN, the ninth information including the identification of the at least one UE, and the ninth information being used to request the second RAN to release the context of the UE corresponding to the ninth information.

[0217] S1002, the second RAN sends tenth information to the AMF.

[0218] Optionally, the ninth information can be triggered by the ninth information, that is, after the second RAN receives the ninth information, the tenth information is sent to the core network side for confirmation of the ninth information.

[0219] In this way, the release of the context of at least one UE on the radio access network side can be realized through one signaling interaction initiated by the core network side to the radio access network side, the signaling interaction between the core network and the radio access network is reduced, and the switching efficiency is improved.

[0220] Optionally, the core network side sends a UE CONTEXT RELEASE COMMAND to the radio access network side, the UE CONTEXT RELEASE COMMAND carrying the ninth information, and the radio access network side sends a UE CONTEXT RELEASE COMPLETE to the core network side, the UE CONTEXT RELEASE COMPLETE carrying the tenth information.

[0221] Optionally, the ninth information includes the identities of the plurality of UEs, including NGAP IDs and PDU session IDs.

[0222] Optionally, the ninth information includes a message header and the identities of the plurality of UEs, the same message header being shared by the plurality of UEs to reduce the total amount of information transmission between the radio access network side and the core network side.

[0223] Optionally, the first RAN can compress the identities of the plurality of UEs into one sixth information or into the path switching request carrying the sixth information by compression.

[0224] Referring to FIG. 11, FIG. 11 is a schematic diagram of the sixth information provided by an embodiment of the present application. The NGAP PDU of the sixth information includes an NGAP header, an NGAP common part, and an NGAP UE-specific part. The NGAP UE-specific part includes the identities of the plurality of UEs, such as NGAP UE1 specific Part, NGAP UE2 specific Part, and NGAP UEM specific Part, i.e., the identities of M UEs are compressed into the same sixth information.

[0225] It is understood that for the switching of the UE, the network side can make a prediction based on the UE location, the ephemeris information of the satellite, the coverage area information of the satellite, etc. to determine whether the UE in a specific area meets the switching condition based on the location of the user and the coverage area of the satellite. Then, when the switching condition is met, the UE that meets the switching condition is actively triggered for path switching and / or UE context release without the signaling interaction between the radio access network side and the core network side, e.g., for the UE that meets the switching condition, the core network switches the path of the UE to the target RAN without sending information (e.g., path switching request and path switching confirmation) to the target RAN, to reduce the signaling overhead and switching delay between the radio access network side and the core network side, and to improve the switching efficiency.

[0226] In some embodiments, the method comprises: the AMF obtaining location information of the UE, and determining whether the UE meets a handover condition based on the location information and coverage areas of multiple RANs, and if the UE meets the handover condition, the AMF switches the path of the UE to a target RAN. In this way, by obtaining the location information of the UE, and determining whether the UE meets a handover condition based on the location information of the user and the coverage areas of multiple RANs, i.e., whether the UE switches from the coverage area of one RAN to the coverage area of another RAN or switches from being served by a source RAN to being served by a target RAN, the core network side actively performs path switching of the UE, and the path switching of the UE can be realized without signaling interaction, reducing the signaling overhead and handover delay between the radio access network side and the core network side, and improving the handover efficiency.

[0227] Optionally, the location information of the UE can be the location information reported by the UE when accessing the network.

[0228] Optionally, if the movement range of the UE exceeds a predetermined range, e.g., the distance between the current location of the UE and the initial location of the UE when accessing the network is greater than a first distance threshold, or the distance between the current location of the UE and a reference location is greater than a first distance threshold, the UE reports the current location of the UE to the network side. The core network determines whether the UE meets a handover condition based on the current location of the UE, and if the UE meets the handover condition, the core network side actively performs path switching of the UE.

[0229] Optionally, if the movement range of the UE exceeds a predetermined range, e.g., the distance between the current location of the UE and the initial location of the UE when accessing the network is greater than a first distance threshold, or the distance between the current location of the UE and a reference location is greater than a first distance threshold, the UE also needs to report the frequency point information, polarization information, and layer switching information of the UE to the network side.

