Communication method and apparatus for non-terrestrial network, and readable storage medium

Abstract

The present application relates to the technical field of communications, and particularly relates to a communication method and apparatus for a non-terrestrial network, and a readable storage medium. The method comprises: an eNB receiving an equivalent tunnel identifier of a first tunnel, receiving downlink data of a UE from an S-GW by means of the first tunnel, and associating the downlink data with the equivalent tunnel identifier of the first tunnel; the eNB receiving an access request from the UE; the eNB receiving a first message from an MME, wherein the first message is used for determining the equivalent tunnel identifier of the first tunnel; and on the basis of the first message, the eNB sending to the UE the downlink data associated with the equivalent tunnel identifier of the first tunnel. By means of the present application, user plane transmission of a split MME on-board architecture in a store-and-forward scenario can be supported, thereby increasing the data volume and throughput of the transmission.

Description

Communication method, apparatus and readable storage medium of non-terrestrial network

[0001] The present application claims priority to the Chinese patent application No. 202411089155.7, filed on August 8, 2024, with the State Intellectual Property Office of China, and entitled "Communication method, apparatus and readable storage medium of non-terrestrial network", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a communication method, apparatus and readable storage medium of non-terrestrial network. BACKGROUND

[0003] Non-terrestrial network (NTN) has its unique advantages compared to ground communication. Taking satellite communication as an example, satellite communication has advantages such as wide coverage, long communication distance, high reliability, great flexibility, high throughput, etc. It is not affected by geographical environment, climate conditions and natural disasters, and can be widely used in aviation communication, maritime communication, military communication and other fields. Introducing satellite communication into the 5th-Generation (5G) mobile communication network can provide communication services for areas that are difficult to cover by ground communication networks, such as oceans, forests, etc. It can enhance the reliability of 5G communication, such as providing more stable and high-quality communication services for trains, airplanes and users on these transportation tools. It can also provide more data transmission resources to support a larger number of connections.

[0004] In the 3rd generation partnership project (3GPP), the related issues of non-terrestrial network (NTN) include new radio (NR) non-terrestrial network (NR NTN) and internet of things (IoT) non-terrestrial network (IoT NTN). In 3GPP R19, IoT NTN will study the store and forward (S&F or SF) technology based on the regenerative satellite architecture. Currently, the system architecture (SA) Working Group 2 (SA2) has proposed two architectures for the store and forward scenario, which are split MME on-board (split mobility management entity (MME) on satellite) and whole CN on-board (whole core network on satellite).

[0005] SA2 mainly analyzes the control plane (CP) transmission scheme in the Split MME on-board architecture. The CP transmission scheme refers to that in the IoT, data of a user equipment (UE) can be allowed to be carried in a non-access stratum (NAS) message for a small amount of data transmission, and the data is forwarded by a mobility management entity (MME) to a data network without a serving gateway (S-GW) in a user plane. However, in the Split MME on-board architecture, the user plane (UP) transmission scheme needs to be explored. SUMMARY

[0006] The present application provides a communication method, device and readable storage medium of a non-terrestrial network, which can support user plane transmission of a Split MME on-board architecture in a store-and-forward scenario, and improve the amount of data transmission and throughput.

[0007] The present application is described below from different aspects. It should be understood that the implementation and advantages of the different aspects below can be referred to each other.

[0008] In a first aspect, the present application provides a communication method of a non-terrestrial network, which can be applied to an access network device. The method comprises: the access network device receives an equivalent tunnel identifier of a first tunnel; the access network device can receive downlink data of a terminal device from an S-GW through the first tunnel, and can associate the downlink data to the equivalent tunnel identifier of the first tunnel. When the access network device covers the terminal device, an access request from the terminal device is received, the access request comprising a NAS protocol data unit (PDU), and the NAS PDU can comprise an attach request or a service request; the access network device sends the NAS PDU to a mobility management entity. The access network device receives a first message from the mobility management entity, the first message being used to determine the equivalent tunnel identifier of the first tunnel. The access network device sends downlink data associated with the equivalent tunnel identifier of the first tunnel to the terminal device according to the first message.

[0009] The first tunnel is a tunnel between the access network device and the S-GW. The equivalent tunnel identifier of the first tunnel is used to identify the first tunnel.

[0010] Exemplarily, after receiving the downlink data, the access network device can also store the downlink data and the equivalent tunnel identifier of the first tunnel, and / or the association relationship between the two.

[0011] Exemplarily, the access request can be an RRC connection establishment complete message.

[0012] For network-side initiated data, when the terminal device has not yet accessed the access network device, the mobility management entity establishes a user plane tunnel (i.e., a first tunnel) for the terminal device. The access network device stores the data packet received from the S-GW (i.e., received through the first tunnel) in association with the equivalent tunnel identifier of the first tunnel. After the terminal device accesses, the mobility management entity instructs the access network device of the equivalent tunnel identifier associated with the terminal device, and the access network device transmits the data packet associated with the equivalent tunnel identifier to the terminal device. Thus, the application can support user plane transmission in the Split MME on-board architecture in the store-and-forward scenario, and improve the data volume and throughput of transmission.

[0013] In combination with the first aspect, in a possible implementation, the access request can include indication information A, which can be used to indicate whether the terminal device is accessing the network for the first time, or to indicate the number of times the terminal device accesses the network, or to indicate whether the terminal device has performed a registration process. After receiving the indication information A, the access network device can determine the priority of the terminal device access according to the indication information A. Specifically, the access network device admits (preferentially admits) the access request of the terminal device that has not accessed for the first time or has performed a registration process with high priority, and preferentially sends the NAS PDU about the terminal device that has not accessed for the first time or has performed a registration process to the mobility management entity. In this way, the network side can ensure that the terminal device with context has priority access, which can reduce the situation that the terminal device that has initiated an attach request cannot access the network under the planned satellite due to load problems, thereby causing the terminal device to fail to access the network.

[0014] In a possible implementation of the first aspect, the equivalent tunnel identifier of the first tunnel comprises one or more of the following: a first identifier, a tunnel identifier of the first tunnel, or a S1 application protocol (S1AP) identifier (UE S1AP ID) of the terminal device. The first identifier is used to indicate the terminal device or the first tunnel. The UE S1AP ID comprises a UE S1AP ID on the side of the access network device (e.g., eNB UE S1AP ID) and / or a UE S1AP ID on the side of the mobility management entity (e.g., MME UE S1AP ID). It can be understood that the S1 application protocol (S1AP) refers to an application layer protocol between the access network device and the mobility management entity.

[0015] For example, the tunnel identifier of the first tunnel can comprise a tunnel endpoint ID (TEID) and / or an evolved universal terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) identifier.

[0016] For example, if the first identifier is used to indicate the first tunnel, the equivalent tunnel identifier of the first tunnel can be the first identifier. If the first identifier is used to indicate the terminal device, the equivalent tunnel identifier of the first tunnel can comprise the first identifier and the tunnel identifier of the first tunnel, i.e., {first identifier + TEID / E-RAB ID}. Alternatively, the equivalent tunnel identifier of the first tunnel can comprise the UE S1AP ID and the tunnel identifier of the first tunnel, i.e., {UE S1AP ID + TEID / E-RAB ID}. By introducing the equivalent tunnel identifier, the tunnel identifier (e.g., TEID / E-RAB ID) of the first tunnel can be recycled for use by other terminal devices when the first tunnel is no longer used, which can reduce the occupation of TEID / E-RAB ID when the first tunnel is not in use, and save resources.

[0017] For example, the equivalent tunnel identifier of the first tunnel is the tunnel identifier of the first tunnel, i.e., {TEID / E-RAB ID}. When the first tunnel is no longer used, the tunnel identifier (e.g., TEID / E-RAB ID) of the first tunnel still needs to be retained. There is no need to add a new identifier to identify the first tunnel, which is simple to implement.

[0018] With reference to the first aspect, in a possible implementation manner, the access network device receives the equivalent tunnel identifier of the first tunnel, including: the access network device receives a second message from the mobility management entity, the second message can be used to establish the first tunnel, and the second message can include the equivalent tunnel identifier of the first tunnel.

[0019] For example, the second message includes a tunnel endpoint identifier on the side of the SGW. The second message can also include an MME UE S1AP ID.

[0020] For example, the second message can also include a first identifier. The first identifier can be used to indicate the terminal device or the first tunnel.

[0021] For example, the second message does not carry an eNB UE S1AP ID, or carries a dummy eNB UE S1AP ID.

[0022] For example, the second message can be an INITIAL CONTEXT SETUP REQUEST message, an E-RAB SETUP REQUEST message, or a HANDOVER REQUEST message.

[0023] For example, after the access network device receives the second message, the access network device can allocate an eNB UE S1AP ID for the terminal device.

[0024] With reference to the first aspect, in a possible implementation manner, after receiving the downlink data of the terminal device from the S-GW through the first tunnel, the method further includes: the access network device receives a third message from the mobility management entity, the third message can be used to request to release the context of the terminal device. The context of the terminal device includes an eNB UE S1AP ID.

[0025] For example, the third message includes first indication information, the first indication information is used to indicate to reserve the first identifier and / or the tunnel identifier of the first tunnel.

[0026] With reference to the first aspect, in a possible implementation manner, the first message includes any one of the following: the first identifier, a UE S1AP ID, or an equivalent tunnel identifier of the first tunnel. The first identifier or the UE S1AP ID corresponds to the equivalent tunnel identifier of the first tunnel. At this time, the first identifier is used to indicate the terminal device.

[0027] For example, the first message can be an INITIAL CONTEXT SETUP REQUEST message.

[0028] For example, the first message further includes a quality of service (QoS) parameter of the E-RAB corresponding to the first tunnel. Alternatively, the access network device receives the second message, and saves the QoS parameter of the E-RAB corresponding to the first tunnel. After receiving the first message, the access network device can establish a data radio bearer (DRB) for the first tunnel based on the QoS parameter. The access network device sends downlink data associated with the equivalent tunnel identifier of the first tunnel to the terminal device through the DRB.

[0029] It can be understood that the E-RAB includes two parts of a tunnel between the access network device and the S-GW (such as the first tunnel) and a DRB. In this application, the QoS parameter of the E-RAB corresponding to the first tunnel can be understood as the QoS parameter at the E-RAB level, or as the QoS parameter of the data packet transmitted on the first tunnel, which will not be described below.

[0030] After the terminal device accesses, the mobility management entity instructs the access network device to indicate the equivalent tunnel identifier associated with the terminal device, so that the access network device can transmit the data packet associated with the equivalent tunnel identifier to the terminal device. The user plane transmission of the Split MME on-board architecture in the store-and-forward scenario can be supported, and the amount of data and throughput of transmission can be improved.

[0031] In combination with the first aspect, in a possible implementation, the first message further includes a tunnel identifier or an equivalent tunnel identifier of the second tunnel. The second tunnel can be used to transmit data initiated by the terminal device. The second tunnel is also a tunnel between the access network device and the SGW, and the difference between the first tunnel and the second tunnel includes different QoS parameters of the E-RABs corresponding to the two tunnels.

[0032] After the terminal device accesses the access network device, although the access network device has not been connected to the ground SGW, the mobility management entity can allocate a tunnel identifier or an equivalent tunnel identifier to the access network device, so as to be associated with a second tunnel that is actually established later, and transmit uplink data associated with the tunnel identifier or the equivalent tunnel identifier through the second tunnel.

[0033] In a second aspect, the present application provides a communication method of a non-terrestrial network, which can be applied to a mobility management entity. The method comprises: sending, by the mobility management entity, an equivalent tunnel identifier of a first tunnel, the equivalent tunnel identifier of the first tunnel being used to identify a first tunnel between an access network device and an S-GW; receiving, by the mobility management entity, a NAS PDU from the access network device after determining that the first tunnel is established between the access network device and the S-GW, the NAS PDU comprising an attach request or a service request; and sending, by the mobility management entity, a first message to the access network device, the first message being used to determine the equivalent tunnel identifier of the first tunnel.

[0034] In an example, the equivalent tunnel identifier of the first tunnel is used to identify the first tunnel.

[0035] In an example, the first tunnel can be used to transmit downlink data of a terminal device.

[0036] In an example, after determining that the first tunnel is established between the access network device and the S-GW, the mobility management entity can further store the equivalent tunnel identifier of the first tunnel.

[0037] In combination with the second aspect, in a possible implementation manner, the equivalent tunnel identifier of the first tunnel comprises one or more of the following: a first identifier, a tunnel identifier of the first tunnel, or a UE S1AP ID. The first identifier is used to indicate the terminal device or the first tunnel. The UE S1AP ID comprises an eNB UE S1AP ID and / or an MME UE S1AP ID.

[0038] In an example, the tunnel identifier of the first tunnel can comprise a TEID and / or an E-RAB identifier.

[0039] In an example, if the first identifier is used to indicate the first tunnel, the equivalent tunnel identifier of the first tunnel can be the first identifier. If the first identifier is used to indicate the terminal device, the equivalent tunnel identifier of the first tunnel can comprise the first identifier and the tunnel identifier of the first tunnel, i.e., {first identifier + TEID / E-RAB ID}. Alternatively, the equivalent tunnel identifier of the first tunnel can comprise the UE S1AP ID and the tunnel identifier of the first tunnel, i.e., {UE S1AP ID + TEID / E-RAB ID}. By introducing the equivalent tunnel identifier, when the first tunnel is no longer used, the tunnel identifier (such as the TEID / E-RAB ID) of the first tunnel can be recycled for use by other terminal devices, thereby reducing the occupation of the TEID / E-RAB ID when the first tunnel is not in use.

[0040] Exemplarily, the equivalent tunnel identifier of the first tunnel is the tunnel identifier of the first tunnel, such as {TEID / E-RAB ID}. When the first tunnel is no longer used, the tunnel identifier of the first tunnel (such as TEID / E-RAB ID) still needs to be reserved.

[0041] With reference to the second aspect, in a possible implementation, the sending, by the mobility management entity, of the equivalent tunnel identifier of the first tunnel comprises: when it is determined that there is downlink data, the mobility management entity sends a second message to the access network device, the second message being used for establishing the first tunnel, and the second message comprising the equivalent tunnel identifier of the first tunnel.

[0042] Exemplarily, the second message comprises a tunnel endpoint identifier on the side of the SGW. The second message can further comprise an MME UE S1AP ID.

[0043] Exemplarily, the second message can further comprise a first identifier. The first identifier can be used for indicating the terminal device or the first tunnel.

[0044] Exemplarily, the second message does not carry an eNB UE S1AP ID, or carries a dummy eNB UE S1AP ID.

[0045] Exemplarily, the second message can be an INITIAL CONTEXT SETUP REQUEST message, or an E-RAB SETUP REQUEST message, or a HANDOVER REQUEST message.

[0046] With reference to the second aspect, in a possible implementation, after the first tunnel is established between the access network device and the S-GW, the method further comprises: sending a third message to the access network device, the third message being used for requesting to release a context of the terminal device, the context of the terminal device comprising an eNB UE S1AP ID.

[0047] Exemplarily, the third message comprises first indication information, the first indication information being used for indicating to reserve a first identifier and / or a tunnel identifier of the first tunnel.

