Connection recovery method and apparatus, related device, storage medium and computer program product

Abstract

Provided in the present disclosure are a connection recovery method and apparatus, a first user unit of an access network, a control unit of an access network, a storage medium, and a computer program product. The method comprises: a first user unit of an access network receiving connection recovery information, and receiving first information sent by a terminal in an inactive state, wherein the first information is used for requesting the recovery of a radio resource control (RRC) connection; and completing RRC connection recovery with the terminal, wherein the access network comprises a control unit and one or more user units, the one or more user units include the first user unit, the user unit is at least configured to maintain a user plane connection between the access network and a core network, there is a control plane connection and a user plane connection between the user units, the control unit is at least configured to maintain a control plane connection between the access network and the core network, and there is a control plane connection and no data plane connection between the control unit and the user unit.

Description

Connection recovery methods, devices, related equipment, storage media, and computer program products

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202411942936.6, filed in China on December 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of wireless communication technology, and in particular to a connection restoration method, apparatus, related equipment, storage medium, and computer program product. Background Technology

[0004] In a mobile wireless communication system, a terminal in an inactive state (also known as an inactive state, Radio Resource Control (RRC) INACTIVE state, or RRC_INACTIVE) can switch to a connected state (also known as a connected state or RRC_CONNECTED state) to resume service data transmission with the network side.

[0005] However, in related technologies, the signaling interaction process for the terminal to restore the RRC connection with the network side (i.e., switch to connection state) is relatively complex, has high latency, and results in poor quality of experience (QoE) for user services. Summary of the Invention

[0006] To address the related technical problems, this disclosure provides a connection restoration method, apparatus, related devices, storage medium, and computer program product.

[0007] The technical solution of this disclosure embodiment is implemented as follows:

[0008] This disclosure provides a connection restoration method applied to a first user unit of an access network. The access network includes a control unit and one or more user units, the one or more user units including the first user unit. Each user unit is at least used to maintain a user plane connection between the access network and the core network. There are control plane connections and user plane connections between the user units. The control unit is at least used to maintain a control plane connection between the access network and the core network. There is a control plane connection between the control unit and the user units, but no data plane connection. The method includes:

[0009] Receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection;

[0010] The RRC connection was restored with the terminal.

[0011] In the above scheme, the step of restoring the RRC connection with the terminal includes:

[0012] Using the first information, the context information of the terminal is obtained;

[0013] Using the context information of the terminal, the RRC connection is restored with the terminal.

[0014] In the above scheme, the first information includes an Inactive Radio Network Temporary Identifier (I-RNTI); obtaining the context information of the terminal using the first information includes:

[0015] Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the first user unit;

[0016] The context information of the terminal is retrieved locally.

[0017] In the above scheme, the first information includes I-RNTI; the one or more user units further include a second user unit, and obtaining the context information of the terminal using the first information includes:

[0018] Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the second user unit;

[0019] Send third information to the second user unit, the third information being used to request the acquisition of the terminal's context information;

[0020] Receive the context information of the terminal sent by the second user unit.

[0021] The method in the above scheme further includes:

[0022] Send a fourth message to the control unit, the fourth message being used to request the control unit to establish or modify the context of the terminal;

[0023] The system receives a fifth message sent by the control unit. The fifth message is used to indicate that the context of the terminal has been established or modified. The fourth and fifth messages are also used to establish a data channel between the first user unit and the core network.

[0024] The method in the above scheme further includes:

[0025] A sixth message is sent to the second user unit, the sixth message being used to instruct the second user unit to release the context information of the terminal.

[0026] In the above scheme, when downlink traffic from the core network to the terminal is detected, the downlink traffic is buffered and the terminal is paged to trigger the terminal to send the first information.

[0027] This disclosure also provides a connection restoration method applied to a control unit of an access network. The access network further includes one or more user units, each user unit including a first user unit. Each user unit is at least used to maintain a user plane connection between the access network and the core network. There are control plane connections and user plane connections between the user units. The control unit is at least used to maintain a control plane connection between the access network and the core network. There is a control plane connection between the control unit and the user units, but no data plane connection. The method includes:

[0028] The system receives a fourth message sent by the first user unit, the fourth message being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including a terminal requesting the restoration of the RRC connection;

[0029] The control unit sends a fifth message to the first user unit, the fifth message indicating that the control unit has completed the establishment or modification of the terminal's context information, and the fourth and fifth messages are also used to establish a data channel between the first user unit and the core network.

[0030] In the above scheme, the fifth information includes first relevant information for establishing a data channel between the first user unit and the core network, and the method further includes:

[0031] Send the first relevant information to the core network;

[0032] The system receives second relevant information sent by the core network for establishing a data channel between the first user unit and the core network, and the second relevant information is included in the fifth information sent to the first user unit.

[0033] This disclosure also provides a connection restoration device, disposed in a first user unit of an access network. The access network includes a control unit and one or more user units, the one or more user units including the first user unit. Each user unit is at least used to maintain the user plane connection between the access network and the core network. There are control plane connections and user plane connections between the user units. The control unit is at least used to maintain the control plane connection between the access network and the core network. There is a control plane connection between the control unit and the user units, but no data plane connection. The device includes:

[0034] The first receiving unit is configured to receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection;

[0035] A connection unit is used to restore the RRC connection with the terminal.