[0230] Optionally, a correspondence between each UE and the RAN serving the UE is constructed, and the correspondence is stored at the core network side. The core network side determines whether the UE meets a handover condition and a handover time period corresponding to the handover condition by obtaining the location information of the UE and the changes in the coverage areas of multiple RANs, and actively performs path switching of the UE in the time period corresponding to the handover condition without interaction with the radio access network side, without signaling interaction between the radio access network side and the core network side, to improve the efficiency of handover. For example, for a high-speed moving satellite, the coverage area changes of the satellite can be determined by the ephemeris information of the satellite, and based on the coverage area changes of the satellite, it is determined that the area where the target UE is located changes from the coverage area of one satellite to the coverage area of another satellite, and it is determined that the UE meets the handover condition in the handover time period, and the path of the UE is switched in the handover time period.

[0231] In some embodiments, the core network side stores location information of the UE, ephemeris information of a satellite serving the UE, cell information of the satellite, and a mapping relationship between the geographic location, and then determines the area of the current cell of the satellite according to the ephemeris information of the satellite. Then, the location information of the UE is obtained, and then it is determined whether the UE meets the handover condition according to the location information of the UE and the area of the current cell of the satellite. Then, the core network side actively performs path switching of the UE that meets the handover condition, without signaling interaction between the radio access network side and the core network side, so as to improve the efficiency of handover.

[0232] Optionally, the method further includes: if the first RAN receives downlink data sent by the core network to the UE, sending third information to the second RAN. After the first RAN receives the downlink data sent to the UE, the radio access network side determines that the core network side completes the path switching of the UE, that is, the core network side sets the data path of the UE to the first RAN (that is, the target RAN), and triggers the target RAN to send third information to the source RAN, the third information being used to request the source RAN to release the context of the UE.

[0233] It is easy to understand that for a specific type of UE, for example, a UE with a high moving speed, a UE located at the edge of a cell, a handover triggering event can be configured at the core network side, and after the event is detected at the core network side, the core network side actively performs path switching of the UE that meets the handover condition. For example, for a high-speed UE, the trajectory of the UE can be predicted according to the historical location of the UE, and then after it is determined that the UE meets the handover condition according to the predicted trajectory of the user, the core network side actively performs path switching of the UE that meets the handover condition and sets the path to the target RAN.

[0234] Optionally, if the core network side actively performs path switching of the UE that meets the handover condition and the path switching fails, it can fall back to the existing handover process, such as the handover process shown in FIG. 3 or FIG. 4.

[0235] It should be noted that the division of the modules in the various communication devices provided in the above embodiments is illustrative, and is merely a logical function division. In actual implementation, another division manner can be used. In addition, each function module in each embodiment of the present application can be integrated in one processor, or can be physically separated, or two or more modules can be integrated into one module. The above integrated module can be realized in the form of hardware or in the form of a software function module.

[0236] The integrated module, if implemented in the form of a software function module and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such an understanding, the technical solutions of the embodiments of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to enable a computer device or a processor to perform all or part of the steps of the methods of the embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0237] Referring to FIG. 12, FIG. 12 shows a structural schematic diagram of an exemplary communication device according to the present application. The communication device shown in FIG. 12 can perform the steps in the communication method performed by any one of the communication devices (such as RAN and AMF) provided by the embodiments of the present application. The hardware structure of the RAN and AMF in the embodiments of the present application can all refer to the hardware structure schematic diagram of the communication device as shown in FIG. 12.

[0238] The communication device 1200 includes at least one processor 1201, a memory 1203, and at least one network interface 1204.

[0239] The processor 1201 is, for example, a general-purpose CPU, a digital signal processor (DSP), a network processer (NP), a GPU, a neural network processing units (NPU), a data processing unit (DPU), a microprocessor, or one or more integrated circuits or application specific integrated circuits (ASICs) for implementing the schemes of the present application, programmable logic devices (PLDs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The PLD is, for example, a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. It can implement or execute various logical blocks, modules, and circuits described in connection with the disclosure of the present application. The processor can also be a combination of implementing computing functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, and the like.