[0048] With reference to the second aspect, in a possible implementation, the first message comprises any one of the following: the first identifier, a UE S1AP ID, or the equivalent tunnel identifier of the first tunnel. The first identifier or the UE S1AP ID corresponds to the equivalent tunnel identifier of the first tunnel. At this time, the first identifier is used for indicating the terminal device.

[0049] Exemplarily, the first message can be an INITIAL CONTEXT SETUP REQUEST message.

[0050] Exemplarily, the first message further comprises a QoS parameter of an E-RAB corresponding to the first tunnel. Alternatively, after the mobility management entity sends the second message, the mobility management entity saves the QoS parameter of the E-RAB corresponding to the first tunnel.

[0051] In combination with the second aspect, in a possible implementation manner, the first message further comprises a tunnel identifier or an equivalent tunnel identifier of a second tunnel. The second tunnel can be used to transmit data initiated by the terminal device. The second tunnel is also a tunnel between the access network device and the SGW, and the difference between the first tunnel and the second tunnel comprises that the QoS parameters of the E-RABs corresponding to the first tunnel and the second tunnel are different.

[0052] In the third aspect, the present application provides a communication apparatus, which can be the access network device or a chip in the access network device. The communication apparatus is configured to execute the method in the first aspect or any possible implementation manner of the first aspect. The communication apparatus comprises a module configured to execute the method in the first aspect or any possible implementation manner of the first aspect.

[0053] In the fourth aspect, the present application provides a communication apparatus, which can be the mobility management entity or a chip in the mobility management entity. The communication apparatus is configured to execute the method in the second aspect or any possible implementation manner of the second aspect. The communication apparatus comprises a module configured to execute the method in the second aspect or any possible implementation manner of the second aspect.

[0054] In the third aspect or the fourth aspect, the communication apparatus can comprise a transceiver module and a processing module. The specific description of the transceiver module and the processing module can also be referred to the apparatus embodiment shown below. The beneficial effects of the third aspect and the fourth aspect can be referred to the foregoing description of the first aspect and the second aspect, and will not be described here.

[0055] In the fifth aspect, the present application provides a communication method of a non-terrestrial network, which can be applied to the access network device. The method comprises: the access network device receives a first message from the mobility management entity, the first message comprising a second identifier of a second tunnel and a QoS parameter of an E-RAB corresponding to the second tunnel; the access network device receives uplink data from the terminal device and associates the uplink data to the second identifier of the second tunnel. When the access network device covers the S-GW on the ground, the second tunnel is established, and the uplink data associated with the second identifier is sent to the S-GW through the second tunnel.

[0056] The second tunnel is a tunnel between the access network device and the S-GW.

[0057] In the present application, the E-RAB corresponding to the second tunnel includes two parts of the second tunnel and the DRB. The QoS parameter of the E-RAB corresponding to the second tunnel can be understood as the QoS parameter at the E-RAB level, or can be understood as the QoS parameter of the data packet transmitted on the second tunnel, which will not be described below.

[0058] For example, after receiving the uplink data from the terminal device, the access network device can also store the uplink data and the second identifier, and / or the association relationship between the two.

[0059] For example, after receiving the first message, the access network device can establish a data radio bearer (DRB) based on the QoS parameter of the E-RAB corresponding to the second tunnel. The terminal device can transmit uplink data to the access network device through the DRB.

[0060] For the data initiated by the terminal device, after the terminal device accesses, although the access network device has not yet connected to the S-GW, the mobility management entity can allocate a second identifier to the access network device, which can be an equivalent tunnel identifier or a tunnel identifier, for identifying the second tunnel between the access network device and the S-GW (at this time the second tunnel has not been established). The access network device can associate the data packets received from the terminal device to the second identifier. After the access network device covers the S-GW, the mobility management entity can establish the second tunnel for the terminal device, and can instruct the access network device the second tunnel associated with the second identifier. The access network device can transmit those data packets associated with the second identifier on the second tunnel to the S-GW. Thus, the user plane transmission of the Split MME on-board architecture in the store-and-forward scenario can be supported, and the amount of data and throughput of transmission can be improved.

[0061] In combination with the fifth aspect, in a possible implementation manner, the second identifier is a TEID and / or an E-RAB identifier.

[0062] In combination with the fifth aspect, in a possible implementation manner, the second identifier is an equivalent tunnel identifier. The equivalent tunnel identifier of the second tunnel includes one or more of the following: a third identifier, a TEID of the second tunnel, an E-RAB identifier of the second tunnel, or a UE S1AP ID. The third identifier is used to indicate the second tunnel.

[0063] Alternatively, the equivalent tunnel identifier of the second tunnel includes the third identifier and one or more of the following: a TEID of the second tunnel, or an E-RAB identifier of the second tunnel. The third identifier is used to indicate the terminal device.

[0064] The UE S1AP ID includes an eNB UE S1AP ID and / or an MME UE S1AP ID.

[0065] The application can reduce the occupation of TEID / E-RAB ID when the second tunnel is not working, and save resources.

[0066] In a possible implementation manner, in combination with the fifth aspect, the establishing the second tunnel comprises: receiving a second message from the mobility management entity, the second message being used to establish the second tunnel. The second message comprises first indication information, the first indication information being used to indicate a correspondence between the equivalent tunnel identifier of the second tunnel and the tunnel identifier of the second tunnel.

[0067] In the sixth aspect, the application provides a communication method of a non-ground network, which can be applied to a mobility management entity. The method comprises: the mobility management entity sending a first message to an access network device, the first message comprising a second identifier of a second tunnel and a QoS parameter of an E-RAB corresponding to the second tunnel, the second tunnel being used to transmit uplink data of a terminal device; the mobility management entity establishing a connection with an S-GW and establishing the second tunnel, the second tunnel being a tunnel between the access network device and the S-GW.

[0068] For example, after the second tunnel is established, the mobility management entity can further store the second identifier of the second tunnel.

[0069] In a possible implementation manner in combination with the sixth aspect, the second identifier is a TEID and / or an E-RAB identifier.

[0070] In a possible implementation manner in combination with the sixth aspect, the second identifier is an equivalent tunnel identifier. The equivalent tunnel identifier of the second tunnel comprises one or more of the following: a third identifier, a TEID of the second tunnel, an E-RAB identifier of the second tunnel, or a UE S1AP ID. The third identifier is used to indicate the second tunnel.

[0071] Alternatively, the equivalent tunnel identifier of the second tunnel comprises the third identifier and one or more of the following: a TEID of the second tunnel, or an E-RAB identifier of the second tunnel. The third identifier is used to indicate the terminal device.

[0072] The UE S1AP ID comprises an eNB UE S1AP ID and / or an MME UE S1AP ID.

[0073] With reference to the sixth aspect, in a possible implementation manner, the establishing the second tunnel comprises: the mobility management entity sending a second message to the access network device, the second message being used for establishing the second tunnel. The second message comprises first indication information, the first indication information being used for indicating a correspondence between the equivalent tunnel identifier of the second tunnel and the tunnel identifier of the second tunnel.

[0074] With reference to the seventh aspect, the present application provides a communication apparatus, which can be the access network device or a chip in the access network device. The communication apparatus is configured to execute the method in the fifth aspect or any possible implementation manner of the fifth aspect. The communication apparatus comprises a module configured to execute the method in the fifth aspect or any possible implementation manner of the fifth aspect.

[0075] With reference to the eighth aspect, the present application provides a communication apparatus, which can be the mobility management entity or a chip in the mobility management entity. The communication apparatus is configured to execute the method in the sixth aspect or any possible implementation manner of the sixth aspect. The communication apparatus comprises a module configured to execute the method in the sixth aspect or any possible implementation manner of the sixth aspect.

[0076] In the seventh aspect or the eighth aspect, the communication apparatus can comprise a transceiver module and a processing module. The specific description of the transceiver module and the processing module can also be referred to the apparatus embodiment shown below. The beneficial effects of the seventh aspect and the eighth aspect can be referred to the foregoing description of the fifth aspect and the sixth aspect, which will not be described here.

[0077] With reference to the ninth aspect, the present application provides a communication method of a non-terrestrial network, which can be applied to an access network device. The method comprises: the access network device receiving an access request from a terminal device, the access request comprising indication information A, the indication information A being used for indicating whether the terminal device is a first-time access; when the indication information A indicates that the terminal device is not a first-time access, the access network device accepting the access request of the terminal device with high priority; when the indication information A indicates that the terminal device is a first-time access, the access network device accepting the access request of the terminal device with low priority.

[0078] For example, when the indication information A indicates that the terminal device is not a first-time access, the access network device accepts the access request of the terminal device; when the indication information A indicates that the terminal device is a first-time access, the access network device determines whether to accept the access request of the terminal device according to the load condition.

[0079] Of course, when the indication information A indicates that the terminal device is not a first-time access, the access network device can also determine whether to accept the access request of the terminal device according to the current load condition of the access network device. The embodiments of the present application are not limited.

[0080] Exemplarily, the use of the indication information A can also be described as: indicating the number of times of network access request of the terminal device, or indicating whether the terminal device has performed the registration process. It can be understood that the initial network access indicates that the terminal device has not performed the registration process, and the non-initial network access indicates that the terminal device has performed the registration process.

[0081] Exemplarily, the access request can be an RRC connection establishment completion message, also known as message 5 (msg5), or an RRC establishment request message, also known as message 3 (msg3).

[0082] The access network device of the present application has high priority to admit (preferentially admit) the access request of the terminal device that is not the first time to access or has performed the registration process, and preferentially sends the NAS PDU (such as an attachment request or a service request) of the terminal device that is not the first time to access or has performed the registration process to the mobility management entity. In this way, the network side can ensure that the terminal device with context has priority to access, and can reduce the situation that the terminal device that has initiated the attach request cannot access the network under the planned satellite due to load problems, thereby causing the terminal device to fail to access the network.

[0083] In a tenth aspect, the present application provides a communication device, which includes a transceiver module and a processing module. The transceiver module is configured to receive an access request from a terminal device, and the access request includes indication information A, which can be used to indicate whether the terminal device is the first time to access the network. The transceiver module is configured to send the NAS PDU (such as an attachment request or a service request) of the terminal device to the mobility management entity when the indication information A indicates that the terminal device is not the first time to access the network. The processing module is configured to determine whether to send the NAS PDU (such as an attachment request or a service request) of the terminal device to the mobility management entity according to the load condition when the indication information A indicates that the terminal device is the first time to access the network.

[0084] In an eleventh aspect, the present application provides a communication method of a non-terrestrial network, which can be applied to a mobility management entity. The method includes: the mobility management entity sends an attachment rejection message to a terminal device, and the attachment rejection message includes a first temporary mobile subscriber identity (TMSI). The first TMSI can be used to page the terminal device in the case that the terminal device has not been authenticated at the current time but is likely to be authenticated in the future.

[0085] It can be understood that in the prior art, the terminal device is only assigned a TMSI after authentication is passed, and the TMSI is indicated to the terminal device in an attach accept message. In the present application, a TMSI (i.e., a first TMSI) is assigned to the terminal device before the terminal device passes authentication, so that the network side can page the terminal device after the next satellite arrives.

[0086] In a twelfth aspect, the present application provides a communication apparatus, which comprises a transceiver module and a processing module. The processing module is configured to generate an attach reject message, the attach reject message comprising a first TMSI. The transceiver module is configured to send the attach reject message to a terminal device. The first TMSI can be used to page the terminal device in a case that the terminal device has not passed authentication at a current time but is likely to pass authentication subsequently.

[0087] In a thirteenth aspect, an embodiment of the present application provides a communication apparatus, which comprises a processor configured to perform the method in the first aspect, the second aspect, the fifth aspect, the sixth aspect, the ninth aspect, the eleventh aspect, or any possible implementation of any of the aspects. The processor is configured to execute a program stored in a memory, and when the program is executed, the method in the first aspect, the second aspect, the fifth aspect, the sixth aspect, the ninth aspect, the eleventh aspect, or any possible implementation of any of the aspects is executed.

[0088] In combination with the thirteenth aspect, in a possible implementation, the memory is located outside the communication apparatus.

[0089] In combination with the thirteenth aspect, in a possible implementation, the memory is located inside the communication apparatus.

[0090] In the embodiments of the present application, the processor and the memory can also be integrated into one device, i.e., the processor and the memory can also be integrated together. For example, the communication apparatus can be a chip.

[0091] In a fourteenth aspect, the present application provides a communication apparatus, which is an access network device, or a mobility management entity, or a chip thereof. The communication apparatus can include a logic circuit and an interface coupled to each other. The interface is configured to interact (or transceive or input / output) information or data, and the logic circuit is configured to execute program instructions, so that the communication apparatus performs the method described in any possible implementation manner of the first aspect, or the second aspect, or the fifth aspect, or the sixth aspect, or the ninth aspect, or the eleventh aspect, or any of the aspects of the present application. The interface can be a communication interface or a transceiver. The transceiver can be a radio frequency module in the communication apparatus, or a combination of a radio frequency module and an antenna, or an input / output interface of a chip or a circuit.

[0092] In a fifteenth aspect, the present application provides a readable storage medium, which stores program instructions, and when the program instructions are executed on a computer, the computer performs the method described in any possible implementation manner of the first aspect, or the second aspect, or the fifth aspect, or the sixth aspect, or the ninth aspect, or the eleventh aspect, or any of the aspects of the present application.

[0093] In a sixteenth aspect, the present application provides a computer program product containing program instructions, and when the program instructions are executed, the method described in any possible implementation manner of the first aspect, or the second aspect, or the fifth aspect, or the sixth aspect, or the ninth aspect, or the eleventh aspect, or any of the aspects of the present application is performed.

[0094] In a seventeenth aspect, the present application provides a communication system, which includes an access network device and a mobility management entity; the access network device is configured to perform the method described in any possible implementation manner of the first aspect, or the fifth aspect, or the ninth aspect, or any of the aspects of the present application, and the second device is configured to perform the method described in any possible implementation manner of the second aspect, or the sixth aspect, or the eleventh aspect, or any of the aspects of the present application.

[0095] The technical effects achieved by the above aspects can be mutually referred to or referred to the beneficial effects of the method embodiments shown below, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0096] FIG. 1 is a schematic diagram of a transparent satellite architecture provided by an embodiment of the present application;

[0097] FIG. 2 is a schematic diagram of a regenerative satellite architecture without inter-satellite links provided by an embodiment of the present application;

[0098] FIG. 3 is a schematic diagram of a regenerative satellite architecture with inter-satellite links provided by an embodiment of the present application;

[0099] FIG. 4 is a schematic diagram of a regenerative satellite architecture with distributed unit processing functions according to embodiments of the present application;

[0100] FIG. 5 is a schematic diagram of a store-and-forward scenario according to embodiments of the present application;

[0101] FIG. 6 is a schematic diagram of a control plane transport scheme in a Split MME on-board architecture according to embodiments of the present application;

[0102] FIG. 7 is a schematic diagram of a satellite-to-ground GTP-U Tunnel in a Split MME on-board architecture according to embodiments of the present application;

[0103] FIG. 8 is a schematic diagram of an E-RAB architecture for LTE according to embodiments of the present application;

[0104] FIG. 9 is a schematic diagram of an O-RAN architecture according to embodiments of the present application;

[0105] FIG. 10 is a flow diagram of a communication method for a non-terrestrial network according to embodiments of the present application;

[0106] FIG. 11 is a schematic diagram of a method for obtaining an equivalent tunnel identifier in an O-RAN architecture according to embodiments of the present application;

[0107] FIG. 12 is another flow diagram of a communication method for a non-terrestrial network according to embodiments of the present application;

[0108] FIG. 13 is a schematic diagram of a structure of a communication apparatus according to embodiments of the present application;

[0109] FIG. 14 is another schematic diagram of a structure of a communication apparatus according to embodiments of the present application;

[0110] FIG. 15 is yet another schematic diagram of a structure of a communication apparatus according to embodiments of the present application. DETAILED DESCRIPTION

[0111] In the description of the present application, "first" and "second" are used only to distinguish different objects, and are not used to describe a specific order. In addition, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this paper is only a description of the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean: A exists alone, A and B exist together, and B exists alone. In addition, "at least one" means one or more, and "multiple" means two or more. "One or more" or the like means any combination of these items, including single or multiple combinations. For example, at least one of a, b, or c can mean: a, b, c; a and b; a and c; b and c; or a and b and c. Where a, b, and c can be single or multiple.

