A communication method, an access network device, a core network device, a communication system, and a computer-readable storage medium.

Abstract

The embodiments of this application provide a communication method, an access network device, and a terminal. The method includes: determination, by a first access network device, that a terminal needs to enter an inactive radio resource control (RRC) state, wherein the first access network device is a terminal service access network device; sending, by the first access network device, of a first message to a second access network device, wherein the first message includes terminal context; and sending, by the first access network device, of a second message to the terminal, wherein the second message is used to instruct the terminal to enter the inactive RRC state. The communication method, the access network device, and the terminal in the embodiments of this application can reduce the time for the terminal to restore from the inactive RRC state to a connected RRC state.

Description

1 / 56 COMMUNICATION METHOD, ACCESS NETWORK DEVICE, CORE NETWORK DEVICE, COMMUNICATION SYSTEM, AND STORAGE MEDIUM THAT CAN BE READ BY A COMPUTER TECHNICAL FIELD

[0001] The modalities of this application relate to the field of communications and, more specifically, to a communication method, an access network device and a terminal. BACKGROUND

[0002] To meet the growing demands of traffic and services of various requirements, the 3GPP standardization organization is currently developing standards for a next-generation mobile communications system. Idle state (idle state) is a newly introduced Radio Resource Control (RRC) state, which is referred to as “RRC idle state” or an “idle state” below. As in a resting state, in the idle state, an RRC connection between a terminal and a network is disconnected, and the terminal does not need to receive downlink data, thus achieving the same power saving effect as in the resting state.Unlike the resting state, in the inactive state, when a terminal needs to enter a connected state—for example, the terminal has uplink data that needs to be sent, or a network radio calls the terminal to enter the connected state—the terminal can restore the connected state based on a saved terminal context. On one side of the network, a network access device requested by the terminal requests a terminal context from the terminal's original service access network device, so that... Petition 870250011963, dated 02 / 13 / 2025, page 13 / 138 2 / 56 The network access device can also obtain the terminal context and restore a connection to the terminal based on that context.

[0003] The next-generation mobile communications system has a higher latency requirement, and how to reduce the time for a terminal to restore from an inactive RRC state to a connected RRC state becomes a technical problem that needs to be urgently resolved. SUMMARY

[0004] The embodiments of this application provide a communication method, an access network device and a terminal, so as to reduce the time for the terminal to restore itself from an inactive RRC state to a connected RRC state.

[0005] According to a first aspect, a method of communication is provided, which includes: determination, by a first access network device, that a terminal needs to enter an inactive state of radio resource control (RRC), where the first access network device is a terminal service access network device; The first access network device sends a first message to a second access network device, where the first message includes terminal context; and the first access network device sends a second message to the terminal, where the second message is used to instruct the terminal to enter the RRC inactive state.

[0006] In this type of request, when Petition 870250011963, dated 02 / 13 / 2025, page 14 / 138 3 / 56 determines that the terminal needs to enter the RRC inactive state; the first access network device sends the terminal context to the second access network device. In this way, when the terminal requests, from the second access network device, to be restored to the RRC inactive state, the second access network device no longer needs to obtain the terminal context from the first access network device, so the time for restoring the terminal from the RRC inactive state to the RRC connected state can be reduced, and thus a data transmission delay can be reduced.

[0007] In some possible implementations, the second message includes information about a terminal radio network area in an inactive RRC state.

[0008] In some possible implementations, the radio network area is not used to notify the network when the terminal reselects a cell in the radio network area in the inactive RRC state, or the radio network area is used to notify the network when the terminal reselects a cell outside the radio network area.

[0009] In some possible implementations, the radio network area includes a first cell set.

[0010] The method also includes: The first access network device receives a first reply message that is the first message sent by the second access network device, wherein the first reply message includes information about a second cell set, and the second cell set is a set that includes one or more cells belonging to the second access network device. Petition 870250011963, dated 02 / 13 / 2025, page 15 / 138 4 / 56 access; and determination, by the first access network device, of the first cell set based on the second cell set, where the first cell set includes the second cell set.

[0011] In some possible implementations, the radio network area includes a first set of access network devices.

[0012] The method also includes: receipt, by the first access network device, of a second reply message that is a response to the first message and that is sent by the second access network device, wherein the second reply message indicates whether the second access network device accepts or refuses to join the radio network area; and determination, by the first access network device, of the first access network device set based on the second reply message, wherein the first access network device set includes at least one second access network device that accepts to join the radio network area.

[0013] A cell included in the specified radio network area is a cell accepted by the second access network device. This can reduce the probability of the terminal failing to be restored.

[0014] In some possible implementations, the terminal context includes key communication information between the terminal and the second access network device, and the key information includes a key generated based on an identifier of the second network device. Petition 870250011963, dated 02 / 13 / 2025, page 16 / 138 5 / 56 access, or a key generated based on a random value, or one or more keys generated based on a cell identity or cell identities from one or more cells of the second access network device.

[0015] In some possible implementations, the first message still includes a third cell set, and the third cell set is a set of one or more cells that are from the second access network device and that the first access network device requests to be accepted.

[0016] In some possible implementations, the first message still includes initial validity period information, and the initial validity period information indicates a validity period for the terminal context.

[0017] In some possible implementations, the first message still includes an authentication code generated based on a key between the terminal and the first access network device, where the authentication code is used by the second access network device for terminal identification or terminal authentication when the terminal accesses the second access network device.

[0018] In some possible implementations, the second message still includes a signal strength threshold, and the signal strength threshold is used by the terminal to perform cell replacement in the radio network area when a cell's signal strength in the radio network area is greater than or not less than the signal strength threshold. Petition 870250011963, dated 02 / 13 / 2025, page 17 / 138 6 / 56

[0019] In some possible implementations, the signal strength limit may be a uniform limit, or it may be a cell-level limit, for example, a limit may be set for some cells.

[0020] In some possible implementations, the second message also includes a second validity period information, and the second validity period information indicates a validity period during which the terminal can be restored to an RRC connected state.

[0021] In some possible implementations, after the validity period, the terminal can no longer be restored, or it needs to clear the saved context and enter a sleep state. When the terminal needs to enter a connected state, the terminal can initiate an initial access and enter the connected state in a way that initiates the initial access.

[0022] In some possible implementations, the second message still includes a random value used for key generation.

[0023] In some possible implementations, the first message may still include a list of all second access network devices.

[0024] In some possible implementations, an access network device may include a CU and a DU. A message, such as an RRC signal, sent by the access network device to the terminal may be generated by the CU and sent to the terminal via the DU, or it may be sent to the terminal directly after being generated by the DU.

[0025] In some possible implementations, the method Petition 870250011963, dated 02 / 13 / 2025, page 18 / 138 7 / 56 also includes: The first network access device receives a notification message indicating that the terminal has entered a connected state; and the first network access device releases the terminal's context.

[0026] In some possible implementations, the method also includes: The first access network device sends a notification to release the terminal context to another access network device, in addition to the first access network device, within the access network devices corresponding to the terminal's radio network area in the inactive RRC state.

[0027] In some possible implementations, the method also includes: When a terminal in an inactive RRC state needs to be called by radio, the first access network device in a cell that corresponds to the radio network area of ​​the terminal in the inactive RRC state sends a first radio call message to the terminal; and the first access network device sends a radio call request message to a third access network device to request a radio call to the terminal, wherein the third access network device is a different access network device than the first access network device in access network devices corresponding to the radio network area. Petition 870250011963, dated 02 / 13 / 2025, page 19 / 138 8 / 56

[0028] In some possible implementations, the radio call request message includes information about a fourth cell set, and is used to instruct the third access network device to send, in all cells in the fourth cell set, a second radio call message to radio call the terminal, wherein the fourth cell set is a set of cells that are included in the radio network area and that belong to the third access network device.