[0036] This disclosure also provides a connection restoration device, disposed in a control unit of an access network, the access network further comprising one or more user units, the one or more user units including a first user unit, each user unit being at least used to maintain a user plane connection between the access network and the core network, and the user units having both a control plane connection and a user plane connection, the control unit being at least used to maintain a control plane connection between the access network and the core network, and the control unit having a control plane connection with the user units but no data plane connection, including:

[0037] The second receiving unit is configured to receive fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including a terminal requesting the restoration of the RRC connection;

[0038] The sending unit is used to send fifth information to the first user unit. The fifth information indicates that the control unit has completed the establishment or modification of the terminal's context information. The fourth and fifth information are also used to establish a data channel between the first user unit and the core network.

[0039] This disclosure also provides a first user unit belonging to an access network. The access network includes a control unit and one or more user units, each including the first user unit. Each user unit is at least used to maintain a user plane connection between the access network and the core network. There are control plane connections and user plane connections between the user units. The control unit is at least used to maintain a control plane connection between the access network and the core network. There is a control plane connection between the control unit and the user units, but no data plane connection.

[0040] The first communication interface is used to receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection;

[0041] A first processor is configured to restore the RRC connection with the terminal via the first communication interface.

[0042] This disclosure also provides a control unit belonging to an access network, which further includes one or more user units, each user unit including a first user unit. Each user unit is at least used to maintain a user plane connection between the access network and a core network. The user units have both control plane and user plane connections. The control unit is at least used to maintain a control plane connection between the access network and the core network. The control unit has a control plane connection with the user units but no data plane connection. The control unit includes a second processor and a second communication interface.

[0043] The second communication interface is used to receive fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the context information of a terminal in the control unit, the terminal including a terminal requesting the restoration of an RRC connection; and to send fifth information to the first user unit, the fifth information indicating that the control unit has completed the establishment or modification of the context information of the terminal, the fourth information and the fifth information also being used to establish a data channel between the first user unit and the core network.

[0044] This disclosure also provides a user unit, including: a first processor and a first memory for storing a computer program capable of running on the processor.

[0045] Wherein, when the first processor is used to run the computer program, it executes the steps of any of the methods described above on the first user unit side.

[0046] This disclosure also provides a control unit, including: a second processor and a second memory for storing a computer program capable of running on the processor.

[0047] Wherein, when the second processor runs the computer program, it executes the steps of any of the methods described above on the control unit side.

[0048] This disclosure also provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of any of the methods described above for the first user unit side, or implements the steps of any of the methods described above for the control unit side.

[0049] This disclosure also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the methods described above for the first user unit side, or implements the steps of any of the methods described above for the control unit side.

[0050] The connection restoration method, apparatus, related devices, storage medium, and computer program products provided in this disclosure include: a first user unit of an access network receiving connection restoration information and receiving first information sent by a terminal in an inactive state, the first information being used to request the restoration of an RRC connection; and completing the RRC connection restoration with the terminal. The access network includes a control unit and one or more user units, the one or more user units including the first user unit. Each user unit is at least used to maintain a user plane connection between the access network and the core network, and there are control plane connections and user plane connections between the user units. The control unit is at least used to maintain a control plane connection between the access network and the core network, and there is a control plane connection between the control unit and the user units but no data plane connection. The control unit of the access network receives fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including the terminal requesting the restoration of the RRC connection; the control unit of the access network sends fifth information to the first user unit, the fifth information indicating that the control unit has completed the establishment or modification of the terminal's context information, and the fourth and fifth information are also used to establish a data channel between the first user unit and the core network. The solution provided in this disclosure addresses a scenario where the access network architecture includes a control unit and a user unit, and the architecture satisfies the following conditions: the user unit is at least used to maintain the user plane connection between the access network and the core network; there are control plane connections and user plane connections between the user units; the control unit is at least used to maintain the control plane connection between the access network and the core network; and there is a control plane connection between the control unit and the user unit but no data plane connection. In this scenario, the first user unit corresponding to the terminal (i.e., used to serve the terminal) can directly restore the RRC connection with the terminal upon receiving a request from an inactive terminal to restore the RRC connection. This eliminates the need for complex signaling procedures between the user unit and the control unit, reducing the RRC restoration latency and thereby improving the user's service QoE.

[0051] At the same time, the control unit can interact with the user unit to establish or modify the terminal context and establish a data channel between the user unit and the core network, thus ensuring accurate data transmission between the core network and the user unit. Attached Figure Description

[0052] Figure 1 is a schematic diagram of an access network architecture in related technologies;

[0053] Figure 2 is a flowchart illustrating a connection restoration method in related technologies;

[0054] Figure 3 is a flowchart illustrating another connection restoration method in related technologies;

[0055] Figure 4 is a flowchart illustrating the connection restoration method when the terminal moves in the related technology;

[0056] Figure 5 is a schematic diagram of a network protocol framework in related technologies;

[0057] Figure 6 is a schematic diagram comparing the new access network architecture and the traditional access network architecture in the application example of this disclosure;

[0058] Figure 7 is a flowchart illustrating a connection restoration method according to an embodiment of this disclosure;

[0059] Figure 8 is a flowchart illustrating another connection restoration method according to an embodiment of this disclosure;

[0060] Figure 9 is a flowchart illustrating the first method for quickly activating the RRC inactive state in this application example.