[0240] Optionally, the communication device 1200 further includes a bus 1202. The bus 1202 is used to transmit information between the components of the communication device 1200. The bus 1202 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus 1202 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is shown in FIG. 12, but it does not mean that there is only one bus or only one type of bus.

[0241] The memory 1203 is, for example, a read only memory (ROM) or other type of storage device that can store static information and instructions, a random access memory (RAM), or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read only memory (EEPROM), a compact disc read only memory (CD ROM) or other optical disk storage, a magnetic disk storage or other magnetic storage devices, or any other medium capable of storing desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto. The memory 1203 may, for example, exist independently of the processor 1201 and be connected to the processor 1201 via the bus 1202. The memory 1203 may, for example, also be integrated with the processor 1201.

[0242] The network interface 1204 uses any transceiver-type device to communicate with other devices or communication networks, which can be an Ethernet, a radio access network (RAN), a wireless local area network (WLAN), etc. The network interface 1204 can include a wired network interface and can also include a wireless network interface. Specifically, the network interface 1204 can be an Ethernet interface, such as a fast Ethernet (FE) interface, a gigabit Ethernet (GE) interface, an asynchronous transfer mode (ATM) interface, a WLAN interface, a cellular network interface, or a combination thereof. The Ethernet interface can be an optical interface, an electrical interface, or a combination thereof. In some embodiments of the present application, the network interface 1204 can be used for the communication device 1200 to communicate with other devices.

[0243] In a specific implementation, as some embodiments, the processor 1201 can include one or more CPUs. Each of the processors can be a single core processor or a multiple core processor. The processor herein can refer to one or more devices, circuits, and processing cores for processing data (e.g., computer program instructions).

[0244] In a specific implementation, as some embodiments, the communication apparatus 1200 can include a plurality of processors. Each of the processors can be a single-core processor, or a multi-core processor. The processor herein can refer to one or more devices, circuits, and processing cores for processing data, such as computer program instructions.

[0245] In some embodiments, the memory 1203 is configured to store program instructions for performing the methods of the present application, and the processor 1201 can execute the program instructions stored in the memory 1203. That is, the communication apparatus 1200 can implement the methods provided by the method embodiments shown in the above embodiments by means of the processor 1201 and the program instructions in the memory 1203. The program instructions can include one or more software modules. Alternatively, the processor 1201 itself can also store program instructions for performing the methods of the present application.

[0246] In the implementation process, the processor 1201 in the communication apparatus 1200 of the present application reads the instructions in the memory 1203, so that the communication apparatus 1200 shown in FIG. 12 can execute all or part of the steps of the communication method performed by the communication apparatus in the above embodiments.

[0247] In the implementation process, the processor 1201 in the communication apparatus 1200 of the present application reads the instructions in the memory 1203, so that the communication apparatus 1200 shown in FIG. 12 can execute all or part of the steps of the communication method performed by the communication apparatus in the above embodiments.

[0248] It is to be understood that the above-described processor can be a central processing unit (CPU), but can also be other general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic components, discrete hardware components, etc. The general purpose processor can be a microprocessor or any conventional processor, etc. It is to be noted that the processor can be an advanced RISC machine (ARM) architecture processor.

[0249] Further, in an optional embodiment, the above-described memory can include a read only memory and a random access memory, and provide instructions and data to the processor. The memory can also include a non-volatile random access memory. For example, the memory can also store device type information.

[0250] The memory can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example but not limitation, many forms of RAM are available. For example, static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM) and direct rambus RAM (DR RAM).

[0251] The embodiments of the present application further provide a communication system, comprising a communication device, wherein the communication device can perform the steps in the communication method performed by any of the communication devices provided by the embodiments of the present application.

[0252] In the example embodiments, the embodiments of the present application provide a computer program (product), which comprises computer program codes, and when the computer program codes are run on a computer, the computer is caused to perform the steps in the communication method performed by any of the communication devices provided by the embodiments of the present application.