[0029] In some possible implementations, the method also includes: The sending, by the first access network device, of a third message to a core network device, if the first access network device does not receive, within a predetermined period of time, a radio call response sent by the terminal or a notification indicating that the terminal enters a connected state and which is sent by the third access network device, wherein the third message is used to request that the core network device release a connection between a terminal access network and a core network.

[0030] By releasing the connection between the terminal's access network and the core network in the preceding manner, sending a radio call to radio-call the terminal can be triggered by the core network over a wider range, so that the terminal can be radio-called easily.

[0031] In some possible implementations, the method also includes: receipt, by the first network device of Petition 870250011963, dated 02 / 13 / 2025, page 20 / 138 9 / 56 access, from a response message that is from the third message and that is sent by the core network device, in which the response message from the third message indicates that the connection between the first terminal access network device and the core network device has been released; Release of the terminal context by the first access network device; and sending of a notification by the first access network device to the third access network device to release the terminal context.

[0032] In some possible implementations, each access network device can regulate a timer based on a validity period of the terminal context. Before the timer expires, if no terminal restore request is received, or no notification indicating that the terminal enters the connected state or that is used to release the terminal context, which is sent by the other access network device, is received, or no notification at all, the terminal context will be released when the timer expires.

[0033] Promptly releasing the terminal context can reduce a load on an access network device.

[0034] According to a second aspect, a method of communication is provided, which includes: Receipt, by a second access network device, of a first message sent by a first access network device, wherein the first message includes a terminal context, and the first access network device is an access network device of Petition 870250011963, dated 02 / 13 / 2025, page 21 / 138 10 / 56 terminal service; The second access network device receives a fourth message sent by the terminal, wherein the fourth message is used to request a restoration from an inactive RRC radio resource control state to a connected RRC state; and the second access network device restores the terminal from the inactive RRC radio resource control state to the connected RRC state based on the terminal context.

[0035] In this mode of this request, the second access network device obtains the terminal context from the first access network device beforehand. In this way, when the terminal requests, from the second access network device, to be restored to the RRC inactive state, the second access network device no longer needs to obtain the terminal context from the first access network device, so the time for restoring the terminal from the RRC inactive state to the RRC connected state can be reduced, and thus, a data transmission delay can be reduced.

[0036] In some possible implementations, the method also includes: determination, by the second access network device, of a second cell set, wherein the second cell set is a set of cells that are accepted by the second access network device, which correspond to a radio network area of ​​the terminal in the inactive RRC state, and which belong to the second access network device; and Petition 870250011963, dated 02 / 13 / 2025, page 22 / 138 11 / 56 sending, by the second access network device, of a first reply message to the first access network device, wherein the first reply message includes a second cell set.

[0037] In some possible implementations, the method also includes: The second network access device sends a notification to the first network access device indicating that the terminal has entered a connected state.

[0038] In some possible implementations, the method also includes: The second access network device sends a notification to release the terminal context to another access network device in addition to the second access network device, in access network devices corresponding to the terminal's radio network area in the inactive RRC state.

[0039] In some possible implementations, before the second access network device receives a fourth message sent by the terminal, the method still includes: The second access network device receives a radio call request message sent by the first access network device, which is used to request a radio call to the terminal; and the second access network device, based on the radio call request message, sends a second radio call message to radio the terminal.

[0040] In some possible implementations, the Petition 870250011963, dated 02 / 13 / 2025, page 23 / 138 The 12 / 56 radio call request message includes information about a cell that belongs to the second access network device and corresponds to the radio network area of ​​the terminal in the inactive RRC state.

[0041] In some possible implementations, the sending, by the second access network device based on the radio call request message, of a second radio call message to radio call the terminal includes: The second access network device sends the second radio call message to a cell belonging to the second access network device, which corresponds to the radio network area of ​​the terminal in the inactive RRC state.

[0042] Sending a radio call message only in a cell that is from the second access network device and that corresponds to the radio network area can implement more accurate radio call sending and save air interface resources.

[0043] According to a third aspect, a method of communication is provided, including: Receipt, by a terminal, of a second message sent by a first access network device, wherein the second message is used to instruct the terminal to enter an inactive Radio Resource Control (RRC) state; the second message includes a terminal's radio network area in the inactive RRC state; the first access network device is a terminal service access network device; the radio network area includes a second access network device or a cell of the second access network device. Petition 870250011963, dated 02 / 13 / 2025, page 24 / 138 13 / 56 access network device, the second access network device is an access network device that receives a terminal context, and the terminal context is used by the terminal to restore from the inactive RRC state to a connected RRC state; and input, by the terminal, into the inactive RRC state from the connected RRC state based on the second message.

[0044] In some possible implementations, the second message still includes a signal strength limit.

[0045] The method also includes: When the signal strength of a cell in the radio network area is greater than or not less than the signal strength limit, the terminal will perform a cell replacement in the radio network area.

[0046] In some possible implementations, the second message also includes a second validity period information, and the second validity period information indicates a validity period during which the terminal can be restored to an RRC connected state.

[0047] In some possible implementations, after the validity period, the terminal may initiate an initial access when the terminal needs to enter the connected state, so as to enter the connected state in an initial access manner.

[0048] In some possible implementations, the second message still includes a random value used for key generation.

[0049] In some possible implementations, the Petition 870250011963, dated 02 / 13 / 2025, page 25 / 138 14 / 56 Entry, by the terminal, into the inactive RRC state from the connected RRC state based on the second message includes: when the terminal enters the inactive RRC state, remaining, by the terminal, in a cell in which the terminal is located, when the terminal is in the original connected RRC state.

[0050] In some possible implementations, the method also includes: Sending, by the terminal, a fourth message to the second access network device, wherein the fourth message is used to request restoration from an inactive RRC state to a connected RRC state; and restoration, by the terminal based on the terminal context, from the inactive RRC state to the connected RRC state in a cell of the second access network device.

[0051] According to a fourth aspect, an access network device is provided, including modules that execute the method according to any of the first aspect or possible implementations of the first aspect.

[0052] According to a fifth aspect, an access network device is provided, including modules that execute the method according to either of the second aspect or possible implementations of the second aspect.

[0053] According to a sixth aspect, a terminal is provided, including modules that execute the method according to any of the third aspect or possible implementations of the third aspect. Petition 870250011963, dated 02 / 13 / 2025, p. 26 / 138 15 / 56

[0054] According to a seventh aspect, an access network device is provided. The access network device includes a processor, a memory, and a communications interface. The processor is connected to the memory and the communications interface. The memory is configured for storing an instruction; the processor is configured for executing the instruction; and the communications interface is configured for communication with another network element under the control of the processor. When the processor executes the instruction stored in memory, the execution allows the processor to execute the method according to either of the first aspect or possible implementations of the first aspect, or according to either of the second aspect or possible implementations of the second aspect.

[0055] According to an eighth aspect, a terminal is provided. The terminal device includes a processor, a memory, and a communications interface. The processor is connected to the memory and the communications interface. The memory is configured for storing an instruction; the processor is configured for executing the instruction; and the communications interface is configured for communication with another network element under the processor's control. When the processor executes the instruction stored in memory, the execution allows the processor to execute the method according to any one of the third aspect or possible implementations of the third aspect.