[0061] Figure 10 is a flowchart illustrating the second method for quickly activating the RRC inactive state in this application example.

[0062] Figure 11 is a schematic diagram of a connection restoration device according to an embodiment of the present disclosure;

[0063] Figure 12 is a schematic diagram of another connection restoration device according to an embodiment of the present disclosure;

[0064] Figure 13 is a schematic diagram of the structure of the first user unit of the access network according to an embodiment of this disclosure;

[0065] Figure 14 is a schematic diagram of the control unit structure of the access network according to an embodiment of this disclosure;

[0066] Figure 15 is a schematic diagram of the connection recovery system structure according to an embodiment of this disclosure. Detailed Implementation

[0067] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments.

[0068] In related technologies, in mobile wireless communication systems, terminals without service data transmission can release the air interface-allocated radio resources by entering the inactive state, thereby gaining the following advantages:

[0069] Terminal energy saving: Terminals in inactive mode can enter deep sleep mode to extend battery life;

[0070] Improve air interface resource utilization: When a terminal enters the inactive state, the air interface resources released can be allocated to other terminals (or other users), thereby saving air interface resources.

[0071] In practical applications, terminals in the inactive state can maintain a Connection Management (CM) connection (CM_CONNECTED). In this case, the connection between the terminal and the core network remains valid, that is, the configuration data of the terminal's higher-level protocol stack is maintained, so that the network side can search, match, identify, and release relevant radio resources for terminals in the inactive state.

[0072] When there is a business need, the terminal in the inactive state can interact with the access network side to restore the RRC connection, that is, restore to the connection state, so as to be able to transmit business data with the network side.

[0073] In related technologies, as shown in Figure 1, traditional access network architectures typically include Centralized Units (CUs) and Distributed Units (DUs). Each CU can connect to one or more (or at least one) DUs, and the CU can manage and control the connected DUs (or DUs accessing the CU). Specifically, the CU can include a control plane (CU-ControlPlane, CU-CP) and a user plane (CU-User Plane, CU-UP).

[0074] When using a traditional access network architecture, the specific implementation methods for a terminal in the inactive state to return to the connection state can include one of the following:

[0075] The first method: The terminal in the inactive state actively initiates a recovery request to the access network device to request a switch to the connection state;

[0076] The second method: When the access network device receives a data plane transmission from the core network for a terminal in the inactive state, it can page the terminal in the inactive state to trigger the terminal in the inactive state to initiate a recovery request.

[0077] Regarding the first method described above, as shown in Figure 2, it may specifically include the following steps (which can also be understood as a signaling process):

[0078] Step 201: The terminal in the inactive state actively sends an RRC recovery request (RRCResumeRequest) message to the DU (hereinafter referred to as DU) of the access network;

[0079] The terminal can be referred to as User Equipment (UE), user, etc., and the DU of the access network can also be understood as gNB DU.

[0080] Step 202: After receiving the RRC Resume Request message, the DU sends an Initial Uplink (UL) RRC Message Transmission (INITIAL UL RRC MESSAGE TRANSFER) message to the CU-CP (hereinafter referred to as CU-CP) of the access network. The INITIAL UL RRC MESSAGE TRANSFER message contains the RRC Resume Request message.

[0081] Step 203: After receiving the INITIAL UL RRC MESSAGE TRANSFER message, the CU-CP sends a UE CONTEXT SETUP REQUEST message to the DU to request the DU to establish a context for the terminal (which may specifically include configuring the RRC connection and related radio bearers); the UE CONTEXT SETUP REQUEST message may include an uplink tunnel endpoint identifier (UL Tunnel Endpoint Identifier, UL TEID), which can also be understood as an uplink transport network layer identifier, used by the DU to carry the UL TEID when sending terminal-related data streams, thereby ensuring that the data stream can be accurately routed to the CU-UP of the access network (hereinafter referred to as CU-UP);

[0082] Step 204: After receiving the UE CONTEXT SETUP REQUEST message, the DU performs context setting; and after the context setting is completed, the DU sends a terminal context setting response (UE CONTEXT SETUP RESPONSE) message to the CU-CP to inform the CU-CP that the terminal context has been established; wherein, the UE CONTEXT SETUP RESPONSE may include the downlink tunnel endpoint identifier (DownLink TEID, DL TEID);

[0083] Step 205: After receiving the UE CONTEXT SETUP RESPONSE message, the CU-CP informs the terminal that the RRC connection has been successfully restored; accordingly, the terminal enters the connection state.

[0084] Specifically, CU-CP can send an RRC recovery response (RRCResumeResponse) message to the terminal through DU to inform the terminal that the RRC connection recovery is complete; after receiving the RRCesumeResponse message, the terminal can enter the connection state.