[0112] The terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device, etc. containing a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices, etc.

[0113] In this application, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design scheme described as "exemplary", "for example" or "for example" in this application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the use of "exemplary", "for example" or "for example" is intended to present the relevant concept in a specific manner.

[0114] In this application, "when", "if" and "if" all refer to the device will make corresponding processing under certain objective conditions, not limited to time, and also does not require the device to have a judgment action when implemented, nor does it mean that there are other limitations.

[0115] In this application, the element expressed by the singular is intended to represent "one or more", not "one and only one", unless otherwise specified.

[0116] In addition, the terms "system" and "network" are often used interchangeably in this paper.

[0117] In the present application, "indication" can include direct indication, indirect indication, display indication, and implicit indication. When describing that a certain information is used to indicate A, it can be understood that the information carries A, directly indicates A, or indirectly indicates A. Among them, directly indicating A can be understood as including the information A; implicitly indicating A can be understood as indicating A by the corresponding relationship between A and B and directly indicating B. Among them, the corresponding relationship between A and B can be pre-defined, pre-stored, pre-burned, or pre-configured.

[0118] In the present application, determining information D according to information C includes determining information D only according to information C, and determining information D according to information C and other information. In addition, information C is used to determine information D, which can also include the case of indirect determination, such as the case where information D is determined according to information E, and information E is determined according to information C.

[0119] In the present application, "sending" and "receiving" represent the direction of signal transmission. For example, "sending information to XX" can be understood as that the destination of the information is XX, which can include direct sending through the air interface, and also includes indirect sending through the air interface by other units or modules. "Receiving information from YY" can be understood as that the source of the information is YY, which can include direct receiving from YY through the air interface, and also includes indirect receiving from YY through the air interface from other units or modules. "Sending" can also be understood as "output" of the chip interface, and "receiving" can also be understood as "input" of the chip interface. In other words, sending and receiving can be between devices, such as sending or receiving between components, modules, chips, software modules or hardware modules in a device through a bus, wire or interface.

[0120] The following introduces some technical terms and application scenarios related to the present application, so as to facilitate understanding by those skilled in the art.

[0121] I. Radio access network (RAN) architecture based on NTN

[0122] Non-terrestrial network (NTN) communications include satellite communications and unmanned aerial vehicle communications, etc. Taking satellite communications as an example, generally speaking, the higher the orbit of a satellite, the larger the coverage area, but the longer the communication delay. Generally, the orbit of a satellite can be divided into low earth orbit (LEO), medium earth orbit (MEO) and geostationary orbit (GEO) according to the altitude. Among them, the orbit height of low earth orbit is 160-2000 km, the orbit height of medium earth orbit is 2000-35786 km, and the orbit height of geostationary orbit is 35786 km. The relative position of a satellite running in geostationary orbit and the earth is not affected by the rotation of the earth.

[0123] Currently, 3GPP TR 38.821 defines five radio access network (RAN) architectures based on NTN. Referring to FIG. 1, FIG. 1 is a schematic diagram of a transparent satellite architecture provided by an embodiment of the present application. In the transparent satellite architecture, the role of the satellite includes wireless frequency filtering, frequency conversion and amplification, such as the main role of the satellite is to act as a layer 1 relay (L1 relay), to regenerate the physical layer signal, and does not have other higher protocol layer functions. As shown in FIG. 1, the satellite communicates with the ground NTN gateway through wireless signals, and the NTN gateway is connected with the next generation node B (generation node B, gNB) through a wired connection. In this architecture, the satellite can be understood as a remote radio unit of the ground gNB, and the satellite only provides coverage of the physical signal, and the function of the remote radio unit needs to pass through the NTN gateway and the microwave link between the satellite and the NTN gateway to reach the satellite, and in the middle, no protocol layer processing is performed and no logical interface is established.

[0124] Referring to FIG. 2, FIG. 2 is a schematic diagram of a regenerative satellite architecture without inter-satellite links according to an embodiment of the present application. In the regenerative satellite architecture, the satellite acts as a base station, such as a gNB, with full protocol layer processing functions of a base station. As shown in FIG. 2, the satellite gNB can transmit data / signaling back to the ground NTN gateway station via microwave, and the NTN gateway station is connected to the 5G core network via wire. In the regenerative satellite scenario, the link between the gNB and the NTN gateway station can be referred to as a satellite radio interface (SRI). Referring to FIG. 3, FIG. 3 is a schematic diagram of a regenerative satellite architecture with inter-satellite links according to an embodiment of the present application. In this architecture, the satellite also acts as a base station, such as a gNB, with full protocol layer processing functions of a base station. As shown in FIG. 3, the difference between the architecture shown in FIG. 3 and the architecture shown in FIG. 2 includes that there is an inter-satellite link (ISL) in the architecture shown in FIG. 3, an Xn interface can be established between satellites, and when the satellite is not visible to the ground NTN gateway station, the data of the satellite can be transmitted to the ground via other satellites. Currently, the starlink uses the regenerative satellite architecture shown in FIG. 3.

[0125] Referring to FIG. 4, FIG. 4 is a schematic diagram of a regenerative satellite architecture with distributed unit processing functions according to an embodiment of the present application. As shown in FIG. 4, in this architecture, the satellite acts as a base station with distributed unit (DU) processing functions, such as a gNB-DU, which can be connected to a ground base station with centralized unit (CU) processing functions, such as a gNB-CU, via a ground NTN gateway station.

[0126] In addition, there is also a satellite architecture with integrated access and backhaul (IAB) functions. In this architecture, the satellite acts as an IAB node, similar to FIG. 4, but the difference includes that in the satellite architecture with IAB functions, a mobile terminal (MT) module is also deployed on the satellite in addition to the DU, and the data can be transmitted to the ground base station via the air interface by using the MT module, without the need to separately establish a microwave backhaul link between the satellite and the NTN gateway station.

[0127] II. Store and forward

[0128] In 3GPP, the related issues of non-terrestrial network (NTN) include NR NTN and IoT NTN, which use basically the same architecture, but also have some different characteristics, such as: IoT NTN is based on the evolution of LTE (long term evolution), and the base station is an evolved node (eNB). In 3GPP R19, IoT NTN will study the store and forward (S&F) technology based on the regenerative star architecture. The requirement of store and forward (S&F) is to consider that when the number of satellites and the number of ground gateway stations are small, it is impossible to connect the satellite with the ground gateway station at all times. When the satellite covers the user equipment (UE), the satellite and the gateway station cannot be connected, and cannot communicate with the core network. When the satellite can be connected with the gateway station and the core network, there is no UE under the satellite. In this scenario, real-time services may not be completed, but for some non-real-time IoT services (such as sensor data reporting), communication between the satellite and the UE can be performed when the satellite covers the UE, and communication between the satellite and the core network can be performed when the satellite covers the gateway station. This requires the satellite to have certain storage and processing capabilities to buffer the data from the UE or the core network, and then forward the data at a later time.

[0129] Referring to FIG. 5, FIG. 5 is a schematic diagram of a store and forward scenario provided by an embodiment of the present application. As shown in FIG. 5, the satellite moves along the flight direction. At a certain time, the satellite is connected with the NTN gateway station on the ground, and can communicate with the network element on the ground, but there is no UE under the satellite at this time. At this time, communication between the satellite and the network element on the ground can be performed first. With the movement of the satellite, when the satellite covers the UE, communication between the satellite and the UE is performed again. Alternatively, at a certain time, the satellite covers the UE, but the satellite cannot be connected with the NTN gateway station on the ground, and cannot communicate with the network element on the ground. At this time, communication between the satellite and the UE can be performed first. With the movement of the satellite, when the satellite covers the NTN gateway station on the ground, communication between the satellite and the network element on the ground is performed again.

[0130] III. Control plane (CP) transmission scheme in Split MME on-board architecture

[0131] Currently, SA2 proposes two architectures for the store-and-forward scenario, which are split MME on-board and whole CN on-board. In the two architectures, at least part of the core network elements are deployed on the satellite. In the whole CN on-board architecture, all core network elements are deployed on each satellite. In the split MME on-board architecture, part of the mobility management entity (MME) is deployed on the satellite, and the other part of the MME and other core network elements (such as a serving gateway (S-GW) and a home subscriber server (HSS)) are deployed on the ground. The MME deployed on the satellite and the MME on the ground have no functional division and can be understood as the same MME. In other words, the MME deployed on the satellite also has all the functions of the MME. When the satellite is connected to the ground feeder link, the MME deployed on the satellite and the MME on the ground can be understood as the same MME. When the satellite is not connected to the ground feeder link, the MME deployed on the satellite can independently process non-access stratum (NAS) messages (messages between the UE and the MME), but cannot communicate with the MME on the ground and other core network elements.

[0132] Since, in the split MME on-board architecture, only the MME of the control plane of the core network is deployed on the satellite, and the MME can process the control plane (CP) service, SA2 mainly analyzes the control plane (CP) transmission scheme in the split MME on-board architecture. The CP transmission scheme refers to that, in the Internet of Things (IoT), data of the UE can be carried in the NAS message to allow a small amount of data transmission, and the data is forwarded to the data network by the MME without passing through the user plane S-GW. For example, in the control plane (CP) transmission scheme, the data of the UE can be carried in the NAS protocol data unit (PDU) of the radio resource control (RRC) message in the air interface. After the eNB receives the RRC message, the NAS PDU in the RRC message is transparently transmitted to the MME.

[0133] Referring to FIG. 6, FIG. 6 is a schematic diagram of a control plane transmission scheme in a Split MME on-board architecture according to an embodiment of the present application. As shown in FIG. 6, eNB1 and MME1 are deployed on satellite 1, eNB2 and MME2 are deployed on satellite 2, and eNB3 and MME3 are deployed on satellite 3. The control plane transmission scheme in the Split MME on-board architecture includes, but is not limited to, (1)-(7).

[0134] (1) At T1, satellite 1 covers the UE, and the UE can send a NAS message of a network access request, such as an attach request, to MME1 through eNB1. Optionally, the NAS message can also carry uplink (UL) data of the UE. After receiving the attach request, MME1 does not know whether the UE is a legal UE because a server for UE authentication, such as a home subscriber server (HSS), is on the ground. Therefore, MME1 first replies to an attach reject message and carries a waiting time for the arrival of the next satellite in the message. If the attach request carries UL data of the UE, the UL data of the UE can be stored in MME1. It can be understood that the next satellite can be the same as the current satellite, and the next satellite is different from the current satellite in the following description.

[0135] (2) At T2, satellite 1 covers a ground gateway, and a connection is established between the ground gateway and a core network element on the ground. The information of the UE sent by MME1 at T1 is forwarded to the corresponding core network element on the ground. For example, MME1 sends the information of the UE to HSS for authentication. If the UE passes the authentication, MME1 forwards the UL data of the UE sent by MME1 at T1 to a data network.

[0136] (3) At T3, the network determines satellite 2 that covers the UE next time. When satellite 2 has a connection with the ground gateway, the ground gateway backs up the context of the UE on the core network side, such as authentication information of the UE, to MME2, and the data network sends downlink (DL) data sent to the UE to MME2. It can be understood that before satellite 2 has a connection with the ground gateway, the DL data of the UE is stored in MME on the ground. After satellite 2 has a connection with the ground gateway, the DL data of the UE is sent to MME2 and stored in MME2.

[0137] (4) T4 time: after satellite 2 covers the UE, the UE determines that satellite 2 has arrived according to the waiting time configured by MME1 at T1 time, at this time the UE initiates attach request to MME2 again. Optionally, the attach request can also carry uplink data. The UE carries its own permanent identifier, such as subscription permanent identifier (SUPI), in the attach request. MME2 determines that the context of the UE has been synchronized to MME2 at T3 time based on the SUPI of the UE, at this time the MME2 has information that the UE has passed authentication, and therefore the MME2 returns an attach accept message to the UE. Optionally, the DL data can be carried in the attach accept message. At this time, the registration process of the UE has been completed, and the UE can perform UL / DL data transmission with MME2, and the uplink data of the UE is stored in MME2. When the data transmission is completed or satellite 2 is about to leave the UE, eNB2 sends an RRC release message to the UE to release the UE to an idle state, at this time the access network side (such as eNB2) does not have the context of the UE, but the core network side (such as MME2) considers that the UE is still in the registered state.

[0138] (5) T5 time: satellite 2 covers the ground gateway again, and sends the stored uplink data of the UE to the ground data network.

[0139] (6) T6 time: the same as T3 time. The network determines satellite 3 that covers the UE next time, when satellite 3 has a connection with the ground gateway, the gateway backs up the context of the UE (such as: authentication information of the UE) at the core network side to MME3, and the data network sends the downlink data to MME3. It can be understood that before satellite 3 has a connection with the ground gateway, the downlink data of the UE is stored in the ground MME; after satellite 3 has a connection with the ground gateway, the downlink data of the UE is sent to MME3 and stored in MME3.

[0140] (7) T7 moment: similar to T4 moment. After satellite 3 covers UE, since UE has completed registration, at this time UE can directly initiate service request message to MME 3, without the need to send attach request message again. Optionally, the service request can also carry uplink data. UE carries its own permanent identifier, such as SUPI, in the service request. MME 3 determines, based on the SUPI of UE, that the context of this UE has been synchronized to MME 3 at T6 moment, at this time MME 3 already has information that UE authentication is passed, therefore MME 3 returns service accept message to UE. Optionally, DL data can be carried in the service accept message. After that, UE can perform UL / DL data transmission with MME 3, and the uplink data of UE is stored on MME 3. When data transmission is completed, or satellite 3 is about to leave UE, eNB 3 sends RRC release message to UE, and releases UE to IDLE state.

[0141] It can be understood that the processes of (5) to (7) can be repeated multiple times, and the satellite covering UE each time can be the same or different, and the present application does not limit this.

[0142] It can also be understood that the "certain moment" described in the present application can be understood as a certain time node, or can be understood as a certain period of time, which can be understood in combination with the context.

[0143] As can be known from the above, the Internet of Things (IoT) network supports a control plane (CP) transmission scheme for transmitting IoT data with small data volume and low quality of service (QoS) requirement. However, the IoT network also needs to support a user plane (UP) transmission scheme for transmitting IoT data with large data volume and high QoS requirement. At present, in the Split MME on-board architecture, the user plane (UP) transmission scheme needs to be explored.