[0056] According to a ninth aspect, a computer-readable medium is provided, configured for the storage of a computer program, in which the program Petition 870250011963, dated 02 / 13 / 2025, page 27 / 138 16 / 56 of the computer includes an instruction used to execute the method according to any one of the first aspect or possible implementations of the first aspect.

[0057] According to a tenth aspect, a computer-readable medium is provided, configured for the storage of a computer program, wherein the computer program includes an instruction used for executing the method according to any one of the second aspect or possible implementations of the second aspect.

[0058] According to an eleventh aspect, a computer-readable medium is provided, configured for the storage of a computer program, wherein the computer program includes an instruction used for the execution of the method according to any one of the third aspect or possible implementations of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 is a schematic diagram of a network applied in one embodiment of this application; Figure 2 is a schematic flowchart of a communication method according to one modality of this request; Figure 3 is a schematic flowchart of a communication method according to another modality of this request; Figure 4 is a schematic flowchart of a communication method according to yet another modality of this request; Figure 5 is a schematic flowchart of a communication method according to yet another modality of this request; Figure 6 is a schematic block diagram of a Petition 870250011963, dated 02 / 13 / 2025, page 28 / 138 17 / 56 network access device according to an embodiment of this application; Figure 7 is a schematic block diagram of an access network device according to another embodiment of this application; Figure 8 is a schematic block diagram of a terminal according to one embodiment of this application; Figure 9 is a schematic structural diagram of an access network device according to yet another embodiment of this application; and Figure 10 is a schematic structural diagram of a terminal according to yet another embodiment of this application. DESCRIPTION OF MODALITIES

[0060] What follows describes the technical solutions of modalities in this application with reference to the associated drawings.

[0061] Figure 1 is a schematic diagram of a network applied in an embodiment of this application. As shown in Figure 1, the network may include a plurality of access network devices, such as an access network device 101, an access network device 102, and an access network device 103. A current service access network device of terminal 111 is access network device 101. Access network device 101 may configure, for terminal 111, a radio network area of ​​terminal 111 in an inactive RRC state. The radio network area may be referred to as a RAN-based notification area (RNA). Access network device 101 may deliver information about the radio network area to terminal 111 by using dedicated signaling. The area of Petition 870250011963, dated 02 / 13 / 2025, page 29 / 138 The 18 / 56 radio network may include one or more cells. The radio network area does not notify the network when terminal 111 reselects a cell within the radio network area while in the RRC inactive state. In other words, the radio network area notifies the network when terminal 111 reselects a cell outside the radio network area. Therefore, when terminal 111, which enters the RRC inactive state, needs to be radio-called, terminal 111 can be radio-called within the radio network area.

[0062] It should be understood that figure 1 is described using only one terminal as an example, but this application is not limited to that.

[0063] In this descriptive report, the embodiments are described with reference to a terminal. The terminal may also be referred to as a terminal device, user equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile console, remote station, remote terminal, mobile device, user terminal, wireless communications device, user agent or user appliance.The access terminal can be a cell phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local circuit station (WLL), a personal digital assistant (PDA), a portable device having a wireless communication function, a computing device, another processing device connected to a wireless modem, a vehicular device, a wearable device, a terminal device in a future 5G network, or a terminal device in a public terrestrial mobile network (PLMN). Petition 870250011963, dated 02 / 13 / 2025, page 30 / 138 19 / 56 developed in the future, or similar.

[0064] In this descriptive report, the embodiments are described with reference to an access network device. The access network device may also refer to a network device. The network device may be a device configured for communication with a terminal device. The network device may be a base transceiver station (BTS) in GSM or CDMA, it may be a B Node (NB) in a WCDMA system, it may be an evolved B Node (eNB or eNode B) in an LTE system, or it may be a wireless controller in a Cloud Radio Access Network (CRAN) scenario, or the network device may be a relay station, an access point, a vehicular device, a wearable device, a network device in a future 5G network, or a network device in a future evolved PLMN.

[0065] In this embodiment of this application, to reduce the time for restoring the terminal from an inactive RRC state to a connected RRC state, a terminal service access network device sends a terminal context to another access network device beforehand. In this way, the terminal can quickly restore from the inactive RRC state to the connected RRC state of the other access network device, thereby further reducing delay and saving signaling cost time.

[0066] Figure 2 is a schematic flowchart of a communication method according to one modality of this request. In Figure 2, a first access network device is a service access network device of a Petition 870250011963, dated 02 / 13 / 2025, page 31 / 138 20 / 56 terminal, and a second access network device is another access network device. For example, the second access network device could be an access network device adjacent to the first access network device. The first access network device, the second access network device, and the terminal in Figure 2 could be, respectively, access network device 101, access network device 102 or 103, and terminal 111 in Figure 1.

[0067] 201. A first access network device determines that a terminal needs to enter an inactive RRC state.

[0068] Specifically, the first access network device may determine, based on a terminal service status and similar, to allow the terminal to enter the RRC inactive state from a connected RRC state. For example, if it is determined that the terminal does not transmit service data for a period of time, for example, does not transmit uplink or downlink data, the terminal may be allowed to enter the RRC inactive state from the connected RRC state, thereby achieving energy savings. It may be understood that, in this embodiment of this request, no limitation is imposed on when the first access network device allows the terminal to enter the RRC inactive state.

[0069] 202. The first access network device sends a first message to a second access network device, where the first message includes a terminal context. Petition 870250011963, dated 02 / 13 / 2025, page 32 / 138 21 / 56

[0070] The terminal context is used to restore the terminal from the RRC inactive state to the RRC connected state.

[0071] The first access network device sends the terminal context to the second access network device beforehand. In this way, if the terminal subsequently requests the second access network device to be restored to the RRC connected state, the second access network device can quickly restore the terminal from the RRC inactive state to the RRC connected state based on the terminal context that is obtained beforehand.

[0072] It should be noted in this descriptive report that the first access network device can send the first message to a plurality of adjacent access network devices. The second access network device in this descriptive report is merely a general name and is not limited to an access network device.

[0073] The terminal context includes, for example, a terminal capability, an application protocol identifier, a service access network device identifier, authentication information, a negotiated security algorithm, a generated key, created connection information, and bearer information.

[0074] Optionally, in one embodiment of this application, the terminal context may include key communication information between the terminal and the second access network device, and the key information includes a key generated based on an identifier of the second access network device, or a key generated based on a value. Petition 870250011963, dated 02 / 13 / 2025, page 33 / 138 22 / 56 random, or one or more keys generated based on a cell identity or cell identities from one or more cells of the second access network device.

[0075] Specifically, the key information includes a new key for the endpoint. The new key may be derived by the first access network device based on an initial key and newly added information. For example, the initial key may be a key between the endpoint and the first access network device, or it may be another basic key, such as a next hop (NH) derived based on the next hop chain count (NCC). The newly added information may include the identifier of the second access network device, the random value, or the cell identity of the second access network device.If the new key is derived based on cell identity, each of the multiple cells of the second access network device corresponds to one key; or if the new key is derived based, for example, on the random value, or the identifier of the second access network device, the multiple cells of the second access network device only need to carry one key.

[0076] Optionally, the first access network device may first determine a candidate cell list from a terminal radio network area in the inactive RRC state, and then send the first message to an access network device (i.e., the second access network device) in which a cell in the cell list is located. Optionally, the first message may also include information about one or more cells of Petition 870250011963, dated 02 / 13 / 2025, page 34 / 138 23 / 56 second access network device, for example, a cell identity, and the first access network device requests that the second access network device accept one or more cells as cells in the radio network area. That is, the first message may still include information about a cell set (represented as a third cell set), where the third cell set is a set of one or more cells that belong to the second access network device and that the first access network device requests be accepted.