[0253] The embodiments of the present application provide a computer readable storage medium, which stores programs or instructions, and when the programs or instructions are run on a computer, the communication method performed by any of the communication devices provided by the embodiments of the present application is performed.

[0254] The embodiments of the present application provide a chip, comprising a processor, configured to call and run instructions stored in a memory, so that a communication device installed with the chip performs the communication method performed by any of the communication devices provided by the embodiments of the present application.

[0255] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available media. The available media can be magnetic media (such as floppy disk, hard disk, magnetic tape), optical media (such as DVD), or semiconductor media (such as solid state disk) and the like.

[0256] The terms "first", "second", etc. are used to distinguish between similar or identical items having substantially the same function, and it should be understood that there is no logical or chronological dependency between "first", "second", "n-th", and that the number and execution order are not limited. It should also be understood that although the following description uses the terms first, second, etc. to describe various elements, these elements should not be limited by the terms. These terms are only used to distinguish one element from another.

[0257] It should also be understood that the size of the serial number of various processes in various embodiments of the present application does not mean the order of execution, and the execution order of the processes should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0258] In the present application, the term "at least one" means one or more, and the term "multiple" in the present application means two or more, for example, multiple second devices means two or more second devices. The terms "system" and "network" are often used interchangeably herein.

[0259] It should be understood that the terms used in the description of various described examples herein are merely for the purpose of describing specific examples and are not intended to be limiting. As used in the description of various described examples and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms as well, unless the context clearly indicates otherwise.

[0260] It should also be understood that the term "and" used herein means and encompasses any and all possible combinations of one or more of the associated listed items. The term "and" is a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and B, which can represent: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects are in an "or" relationship.

[0261] It should also be understood that the terms "if" and "when" can be interpreted to mean "when" or "upon" or "in response to a determination" or "in response to detecting". Similarly, the phrase "if determined" or "if detecting [stated condition or event]" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]", depending on the context.

[0262] The above description is only an embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A communication method characterized by comprising: The method applied to a first radio access network node RAN comprises: sending first information to a core network, the first information comprising a first group identifier, the first group identifier being associated with at least one UE, the first group identifier being determined based on a service area identifier of the first RAN, a coverage area of the first RAN comprising at least one service area, the service area identifier being used to identify a service area in the coverage area of the first RAN and the first group identifier being associated with UEs located in the service area, the first information being used to request path switching of the UEs associated with the first group identifier; receiving second information sent by the core network, the second information comprising a second group identifier, the second group identifier being associated with at least one UE, so that the first RAN determines the UEs completing path switching according to the second information.

2. The method of claim 1, wherein, The method further comprises: sending third information to a second RAN, the third information comprising a third group identifier, the third group identifier being associated with at least one UE, the third information being used to request the second RAN to release the context of the at least one UE associated with the third group identifier.

3. The method according to claim 1 or 2, characterized in that, The service area identifier comprises at least one of a cell identifier, a geographical area, a tracking area identifier, and a beam identifier.

4. The method according to any one of claims 1 to 3, characterized in that, The first information further comprises time information corresponding to the service area identifier, the time information being used to indicate a switching time period of the UEs corresponding to the service area identifier.

5. The method according to any one of claims 1 to 4, characterized in that, The method further comprises: sending sixth information to the core network, the sixth information comprising identifiers of at least two UEs, the sixth information being used to request path switching of the UEs corresponding to the sixth information; receiving seventh information sent by the core network, the seventh information comprising identifiers of at least one UE, the seventh information being used to confirm to the first RAN the UEs completing path switching.

6. The method of claim 5, wherein, The method further comprises: sending eighth information to a second RAN, the eighth information comprising identifiers of at least one UE, the eighth information being used to request the second RAN to release the context of the UEs corresponding to the eighth information.

7. The method of claim 1, wherein, The method further comprises: after receiving downlink data sent to the UE, sending third information to a second RAN, the third information comprising a third group identifier, the third group identifier being associated with at least one UE, the third information being used to request the second RAN to release the context of the at least one UE associated with the third group identifier.