[0144] In one possible implementation, in a user plane (UP) transmission scheme, the core network side responsible for data forwarding is no longer the MME, but the S-GW. Generally, the eNB needs to establish a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) tunnel (also referred to as an S1-U tunnel) with the S-GW to transmit user plane data. Referring to FIG. 7, FIG. 7 is a schematic diagram of a star-ground GTP-U tunnel in a Split MME on-board architecture according to an embodiment of the present application. As shown in FIG. 7, in the user plane transmission scheme, when data needs to be stored on the satellite, for example, before the satellite covers the ground gateway station, the uplink data of the UE is stored on the eNB; when data needs to be stored on the ground, for example, before the satellite covers the ground gateway station, the downlink data of the UE is stored on the S-GW. In the user plane transmission scheme, the MME does not store user data.

[0145] Four, Tunnel establishment mechanism in LTE

[0146] In a non-IoT scenario, the data of the UE is generally transmitted based on a user plane. Specifically, in LTE, a GTP-U tunnel is established between the eNB and the S-GW, and each GTP-U tunnel corresponds to an E-RAB with QoS parameters. The eNB allocates a data radio bearer (DRB) for the UE based on the QoS parameters, the eNB and the UE transmit user plane data through the DRB, and the eNB and the S-GW transmit user plane data through the GTP-U tunnel.

[0147] Exemplarily, in the prior art, after the UE is registered, the eNB sends an INITIAL UE MESSAGE to the MME, the INITIAL UE MESSAGE carrying a NAS PDU, the eNB transparently transmitting the NAS PDU of the UE to the MME, the NAS PDU carrying the service requirement of the UE. After receiving the INITIAL UE MESSAGE, the MME authenticates the UE through the HSS of the core network; and through interaction in the core network, the MME obtains the tunnel endpoint identification {transport network layer (TNL) address + tunnel endpoint ID (TEID)} of the S-GW side and the QoS parameter based on the service requirement of the UE. The MME sends the tunnel endpoint identification {TNL address + TEID} of the S-GW side, the evolved universal terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) identification, and the QoS parameter at the E-RAB level to the eNB through an INITIAL CONTEXT SETUP REQUEST message.

[0148] It can be understood that in LTE, the logical end-to-end transmission channel between the UE and the S-GW is called E-RAB. Referring to FIG. 8, which is a schematic diagram of an E-RAB architecture of LTE provided by the embodiments of the present application. As shown in FIG. 8, the form of the E-RAB between the eNB and the S-GW is a GTP-U tunnel (or S1-U tunnel, denoted as "S1 bearer" in FIG. 8), and each E-RAB corresponds to one GTP-U tunnel; the form of the E-RAB between the UE and the eNB is a DRB, and each E-RAB corresponds to one DRB. Based on the description of the E-RAB, it can be known that the granularity of the E-RAB and the GTP-U tunnel is the same, and the MME establishes one or more E-RABs for the service of the UE, or one or more tunnels for the service of the UE according to the service requirement of the UE in the INITIAL CONTEXT SETUP REQUEST message. Each E-RAB corresponds to one QoS parameter and one tunnel endpoint identifier {TNL address + TEID} on the S-GW side. For example, the E-RAB TO BE SETUP LIST information element in the INITIAL CONTEXT SETUP REQUEST message includes but is not limited to one or more E-RAB identifiers, the QoS parameter corresponding to each E-RAB identifier at the E-RAB level, and the tunnel endpoint identifier {TNL address + TEID} on the S-GW side corresponding to each E-RAB identifier.

[0149] After the eNB receives the INITIAL CONTEXT SETUP REQUEST message, the eNB sends an RRC message to the UE to establish a DRB, and then replies to the MME with an INITIAL CONTEXT SETUP RESPONSE message. The E-RAB SETUP LIST information element is included in the INITIAL CONTEXT SETUP RESPONSE message. The E-RAB SETUP LIST information element carries the tunnel endpoint identifier {TNL address + TEID} on the eNB side for each E-RAB, such as one or more E-RAB identifiers and the tunnel endpoint identifier {TNL address + TEID} on the eNB side corresponding to each E-RAB identifier in the E-RAB SETUP LIST information element. At this point, the tunnel between the eNB and the S-GW has been established.

[0150] Therefore, in the prior art, the GTP-U Tunnel can be established only after the UE is on-board. In the split MME on-board architecture of the store and forward, the GTP-U Tunnel about the UE can be established between the new satellite and the ground S-GW to transmit the user plane (UP) data before the UE accesses the new satellite for the first time, the data is stored in the new satellite, and then the data is transmitted to the UE after the new satellite covers the UE. Taking the foregoing FIG. 6 as an example, at T3, the satellite 2 is connected with the ground gateway, and for the user plane (UP) transmission scheme, if there is downlink data to be transmitted to the UE, the GTP-U Tunnel about the UE needs to be established between the eNB 2 and the ground S-GW, but before this, the UE has never accessed the eNB 2. Therefore, the prior art cannot support the establishment of the GTP-U Tunnel for a UE that has never accessed. Further, even if the GTP-U Tunnel is successfully established at T3, after the UE accesses at T4, for the eNB 2, the UE is a new UE (because at T4, the MME 2 identifies that the context of the UE is sent to the MME 2 through the SUPI of the UE, but for the eNB 2, the SUPI is invisible to the eNB, and the eNB 2 does not recognize the UE, but regards it as a new UE), the prior art cannot associate the UE to the GTP-U Tunnel established at T3. These problems can make the split MME on-board architecture of the store and forward scenario unable to support the user plane (UP) transmission scheme.

[0151] Based on this, the embodiments of the present application provide a communication method, device and readable storage medium of a non-terrestrial network, which can support the user plane transmission of the split MME on-board architecture in the store and forward scenario, and improve the data amount and throughput of transmission.

[0152] Before introducing the method of the embodiments of the present application, some network elements involved in the embodiments of the present application are introduced.

[0153] The embodiments of the present application mainly relate to a terminal device, an access network device, an open RAN (O-RAN) intelligent controller, a first network element and a second network element.

[0154] Among them, the terminal device, also known as user equipment (UE), mobile station (MS), mobile terminal (MT), etc., can refer to a device that provides voice and / or data connectivity to users. For example, handheld devices with wireless connection functions, vehicle-mounted devices, etc. At present, some examples of terminal devices are: mobile phones, tablet computers, notebook computers, palm computers, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self driving, wireless terminals in remote medical surgery, wireless terminals in smart grid, wireless terminals in transportation safety, wireless terminals in smart city, wireless terminals in smart home, etc.

[0155] An access network device can refer to a radio access network (RAN) node (or device) that accesses a terminal device to a wireless network, which can also be referred to as a base station. Currently, some examples of the RAN node are: an evolved Node B (eNB), a gNB, a transmission reception point (TRP), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (for example, home eNodeB, or home gNB, HNB), a base band unit (BBU), or a wireless fidelity (WiFi) access point (AP), and the like. In addition, in a network structure, the access network device can include a centralized unit (CU) node, or a distributed unit (DU) node, or a RAN device including the CU node and the DU node. The RAN device including the CU node and the DU node splits the protocol layers of the gNB in the NR system, and the functions of part of the protocol layers are placed in the CU for centralized control, and the functions of the remaining part or all of the protocol layers are distributed in the DU, which is controlled by the CU. Further, the centralized unit CU can be further divided into a control plane (CU-CP) and a user plane (CU-UP). The CU-CP is responsible for the control plane function, mainly including the RRC and the control plane corresponding packet data convergence protocol (PDCP), that is, PDCP-C. The PDCP-C is mainly responsible for the encryption and decryption of the control plane data, the integrity protection, the data transmission, and the like. The CU-UP is responsible for the user plane function, mainly including the service data adaptation protocol (SDAP) and the user plane corresponding PDCP, that is, PDCP-U. The SDAP is mainly responsible for processing the data of the core network and mapping the flow to the bearer. The PDCP-U is mainly responsible for the encryption and decryption of the data plane, the integrity protection, the header compression, the sequence number maintenance, the data transmission, and the like. The CU-CP and the CU-UP are connected through an E1 interface. The CU-CP represents the gNB to connect to the core network through an NG interface. The control plane of the F1 interface, that is, F1-C, is connected to the DU.The CU-UP connects with the DU through the F1 interface user plane, i.e., F1-U. Of course, there is also a possible implementation that the PDCP-C is also in the CU-UP.

[0156] In another network structure, the access network device can include various types of nodes and an open RAN (O-RAN) intelligent controller (RIC). The O-RAN intelligent controller (RIC) can also be referred to as a near-real-time RAN intelligent controller, and both can be used interchangeably in the embodiments of the present application. For example, the nodes herein can be eNBs, gNBs, DUs, O-DUs (open DUs), and the like. It can be understood that the eNBs herein are eNBs supporting O-RAN functions. Referring to FIG. 9, FIG. 9 is a schematic diagram of an O-RAN architecture provided in an embodiment of the present application. As shown in FIG. 9, the O-RAN intelligent controller or the near-real-time RAN intelligent controller can communicate with the nodes. For example, the O-RAN intelligent controller (RIC) can communicate with the eNB through an E2 interface. For example, the O-RAN intelligent controller (RIC) controls the eNB to send a message to the UE through the E2 interface. The O-RAN intelligent controller (RIC) can be used to collect network information and perform necessary optimization operations.

[0157] The first network element and the second network element are both core network elements. The first network element can be responsible for terminal device mobility management, user context and mobile state management, or allocation of a user temporary identity, and the like. For example, in LTE, the first network element can be a mobility management entity (MME), and in 5G or NR, the first network element can be an access and mobility management function (AMF) entity. The second network element can be responsible for data exchange of the user plane. For example, in LTE, the second network element can be a serving gateway (S-GW), and in 5G or NR, the first network element can be a user plane function (UPF) entity. In the split MME on-board architecture of Store and Forward, the first network element is deployed on the satellite, and the second network element is deployed on the ground. It can be understood that, with the development of communication technology, the first network element and the second network element can also be network elements in future communication networks (such as 6th-Generation (6G) communication networks), and the embodiments of the present application are not limited.

[0158] It can be understood that the "entity" in the present application can also be referred to as a network element or a functional entity. For example, the AMF entity can also be referred to as an AMF network element or an AMF functional entity; for another example, the UPF entity can also be referred to as a UPF network element or a UPF functional entity; for another example, the mobility management entity MME can also be referred to as a mobility management network element or a mobility management functional entity.

[0159] For the sake of clarity, the embodiments of the present application take the first network element as MME and the second network element as S-GW as an example to describe the communication method of the non-terrestrial network provided by the present application. In some scenarios, the mobility management entity (MME) described below can be replaced by an AMF network element, and the serving gateway (S-GW) can be replaced by a UPF network element. Correspondingly, the terms in the LTE network described below can also be replaced by the corresponding terms in the 5G / NR network, which are not listed one by one here.

[0160] In the present application, the same or similar parts between various embodiments or implementation manners can be mutually referred to, unless otherwise specified. In the various embodiments of the present application, and the various implementation manners / implementation methods / implementation manners in each embodiment, the terms and / or descriptions between different embodiments, and the various implementation manners / implementation methods / implementation manners in each embodiment have consistency and can be mutually referred to, unless otherwise specified and there is no logical conflict. The technical features in different embodiments, and the various implementation manners / implementation methods / implementation manners in each embodiment can be combined to form new embodiments, implementation manners, implementation methods, or implementation methods according to their inherent logical relationship. The implementation manners of the present application described below do not constitute a limitation on the protection scope of the present application.

[0161] In a possible implementation manner, the first access network device and the first mobility management entity described in the present application are deployed on the same satellite, the second access network device and the second mobility management entity are deployed on another satellite, and the serving gateway (S-GW) is deployed on the ground. For example, the first access network device and the first mobility management entity are located on the satellite that first covers the terminal device (such as UE), and for the sake of description, the satellite that first covers the terminal device is recorded as satellite 1 in the present application. The second access network device and the second mobility management entity are located on the satellite that does not first cover the terminal device (such as UE), and for the sake of description, the satellite that does not first cover the terminal device is recorded as satellite 2 in the present application.

[0162] The "S1 message" described in the present application can be understood as a message sent or received through an S1 interface. For example, the first S1 message can be understood as a first message sent or received through an S1 interface, the second S1 message can be understood as a second message sent or received through an S1 interface, the third S1 message can be understood as a third message sent or received through an S1 interface, and so on, which are not listed one by one in the present application. The S1 interface can be understood as a logical interface between the mobility management entity and the access network device. Of course, with the evolution of communication technology, the logical interface between the first network element and the second network element can also have other names, which are not limited by the present application.

[0163] Referring to FIG. 10, FIG. 10 is a flow diagram of a communication method of a non-terrestrial network according to an embodiment of the present application. The method mainly introduces that before a terminal device accesses an access network device on a satellite, a mobility management entity on the satellite establishes a GTP-U Tunnel for the terminal device, and after the terminal device accesses, the terminal device is associated with the GTP-U Tunnel established before, and the access network device on the satellite establishes a DRB based on the QoS parameter of the E-RAB corresponding to the GTP-U Tunnel to transmit downlink data.

[0164] As shown in FIG. 10, the communication method of the non-terrestrial network includes but is not limited to the following steps:

[0165] S101, the terminal device (such as UE) sends a message X to the first access network device (such as eNB1), and the message X includes a NAS PDU.

[0166] S102, the first access network device (such as eNB1) sends a message Y to the first mobility management entity (such as MME1), and the message Y includes the NAS PDU.

[0167] In one possible implementation, from the initial access after the terminal device is powered on, in the case that the satellite 1 covers the terminal device, the terminal device can send a message X to the first access network device, and the message X includes a NAS PDU. For example, the NAS PDU in the message X carries an attach request. For example, the message X is an RRC connection setup complete message (RRCConnectionSetupComplete), also known as message 5 (msg5). After receiving the message X, the first access network device can send a message Y to the first mobility management entity, and the message Y includes the NAS PDU. For example, the message Y is an INITIAL UE MESSAGE.

[0168] In a possible implementation, the message X can further include indication information A, which can be used to indicate whether the terminal device is first-time (i.e., first-time) access, or used to indicate the number of times of access request of the terminal device, or used to indicate whether the terminal device has performed a registration procedure. First-time access means that the terminal device has not performed a registration procedure, and non-first-time access means that the terminal device has performed a registration procedure. The indication information A can also be carried in an establishment cause value (EstablishmentCause) in the RRC establishment request message, to indicate whether the current establishment of the RRC connection is first-time or non-first-time access of the UE, or to indicate the number of times of access of the UE, or to indicate whether the UE has performed a registration procedure.

[0169] In another possible implementation, the message (for example, msg5 or msg3) carrying the indication information A can be an access stratum (AS) message, and the indication information A can be generated by a non-access stratum (NAS) of the terminal device, so that the NAS layer in the terminal device can send the indication information A to the AS layer of the terminal device, and the indication information A can be carried in the AS message.

[0170] After receiving the indication information A, the first access network device can determine the priority of the terminal device according to the indication information A. Specifically, the first access network device preferentially receives the access request (for example, the message X) of the terminal device that is not first-time access or has performed a registration procedure, and preferentially sends a message Y about the terminal device that is not first-time access or has performed a registration procedure to the first mobility management entity.