[0077] Optionally, the first access network device can first determine a list of access network devices, and then send the first message to an access network device (i.e., the second access network device) in the access network device list.

[0078] Optionally, if the first message does not include information about the third cell set, it indicates that all cells from the second access network device are requested.

[0079] Optionally, the first access network device may determine the preceding cell list or the access network device list based on information such as network employment, network status, or terminal activity status. However, this is not limited to this embodiment of this application.

[0080] Optionally, the first message may also include a list of all second access network devices. In this way, after the terminal subsequently initiates a restore procedure on a device of Petition 870250011963, dated 02 / 13 / 2025, page 35 / 138 24 / 56 access network, the access network device can instruct the access network device on the list to release the terminal context.

[0081] Optionally, the first message may also include initial validity period information, and the initial validity period information indicates a validity period for the terminal context.

[0082] Specifically, if the second access network device does not receive a terminal restore request within the validity period, the second access network device releases the terminal context. For example, the second access network device may start a timer whose duration is the validity period of the terminal. Optionally, if the second access network device receives, within the validity period, an updated first message sent by the first access network device that is specific to the terminal, the second access network device restarts the timer.

[0083] Optionally, the first message may also include an authentication code generated based on a key between the terminal and the first access network device, where the authentication code is used by the second access network device for terminal identification or terminal authentication when the terminal accesses the second access network device.

[0084] Optionally, if the first message does not include an authentication code, when the terminal initiates the restore procedure on the second access network device, the second access network device can generate an authentication code based on a new key (by Petition 870250011963, dated 02 / 13 / 2025, page 36 / 138 25 / 56 example, a key between the terminal and the second network access device) for terminal authentication.

[0085] Optionally, after the second access network device receives the first message sent by the first access network device, the second access network device may determine a second cell set, wherein the second cell set is a set of cells that are accepted by the second access network device, which correspond to the terminal's radio network area in the inactive RRC state, and which are from the second access network device; and send a first reply message to the first access network device, wherein the first reply message includes information about the second cell set.

[0086] The second cell set is a set of cells that are accepted by the second access network device and added to the radio network area. For example, the second access network device can determine, based on a status of the second access network device, such as a load status, whether the terminal is allowed to restore itself, or determine which cells can be restored. Optionally, if the first message includes information about the third cell set, the second access network device can determine, in the third cell set, the cell in the second cell set; or if the first message does not include information about the third cell set, the second access network device can determine the cell in the second cell set from all the cells of the second access network device. After the second device of Petition 870250011963, dated 02 / 13 / 2025, page 37 / 138 26 / 56 access network determines the second cell set; information about the second cell set can be included in a reply message sent to the first access network device. Optionally, if no cell from the second access network device can join the radio network area, the reply message sent by the second access network device to the first access network device is a reject message.

[0087] Optionally, the second access network device may also send a second reply message to the first access network device, wherein the second reply message indicates whether the second access network device accepts or refuses to join the radio network area.

[0088] Specifically, if the second access network device accepts to join the radio network area, it will indicate that all cells of the second access network device join the radio network area; or if the second access network device refuses to join the radio network area, it will indicate that no cells of the second access network device join the radio network area.

[0089] Optionally, in step 203, the first access network device receives a reply message that is from the first message and that is sent by the second access network device.

[0090] The reply message to the first message can be either the first reply message or the second reply message.

[0091] Optionally, when the first access network device receives the first response message that Petition 870250011963, dated 02 / 13 / 2025, pages 38 / 138 27 / 56 refers to the first message, which is sent by the second access network device. The first access network device determines a first cell set based on the second cell set.

[0092] The first cell set includes the second cell set. Optionally, the first cell set may include at least one second cell set and one or more cells from the first access network device. In this case, the first cell set forms the terminal's radio network area in the RRC inactive state. Optionally, the first cell set may include only at least one second cell set. In this case, the first cell set and one or more cells from the first access network device form the radio network area.

[0093] Optionally, when the first access network device receives the second reply message that is from the first message and that is sent by the second access network device, the first access network device determines a first access network device set based on the second reply message.

[0094] The first access network device set includes at least one second access network device that accepts joining the radio network area. Optionally, the first access network device set may include at least one second access network device and the first access network device. In this case, the first access network device set forms the radio network area. Optionally, the first access network device set may Petition 870250011963, dated 02 / 13 / 2025, pp. 39 / 138 28 / 56 include only a second access network device. In this case, the first set of access network devices and the first access network device form the radio network area.

[0095] 204. The first access network device sends a second message to the terminal, where the second message is used to instruct the terminal to enter the RRC inactive state.

[0096] The terminal receives the second message sent by the first access network device and enters the RRC inactive state from a connected RRC state based on the second message.

[0097] Optionally, when the terminal enters the RRC inactive state, the terminal remains in the service cell where the terminal is located when the terminal is in the original RRC connected state. Furthermore, if the terminal has multiple service cells, the terminal will camp in one of the service cells, or the terminal will camp in a service cell from which the terminal receives the second message. That is, when the terminal enters the RRC inactive state, the terminal does not perform a cell selection, but remains in the service cell where the terminal is located when the terminal is in the original RRC connected state. Subsequently, for example, after the terminal moves, the terminal switches to another cell through a cell re-selection process, so that the terminal can enter the RRC inactive state more quickly, and terminal behavior is more controllable.It should be noted that when the terminal enters the inactive RRC state, the solution in which... Petition 870250011963, dated 02 / 13 / 2025, p. 40 / 138 29 / 56 The terminal remains in the service cell in which the terminal is located when the terminal is in the connected state of the original RRC. This can alternatively be implemented separately, i.e., it can be implemented as an independent mode without depending on another mode in this descriptive report.

[0098] Optionally, the second message may be an RRC signal, but this is not limited to this type of request.

[0099] It should be understood that the access network device may include a central unit (CU) and a distributed unit (DU). A message, such as an RRC signal, sent by the access network device to the terminal may be generated by the CU and sent by the DU to the terminal, or it may be generated and sent directly by the DU to the terminal.

[0100] Optionally, the second message includes information about the terminal's radio network area in the RRC inactive state. To be specific, when instructing the terminal to enter the RRC inactive state, the first access network device also notifies the terminal's radio network area. The information about the radio network area can be a list of radio network area cells, or it can be a list of radio network area access devices.

[0101] The radio network area does not notify the network when the terminal reselects a cell in the radio network area in the inactive RRC state, or the radio network area does not notify the network when the terminal reselects a cell outside the radio network area. Petition 870250011963, dated 02 / 13 / 2025, page 41 / 138 30 / 56

[0102] Optionally, in one embodiment of this application, the radio network area includes the first preceding cell set.

[0103] In this mode, the first access network device sends the radio network area cell list to the terminal. As described above, the first cell set may include a cell from the first access network device, or it may not include a cell from the first access network device. When the first cell set does not include the cell from the first access network device, the radio network area includes the cell from the first access network device by default, that is, the terminal uses the first cell set and the cell from the first access network device (e.g., all cells from the first access network device, or a primary cell, or a cell from which the second message is received) as the radio network area.

[0104] Optionally, in another embodiment of this application, the radio network area includes the first set of preceding access network devices.