8. A communication method characterized by comprising: The method applied to a core network side node comprises: receiving first information sent by a first RAN, the first information comprising a first group identifier, the first group identifier being associated with at least one UE, the first group identifier being determined based on a service area identifier of the first RAN, a coverage area of the first RAN comprising at least one service area, the service area identifier being used to identify a service area in the coverage area of the first RAN and the first group identifier being associated with UEs located in the service area, the first information being used to request path switching of the UEs associated with the first group identifier; sending second information to the first RAN, the second information comprising a second group identity, the second group identity being associated with at least one UE, so that the first RAN determines the UE completing path switching according to the second group identity.

9. The method of claim 8, wherein, The service area identity comprises at least one of a cell identity, a geographical area, a tracking area identity, and a beam identity.

10. The method according to claim 8 or 9, characterized in that, The first information further comprises time information corresponding to the service area identity, the time information being used to indicate a switching time period of the UE corresponding to the service area identity.

11. The method according to any one of claims 8 to 10, characterized in that, The method further comprises: sending fourth information to the second RAN, the fourth information comprising a third group identity, the fourth information being used to request the second RAN to release a context of the UE associated with the third group identity; receiving fifth information sent by the second RAN.

12. The method according to any one of claims 8 to 11, characterized in that, The method further comprises: receiving sixth information sent by the first RAN, the sixth information comprising identities of at least two UEs, the sixth information being used to request path switching of the UEs corresponding to the sixth information; sending seventh information to the first RAN, the seventh information comprising an identity of at least one UE, the seventh information being used to confirm the UE completing path switching to the first RAN.

13. The method of claim 12, wherein, The method further comprises: sending ninth information to the second RAN, the ninth information comprising an identity of at least one UE, the ninth information being used to request the second RAN to release a context of the UE corresponding to the ninth information; receiving tenth information sent by the second RAN.

14. The method according to any one of claims 8 to 13, characterized in that, The method further comprises: obtaining location information of the UE; determining whether the UE satisfies a switching condition based on the location information and coverage areas of multiple RANs; if the UE satisfies the switching condition, switching a path of the UE to the first RAN.

15. A method of communication, comprising: The method applied to the first RAN comprises: sending sixth information to a core network, the sixth information comprising identities of at least two UEs, the sixth information being used to request path switching of the UEs corresponding to the sixth information; receiving seventh information sent by the core network, the seventh information comprising an identity of at least one UE, the seventh information being used to confirm the UE completing path switching to the first RAN.

16. The method of claim 15, wherein, The method further comprises: sending eighth information to a second RAN, the eighth information comprising an identity of at least one UE, the eighth information being used to request the second RAN to release a context of the UE corresponding to the eighth information.

17. A method of communication, comprising: The method applied to the core network side node comprises: receiving sixth information sent by the first RAN, the sixth information comprising identities of at least two UEs, the sixth information being used to request path switching of the UEs corresponding to the sixth information; sending seventh information to the first RAN, the seventh information comprising an identity of at least one UE, the seventh information being used to confirm the UE completing path switching to the first RAN.

18. The method of claim 17, wherein, The method further comprises: sending ninth information to a second RAN, the ninth information comprising an identity of at least one UE, the ninth information being used to request the second RAN to release a context of the UE corresponding to the ninth information; receiving tenth information sent by the second RAN.

19. A communications device, characterized by The apparatus comprises a processor and a memory for storing computer-executable instructions, the processor being configured to execute the computer-executable instructions stored in the memory to cause the apparatus to perform the method of any one of claims 1-18.

20. A chip, characterized by The chip comprises at least one processor and a communication interface, the communication interface being coupled with the at least one processor, the at least one processor being configured to run computer programs or instructions to implement the communication method of any one of claims 1-18. The communication interface is configured to communicate with other modules outside the chip.

21. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions, which, when executed, implement the communication method of any one of claims 1-18.

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