[0085] Step 206: The CU-CP sends a Bearer Context Modification Request (BEARER CONTEXT MODIFICATION REQUEST) message to the CU-UP to request the CU-UP to perform routing configuration. The BEARER CONTEXT MODIFICATION REQUEST message may contain a DL TEID, which is used by the CU-UP to perform routing configuration. When the CU-UP receives downlink data streams for the terminal from the core network side, it can accurately route the data to the corresponding DU according to the routing configuration.

[0086] In practical applications, steps 205 and 206 can be executed simultaneously, or steps 205 can be executed first and then steps 206. Alternatively, steps 206 can be executed first and then steps 205. The specific settings can be configured according to actual needs.

[0087] Step 207: After receiving the BEARER CONTEXT MODIFICATION REQUEST message, CU-UP modifies the bearer context; and after the modification is completed, CU-UP sends a Bearer CONTEXT MODIFICATION RESPONSE message to CU-CP to inform CU-CP that the routing configuration is complete.

[0088] Meanwhile, regarding the second method mentioned above, as shown in Figure 3, it can specifically include the following steps (which can also be understood as a signaling process):

[0089] Step 301: After the CU-UP detects downlink traffic (DL Traffic) for an inactive terminal on the NG-U tunnel, it caches the detected traffic and executes step 302; wherein, the downlink traffic may include traffic sent from the User Plane Function (UPF) on the core network side to the CU-UP for an inactive terminal.

[0090] Step 302: CU-UP sends a downlink data notification (DL DATA NOTIFICATION) message to CU-CP to inform CU-CP that downlink data for the terminal has been received;

[0091] Step 303: After receiving the DL DATA NOTIFICATION message, the CU-CP paging message is sent to the DU corresponding to the terminal.

[0092] Step 304: After receiving the paging message sent by CU-CP, DU pages the corresponding terminal, that is, sends a paging message to the terminal to trigger the terminal in the inactive state to initiate the RRC connection recovery process;

[0093] Step 305: After receiving the paging message sent by the DU, the terminal in the inactive state sends an RRRCResumeRequest message to the DU;

[0094] Step 306: After receiving the RRC Resume Request message, DU sends an INITIAL UL RRC MESSAGE TRANSFER message to CU-CP;

[0095] Step 307: After receiving the INITIAL UL RRC MESSAGE TRANSFER message, the CU-CP sends a UE CONTEXT SETUP REQUEST message to the DU to request the DU to establish a context for the terminal;

[0096] Step 308: After receiving the UE CONTEXT SETUP REQUEST message, the DU performs context setting; and after the context setting is completed, the DU sends a UE CONTEXT SETUP RESPONSE message to the CU-CP to inform the CU-CP that the terminal context has been established.

[0097] Step 309: After receiving the UE CONTEXT SETUP RESPONSE message, the CU-CP informs the terminal that the RRC connection has been successfully restored; accordingly, the terminal enters the connection state.

[0098] Step 310: CU-CP sends a BEARER CONTEXT MODIFICATION REQUEST message to CU-UP to request CU-UP to configure routing;

[0099] Step 311: After receiving the BEARER CONTEXT MODIFICATION REQUEST message, CU-UP modifies the bearer context; and after the modification is completed, CU-UP sends a BEARER CONTEXT MODIFICATION RESPONSE message to CU-CP to inform CU-CP that the routing configuration is complete.

[0100] In practical applications, the specific implementation of steps 305 to 311 can be understood by referring to steps 201 to 207, and will not be repeated here. The uplink can include the direction of information transmission from the terminal to the access network, or the direction of information transmission from the access network to the core network; that is, from a directional perspective, it refers to the direction from the terminal to the access network and then to the core network. The downlink can include the direction of information transmission from the core network to the access network, or the direction of information transmission from the access network to the terminal; that is, from a directional perspective, it refers to the direction from the core network to the access network and then to the terminal.

[0101] In practical applications, terminals in the inactive state may move. For example, suppose there are two base stations providing access services, base station 1 and base station 2. A terminal accessing base station 1 moves from the service area of ​​base station 1 to the service area of ​​base station 2 after entering the inactive state. At this time, the terminal can send a request message (such as an RRC ResumeResponse message) to base station 2 to request the restoration of the RRC connection. Base station 1 is called the last serving gNB (Last Serving gNB, which can also be understood as the source gNB); base station 1 and base station 2 each contain their corresponding CU and DU.

[0102] Specifically, as shown in Figure 4, the steps to restore a terminal in the inactive state to the connection state after it moves may include:

[0103] Step 401a: The terminal in the inactive state actively sends an RRRCResumeRequest message to the base station corresponding to the cell it is currently in (hereinafter referred to as the current base station, which can also be understood as the target gNB);

[0104] Step 401b: The core network sends downlink traffic to the base station (hereinafter referred to as the previous serving base station) that the terminal connected to (or accessed) before entering the inactive state; when the previous serving base station receives the downlink traffic, it pages the terminal in the inactive state; after receiving the paging message, the terminal in the inactive state sends an RRRCResumeRequest message to the current base station.

[0105] In practical applications, step 401a or step 401b can be executed as needed to initiate the RRC connection recovery process, and then step 402 can be executed.