[0105] In this mode, the first access network device sends the list of access network devices from the radio network area to the terminal. All cells corresponding to each access network device in the list are included in the radio network area. As described above, the first set of access network devices may include the first access network device, or it may not include the first access network device. When the first set of access network devices Petition 870250011963, dated 02 / 13 / 2025, page 42 / 138 31 / 56 does not include the first access network device; the radio network area includes the first access network device by default, that is, the terminal uses the first set of access network devices and the first access network device as the radio network area.

[0106] Optionally, the first access network device saves the first preceding cell set or the first access network device set, that is, it saves the cell list or the access network device list of the radio network area.

[0107] Optionally, the second message may also include a signal strength limit.

[0108] When a cell signal strength in the radio network area is greater than or not less than the signal strength threshold, the terminal performs a cell replacement or a cell re-selection in the radio network area.

[0109] Specifically, the terminal may preferably perform a cell replacement or a re-selection in the radio network area. For example, when the signal strength of a cell in the cell list or of an access network device in the access network device list of the radio network area is greater than or not less than the signal strength threshold, the terminal may preferably perform a cell re-selection in these cells. Optionally, the signal strength threshold may be a uniform threshold, or it may be a cell-level threshold. For example, a threshold may be set for some cells.

[0110] It should be understood that the terminal can also Petition 870250011963, dated 02 / 13 / 2025, page 43 / 138 32 / 56 perform a cell replacement based on other information, for example, a cell's priority information. This is not limited to this mode of this request. It should be further understood that if no cell in the radio network area meets a replacement condition, and a cell outside the radio network area meets the replacement condition, the terminal may also be switched to the cell outside the radio network area.

[0111] Optionally, the second message may also include a second validity period information, and the second validity period information indicates a validity period during which the terminal can be restored to the RRC connected state.

[0112] The validity period is a period of time during which the terminal can perform a restore or a validity period during which the terminal context is saved. After the validity period, the terminal can no longer be restored, or it needs to clear the saved context and enter a sleep state. When the terminal needs to enter a connected state, the terminal can initiate an initial access and enter the connected state in a way that initiates the initial access. Optionally, the validity period is usually obtained by a timer. After receiving the second message that includes the second validity period, the terminal starts the timer and determines the validity period when it determines if the timer expires.

[0113] Optionally, the second message may also include a random value and / or an NCC used for key generation.

[0114] Specifically, if the new key is generated Petition 870250011963, dated 02 / 13 / 2025, page 44 / 138 Based on the random value (33 / 56), the second message will carry the random value used to derive the new key. If the first access network device derives the new key based on the NH (not based on the key used between the first access network device and the terminal), the second message will carry the NCC, so that the terminal can derive the new key earlier based on the random value and / or the NCC, and can send data using the new key for security protection during a terminal restore to the connected state, thus reducing data delay. It should be noted that the solution can also be used as a standalone mode without depending on another mode in this descriptive report.

[0115] In this mode of this request, when it is determined that the terminal needs to enter the RRC inactive state, the first access network device sends the terminal context to the second access network device. In this way, when the terminal requests, from the second access network device, to be restored to the RRC inactive state, the second access network device no longer needs to obtain the terminal context from the first access network device, so that the time for restoring the terminal from the RRC inactive state to the RRC connected state can be reduced, and thus a data transmission delay can be reduced.

[0116] It should be understood that the information included in multiple messages in this modality of this request may be sent in one message, or may be sent separately in a plurality of messages. This is not limited in this modality of this request. Petition 870250011963, dated 02 / 13 / 2025, p. 45 / 138 34 / 56

[0117] In the embodiment shown in Figure 2, the first access network device first sends the terminal context to the second access network device, and then instructs the terminal to enter the RRC inactive state. In this way, the first access network device can determine the terminal's radio network area based on the response message from the second access network device. In this case, a cell included in the determined radio network area is a cell accepted by the second access network device, thus reducing the probability of the terminal failing to be restored. Optionally, in another embodiment of this application, the first access network device can first instruct the terminal to enter the RRC inactive state, and then send the terminal context to the second access network device.In this case, the first access network device can determine the terminal's radio network area by itself. What follows describes this mode with reference to Figure 3.

[0118] Figure 3 is a schematic flowchart of a communication method according to another modality of this request. In addition to the description below, for other descriptions of the modality shown in Figure 3, refer to the modality shown in Figure 2. For brevity, details are not described below again.

[0119] 301. A first access network device determines that a terminal needs to enter an inactive RRC state.

[0120] Optionally, in step 302, the first access network device determines a network area of Petition 870250011963, dated 02 / 13 / 2025, page 46 / 138 35 / 56 radio terminal in inactive RRC state.

[0121] In this embodiment, the first access network device can determine the radio network area by itself. Similar to the preceding embodiment, the first access network device can determine a cell list or an access network device list of the radio network area. Unlike the preceding embodiment, the cell list or the access network device list does not need to be determined based on a response message from a second access network device, but can be determined by the first access network device itself. For example, the first access network device can determine the radio network area based on information such as a network job, a network status, or a terminal activity status.

[0122] 303. The first access network device sends a second message to the terminal, where the second message is used to instruct the terminal to enter the RRC inactive state.

[0123] Optionally, the second message may include the radio network area specified in step 302.

[0124] 304. The first access network device sends a first message to a second access network device, wherein the first message includes a terminal context, and the terminal context is used by the terminal to restore the inactive RRC state to a connected RRC state.

[0125] Unlike the previous mode, in this mode, the second access network device cannot refuse to join the radio network area. Petition 870250011963, dated 02 / 13 / 2025, page 47 / 138 36 / 56

[0126] After the terminal enters the RRC inactive state from the RRC connected state, if the terminal subsequently needs to be restored to the RRC connected state, for example, the terminal needs to send uplink data, or a network calls the terminal by radio, and the terminal and an access network device can quickly restore the terminal to the RRC connected state based on the terminal's saved context. What follows describes a restoration procedure with reference to Figure 4 and Figure 5.

[0127] Figure 4 is a schematic flowchart of a communication method according to yet another modality of this request.

[0128] In this mode, a terminal is restored from an inactive RRC state to a connected RRC state by a second access network device. A first access network device in Figure 4 is an original service access network device of the terminal, and a third access network device indicates another access network device in the access network devices corresponding to a radio network area of ​​the terminal.

[0129] It should be understood that if the terminal is still restored on the original service access network device, the second access network device in this mode will be the first access network device and, correspondingly, an interaction procedure between the second access network device and the first access network device will not be required. Furthermore, if the access network devices corresponding to the area Petition 870250011963, dated 02 / 13 / 2025, page 48 / 138 37 / 56 radio network only includes the first access network device and the second access network device; the third access network device will not be required.

[0130] 401. The second access network device receives a fourth message sent by the terminal.

[0131] The fourth message is used to request a restoration from the RRC inactive state to the RRC connected state. For example, the fourth message may be a restoration request. If the terminal in the RRC inactive state needs to be restored to the RRC connected state, for example, the terminal needs to send uplink data, or a network radio calls the terminal, the terminal will send the fourth message to an access network device in a cell where the terminal is currently located, i.e., the second access network device, to request to be restored to the RRC connected state. The fourth message may carry a terminal identifier.

[0132] 402. The second access network device restores the terminal from the RRC inactive state to the RRC connected state based on a terminal context.