[0171] For example, in a store-and-forward (S&F) scenario, if the indication information A indicates that the terminal device is not the first access, since there is already a context (and optionally downlink data) of the terminal device on the satellite, the first access network device can agree to the access of the terminal device, for example, the first access network device sends the NAS PDU included in the message X to the first mobility management entity through an initial UE message. If the indication information A indicates that the terminal device is the first access, the first access network device can determine whether to send the NAS PDU included in the message X to the first mobility management entity according to the current load of the first access network device. For example, when the load of the first access network device is too heavy, the terminal device can be refused to access, for example, the first access network device does not send the NAS PDU included in the message X to the first mobility management entity. In this way, the network side can try to ensure that the terminal device with a context has priority to access, and can reduce the situation that the terminal device which has initiated an attach request fails to access the network under the planned satellite due to load problems, thereby causing the terminal device to fail to access the network.

[0172] Of course, when the indication information A indicates that the terminal device is not the first access, the first access network device can also determine whether to send the NAS PDU included in the message X to the first mobility management entity according to the current load of the first access network device. The embodiments of the present application are not limited.

[0173] It can be understood that whether the terminal device accesses successfully this time or not, the terminal device can access other satellites subsequently. In other words, whether the terminal device accesses successfully this time or not does not affect the terminal device to access other satellites subsequently.

[0174] In S103, the first mobility management entity (such as MME1) sends an attach reject message to the terminal device (such as UE) through the first access network device (such as eNB1).

[0175] In a possible implementation, after the first mobility management entity receives the message Y, since the server (such as HSS) for authenticating the terminal device is on the ground, the first mobility management entity does not know whether the terminal device is legal or not, so the first mobility management entity can send an attach reject message to the terminal device through the first access network device. The attach reject message can carry a waiting time for the arrival of the next satellite (such as satellite 2 or satellite 3). It can be understood that the next satellite can be the same as or different from the current satellite, and the embodiments of the present application are described below with the next satellite being different from the current satellite as an example.

[0176] In a possible implementation, the attach reject message can further carry a temporary mobile subscriber identity (TMSI). In order to distinguish the TMSI from the TMSI carried in the attach accept message in the prior art, the TMSI carried in the attach reject message is referred to as a first TMSI in the embodiments of the present application. The first TMSI can be used to page the terminal device in a case that the terminal device has not passed authentication at the current time but is likely to pass authentication subsequently.

[0177] It can be understood that, in the prior art, the terminal device is allocated a TMSI only after passing authentication, and the TMSI is indicated to the terminal device in the attach accept message. In the embodiments of the present application, the terminal device is allocated a TMSI (that is, the first TMSI) before passing authentication, which can enable the network side to page the terminal device after the next satellite (for example, satellite 2) arrives. It can also be understood that, since the terminal device has not passed authentication at this time, the first TMSI can not be a real TMSI but a temporary or special TMSI.

[0178] In a possible implementation, after step S103, as satellite 1 moves, satellite 1 covers the ground gateway station, establishes a connection with the ground core network element, and completes authentication of the terminal device.

[0179] In step S104, the second mobility management element (for example, MME2) sends a second S1 message to the second access network device (for example, eNB2), where the second S1 message is used to request establishment of a first tunnel. The first tunnel is a GTP-U Tunnel established between the second access network device (for example, eNB2) and the S-GW.

[0180] In a possible implementation, satellite 2 covers the ground gateway station and establishes a connection with the ground gateway station. The ground core network element can deliver a context of the terminal device to the second mobility management element on satellite 2.

[0181] In a possible implementation, when the second mobility management entity determines that there is downlink data of the terminal device, for example, the S-GW on the ground indicates that the second mobility management entity has downlink data of the terminal device, the second mobility management entity can send a second S1 message to the second access network device, and the second S1 message can be used to request to establish a first tunnel (such as a GTP-U Tunnel). The second S1 message can include a tunnel endpoint identifier on the S-GW side, for example, {TNL address + TEID}. For example, the second S1 message can further include a terminal device S1 application protocol (S1AP) identifier on the mobility management entity side, that is, MME UE S1AP ID. It can be understood that the S1 application protocol (S1AP) refers to an application layer protocol between the eNB and the MME.

[0182] For example, the second S1 message can be an INITIAL CONTEXT SETUP REQUEST message, or an E-RAB SETUP REQUEST message, or a HANDOVER REQUEST message.

[0183] It can be understood that, in the embodiment of the application, the second mobility management entity does not need to wait for the second access network device to send an INITIAL UE MESSAGE to the second mobility management entity before the second mobility management entity sends an INITIAL CONTEXT SETUP REQUEST message to the second access network device. In addition, since the terminal device has not accessed the second access network device, the embodiment of the application can not carry a UE S1AP ID (that is, an eNB UE S1AP ID) on the access network device side in the second S1 message, or carry a dummy eNB UE S1AP ID. Here, the dummy eNB UE S1AP ID is used to distinguish from the eNB UE S1AP ID allocated by the second access network device for the terminal device subsequently, and can represent a temporary or special eNB UE S1AP ID.

[0184] In a possible implementation, the second S1 message further includes a first identifier. The first identifier can be a UE level identifier, and can be used to indicate the terminal device. Alternatively, the first identifier can be an E-RAB level (or tunnel level) identifier, and can be used to indicate the first tunnel.

[0185] In another possible implementation, the second S1 message can include the equivalent tunnel identifier of the first tunnel. In this case, the second S1 message can or can not include the tunnel endpoint identifier at the S-GW side and / or the MME UE S1AP ID, which is not limited in the embodiments of the present application. The composition of the equivalent tunnel identifier of the first tunnel can be referred to the description below, which is not described here. It can be understood that in this implementation, the first identifier can not be included in the second S1 message.

[0186] S105, the second access network device (e.g., eNB2) allocates an eNB UE S1AP ID for the terminal device.

[0187] S106, the second access network device (e.g., eNB2) sends a fourth S1 message to the second mobility management entity (e.g., MME2), where the fourth S1 message includes the tunnel endpoint identifier at the second access network device side. For example, {TNL address + TEID}.

[0188] In a possible implementation, after receiving the second S1 message, the second access network device can allocate an eNB UE S1AP ID for the terminal device, although the terminal device has not accessed the second access network device on the satellite 2. Then, the second access network device can send the fourth S1 message to the second mobility management entity. The fourth S1 message carries the tunnel endpoint identifier at the second access network device side, for example, {TNL address + TEID}, and the eNB UE S1AP ID allocated for the terminal device.

[0189] For example, the fourth S1 message can be an INITIAL CONTEXT SETUP RESPONSE message, an E-RAB SETUP RESPONSE message, or a HANDOVER RESPONSE message.

[0190] So far, the first tunnel is established. For example, the first tunnel can be a GTP-U Tunnel between the second access network device and the S-GW.

[0191] In a possible implementation, after the first tunnel is established or after the second access network device sends the fourth S1 message, the second access network device can determine the equivalent tunnel identifier of the first tunnel and save / store the equivalent tunnel identifier of the first tunnel. The equivalent tunnel identifier of the first tunnel can be used to identify the first tunnel.

[0192] In a possible implementation, the equivalent tunnel identifier of the first tunnel can include one or more of the following: the first identifier, a tunnel identifier of the first tunnel, or a S1 interface application protocol identifier of the terminal device (UE S1AP ID). The tunnel identifier of the first tunnel can include a tunnel endpoint number (TEID) and / or an E-RAB identifier (E-RAB ID). The tunnel endpoint number can include only the TEID, or a full tunnel endpoint number (Full-TEID, F-TEID), i.e., {TNL address + TEID}. The TEID described in the embodiments of the present application can represent only the TEID or the F-TEID, and no distinction is made. When the tunnel identifier of the first tunnel includes the TEID, the TEID can include a TEID on the eNB side and / or a TEID on the MME side, which is not limited in the embodiments of the present application. The UE S1AP ID can include a UE S1AP ID on the eNB side (eNB UE S1AP ID) and / or a UE S1AP ID on the MME side (MME UE S1AP ID), which is not limited in the embodiments of the present application.

[0193] In a possible implementation, the equivalent tunnel identifier of the first tunnel can include, but is not limited to, the following four cases: (1) If the first identifier is at the E-RAB level (or tunnel level), the equivalent tunnel identifier of the first tunnel can be the first identifier. (2) If the first identifier is at the UE level, the equivalent tunnel identifier of the first tunnel can include the first identifier and the tunnel identifier of the first tunnel, i.e., {first identifier + TEID / E-RAB ID}. (3) The equivalent tunnel identifier of the first tunnel can include the UE S1AP ID and the tunnel identifier of the first tunnel, i.e., {UE S1AP ID + TEID / E-RAB ID}. (4) The equivalent tunnel identifier of the first tunnel is the tunnel identifier of the first tunnel, such as {TEID / E-RAB ID}.

[0194] It can be understood that for the case (4) that the equivalent tunnel identifier of the first tunnel is the tunnel identifier of the first tunnel, when the first tunnel is no longer used, the tunnel identifier (such as TEID / E-RAB ID) of the first tunnel still needs to be retained. For the case (4), since the equivalent tunnel identifier is the real tunnel identifier, there is no need to add an identifier to identify the first tunnel, and the implementation is simple.

[0195] It can be understood that for any one of the above cases (1) to (3), when the first tunnel is no longer used, the tunnel identifier (such as TEID / E-RAB ID) of the first tunnel can be recycled for use by other terminal devices. In other words, for the equivalent tunnel identifier of the above first tunnel, in the case of any one of the above cases (1) to (3), the equivalent tunnel identifier can be understood as an identifier that can uniquely identify the tunnel after the tunnel identifier (such as TEID and / or E-RAB ID) is recycled, and can be used for subsequent second access network devices to transmit user data associated with the tunnel.

[0196] The embodiment of the present application represents the terminal device by the first identifier or UE S1AP ID, so that even if the tunnel identifier (such as TEID / E-RAB ID) of the first tunnel is recycled and reused by other terminal devices, a tunnel can be uniquely identified by a UE identifier (that is, the first identifier or UE S1AP ID) and TEID / E-RAB ID. This can reduce the waste of configuration information and improve the address space utilization of TEID (because the address space of the protocol supported TEID is limited, only 32 bits). In addition, the first identifier can also be used as the equivalent tunnel identifier of the first tunnel, which can be understood as a semi-permanent TEID value used to identify a tunnel and is not affected by the recycling and reuse of the existing TEID / E-RAB ID.

[0197] In a possible implementation, after the establishment of the first tunnel is completed or the second mobility management entity receives the fourth S1 message, the second mobility management entity can determine the equivalent tunnel identifier of the first tunnel and save / store the equivalent tunnel identifier of the first tunnel. The equivalent tunnel identifier of the first tunnel is described above and will not be repeated here.

[0198] In a possible implementation, after the first tunnel is established or after the fourth S1 message is sent by the second access network device, the second access network device can further save the QoS parameter of the E-RAB corresponding to the first tunnel. The QoS parameter can be used by the second access network device to establish a DRB based on the QoS parameter after a terminal device accesses subsequently. Alternatively, the second access network device can not save the QoS parameter of the E-RAB corresponding to the first tunnel, and the second mobility management entity can save the QoS parameter of the E-RAB corresponding to the first tunnel after the first tunnel is established. Subsequently, the second mobility management entity can indicate the QoS parameter of the E-RAB corresponding to the first tunnel to the second access network device. Of course, the QoS parameter of the E-RAB corresponding to the first tunnel can be saved in both the second access network device and the second mobility management entity. In other words, the QoS parameter of the E-RAB corresponding to the first tunnel can be saved by at least one of the second access network device and the second mobility management entity, or can not be saved by both.

[0199] In a possible implementation, the embodiments of the present application can also be applied to an O-RAN architecture. The RIC in the O-RAN architecture can be mainly responsible for the management and / or control of the network. In the embodiments of the present application, the RIC can be used to indicate the equivalent tunnel identifier to the second access network device. This mode is applicable to the case where the equivalent tunnel identifier of the first tunnel is the first identifier, or the case where the equivalent tunnel identifier of the first tunnel is {first identifier + TEID / E-RAB ID}. For example, referring to FIG. 11, which is a schematic diagram of a method for obtaining an equivalent tunnel identifier in an O-RAN architecture according to an embodiment of the present application. As shown in FIG. 11, after the first tunnel is established, the second access network device determines the equivalent tunnel identifier of the first tunnel, including that the RIC is located on the ground, when the satellite 2 covers the ground-based gateway station, the second access network device sends a message a (if the second access network device is an eNB, the message a can be an E2 interface message) to the RIC, and the message a carries the tunnel identifier (such as TEID / E-RAB ID) of the first tunnel. The tunnel identifier can be on the side of the second access network device and / or on the side of the second mobility management entity. After receiving the message a, the RIC can generate / reason the equivalent tunnel identifier of the first tunnel based on the tunnel identifier of the first tunnel, and can send a message b (if the second access network device is an eNB, the message b can also be an E2 interface message) to the second access network device. The message b includes the equivalent tunnel identifier of the first tunnel. It can be understood that in this implementation, the first identifier is not included in the second S1 message.

[0200] Correspondingly, the second mobility management entity determines the equivalent tunnel identifier of the first tunnel, including that the RIC or the second access network device sends the equivalent tunnel identifier of the first tunnel to the second mobility management entity.

[0201] The embodiment of the present application provides an equivalent tunnel identifier obtaining method under an O-RAN architecture, so that the second access network device can obtain the equivalent tunnel identifier from the RIC and store the equivalent tunnel identifier, and after the terminal device accesses the second access network device, the second access network device can associate the downlink data received from the S-GW to the terminal device.

[0202] S107, the service gateway (S-GW) sends the downlink data of the terminal device to the second access network device (such as eNB2) through the first tunnel.

[0203] S108, the second access network device (such as eNB2) associates the downlink data to the equivalent tunnel identifier of the first tunnel, saves the downlink data and the equivalent tunnel identifier of the first tunnel, and saves the association relationship between the downlink data and the equivalent tunnel identifier of the first tunnel. The equivalent tunnel identifier of the first tunnel is used to identify the first tunnel.

[0204] In a possible implementation, after the first tunnel is established, the ground service gateway (S-GW) can send the downlink data of the terminal device to the second access network device on the satellite 2 through the first tunnel (such as a GTP-U tunnel). The second access network device can associate the received downlink data to the equivalent tunnel identifier of the first tunnel, and correspondingly save or associate store the downlink data and the equivalent tunnel identifier of the first tunnel. The equivalent tunnel identifier of the first tunnel is described above, and details are not repeated here.

[0205] In a possible implementation, after the downlink data transmission of the terminal device is completed, and before the satellite 2 is disconnected from the ground gateway station, the second mobility management entity can send a third S1 message to the second access network device. The third S1 message can be used to request to release the context of the terminal device. The context of the terminal device includes but is not limited to eNB UE S1AP ID. For example, the third S1 message can be a UE context release command (UE CONTEXT RELEASE COMMAND) message or an E-RAB release command (E-RAB RELEASE COMMAND) message.