[0106] Step 402: The current base station sends a RETRIEVE UE CONTEXT REQUEST message to the next serving base station to request the context information of the terminal whose RRC connection is to be restored;

[0107] In practical applications, when a terminal determines it has entered an inactive state, the CU-UP contained in the base station the terminal accesses (i.e., the previous serving base station) can assign a corresponding I-RNTI to the terminal to identify it. Specifically, the I-RNTI can contain the identification information of the previous serving base station (such as the gNB ID). Thus, when a terminal in the inactive state sends an RRCresumeRequest message, it can carry the I-RNTI. Correspondingly, after receiving the RRCresumeRequest message, if the current base station determines that the base station identification information contained in the I-RNTI (i.e., the identifier of the previous serving base station) is different from its own identification information (i.e., the identifier of the current base station), it can determine that the terminal has moved and obtain the terminal's context information by executing step 402. Conversely, if it determines that the base station identification information contained in the I-RNTI is the same as its own identification information, it can determine that the terminal has not moved and can search for the terminal's context information locally at the current base station.

[0108] The current base station and the previous serving base station can communicate through the Xn-C interface between the CU-CP of the current base station and the CU-CP of the previous serving base station.

[0109] Step 403: After receiving the RETRIEVE UE CONTEXT REQUEST message, the previous serving base station sends a RETRIEVE UE CONTEXT RESPONSE message to the current base station; wherein, the RETRIEVE UE CONTEXT RESPONSE message contains the context of the terminal whose RRC connection is to be restored;

[0110] Step 404: After receiving the RETRIEVE UE CONTEXT RESPONSE message, the current base station uses the terminal's context information contained in the RETRIEVE UE CONTEXT RESPONSE message to restore the terminal's RRC connection;

[0111] Specifically, the current base station can send an RRC recovery message to the terminal; correspondingly, after receiving the RRC recovery message, the terminal enters the connection state and sends an RRC recovery complete message to the current base station to inform the current base station that the terminal has entered the connection state.

[0112] In practical applications, if step 401b is executed and the previous serving base station has cached the received downlink traffic, step 405 can be executed first so that the previous serving base station forwards the cached traffic to the current base station, and then step 406 can be executed; if step 401b is not executed, or the previous serving base station has not cached the received downlink traffic, step 406 can be executed directly.

[0113] Step 405: The current base station sends an Xn-U ADDRESS INDICATION message to the previous serving base station to inform the previous serving base station of the user plane communication address of the current base station. In this way, the previous serving base station can forward the buffered traffic to the address indicated by the Xn-U ADDRESS INDICATION message; then proceed to step 406.

[0114] Step 406: The current base station sends a PATH SWITCH REQUEST message to the core network to request the core network to change the data delivery path and directly send the terminal-related data to the current base station;

[0115] In practical applications, the CU-CP of the current base station can send a path change request message to the Access and Mobility Management Function (AMF) on the core network side.

[0116] Step 407: After receiving the path change request message, the core network performs path change; and after the path change is completed, it sends a path change request response (PATH SWITCH REQUEST RESPONSE) message to the current base station to inform the current base station that the path change has been completed and the downlink traffic corresponding to the terminal will be sent to the current base station in the future.

[0117] Step 408: After receiving the PATH SWITCH REQUEST RESPONSE message, the current base station sends a UE CONTEXT RELEASE message to the previous serving base station so that the previous serving base station can release the context of the terminal, thereby saving resources.

[0118] As described above, a terminal in the inactive state can switch to the connection state by executing the above steps, thereby resuming service data transmission. While this process offers significant advantages in control plane and user plane recovery latency compared to initial access, it still involves complex signaling processes involving multiple network elements, making it difficult to guarantee rapid recovery of terminal services. Therefore, a simplified solution for terminal recovery of RRC connections is urgently needed to reduce recovery latency (which can also be understood as link recovery latency) and improve the user's service QoE.

[0119] Based on this, in various embodiments of this disclosure, a scheme for RRC connection recovery is proposed for the new access network architecture. The new access network architecture specifically includes a control unit and a user unit. Under the following conditions, the user unit is used to maintain the user plane connection between the access network and the core network, there are control plane connections and user plane connections between user units, the control unit is used to maintain the control plane connection between the access network and the core network, and there is a control plane connection between the control unit and the user unit but no data plane connection, the first user unit corresponding to the terminal (i.e., used to serve the terminal) can directly restore the RRC connection with the terminal when it receives a request from an inactive terminal to restore the RRC connection. This eliminates the need for complex signaling procedures between the user unit and the control unit, reduces the latency of RRC recovery, and improves the user's service QoE.

[0120] Before introducing the solutions of the embodiments of this disclosure, the above-described access network architecture will be explained first:

[0121] With the development of fifth-generation mobile communication technology (5G) th As 5G (Generation Z, 5G) continues to develop and its user plane functions are continuously enhanced and backward compatible, the concept of the user plane protocol stack may become "thicker and thicker," specifically manifested in one or more of the following issues (one or more can also be understood as at least one):

[0122] 1) Expenses in Baotou are increasing;

[0123] 2) The functions are cumbersome and bloated, with data retransmission mechanisms existing in both the Packet Data Convergence Protocol (PDCP) layer and the Radio Link Control (RLC) layer;

[0124] 3) Both the PDCP layer and the RLC layer have sorting functions. Since control information and user data may be transmitted on the same bearer, the data packets between the PDCP layer and the RLC layer are not in a one-to-one correspondence. Therefore, when data packet loss occurs, management and coordination are complicated and the inter-layer coupling is strong.