[0133] After receiving the fourth message sent by the terminal, the second access network device can look up the terminal context based on the terminal identifier. Because the second access network device has obtained the terminal context beforehand, it can directly restore the terminal from the inactive RRC state to the active state. Petition 870250011963, dated 02 / 13 / 2025, page 49 / 138 38 / 56 connected from RRC based on the terminal context. Furthermore, the second access network device switches a connection (e.g., an S1 connection) between an access network corresponding to the terminal and a core network; that is, it switches an access network end of the connection from the first access network device to the second access network device. Then, the terminal performs a corresponding data transmission with the second access network device.

[0134] 403. The second access network device sends a notification to the first access network device indicating that the terminal has entered the connected state.

[0135] After the terminal enters the connected state, the second access network device can send a notification to the first access network device indicating that the terminal has entered the connected state, so that the first access network device releases the terminal context.

[0136] 404. The first network access device releases the terminal context.

[0137] When the notification message indicating that the terminal has entered the connected state is received, the first access network device determines that the terminal has been restored to the connected state and therefore releases the terminal context.

[0138] 405. The first access network device sends a notification to a third access network device to release the terminal context.

[0139] Due to the fact that the terminal was Petition 870250011963, dated 02 / 13 / 2025, page 50 / 138 39 / 56 restored to the connected state, the original terminal context and radio network area are no longer valid, and the first access network device sends a notification to another access network device in the radio network area to release the terminal context, so that the other access network device also releases the terminal context.

[0140] Optionally, if the second access network device has an access network device list corresponding to the radio network area, for example, the list can be ported in the first preceding message and sent to the second access network device, step 405 can be replaced by step 406 below.

[0141] 406. The second access network device sends a notification to a third access network device to release the terminal context.

[0142] 407. The third access network device releases the terminal context.

[0143] Optionally, if the terminal requests, from the first access network device, to be restored from the RRC inactive state to the RRC connected state, the first access network device may directly restore the terminal from the RRC inactive state to the RRC connected state based on the terminal context. Furthermore, the first access network device sends a notification to the other access network device within the terminal's radio network range to release the terminal context, so that the other access network device also releases the terminal context. Petition 870250011963, dated 02 / 13 / 2025, page 51 / 138 40 / 56

[0144] Optionally, each access network device can regulate a timer based on a terminal context validity period. Before the timer expires, if no terminal restore request is received, or no notification indicating that the terminal enters the connected state, which is sent by the other access network device, is received, or no notification used to release the terminal context, which is sent by the other access network device, is received, the terminal context will be released when the timer expires.

[0145] For example, the first access network device can start a timer after sending the second preceding message to the terminal; and the second access network device can start a timer after saving the terminal context. Optionally, when radio calling the terminal, the first access network device can start a timer after sending a radio call message to radio call the terminal.

[0146] Figure 5 is a schematic flowchart of a communication method according to yet another embodiment of this application. This embodiment is a procedure when a terminal is called by radio, and is a specific case of the embodiment shown in Figure 4. In addition to the preceding description, for other descriptions of the embodiment shown in Figure 5, refer to the embodiment shown in Figure 4. For brevity, the details are not described below again.

[0147] 501. A first network access device Petition 870250011963, dated 02 / 13 / 2025, page 52 / 138 41 / 56 sends a radio call request message to request a radio call from a terminal to a second access network device and a third access network device.

[0148] When a terminal in an inactive RRC state needs to be called by radio, the first access network device sends the radio call request message to the other access network devices within a radio network area of ​​the terminal in the inactive RRC state, that is, the second access network device and the third access network device in Figure 5.

[0149] It should be understood that if access network devices corresponding to the radio network area include only the first access network device and the second access network device, the third access network device will not be required.

[0150] Optionally, the radio call request message may include information about a cell that belongs to each access network device and that corresponds to the radio network area, for example, information about a fourth cell set of the access network device, and is used to instruct the access network device to send, in all cells in the fourth cell set, a radio call message to radio call the terminal.

[0151] In addition, the first access network device sends, in a cell that is of the first access network device and that corresponds to the radio network area, a radio call message to call the terminal by radio. Petition 870250011963, dated 02 / 13 / 2025, page 53 / 138 42 / 56

[0152] Optionally, in step 502, the first access network device starts a timer.

[0153] 503. The second access network device and the third access network device send a radio call message to radio call the terminal.

[0154] After receiving the radio call request message, which is used to request to call the terminal by radio and which is sent by the first access network device, the second access network device and the third access network device send, based on the radio call request message, the radio call message to call the terminal by radio.

[0155] Optionally, if a cell list that is from the first access network device and that corresponds to the radio network area is stored in each access network device, the radio call message can be sent only to one cell in the cell list, based on the cell list, in order to implement a more accurate radio call sending and save air interface resources.

[0156] Optionally, if the radio call request message includes the cell list, the radio call message may be sent only to one cell in the cell list based on the cell list included in the radio call request message, in order to implement more accurate radio call sending and save air interface resources.

[0157] Optionally, if the terminal is currently located in a cell of the second access network device, the following procedure will be performed. Petition 870250011963, dated 02 / 13 / 2025, page 54 / 138 43 / 56

[0158] 504. The second network access device receives a fourth message sent by the terminal.

[0159] If the terminal is currently located in the cell of the second access network device, after receiving the radio call message, the terminal will send the fourth message to the second access network device. Subsequent steps 505 to 510 are similar to steps 402 to 407 in Figure 4, and are not described again. Additionally, optionally, after determining that the terminal has been restored to a connected state, the first access network device can stop the timer.

[0160] Optionally, for a radio call failure, perform the following procedure.

[0161] 511. The timer for the first access network device expires.

[0162] To be specific, the first access network device does not receive, after a predetermined period of time, a radio call response sent by the terminal or a notification indicating that the terminal enters a connected state and that is sent by another access network device.

[0163] 512. The first access network device sends a third message to a core network device.

[0164] The third message can be a connection release request or a notification message, and is used to request or instruct the core network device to release a connection (e.g., an S1 connection) between the terminal access network and the terminal core network. Optionally, a ported cause value can be Petition 870250011963, dated 02 / 13 / 2025, page 55 / 138 44 / 56 a radio access network call transmission failure.

[0165] After the connection is released, subsequently (if necessary), the core network can trigger a radio call transmission to radio call the terminal over a wider range to assist in radio calling the terminal.

[0166] It should be understood that the preceding solution of sending the third message by the first access network device in the event of a radio call transmission failure can be implemented separately. That is, the solution can be independent of other resources. For example, all procedures prior to the radio call transmission failure can be implemented using the solutions provided in this embodiment of this application, or they can be implemented using another solution. When a radio call transmission failure occurs, the third message is sent to the core network device to request or instruct the core network device to release the connection between the terminal's access network and the core network. After the connection is released, the core network device can radio call the terminal over a wider range, for example, within a terminal tracking area.

[0167] After the connection is released, the core network device can send a third message reply to the first access network device, where the third message reply indicates that the connection between the terminal access network and the core network has been released.

[0168] 513. The first network access device releases the terminal context. Petition 870250011963, dated 02 / 13 / 2025, page 56 / 138 45 / 56

[0169] 514. The first access network device sends a notification to the second access network device and the third access network device to release the terminal context.

[0170] 515. The second access network device and the third access network device release the terminal context.

[0171] After radio call transmission fails or the terminal enters the connected state, the load on an access network device can be reduced by releasing the terminal context on a timely basis.

[0172] It should be noted that the cell set information mentioned in the embodiments of this request may be a set including at least one cell identity, or it may be an identifier of a cell set, and there is a mapping relationship between the cell set identifier and a cell in the set. This is not limited to this embodiment of this request.