[0206] In a possible implementation, the third S1 message can further include indication information B, which can be used to indicate to reserve the first identifier and / or the tunnel identifier (such as TEID / E-RAB ID) of the first tunnel. In another possible implementation, the third S1 message can not include the indication information B, but the standard protocol can be specified to reserve the first identifier and / or the tunnel identifier of the first tunnel.

[0207] It can be understood that if the second mobility management entity sends the third S1 message to the second access network device, the equivalent tunnel identifier of the first tunnel can be any one of the above cases (1), (2), (4). If the second mobility management entity does not send the third S1 message to the second access network device, the equivalent tunnel identifier of the first tunnel can be any one of the above cases (1) to (4). In other words, if the second mobility management entity sends the third S1 message to the second access network device, the equivalent tunnel identifier of the first tunnel cannot be the above case (3), that is, the equivalent tunnel identifier of the first tunnel cannot be the UE S1AP ID and the tunnel identifier of the first tunnel, or in other words, the equivalent tunnel identifier of the first tunnel is not {UE S1AP ID+TEID / E-RAB ID}.

[0208] S109, the terminal device (such as a UE) sends an access request to the second access network device (such as eNB2), and the access request includes a NAS PDU.

[0209] S110, the second access network device (such as eNB2) sends the NAS PDU to the second mobility management entity (such as MME2).

[0210] In a possible implementation, after the terminal device is covered by the satellite 2, the terminal device can send an access request to the second access network device to establish an RRC connection. For example, the access request includes an RRC connection establishment request message (such as msg3) and an RRC connection establishment completion message (such as msg5). The NAS PDU can be carried in the msg5. The NAS PDU can include an attach request or a service request, and a permanent identifier (such as SUPI) of the UE. After receiving the RRC connection establishment completion message (such as msg5), the second access network device can send an INITIAL UE MESSAGE to the second mobility management entity, and the NAS PDU is transparently transmitted, for example, the NAS PDU is included in the INITIAL UE MESSAGE.

[0211] In a possible implementation, the RRC connection establishment completion message (such as msg5) or the RRC connection establishment request message (such as msg3) can include indication information A, which can be used to indicate whether the terminal device is initially (that is, for the first time) registered, or to indicate the number of times of registration of the terminal device, or to indicate whether the terminal device has performed a registration process. In the embodiment of the application, the indication information A indicates non-first registration, or indicates second registration, or indicates that the terminal device has performed a registration process. The second access network device can preferentially admit the terminal device that is not registered for the first time or not accessed for the first time, or the terminal device that has performed a registration process, and the related description has been given in the foregoing steps.

[0212] In a possible implementation, after the terminal device is covered by the satellite 2, the second mobility management entity can also initiate paging to the terminal device through the second access network device, carrying the first TMSI. Then, the terminal device can initiate random access to the second access network device to establish an RRC connection.

[0213] S111, the second mobility management entity (e.g., MME2) sends a first S1 message to the second access network device (e.g., eNB2), where the first S1 message is used to determine the equivalent tunnel identifier of the first tunnel.

[0214] In a possible implementation, after receiving the NAS PDU, the second mobility management entity can determine that a tunnel has been established for the terminal device identified by the SUPI in the NAS PDU. The second mobility management entity can send a first S1 message to the second access network device. For example, the first S1 message can be an INITIAL CONTEXT SETUP REQUEST message. In a possible implementation, after receiving the first S1 message, the second access network device can send an RRC message to the terminal device, where the RRC message includes a NAS PDU, and the NAS PDU can include an attach accept or a service accept.

[0215] In a possible implementation, the first S1 message can include any of the following: the first identifier, a UE S1AP ID, or the equivalent tunnel identifier of the first tunnel. In some scenarios, the first identifier and the UE S1AP ID can be collectively referred to as the identifier of the terminal device.

[0216] For example, the first S1 message includes the first identifier (if the first identifier is UE-level) or a UE S1AP ID. In this implementation, the equivalent tunnel identifier of the first tunnel is case (2) or (3) above, and the second access network device has saved the QoS parameter of the E-RAB corresponding to the first tunnel.

[0217] For example, the first S1 message includes the equivalent tunnel identifier of the first tunnel. For example, the first S1 message includes a tunnel list, and the tunnel list includes the equivalent tunnel identifier of at least one tunnel, and the equivalent tunnel identifier of the at least one tunnel includes the equivalent tunnel identifier of the first tunnel. In this implementation, the equivalent tunnel identifier of the first tunnel can be any of cases (1) to (4) above.

[0218] In a possible implementation, when the first S1 message includes the equivalent tunnel identifier of the first tunnel, the first S1 message can further include the QoS parameter of the E-RAB corresponding to the first tunnel. For example, the tunnel list further includes the QoS parameter of the E-RAB corresponding to at least one tunnel (including the first tunnel).

[0219] In S112, the second access network device (e.g., eNB2) sends, according to the first S1 message, the downlink data associated with the equivalent tunnel identifier of the first tunnel to the terminal device (e.g., UE).

[0220] In a possible implementation, after receiving the first S1 message, the second access network device can determine the equivalent tunnel identifier of the first tunnel based on the first S1 message. For example, if the first S1 message includes the first identifier (if the first identifier is UE-level) or the UE S1AP ID, the second access network device can find, according to the first identifier or the UE S1AP ID included in the first S1 message, the equivalent tunnel identifier corresponding to the first identifier or the UE S1AP ID stored locally, and then find the QoS parameter of the E-RAB corresponding to the equivalent tunnel identifier and the downlink data associated with the equivalent tunnel identifier. For another example, if the first S1 message includes the equivalent tunnel identifier of the first tunnel, the second access network device can find, according to the equivalent tunnel identifier of the first tunnel, the downlink data corresponding to the equivalent tunnel identifier and the QoS parameter of the E-RAB corresponding to the equivalent tunnel identifier stored locally, or the first S1 message includes the QoS parameter of the E-RAB corresponding to the first tunnel, without the need for local searching.

[0221] In a possible implementation, the second access network device can establish a DRB for the first tunnel based on the QoS parameter of the E-RAB corresponding to the first tunnel. Then, the second access network device can send, to the terminal device, the downlink data associated with the equivalent tunnel identifier of the first tunnel through the DRB. At this time, if the terminal device has uplink data on the same EPS bearer, the terminal device can also transmit the uplink data through the DRB. In other words, if the uplink data and the downlink data of the terminal device belong to the same service, the terminal device can transmit the uplink data through the DRB established for the first tunnel.

[0222] In a possible implementation, when the data transmission ends or before satellite 2 leaves the terminal device, the second access network device can send an RRC release message to the terminal device to release the terminal device to an IDLE state.

[0223] In order to reduce the TEID occupied when the tunnel is not working, the embodiment of the present application introduces the concept of equivalent tunnel identifier, and for downlink transmission, when the UE has not accessed the eNB2 on the satellite 2, the MME2 on the satellite 2 establishes a GTP-U Tunnel for the UE, the eNB2 saves the data packets received from the S-GW (i.e. received through the GTP-U Tunnel) in association with the equivalent tunnel identifier of the GTP-U Tunnel, and after the UE accesses, the MME2 indicates the equivalent tunnel identifier associated with the UE to the eNB2, and the eNB2 establishes a DRB based on the QoS parameter of the E-RAB corresponding to the GTP-U Tunnel to transmit the data packets. Therefore, the embodiment of the present application can support the user plane transmission of the Split MME on-board architecture in the store-and-forward scenario, and improve the data volume and throughput of transmission.

[0224] In a possible implementation, the embodiment shown in Figure 10 introduces a user plane transmission scheme of data initiated by the network side in the Split MME on-board architecture, and the embodiment of the present application further provides a user plane transmission scheme of data initiated by the terminal side, which can be understood by referring to the description of the embodiment shown in Figure 12. It can be understood that the embodiment shown in Figure 12 can be implemented alone or in combination with the aforementioned embodiment shown in Figure 10, and the embodiment of the present application does not make any limitation.

[0225] Referring to Figure 12, Figure 12 is another flowchart of the communication method of the non-terrestrial network provided by the embodiment of the present application. The method mainly introduces that after the terminal device accesses the access network device on the satellite, since the access network device cannot be connected to the S-GW on the ground, the mobility management entity on the satellite allocates an identifier for the access network device, which is used to identify the second tunnel between the access network device and the S-GW (at this time, the second tunnel has not been established or has not been used for data transmission), and then the access network device associates the uplink data received from the terminal device with the identifier, and after the satellite gateway station is connected, the mobility management entity establishes the second tunnel for the terminal device (including configuring the tunnel endpoint number TEID of the second tunnel on the S-GW side), and the access network device transmits the uplink data associated with the identifier to the S-GW through the second tunnel.

[0226] As shown in Figure 12, the communication method of the non-terrestrial network includes but is not limited to the following steps:

[0227] S201, the terminal device (such as UE) sends a message X to the first access network device (such as eNB1), and the message X includes NAS PDU. The NAS PDU includes an attachment request.

[0228] S202, the first access network device (e.g., eNB1) sends a message Y to the first mobility management entity (e.g., MME1), where the message Y includes the NAS PDU.

[0229] S203, the first mobility management entity (e.g., MME1) sends an attach reject message to the terminal device (e.g., UE) via the first access network device (e.g., eNB1).

[0230] In a possible implementation, the implementation of steps S201 to S203 of the embodiments of the present application can refer to the implementation of steps S101 to S103 of the embodiment shown in FIG. 10, which will not be described herein.

[0231] S204, the ground core network element (including S-GW) transfers the context of the terminal device to the second mobility management entity (MME2).

[0232] In a possible implementation, after step S203, as the satellite 1 moves, the satellite 1 covers the ground gateway station and establishes a connection with the ground core network element, and completes the authentication of the terminal device. The satellite 2 covers the ground gateway station and establishes a connection with the ground core network element. The ground core network element can transfer the context (e.g., authentication information) of the terminal device to the second mobility management entity on the satellite 2.

[0233] S205, the terminal device (e.g., UE) sends an access request to the second access network device (e.g., eNB2).

[0234] S206, the second access network device (e.g., eNB2) sends an INITIAL UE MESSAGE to the second mobility management entity (e.g., MME2).

[0235] In a possible implementation, as the satellite 2 moves, after the satellite 2 covers the terminal device, the terminal device can initiate random access to the second access network device and establish an RRC connection. For example, the access request includes an RRC connection establishment request message (e.g., msg3) and an RRC connection establishment completion message (e.g., msg5), and the msg5 carries a NAS PDU. The NAS PDU can include an attach request or a service request, and a permanent identifier (e.g., SUPI) of the UE. After the second access network device receives the RRC connection establishment completion message (e.g., msg5), the second access network device can send an INITIAL UE MESSAGE to the second mobility management entity, and the NAS PDU is transparently transmitted, for example, the INITIAL UE MESSAGE includes the NAS PDU.

[0236] In a possible implementation, the RRC connection setup complete message (such as msg5) or the RRC connection setup request message (such as msg3) can further include indication information A, which can be used to indicate whether the terminal device is initially (that is, for the first time) accesses the network, or to indicate the number of times of access to the network of the terminal device, or to indicate whether the terminal device has performed a registration process. In the embodiment of the application, the indication information A indicates non-first access to the network, or indicates second access to the network, or indicates that the terminal device has performed a registration process. The second access network device can preferentially admit the terminal device that does not access the network for the first time or does not access the network for the second time, or the terminal device that has performed a registration process, and the related description has been given in the foregoing steps.

[0237] In S207, the second mobility management entity (such as MME2) sends a first S1 message to the second access network device (such as eNB2), where the first S1 message includes the second identifier of the second tunnel and the QoS parameter of the E-RAB corresponding to the second tunnel.

[0238] In a possible implementation, after receiving the initial UE message, the second mobility management entity can send a first S1 message to the second access network device. For example, the first S1 message can be an INITIAL CONTEXT SETUP REQUEST message. The first S1 message can include the second identifier of the second tunnel and the QoS parameter of the E-RAB corresponding to the second tunnel. The second identifier can be a tunnel identifier of the second tunnel, such as a TEID or a F-TEID on the S-GW side, or the second identifier can be an equivalent tunnel identifier of the second tunnel. The second tunnel can be used to transmit data initiated by the terminal device, such as uplink data. The second tunnel is a tunnel between the second access network device and the S-GW. At this time, the second tunnel has not been established, and the second mobility management entity can pre-allocate a tunnel identifier (such as a TEID or a F-TEID on the S-GW side) or an equivalent tunnel identifier for the second tunnel.

[0239] In the embodiment of the application, the F-TEID is {TNL address + TEID}.

[0240] In a possible implementation, the tunnel identifier of the second tunnel can be a TEID (such as a F-TEID on the S-GW side) and / or an E-RAB ID.

[0241] In a possible implementation, the equivalent tunnel identifier of the second tunnel can include one or more of the following: a third identifier, a TEID of the second tunnel, an E-RAB ID of the second tunnel, or a UE S1AP ID. The third identifier can be used to indicate the second tunnel. For example, the equivalent tunnel identifier of the second tunnel can be the third identifier, or the equivalent tunnel identifier of the second tunnel can be the UE S1AP ID and the TEID / E-RAB ID of the second tunnel, or the equivalent tunnel identifier of the second tunnel can be the TEID / E-RAB ID of the second tunnel.

[0242] Alternatively, the equivalent tunnel identifier of the second tunnel can include the third identifier and one or more of the following: a TEID or an E-RAB ID of the second tunnel. The third identifier can be used to indicate the terminal device in this case.

[0243] In the embodiments of the present application, when the tunnel identifier of the first tunnel is a TEID, the TEID can include an eNB-side TEID and / or an MME-side TEID, which are not limited in the embodiments of the present application. The UE S1AP ID can also include an eNB-side UE S1AP ID and / or an MME-side UE S1AP ID, which are not limited in the embodiments of the present application.

[0244] In a possible implementation, when the embodiments of the present application are combined with the embodiments shown in FIG. 10, the first S1 message in step S207 is the same as the first S1 message in step S111. The second tunnel is different from the first tunnel in FIG. 10 in that the QoS parameter of the E-RAB corresponding to the first tunnel is different from the QoS parameter of the E-RAB corresponding to the second tunnel.

[0245] S208, the second access network device (e.g., eNB2) sends an access response to the terminal device (e.g., UE), and the access response includes a NAS PDU.

[0246] In a possible implementation, after receiving the first S1 message, the second access network device can save the second identifier of the second tunnel and the QoS parameter of the E-RAB corresponding to the second tunnel, and can send an access response to the terminal device, and the access response includes a NAS PDU, which can include an attach accept or a service accept.

[0247] S209, the terminal device (e.g., UE) sends uplink data to the second access network device (e.g., eNB2).

[0248] S210, the second access network device (e.g., eNB2) associates the received uplink data to the second identifier of the second tunnel, stores the uplink data and the second identifier, and stores the association between the uplink data and the second identifier.

[0249] In a possible implementation, after receiving the first S1 message, the second access network device can establish a DRB based on the QoS parameter of the E-RAB corresponding to the second tunnel. The terminal device can send uplink data to the second access network device through the DRB. The second access network device can associate the received uplink data to the second identifier of the second tunnel, and can correspondingly store or associate store the uplink data and the second identifier.

[0250] S211, the second mobility management entity (e.g., MME2) establishes a connection with the S-GW.

[0251] S212, the second tunnel is established. The second tunnel is a GTP-U Tunnel established between the second access network device (e.g., eNB2) and the S-GW.