[0125] 4) The PDCP module's encryption and integrity protection functions are redundantly deployed in both the control plane and the user plane;

[0126] To address the aforementioned issues, as shown in Figure 5, a simplified protocol framework is proposed. Specifically, by introducing a Data Plane Process Layer (DPPL), the Service Data Adaptation Protocol (SDAP) layer, PDCP layer, and RLC layer are merged into one layer, thereby making the network control plane and user plane clearer, more streamlined, and completely separated.

[0127] After introducing the DPPL layer, the access network architecture can be adjusted accordingly to obtain a new network architecture (which can also be understood as a simplified network architecture or a new access network architecture), namely the access network architecture involved in this embodiment. The new network architecture may include: user units for maintaining the user plane connection between the access network and the core network, and control units for maintaining the control plane connection between the access network and the core network. The user unit may also be called a DU or an evolved DU (eDU), and the control unit may also be called a CU or an evolved CU (eCU). This embodiment does not limit the names of the control unit and the user unit.

[0128] In the new network architecture, the access network can specifically include one or more user units, each with a different service scope. User units have control plane connections and user plane connections (which can also be understood as being able to establish control plane and data plane connections). Different user units can transmit service data and control signaling through these connections. Here, user units can include different user units associated with the same control unit, or different user units associated with different control units. The control unit and user units have control plane connections but no data plane connections (which can also be understood as being able to establish control plane connections but not data plane connections). In other words, the control unit and user units transmit control signaling but not service data (which can also be understood as transmitting control plane data but not data plane data). Service data issued by the core network can be directly routed to the user units through the user plane connection between the access network and the core network, without needing to pass through the control unit.

[0129] For example, as shown in Figure 6, the new network architecture includes an eCU and an eDU. The eCU is used to maintain the control plane connection between the access network and the core network, and the eDU is used to maintain the user plane connection between the access network and the core network. There are connections between the eCU and the eDU, links between different eCUs, and connections between different DUs. The eCU is connected to the AMF on the core network side (specifically, it may include the 5G core network (5G Core, 5GC)), and the eDU is connected to the UPF on the core network side. In this case, compared with the traditional access network architecture (which can also be understood as the old network architecture), the new network architecture has one or more of the following characteristics:

[0130] 1) Merging: The functions of the SDAP layer, PDCP layer, and RLC layer in the traditional access network architecture are merged into the DPPL layer in the new network architecture;

[0131] 2) Simplification: The control plane and data plane (also known as CU-CP and CU-UP) of the control unit in the new network architecture are deployed in a unified manner, and the E1 interface is no longer set between the control plane and the data plane;

[0132] 3) The control unit and the user unit include a control interface (which can also be understood as only having a control plane connection), but do not include a data interface (which can also be understood as not having a data plane connection);

[0133] 4) Different control units only include the XN-C interface (i.e., signaling interface), and do not include the Xn-U interface (i.e., data interface);

[0134] 5) There is a user unit network (DU Network, DN) interface between different user units, which is a network interface set between different user units to realize the function of transmitting service data and control signaling between user units. The name of the network interface set between different user units is not limited in this embodiment of the disclosure.

[0135] 6) The data plane and control plane (also known as the signaling plane) are completely separated at the higher protocol levels: the control unit no longer includes the functions of the PDCP layer (also known as the PDCP module function), and the user unit has the functions of the RRC layer (also known as the capability). In other words, when the core network transmits data plane data to the access network, downlink traffic (i.e., downlink data plane data) can be directly routed from the core network (specifically, it may include the UPF) to the user unit, simplifying the user plane routing and link establishment process.

[0136] Based on the above access network architecture, this disclosure provides a connection recovery method applied to a first user unit of the access network, wherein the first user unit belongs to one or more user units included in the access network (i.e., the one or more user units include the first user unit), as shown in FIG7. The method includes:

[0137] Step 701: Receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection;

[0138] Step 702: Complete the RRC connection restoration with the terminal.

[0139] In practical applications, the first user unit can also be referred to as DU or eDU, and the terminal can be referred to as UE, user, etc. This embodiment does not limit the names of the first user unit and the terminal, as long as their functions are implemented.

[0140] In practical applications, the terminal in the inactive state (hereinafter referred to as the terminal) can actively initiate an RRC connection recovery process, that is, actively send the first information to the first user unit to request the recovery of the RRC connection. The terminal is within the service range (or coverage area) of the first user unit. This embodiment of the disclosure does not limit the name of the first information. Specifically, the terminal can send the first information to the first user unit through an RCResumeRequest message, meaning the RCResumeRequest message contains the first information.

[0141] Of course, the first user unit may also send an indication message to the terminal when it detects downlink traffic to the terminal. The indication message is used to instruct the terminal to initiate an RRC connection recovery process so as to receive the downlink traffic. Accordingly, when the terminal receives the indication message, it sends the first information to the first user unit.

[0142] Specifically, in one embodiment, when the first user unit detects downlink traffic from the core network for the terminal, it buffers the downlink traffic and pages the terminal to trigger the terminal to send the first information.