[0173] It should be understood that the sequence numbers of preceding processes do not signify execution sequences in various modalities of this request. The execution sequences of the processes should be determined according to the functions and internal logic of the processes, and should not constitute any limitation in the implementation processes of the modalities of this request.

[0174] It should be understood that the various modalities described in this descriptive report may be implemented in combination or separately.

[0175] It should be understood that specific examples in the modalities of this request are merely Petition 870250011963, dated 02 / 13 / 2025, p. 57 / 138 46 / 56 are intended to help a subject matter expert better understand the modalities of this application, but are not intended to limit the scope of the modalities of this application.

[0176] The preceding described in detail the communication method in the modalities of this application. What follows describes an access network device and a terminal in the modalities of this application. It should be understood that the access network device and the terminal in the modalities of this application can execute the various methods in the preceding modalities of this application, that is, for a detailed working process of the following devices, make a reference to a corresponding process in the preceding method modalities.

[0177] Figure 6 is a schematic block diagram of a 600 access network device according to an embodiment of this application. The 600 access network device may be an access network device in the preceding method embodiments, for example, the first access network device. As shown in Figure 6, the 600 access network device includes: A 610 processor, configured to determine that a terminal needs to enter an inactive Radio Resource Control (RRC) state, where the access network device is a terminal service access network device; and a 620 transceiver, configured to: send a first message to a second access network device, where the first message includes terminal context; and send a second message to the terminal, where the second message is used to instruct the terminal to Petition 870250011963, dated 02 / 13 / 2025, page 58 / 138 47 / 56 enter RRC inactive status.

[0178] Optionally, the second message includes information about a radio network area of ​​the terminal in the inactive RRC state.

[0179] The radio network area is used not to notify the network when the terminal reselects a cell in the radio network area in the inactive RRC state, or the radio network area is used to notify the network when the terminal reselects a cell outside the radio network area.

[0180] Optionally, the radio network area includes a first cell set.

[0181] Transceiver 620 is additionally configured to receive a first reply message that is from the first message and that is sent by the second access network device, wherein the first reply message includes information about a second cell set, and the second cell set is a set that includes one or more cells that are from the second access network device.

[0182] Processor 610 is additionally configured to determine the first cell set based on the second cell set, where the first cell set includes the second cell set.

[0183] Optionally, the radio network area includes a first set of access network devices.

[0184] Transceiver 620 is additionally configured to receive a second reply message that is from the first message and that is sent by the second access network device, where the second message of Petition 870250011963, dated 02 / 13 / 2025, page 59 / 138 A response of 48 / 56 indicates that the second access network device either accepts or refuses to join the radio network area.

[0185] Processor 610 is additionally configured to determine the first access network device set based on the second reply message, wherein the first access network device set includes at least one second access network device that agrees to join the radio network area.

[0186] Optionally, the 620 transceiver is additionally configured to receive a notification message indicating that the terminal enters a connected state.

[0187] Processor 610 is additionally configured to release the terminal context.

[0188] Transceiver 620 is additionally configured to send a terminal context release notification to another access network device in addition to the access network device in the access network devices corresponding to the terminal's radio network area in the RRC inactive state.

[0189] Optionally, the 620 transceiver is additionally configured to: when the terminal in the RRC inactive state needs to be called by radio, send in a cell that is from the access network device and that corresponds to the radio network area of ​​the terminal in the RRC inactive state, a first radio call message to call the terminal by radio; and send a radio call request message to request to call the terminal by radio to a third access network device, wherein the third access network device is a Petition 870250011963, dated 02 / 13 / 2025, pp. 60 / 138 49 / 56 another access network device in addition to the access network device in the access network devices corresponding to the radio network area.

[0190] The 600 access network device in this embodiment of this application may correspond to the first access network device in the communication methods in the embodiments of this application, and the preceding and other operations and / or module functions in the 600 access network device are separately used for the implementation of the corresponding procedures of the methods. For brevity, the details are not described again in this descriptive report.

[0191] Figure 7 is a schematic block diagram of a 700 access network device according to an embodiment of this application. The 700 access network device may be an access network device in the preceding method embodiments, for example, the second access network device. As shown in Figure 7, the 700 access network device includes: A 710 transceiver, configured for: receiving a first message sent by a first access network device, wherein the first message includes a terminal context, and the first access network device is a terminal service access network device; and receiving a fourth message sent by the terminal, wherein the fourth message is used to request a restoration from an inactive Radio Resource Control (RRC) state to a connected RRC state; and a 720 processor, configured for restoring the terminal from the inactive RRC state to the connected RRC state. Petition 870250011963, dated 02 / 13 / 2025, page 61 / 138 50 / 56 connected from RRC based on terminal context.

[0192] Optionally, the 720 processor is additionally configured to determine a second cell set, wherein the second cell set is a set of cells that are accepted by the access network device, which correspond to a radio network area of ​​the terminal in the inactive RRC state, and which are from the access network device.

[0193] Transceiver 710 is additionally configured to send a first reply message to the first access network device, wherein the first reply message includes the second cell set.

[0194] The access network device 700 in this embodiment of this application may correspond to the second access network device in the communication methods in the embodiments of this application, and the preceding and other operations and / or module functions in the access network device 700 are separately used for the implementation of the corresponding procedures of the methods. For brevity, the details are not described again in this descriptive report.

[0195] Figure 8 is a schematic block diagram of an 800 terminal according to an embodiment of this application. The 800 terminal may be the terminal in the preceding method embodiments. As shown in Figure 8, the 800 terminal includes: an 810 transceiver, configured to receive a second message sent by a first network access device, where the second message is used to Petition 870250011963, dated 02 / 13 / 2025, page 62 / 138 51 / 56 instruct the terminal to enter an inactive Radio Resource Control (RRC) state; the second message includes a terminal radio network area in the inactive RRC state; the first access network device is a terminal service access network device; the radio network area includes a second access network device or a cell of the second access network device; the second access network device is an access network device that receives a terminal context, and the terminal context is used by the terminal to restore the inactive RRC state to a connected RRC state; and an 820 processor, configured to enter the inactive RRC state from the connected RRC state based on the second message.

[0196] Optionally, the second message also includes a signal strength limit.

[0197] Processor 820 is additionally configured to: when a cell signal strength in the radio network area is greater than or not less than the signal strength threshold, perform a cell replacement in the radio network area.

[0198] Optionally, the 820 processor is configured to: when the terminal enters the RRC inactive state, remain in a cell in which the terminal is located when the terminal is in the original RRC connected state.

[0199] Optionally, transceiver 810 is additionally configured to send a fourth message to the second access network device, in Petition 870250011963, dated 02 / 13 / 2025, page 63 / 138 52 / 56 that the fourth message is used to request a restoration from the inactive RRC state to the connected RRC state.

[0200] Processor 820 is additionally configured to restore, based on the terminal context, the terminal from the inactive RRC state to the connected RRC state in a cell of the second access network device.

[0201] The 800 terminal in this embodiment of this application may correspond to the terminal in the communication methods in the embodiments of this application, and the preceding and other operations and / or module functions on the 800 terminal are used separately for the implementation of the corresponding procedures of the methods. For brevity, the details are not described again in this descriptive report.