[0252] In a possible implementation, if the second identifier is the F-TEID / E-RABID on the S-GW side, after the second access network device establishes the DRB, the second access network device can send an INITIAL CONTEXT SETUP RESPONSE message to the second mobility management entity, carrying the F-TEID on the second access network device side. As the satellite 2 moves, the satellite 2 covers the ground gateway station, and establishes a connection with the ground core network element (e.g., S-GW). The second mobility management entity sends the F-TEID on the S-GW side, or the E-RABID, to the S-GW. At this point, the second tunnel (GTP-U Tunnel) is established.

[0253] In another possible implementation, if the second identifier is the equivalent tunnel identifier of the second tunnel, when the uplink data transmission is completed, or before the satellite 2 leaves the terminal device, the second access network device can send an RRC release message to the terminal device, and release the terminal device to the IDLE state. If the terminal device has no uplink data transmission (for example, the uplink data of the terminal has been transmitted) before the satellite 2 leaves the terminal device, the second access network device can release the equivalent tunnel identifier (i.e., the second identifier) of the second tunnel at this time.

[0254] After the satellite 2 leaves the terminal device, as the satellite 2 moves, the satellite 2 covers the ground gateway station, and a connection is established with the core network element (such as an S-GW) on the ground. At this time, the second mobility management entity can send a fifth S1 message to the second access network device, and the fifth S1 message can be used to request to establish the second tunnel. The fifth S1 message includes the tunnel identifier (such as an F-TEID on the S-GW side) of the second tunnel. For example, the fifth S1 message can be an INITIAL CONTEXT SETUP REQUEST message. The fifth S1 message can include indication information C, which can be used to indicate the correspondence between the equivalent tunnel identifier of the second tunnel and the tunnel identifier of the second tunnel. The correspondence can be used by the second access network device to send uplink data corresponding to the equivalent tunnel identifier of the second tunnel through the second tunnel. The second access network device can send an INITIAL CONTEXT SETUP RESPONSE message to the second mobility management entity, carrying the F-TEID on the second access network device side, to establish the second tunnel. At this time, the second tunnel (GTP-U Tunnel) is established.

[0255] For example, if the equivalent tunnel identifier of the second tunnel is different from the tunnel identifier of the second tunnel carried in the fifth S1 message at this time, the equivalent tunnel identifier of the second tunnel is no longer used thereafter, and the second access network device can delete the equivalent tunnel identifier of the second tunnel at this time.

[0256] S213, the second access network device (such as eNB2) sends the uplink data associated with the second identifier through the second tunnel to the S-GW.

[0257] In a possible implementation, the second access network device can send the uplink data associated with the second identifier to the serving gateway (S-GW) through the second tunnel established above. For example, the second access network device can send the uplink data associated with the second identifier to the S-GW through the second tunnel based on the tunnel identifier of the second tunnel, or based on the equivalent tunnel identifier of the second tunnel and the correspondence between the equivalent tunnel identifier of the second tunnel and the tunnel identifier of the second tunnel.

[0258] In a possible implementation, after the uplink transmission between the second access network device and the serving gateway ends, if the terminal device accesses the satellite 2 again next time (based on ephemeris information and the location of the terminal device), and the equivalent tunnel identifier of the second tunnel is TEID and / or E-RABID, the second access network device can continue to save the second identifier, otherwise, the second access network device can delete the second identifier.

[0259] For uplink transmission, after the UE accesses, since the eNB2 cannot connect to the S-GW, the MME2 can allocate a second identifier for the eNB2, the second identifier can be an equivalent tunnel identifier or a tunnel identifier (such as an F-TEID on the S-GW side), used to identify a second tunnel between the eNB2 and the S-GW (at this time, the second tunnel has not been established), the eNB2 can associate the data packets received from the UE to the second identifier, after the satellite gateway station is accessed, the MME2 can establish a second tunnel for the UE, and can instruct the eNB2 the second tunnel associated with the second identifier, the eNB2 can transmit those data packets associated with the second identifier on the second tunnel to the S-GW. Therefore, the embodiment of the present application can support the user plane transmission of the Split MME on-board architecture in the store-and-forward scenario, and improve the data volume and throughput of transmission.

[0260] The above describes the method provided by the present application in detail. In order to implement the above scheme of the embodiment of the present application, the embodiment of the present application further provides a corresponding device or equipment.

[0261] The embodiment of the present application divides each network element or device into functional modules according to the above method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above integrated module can be realized in the form of hardware or in the form of a software functional module. It should be noted that the division of the module in the present application is illustrative, and is only a logical function division. When actually implemented, another division mode can be used. The communication device of the embodiment of the present application will be described in detail below with reference to FIGS. 13 to 15.

[0262] Referring to FIG. 13, FIG. 13 is a structural schematic diagram of a communication device provided by the embodiment of the present application. As shown in FIG. 13, the communication device includes a processing module 801 and a transceiver module 802. The transceiver module 802 can implement a corresponding communication function, and the processing module 801 is used to implement a corresponding processing function. For example, the transceiver module 802 can also be referred to as an interface, a communication interface, or a communication module, etc.

[0263] In some embodiments of the present application, the communication device can be used to execute the actions performed by the second access network device in the above method embodiments. At this time, the communication device can be the second access network device itself or a chip or functional module configured in the second access network device, etc. The transceiver module 802 is used to execute the transceiving related operations of the second access network device in the above method embodiments, and the processing module 801 is used to execute the processing related operations of the second access network device in the above method embodiments.

[0264] In one design, the transceiver 802 receives an equivalent tunnel identifier of a first tunnel, and receives downlink data of a terminal device from an S-GW through the first tunnel, the first tunnel being a tunnel established between the second access network device and the S-GW, and the equivalent tunnel identifier of the first tunnel being used to identify the first tunnel. The transceiver 802 receives an access request from the terminal device. The transceiver 802 also receives a first S1 message from a second mobility management entity, the first S1 message being used to determine the equivalent tunnel identifier of the first tunnel. The processing module 801 sends downlink data associated with the equivalent tunnel identifier of the first tunnel to the terminal device according to the first S1 message.

[0265] In one design, the transceiver 802 receives a second S1 message from the second mobility management entity, the second S1 message being used to establish the first tunnel, and the second S1 message including the equivalent tunnel identifier of the first tunnel.

[0266] In one design, the transceiver 802 receives a third S1 message from the second mobility management entity, the third S1 message being used to request to release a context of the terminal device, and the context of the terminal device including an eNB UE S1AP ID.

[0267] In one design, the processing module 801 saves a QoS parameter of an E-RAB corresponding to the first tunnel.

[0268] In embodiments of the present application, the specific description of the terms or names or steps such as equivalent tunnel identifier, access request, first S1 message, second S1 message, third S1 message, QoS parameter, second mobility management entity, S-GW, terminal device, second access network device, etc. can refer to the introduction in the above method embodiments (e.g., FIG. 10), which will not be described in detail here.

[0269] The specific description of the transceiver and the processing module shown in the embodiments of the present application is only an example. For the specific functions or steps of the transceiver and the processing module, etc., reference can be made to the above method embodiments (e.g., FIG. 10), which will not be described in detail here. In addition, the technical effects of the embodiments of the present application are described above, and for the sake of brevity, they will not be described here.

[0270] In another design, the transceiver 802 is configured to receive a first S1 message from the second mobility management entity, the first S1 message including a second identifier of a second tunnel; the transceiver 802 is also configured to receive uplink data from the terminal device; the processor 801 is configured to associate the uplink data to the second identifier of the second tunnel; the processor 801 is also configured to establish the second tunnel, the second tunnel being a tunnel between the second access network device and the S-GW; and the transceiver 802 is also configured to send the uplink data associated with the second identifier to the S-GW through the second tunnel.

[0271] For example, the transceiver 802 is also configured to receive a second S1 message from the second mobility management entity, the second S1 message being used to establish the second tunnel, the second S1 message including first indication information, the first indication information being used to indicate a correspondence between an equivalent tunnel identifier of the second tunnel and a tunnel identifier of the second tunnel.

[0272] In the embodiments of the present application, the specific descriptions of the second identifier, the QoS parameter, the first S1 message, the second S1 message, the second mobility management entity, the S-GW, the terminal device, the second access network device, and the like can refer to the descriptions in the method embodiments (e.g., FIG. 12), which will not be repeated here.

[0273] The specific descriptions of the transceiver and the processor in the embodiments of the present application are only examples. For the specific functions or steps of the transceiver and the processor, refer to the method embodiments (e.g., FIG. 12), which will not be repeated here. In addition, the technical effects of the embodiments of the present application can refer to the technical effects of the method embodiments, which will not be repeated here for brevity.

[0274] Referring to FIG. 13, in some other embodiments of the present application, the communication apparatus can be configured to perform the actions performed by the second mobility management entity in the method embodiments. In this case, the communication apparatus can be the second mobility management entity itself or a chip or a functional module configured in the second mobility management entity. The transceiver 802 is configured to perform the transceiving related operations of the second mobility management entity in the method embodiments, and the processor 801 is configured to perform the processing related operations of the second mobility management entity in the method embodiments.

[0275] In one design, the processing module 801 is configured to determine an equivalent tunnel identifier of a first tunnel, the equivalent tunnel identifier of the first tunnel being used to identify the first tunnel established between the second access network device and the S-GW, the first tunnel being used to transmit downlink data of the terminal device; the transceiver module 802 is configured to send the equivalent tunnel identifier of the first tunnel, and receive a NAS PDU from the second access network device after determining that the first tunnel is established between the second access network device and the S-GW; and the transceiver module 802 is further configured to send a first S1 message to the second access network device, the first S1 message being used to determine the equivalent tunnel identifier of the first tunnel.

[0276] In one design, the transceiver module 802 is further configured to send a second S1 message to the second access network device when it is determined that there is downlink data, the second S1 message being used to request establishment of the first tunnel, the second S1 message including the equivalent tunnel identifier of the first tunnel.

[0277] In one design, the transceiver module 802 is further configured to send a third S1 message to the second access network device after determining that the first tunnel is established between the second access network device and the S-GW, the third S1 message being used to request release of a context of the terminal device, the context of the terminal device including an eNB UE S1AP ID.

[0278] In one design, the processing module 801 is further configured to save a QoS parameter of an E-RAB corresponding to the first tunnel.

[0279] In embodiments of the present application, the specific description of the terms or names or steps such as equivalent tunnel identifier, NAS PDU, first S1 message, second S1 message, third S1 message, QoS parameter, second mobility management entity, S-GW, terminal device, second access network device, etc. can refer to the introduction in the above method embodiments (such as FIG. 10), which will not be described in detail here.

[0280] The specific description of the transceiver module and the processing module shown in the embodiments of the present application is only an example, and for the specific functions or steps of the transceiver module and the processing module, etc. can refer to the above method embodiments (such as FIG. 10), which will not be described in detail here. In addition, the technical effects of the embodiments of the present application are described above, and for the sake of brevity, they will not be described here.

[0281] In another design, the transceiver module 802 is configured to send a first S1 message to the second access network device, the first S1 message including a second identifier of a second tunnel and a QoS parameter of an E-RAB corresponding to the second tunnel, the second tunnel being used to transmit uplink data of the terminal device; the processing module 801 is configured to establish a connection with the S-GW; and the processing module 801 is further configured to establish the second tunnel, the second tunnel being a tunnel between the second access network device and the S-GW.

[0282] The transceiver module 802 is further configured to send a second S1 message to the second access network device, the second S1 message being used to establish the second tunnel, the second S1 message comprising first indication information, the first indication information being used to indicate a correspondence between the equivalent tunnel identifier of the second tunnel and the tunnel identifier of the second tunnel.

[0283] In the embodiments of the present application, the specific description of the terms or nouns or steps such as the second identifier, the QoS parameter, the first S1 message, the second S1 message, the second mobility management entity, the S-GW, the terminal device, the second access network device, etc. can be referred to the introduction in the method embodiments (such as FIG. 12), which will not be described one by one in detail here.

[0284] The specific description of the transceiver module and the processing module shown in the embodiments of the present application is only an example, and for the specific functions or executed steps of the transceiver module and the processing module, etc., reference can be made to the above method embodiments (such as FIG. 12), which will not be described in detail here. In addition, the technical effects of the embodiments of the present application are referred to the technical effects in the foregoing method embodiments, and for the sake of brevity, will not be described here.

[0285] The communication device of the embodiments of the present application is introduced above, and the possible product forms of the communication device are introduced below. Any form of product that has the functions of the communication device described in FIG. 13 falls within the protection scope of the embodiments of the present application. The following introduction is only an example, and does not limit the product form of the communication device of the embodiments of the present application to only this.

[0286] In a possible implementation, in the communication device shown in FIG. 13, the processing module 801 can be one or more processors, and the transceiver module 802 can be a transceiver, or the transceiver module 802 can also be a sending module and a receiving module, the sending module can be a transmitter, and the receiving module can be a receiver, and the sending module and the receiving module are integrated in one device, such as a transceiver. In the embodiments of the present application, the processor and the transceiver can be coupled, etc., and the connection mode of the processor and the transceiver is not limited in the embodiments of the present application. In the process of executing the above method, the process of sending information in the above method can be the process of outputting the above information by the processor. When outputting the above information, the processor outputs the above information to the transceiver for transmission by the transceiver. After the above information is output by the processor, it can also need to be processed further, and then reach the transceiver. Similarly, the process of receiving information in the above method can be the process of receiving inputted above information by the processor. When the processor receives the inputted information, the transceiver receives the above information and inputs it to the processor. Further, after the transceiver receives the above information, the above information can need to be processed further, and then input to the processor.

[0287] Referring to FIG. 14, FIG. 14 is another structure diagram of a communication apparatus provided by the embodiments of the present application. The communication apparatus can be a second access network device or a second mobility management entity, or a chip therein. FIG. 14 only shows the main components of the communication apparatus. In addition to the processor 1001, the communication apparatus can further include a transceiver 1002 and a memory 1003, and an input / output device (not shown in the figure).

[0288] The processor 1001 is mainly used for processing communication protocols and communication data, and controlling the whole communication apparatus, executing software programs, and processing data of the software programs. The memory 1003 is mainly used for storing software programs and data. In one design, the transceiver 1002 can be referred to as a transceiving unit, a transceiver, or a transceiving circuit, etc., for realizing a transceiving function. The transceiver 1002 can include a receiver and a transmitter. The receiver can be referred to as a receiver or a receiving circuit, etc., for realizing a receiving function; the transmitter can be referred to as a transmitter or a transmitting circuit, etc., for realizing a transmitting function. In another design, the transceiver 1002 can include a control circuit and an antenna. The control circuit is mainly used for conversion between a baseband signal and a radio frequency signal, and processing of the radio frequency signal. The antenna is mainly used for transceiving a radio frequency signal in the form of an electromagnetic wave. The input / output device, such as a touch screen, a display screen, a keyboard, etc., is mainly used for receiving data input by a user and outputting data to the user.

[0289] When the communication apparatus is powered on, the processor 1001 can read a software program in the memory 1003, interpret and execute instructions of the software program, process data of the software program, and control a medium access control (MAC) layer and a physical layer (PHY) to implement the method of the embodiments of the present application. When data needs to be transmitted wirelessly, the processor 1001 performs baseband processing on the data to be transmitted, and outputs a baseband signal to a radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal, and transmits a radio frequency signal in the form of an electromagnetic wave through an antenna. When data is transmitted to the communication apparatus, the radio frequency circuit receives a radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 1001. The processor 1001 converts the baseband signal into data and processes the data.