[0143] After the terminal sends the first information, in step 701, the first user unit receives the first information sent by the terminal; after receiving the first information, in step 702, the first user unit can first obtain the context information of the terminal, and then use the obtained context information to restore the RRC connection for the terminal.

[0144] Based on this, in one embodiment, the specific implementation of step 702 may include:

[0145] Using the first information, the context information of the terminal is obtained;

[0146] Using the context information of the terminal, the RRC connection is restored with the terminal.

[0147] In practical applications, before the terminal enters the inactive state, the user unit accessed by the terminal stores the context information of the terminal; however, after entering the inactive state, the terminal may move (for example, move from the coverage area of ​​one user unit to the coverage area of ​​another user unit) or not move. Therefore, the first user unit may be the same as or different from the user unit accessed by the terminal before entering the inactive state.

[0148] To enable the first user unit to determine whether it is the same user unit accessed by the terminal before entering the inactive state, each user unit can assign a corresponding I-RNTI to the terminal before the terminal enters the inactive state, and include the user unit's identification information in the I-RNTI. Thus, when the terminal sends the first information, the first information can include (or be understood as carrying) the I-RNTI corresponding to the terminal; correspondingly, when the first user unit receives the first information, it can use the I-RNTI included in the first information to determine the identification information of the user unit that assigned the I-RNTI; then, the first user unit can compare its own identification information with the identification information of the user unit that assigned the I-RNTI. If the comparison result indicates that the two identification information are the same, the first user unit can determine that the first user unit is the same user unit accessed by the terminal before entering the inactive state; of course, if the comparison result indicates that the two identification information are different, the first user unit can determine that the first user unit is different from the user unit accessed by the terminal before entering the inactive state.

[0149] In practical applications, when obtaining the context information of the terminal, if the first user unit is the same user unit that accessed the terminal before it entered the inactive state, the first user unit can perform a local search to obtain the terminal's context information. That is, in one embodiment, the first user unit uses the I-RNTI to determine that the user unit that allocated the I-RNTI includes itself; and then searches for the terminal's context information locally.

[0150] Of course, if the first user unit is different from the user unit that the terminal accessed before entering the inactive state, the first user unit can send a request message to the user unit that the terminal accessed before entering the inactive state to request to obtain the context information of the terminal.

[0151] Based on this, in one embodiment, the one or more user units further include a second user unit, and the step of obtaining the context information of the terminal using the first information includes:

[0152] Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the second user unit;

[0153] Send third information to the second user unit, the third information being used to request the acquisition of the terminal's context information;

[0154] Receive the context information of the terminal sent by the second user unit.

[0155] In practical applications, the second user unit includes the user unit accessed before the terminal enters the inactive state. The second user unit can also be called the source user unit, source DU, or source eDU. Correspondingly, the first user unit can also be called the target user unit, target DU, or target eDU. This disclosure does not limit this.

[0156] In practical applications, the first user unit can use the user unit identification information contained in the I-RNTI to determine that the second user unit has allocated the I-RNTI, and send the third information to the second user unit to request the acquisition of the terminal's context information; wherein, the third information may specifically include the I-RNTI corresponding to the terminal, and the name of the third information is not limited in this embodiment. Specifically, the first user unit can send the third information to the second user unit through a User Unit Retrieval UE CONTEXT REQUEST message, that is, the DU RETRIVE UE CONTEXT REQUEST message contains the first information.

[0157] After receiving the third information, the second user unit can perform a local search based on the I-RNTI contained in the third information and send the context information of the terminal corresponding to the found I-RNTI to the first user unit. Specifically, the second user unit can send the terminal's context information to the first user unit through a User Unit Retrieval UE CONTEXT RESPONSE message, that is, the DU RETRIVE UE CONTEXT RESPONSE message contains the terminal's context information.

[0158] After obtaining the context information of the terminal, in step 702, the first user unit can perform configuration related to the terminal's RRC connection recovery, such as rebuilding the Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB). After configuration, the first user unit can inform the terminal of the DRB and SRB related information required for RRC connection recovery through an RCResume message; correspondingly, the terminal can use the DRB and SRB related information to perform bearer recovery-related operations, and after recovery, the terminal can inform the first user unit that the terminal is ready to transmit service data through an RCResumeComplete message; wherein, after generating the RCResume message, the first user unit can first perform integrity protection and encryption processing on the RCResume message, and then send the processed RCResume message to the terminal.

[0159] In practical applications, if the first user unit is different from the user unit (i.e., the second user unit) that the terminal accessed before entering the inactive state, the first user unit can interact with the control unit corresponding to the first user unit after receiving the context information of the terminal. On the one hand, the control unit can establish or modify the context of the terminal; on the other hand, the control unit can establish a data channel between the user unit and the core network.

[0160] Based on this, in one embodiment, the method may further include:

[0161] Send a fourth message to the control unit, the fourth message being used to request the control unit to establish or modify the context of the terminal;

[0162] The system receives a fifth message sent by the control unit. The fifth message is used to indicate that the context of the terminal has been established or modified. The fourth and fifth messages are also used to establish a data channel between the first user unit and the core network.