[0202] Figure 9 shows a structure of a network access device according to yet another embodiment of this application, including at least one processor 902 (e.g., a CPU), at least one network interface 905 or another communications interface, and a memory 906. These components are in a communication connection with each other. The processor 902 is configured to execute an executable module, such as a computer program, stored in memory 906. Memory 906 may include high-speed random access memory (RAM), or it may also include non-volatile memory, for example, at least one magnetic disk memory. A communication connection between memory 906 and at least one other network element is implemented by using at least one Petition 870250011963, dated 02 / 13 / 2025, page 64 / 138 53 / 56 network interface 905 (which can be wired or wireless).

[0203] In some implementations, memory 906 stores program 9061, and processor 902 executes program 9061 for execution of the methods in the preceding modes of this request.

[0204] Figure 10 shows a terminal structure according to yet another embodiment of this application, including at least one processor 1002 (e.g., a CPU), at least one network interface 1005 or another communications interface, and a memory 1006. These components are in communication connection with each other. The processor 1002 is configured to execute an executable module, such as a computer program, stored in memory 1006. Memory 1006 may include high-speed random access memory (RAM), or it may include non-volatile memory, for example, at least one magnetic disk memory. A communication connection between memory 1006 and at least one other network element is implemented by using at least one network interface 1005 (which may be wired or wireless).

[0205] In some implementations, memory 1006 stores program 10061, and processor 1002 executes program 10061 for execution of methods in the preceding modes of this request.

[0206] It should be understood that the term and / or in the modalities of this request describes only an association relationship for the description of associated objects and represents that three relationships can exist. For example, A and / or B can represent the following three cases: there is only A, there are A and B, and there is only B. Furthermore, the character / in this Petition 870250011963, dated 02 / 13 / 2025, pp. 65 / 138 54 / 56 A descriptive report generally indicates a relationship between the associated objects.

[0207] A person skilled in the art may be aware that, in combination with the examples described in the embodiments disclosed in this descriptive report, algorithm units and steps may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on particular applications and design constraints of the technical solutions. A person skilled in the art may use different methods for implementing the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application.

[0208] It may be clearly understood by a person skilled in the art that, for the sake of convenient and brief description, for a detailed work process of the preceding system, apparatus and unit, reference is made to a corresponding process in the preceding method modalities, and the details are not described again in this descriptive report.

[0209] In the various embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other ways. For example, the described apparatus embodiment is merely an example. For example, unit division is merely a logical function division and may be another division in a real implementation. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or omitted. Petition 870250011963, dated 02 / 13 / 2025, page 66 / 138 55 / 56 executed. Furthermore, the mutual couplings or direct couplings or communication connectors revealed or discussed can be implemented by using some interfaces. Indirect couplings or communication connections between devices or units can be implemented in electronic, mechanical or other forms.

[0210] The units described as separate parts may or may not be physically separate, and parts revealed as units may or may not be physical units, may be located in one position, or may be distributed across a plurality of network units. Some or all of the units may be selected based on actual requirements for achieving the objectives of the modal solutions.

[0211] In addition, the functional units in the modalities of this application may be integrated into a processing unit, or each of the units may exist physically on its own, or two or more units may be integrated into a unit.

[0212] When functions are implemented in the form of a functional software unit and sold or used as a stand-alone product, the functions may be stored on a storage medium that can be read by a computer. Based on this understanding, the technical solutions of this application essentially either the part contributing to the state of the art, or some of the technical solutions, may be implemented in the form of a software product. The computer software product is stored on a storage medium and includes various instructions to instruct a computer device (which may be a personal computer, a server, a network device, or Petition 870250011963, dated 02 / 13 / 2025, page 67 / 138 56 / 56 similar) for performing all or some of the steps of the methods described in the embodiments of this application. The preceding storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0213] The preceding descriptions are merely specific implementations of this application, but are not intended to limit the scope of protection of this application. Any variation or substitution readily devised by a person skilled in the art within the technical scope disclosed in this application shall fall within the scope of protection of this application. Therefore, the scope of protection of this application shall fall within the subject matter of the scope of protection of the claims. Petition 870250011963, dated 02 / 13 / 2025, pp. 68 / 138

Claims

1 / 5 CLAIMS 1. A communication method, characterized by comprising: sending, by a first access network device, in a cell that is of the first access network device and that corresponds to a radio network area of ​​a terminal in the inactive RRC state, and in response to the terminal in the inactive RRC state needing to be called by radio, of a first radio call message calling the terminal by radio; sending, by the first access network device to a second access network device, of a radio call request message that the second access network device call the terminal by radio, wherein the second access network device corresponds to the radio network area;and the sending, by the first access network device, of a message to a core network device in response to the first access network device not receiving, within a predetermined period of time, a radio call response from the terminal or a notification from the second access network device indicating that the terminal has entered a connected state, wherein the message to the core network device requests that the core network device release a connection between the first access network device and the terminal's core network device.

2. Method, according to claim 1, characterized in that the radio call request message comprises information about a cell set, and is used to instruct the second access network device to send, in all cells in the cell set, a second radio call message to radio call the terminal, wherein the cell set is a set of cells that are comprised within the radio network area and that belong to the second access network device.

3. A method according to claim 1, characterized in that the method further comprises: the first access network device receiving a reply message corresponding to the message to the core network device from the core network device, wherein the reply message indicates that the connection between the first terminal access network device and the core network device has been released; and the first access network device releasing a terminal context.

4. A method according to claim 1, characterized in that the message to the core network device comprises a cause value, wherein the cause value indicates a radio access network call failure.

5. Method, according to claim 1, characterized in that the radio call request message causes the second access network device to radio call the terminal, wherein the second access network device radio calling the terminal causes the second access network device to restore the terminal to an RRC connected state with the second access network device according to a terminal context saved in the second access network device.

6. A method according to claim 5, characterized in that it further comprises the first access network device sending a context message to the second access network device, wherein the context message includes a terminal context and causes the second access network device to store the terminal context.

7. Method, according to claim 1, characterized in that the radio call message identifies one or more cells in which the second access network device radio calls the terminal.

8. A communication method characterized by comprising: receiving, by a core network device, from a first access network device, a message sent in response to the first access network device not receiving, within a predetermined period of time, a radio call response from a terminal or a notification from a second access network device indicating that the terminal has entered a connected state, wherein the message is used to request that the core network device release a connection between the first access network device and the terminal's core network device, and wherein the second access network device is an access network device that received, before the second access network device sent the notification,A radio call request message requesting that the second access network device radio call the terminal from the first access network device; and send a reply message corresponding to the message to the first access network device, wherein the reply message indicates that the connection between the terminal's first access network device and the core network device has been released.

9. A method according to claim 8, characterized in that the radio call request message comprises information about a cell set and instructs the second access network device to send, to all cells in the cell set, a second radio call message to radio call the terminal, wherein the cell set is a set of cells in a radio network area and which are from the second access network device.

10. Method according to claim 8, characterized in that the message comprises a cause value, wherein the cause value indicates a radio access network call failure.

11. Network access device, characterized by being configured for the implementation of the method as defined in any one of claims 1 to 7.

12. Core network device, characterized in that it is configured for the implementation of the method as defined in claim 8 or 10.

13. Communication system, characterized by comprising a first access network device as defined in claim 11 and a core network device as defined in claim 12.

14. System, according to claim 13, Petition 870250011963, dated 02 / 13 / 2025, page 72 / 138 5 / 5 characterized by the fact that it further comprises a second access network device.

15. Computer-readable storage medium, characterized in that the computer-readable storage medium stores an instruction, and when the instruction is executed, causes a device to execute the method as defined in any one of claims 1 to 10. Petition 870250011963, dated 02 / 13 / 2025, pp. 73 / 138

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