[0290] In another implementation, the radio frequency circuit and the antenna can be arranged independently of the processor performing baseband processing, for example, in a distributed scenario, the radio frequency circuit and the antenna can be arranged remotely from the communication apparatus.

[0291] The processor 1001, the transceiver 1002, and the memory 1003 can be connected through a communication bus.

[0292] For example, when the communication apparatus is configured to perform the steps or methods or functions performed by the second access network device in the method embodiment shown in FIG. 10, the processor 1001 can be configured to perform step S105 and step S108 in FIG. 10, and / or other processes described in the present disclosure; the transceiver 1002 can be configured to perform step S106 and step S110 in FIG. 10, and / or other processes described in the present disclosure.

[0293] For example, when the communication apparatus is configured to perform the steps or methods or functions performed by the second mobility management entity in the method embodiment shown in FIG. 10, the processor 1001 can be configured to generate the first S1 message and the second S1 message, and / or other processes described in the present disclosure; the transceiver 1002 can be configured to perform step S104, step S111 and step S112 in FIG. 10, and / or other processes described in the present disclosure.

[0294] For example, when the communication apparatus is configured to perform the steps or methods or functions performed by the second access network device in the method embodiment shown in FIG. 12, the processor 1001 can be configured to perform step S210, step S211 and step S212 in FIG. 12, and / or other processes described in the present disclosure; the transceiver 1002 can be configured to perform step S206, step S208 and step S213 in FIG. 12, and / or other processes described in the present disclosure.

[0295] For example, when the communication apparatus is configured to perform the steps or methods or functions performed by the second mobility management entity in the method embodiment shown in FIG. 12, the processor 1001 can be configured to generate the first S1 message and perform step S211 and step S212 in FIG. 12, and / or other processes described in the present disclosure; the transceiver 1002 can be configured to perform step S207 in FIG. 12, and / or other processes described in the present disclosure.

[0296] In any of the above designs, the processor 1001 can store instructions, which can be a computer program, running on the processor 1001, to cause the communication apparatus to perform the methods described in the above method embodiments. The computer program can be fixed in the processor 1001, in which case the processor 1001 can be implemented by hardware.

[0297] In an implementation, the communication apparatus can include circuitry that can implement the functions of transmitting or receiving or communicating in the foregoing method embodiments. The processor and transceiver described in the present application can be implemented on an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed-signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (NMOS), positive channel metal oxide semiconductor (PMOS), bipolar junction transistor (BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0298] It can be understood that the communication apparatus shown in the embodiments of the present application can also have more components than those shown in FIG. 14, and the embodiments of the present application do not limit this. The methods performed by the processor and transceiver shown above are only examples, and the specific steps performed by the processor and transceiver can refer to the description of the method embodiments above. The optional part in FIG. 14 is indicated by a dashed line.

[0299] In another possible implementation, in the communication apparatus shown in FIG. 13, the processing module 801 can be one or more logic circuits, and the transceiving module 802 can be an input / output interface, also known as a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiving module 802 can also be a sending module and a receiving module, the sending module can be an output interface, and the receiving module can be an input interface. The sending module and the receiving module are integrated into one module, such as an input / output interface.

[0300] Referring to FIG. 15, FIG. 15 is another structural schematic diagram of the communication apparatus provided in the embodiments of the present application. As shown in FIG. 15, the communication apparatus shown in FIG. 15 includes a logic circuit 901 and an interface 902. That is, the processing module 801 can be implemented by the logic circuit 901, and the transceiver module 802 can be implemented by the interface 902. The logic circuit 901 can be a chip, a processing circuit, an integrated circuit or a system on chip (SoC) chip, and the interface 902 can be a communication interface, an input / output interface, a pin, etc. For example, FIG. 13 is a chip including the logic circuit 901 and the interface 902, taking the communication apparatus as the chip.

[0301] In the embodiments of the present application, the logic circuit and the interface can also be coupled with each other. The specific connection manner of the logic circuit and the interface is not limited in the embodiments of the present application.

[0302] For example, the logic circuit 901 can be used to execute the functions or steps implemented by the processing module 801 shown in FIG. 13, and the interface 902 can be used to execute the functions or steps implemented by the transceiver module 802 shown in FIG. 13. The specific description of the logic circuit 901 and the interface 902 can refer to the method embodiments shown in FIG. 13 or the above, which will not be described here in detail.

[0303] The communication apparatus shown in the embodiments of the present application can be used to implement the methods provided in the embodiments of the present application in the form of hardware, or can be used to implement the methods provided in the embodiments of the present application in the form of software, etc. The embodiments of the present application do not limit this.

[0304] In addition, the embodiments of the present application also provide a communication system, which includes a second access network device and a second mobility management entity. Optionally, the communication system further includes one or more of the following: a terminal device, a first access network device, a second access network device, or an S-GW, etc. The second access network device and the second mobility management entity can be used to execute the methods in any of the preceding embodiments.

[0305] The present application also provides a computer program for implementing the operations and / or processes performed by various network elements or devices in the methods provided in the present application.

[0306] The present application also provides a computer readable storage medium, which stores computer codes. When the computer codes run on a computer, the computer is caused to execute the operations and / or processes performed by various network elements or devices in the methods provided in the present application.

[0307] The application further provides a computer program product comprising computer code or a computer program which, when run on a computer, causes the operations and / or processes performed by the various network elements or devices in the method provided by the application to be performed.

[0308] In several embodiments provided by the application, it should be understood that the disclosed system, communication device and method can be implemented in other manners. For example, the embodiments of the communication device described above are merely schematic, and the division of the modules is merely a logical function division, and there can be another division manner in actual implementation. For example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different modules can be indirect couplings or communication connections through some interfaces, communication devices or modules, and can be electrical, mechanical or other forms.

[0309] The modules illustrated as separated components can or can not be physically separated, and the components illustrated as modules can or can not be physical modules, i.e., can be located in one place, or can be distributed on a plurality of network modules. Some or all of the modules can be selected according to actual needs to achieve the technical effects of the solutions provided by the embodiments of the application.

[0310] In addition, each functional module in the various embodiments of the application can be integrated into one processing module, or each module can exist physically independently, 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 functional module.

[0311] The integrated module, if realized in the form of a software functional module and sold or used as an independent product, can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the application essentially or the parts of the prior art that make contributions, or all or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a readable storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the application. The aforementioned readable 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.

[0312] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A communication method of a non-terrestrial network, characterized by, The method comprises: receiving an equivalent tunnel identifier of a first tunnel, and receiving downlink data of a terminal device from a serving gateway S-GW through the first tunnel, the first tunnel being a tunnel between an access network device and the S-GW, and the equivalent tunnel identifier of the first tunnel being used to identify the first tunnel; receiving an access request from the terminal device; receiving a first message from a mobility management entity, the first message being used to determine the equivalent tunnel identifier of the first tunnel; sending, according to the first message, downlink data associated with the equivalent tunnel identifier of the first tunnel to the terminal device.

2. The method of claim 1, wherein, The equivalent tunnel identifier of the first tunnel comprises one or more of the following: a first identifier, a tunnel identifier of the first tunnel, or an S1 interface application protocol identifier UE S1AP ID of the terminal device; The first identifier is used to indicate the terminal device or the first tunnel; and the UE S1AP ID comprises an eNB UE S1AP ID and / or an MME UE S1AP ID.

3. The method according to claim 1 or 2, characterized in that, The receiving of the equivalent tunnel identifier of the first tunnel comprises: receiving a second message from the mobility management entity, the second message being used to establish the first tunnel, and the second message comprising the equivalent tunnel identifier of the first tunnel.

4. The method of claim 3, wherein, The second message comprises a first identifier, the first identifier being used to indicate the terminal device or the first tunnel.

5. The method according to any one of claims 1 to 4, characterized in that, After the receiving of the downlink data of the terminal device from the S-GW through the first tunnel, the method further comprises: receiving a third message from the mobility management entity, the third message being used to request to release a context of the terminal device, and the context of the terminal device comprising an eNB UE S1AP ID.

6. The method of claim 5, wherein, The third message comprises first indication information, the first indication information being used to indicate to reserve a first identifier and / or a tunnel identifier of the first tunnel; and the first identifier being used to indicate the terminal device or the first tunnel.

7. The method according to any one of claims 1 to 6, characterized in that, The first message comprises any one of the following: the first identifier, the UE S1AP ID, or the equivalent tunnel identifier of the first tunnel; The first identifier or the UE S1AP ID corresponds to the equivalent tunnel identifier of the first tunnel, and the first identifier is used to indicate the terminal device.

8. The method of claim 7, wherein, The first message further comprises a quality of service QoS parameter of an evolved universal terrestrial radio access network radio access bearer E-RAB corresponding to the first tunnel.

9. The method of claim 7, wherein, The method further comprises: storing the QoS parameter of the E-RAB corresponding to the first tunnel.

10. A communication method of a non-terrestrial network, characterized by, The method comprises: sending an equivalent tunnel identifier of a first tunnel, the equivalent tunnel identifier of the first tunnel being used to identify the first tunnel between an access network device and a serving gateway S-GW, and the first tunnel being used to transmit downlink data of a terminal device; after determining that the first tunnel is established between the access network device and the S-GW, receiving a non-access stratum NAS protocol data unit PDU from the access network device; sending a first message to the access network device, the first message being used to determine the equivalent tunnel identifier of the first tunnel.

11. The method of claim 10, wherein, The equivalent tunnel identifier of the first tunnel comprises one or more of the following: a first identifier, a tunnel identifier of the first tunnel, or a S1 interface application protocol identifier UE S1AP ID of the terminal device; The first identifier is used to indicate the terminal device or the first tunnel; and the UE S1AP ID comprises an eNB UE S1AP ID and / or an MME UE S1AP ID.

12. The method according to claim 10 or 11, characterized in that, The sending of the equivalent tunnel identifier of the first tunnel comprises: When it is determined that there is downlink data, a second message is sent to the access network device, the second message being used to establish the first tunnel, and the second message comprising the equivalent tunnel identifier of the first tunnel.

13. The method of claim 12, wherein, The second message comprises a first identifier, the first identifier being used to indicate the terminal device or the first tunnel.

14. The method according to any one of claims 10 to 13, characterized in that, After the first tunnel is established between the access network device and the S-GW, the method further comprises: A third message is sent to the access network device, the third message being used to request to release a context of the terminal device, the context of the terminal device comprising an eNB UE S1AP ID.

15. The method of claim 14, wherein, The third message comprises first indication information, the first indication information being used to indicate to reserve a first identifier and / or a tunnel identifier of the first tunnel; and the first identifier being used to indicate the terminal device or the first tunnel.

16. The method according to any one of claims 10 to 15, characterized in that, The first message comprises any one of the following: a first identifier, a UE S1AP ID, or an equivalent tunnel identifier of the first tunnel; The first identifier or the UE S1AP ID corresponds to the equivalent tunnel identifier of the first tunnel, and the first identifier is used to indicate the terminal device.

17. The method of claim 16, wherein, The method further comprises: A quality of service QoS parameter of an evolved universal terrestrial radio access network radio access bearer E-RAB corresponding to the first tunnel is saved.

18. The method of claim 17, wherein, The first message further comprises the QoS parameter of the E-RAB corresponding to the first tunnel.

19. A communication method of a non-terrestrial network, characterized by, Comprise: A first message is received from a mobility management entity, the first message comprising a second identifier of a second tunnel; Uplink data from a terminal device is received, and the uplink data is associated to the second identifier of the second tunnel; The second tunnel is established, the second tunnel being a tunnel between an access network device and a serving gateway S-GW; Through the second tunnel, the uplink data associated to the second identifier is sent to the S-GW.

20. The method of claim 19, wherein, The second identifier is a tunnel endpoint number TEID and / or an evolved universal terrestrial radio access network radio access bearer E-RAB identifier.

21. The method of claim 19, wherein, The second identifier is an equivalent tunnel identifier; The equivalent tunnel identifier of the second tunnel comprises one or more of the following: a third identifier, a TEID of the second tunnel, an E-RAB identifier of the second tunnel, or a S1 interface application protocol identifier UE S1AP ID of the terminal device, the third identifier being used to indicate the second tunnel; Alternatively, the equivalent tunnel identifier of the second tunnel comprises a third identifier and one or more of the following: a TEID of the second tunnel, or an E-RAB identifier of the second tunnel, the third identifier being used to indicate the terminal device; The UE S1AP ID comprises an eNB UE S1AP ID and / or an MME UE S1AP ID.

22. The method of claim 21, wherein, The establishing the second tunnel comprises: receiving a second message from the mobility management entity, the second message being used to establish the second tunnel, the second message comprising first indication information, the first indication information being used to indicate a correspondence between an equivalent tunnel identifier of the second tunnel and a tunnel identifier of the second tunnel.

23. A communication method of a non-terrestrial network, characterized by, comprising: sending a first message to an access network device, the first message comprising a second identifier of a second tunnel, the second tunnel being used to transmit uplink data of a terminal device; establishing a connection with a serving gateway S-GW; establishing the second tunnel, the second tunnel being a tunnel between the access network device and the S-GW.

24. The method of claim 23, wherein, The second identifier is a tunnel endpoint number TEID and / or an evolved universal terrestrial radio access network radio access bearer E-RAB identifier.

25. The method of claim 23, wherein, The second identifier is an equivalent tunnel identifier; The equivalent tunnel identifier of the second tunnel comprises one or more of the following: a third identifier, a TEID of the second tunnel, an E-RAB identifier of the second tunnel, or a S1 interface application protocol identifier UE S1AP ID of the terminal device, the third identifier being used to indicate the second tunnel; Or, the equivalent tunnel identifier of the second tunnel comprises a third identifier and one or more of the following: a TEID of the second tunnel, or an E-RAB identifier of the second tunnel, the third identifier being used to indicate the terminal device; The UE S1AP ID comprises an eNB UE S1AP ID and / or an MME UE S1AP ID.

26. The method of claim 25, wherein, The establishing the second tunnel comprises: sending a second message to the access network device, the second message being used to establish the second tunnel, the second message comprising first indication information, the first indication information being used to indicate a correspondence between an equivalent tunnel identifier of the second tunnel and a tunnel identifier of the second tunnel.

27. A communications device, characterized by comprising means for performing the method of any one of claims 1 to 9, or the method of any one of claims 10 to 18, or the method of any one of claims 19 to 22, or the method of any one of claims 23 to 26.

28. A communications device, characterized by comprising a logic circuit and an interface, the logic circuit and the interface being coupled; The interface is used for inputting and / or outputting information, and the logic circuit is used for performing the method of any one of claims 1 to 9, or the method of any one of claims 10 to 18, or the method of any one of claims 19 to 22, or the method of any one of claims 23 to 26.

29. A readable storage medium, characterized by, a program for storing, the program being executed by one or more processors, so that an apparatus comprising the one or more processors performs the method of any one of claims 1 to 26.

30. A computer program product, characterised in that, The computer program product, when executed, performs the method of any one of claims 1 to 26.

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