[0163] In practical applications, if the control unit corresponding to the first user unit (hereinafter referred to as the first control unit) is different from the control unit corresponding to the second user unit (hereinafter referred to as the second control unit), the first control unit may not have pre-established the context of the terminal. In this case, the first user unit can send the fourth information to the first control unit so that the first control unit can establish the context of the terminal. The fourth information may include relevant information about the terminal and the first user unit. Specifically, the first user unit can send the fourth information to the first control unit through a User Unit Terminal Context Establishment Request (DU UE CONTEXT SETUP REQUEST) message, meaning the DU UE CONTEXT SETUP REQUEST message contains the fourth information. Specifically, the fourth information may include the DL TEID of the data channel between the first control unit and the core network. Accordingly, after receiving the fourth information, the first control unit can, on the one hand, use the fourth information to establish the context of the terminal; on the other hand, the first control unit can send the DL TEID to the core network and receive the UL TEID of the data channel between the first control unit and the core network issued by the core network; after the context of the terminal is established, the first control unit can generate a DU UE CONTEXT SETUP RESPONSE message and send the DU UE CONTEXT SETUP RESPONSE message to the first user unit to inform the first user unit that the terminal context has been established. At the same time, the UL TEID can be carried in the DU UE CONTEXT SETUP RESPONSE so that the first user unit and the core network can establish a data channel using the DL TEID and the UL TEID.

[0164] Of course, if the first control unit is the same as the second control unit, the first control unit may have already pre-established the terminal's context (i.e., the terminal's context established before the terminal enters the inactive state). In this case, the first user unit can send the fourth information to the first control unit so that the first control unit can modify (or change or adjust) the terminal's context. The fourth information may include relevant information about the terminal and the first user unit. Specifically, the first user unit can send the fourth information to the first control unit via a User Unit Terminal Context Modification Request (DU UE CONTEXT MODIFY REQUEST) message, meaning the DU UE CONTEXT MODIFY REQUEST message contains the fourth information. Correspondingly, after the terminal's context modification is completed, the first control unit can generate a User Unit Terminal Context Modification Response (DU UE CONTEXT MODIFY RESPONSE) message and send it to the first user unit to inform them that the terminal context modification has been completed.

[0165] In practical applications, if the first user unit is different from the user unit (i.e., the second user unit) that the terminal accessed before it entered the inactive state, the first user unit can notify the second user unit to release the terminal's context after receiving the terminal's context information, so as to save the second user unit's resources.

[0166] Based on this, in one embodiment, the method may further include:

[0167] A sixth message is sent to the second user unit, the sixth message being used to instruct the second user unit to release the context information of the terminal.

[0168] In practical applications, the first user unit can send the sixth information to the second user unit via a DU UE CONTEXT RELEASE message to inform the first user unit to release the terminal's context. In other words, the DU UE CONTEXT RELEASE message contains the sixth information. Specifically, the sixth information may include relevant information about the terminal (such as I-RNTI). This disclosure does not limit the name or specific implementation of the sixth information.

[0169] After receiving the sixth information, the second user unit can initiate a release process for the terminal context, thereby saving resources.

[0170] Accordingly, this disclosure also provides a connection restoration method applied to a control unit of an access network, wherein the access network further includes one or more user units, the one or more user units including a first user unit, the user unit being at least used to maintain the user plane connection between the access network and the core network, and there are control plane connections and user plane connections between the user units, the control unit being at least used to maintain the control plane connection between the access network and the core network, and there is a control plane connection between the control unit and the user units but no data plane connection, as shown in FIG8, the method includes:

[0171] Step 801: Receive fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including a terminal requesting the restoration of the RRC connection;

[0172] Step 802: Send fifth information to the first user unit. The fifth information indicates that the control unit has completed the establishment or modification of the terminal's context information. The fourth and fifth information are also used to establish a data channel between the first user unit and the core network.

[0173] In practical applications, the specific implementation of steps 801 and 802 can be understood by referring to the method on the first user unit side, and will not be described in detail here.

[0174] The connection restoration method provided in this embodiment includes a first user unit of an access network receiving connection restoration information and receiving first information sent by a terminal in an inactive state, the first information being used to request the restoration of an RRC connection; and completing the RRC connection restoration with the terminal. The access network includes a control unit and one or more user units, the one or more user units including the first user unit. Each user unit is at least used to maintain a user plane connection between the access network and the core network, and there are control plane connections and user plane connections between the user units. The control unit is at least used to maintain a control plane connection between the access network and the core network, and there is a control plane connection between the control unit and the user units but no data plane connection. The control unit of the access network receives fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including the terminal requesting the restoration of the RRC connection; the control unit of the access network sends fifth information to the first user unit, the fifth information indicating that the control unit has completed the establishment or modification of the terminal's context information, and the fourth and fifth information are also used to establish a data channel between the first user unit and the core network. The solution provided in this disclosure addresses a scenario where the access network architecture includes a control unit and a user unit, and the architecture satisfies the following conditions: the user unit is at least used to maintain the user plane connection between the access network and the core network; there are control plane connections and user plane connections between the user units; the control unit is at least used to maintain the control plane connection between the access network and the core network; and there is a control plane connection between the control unit and the user unit but no data plane connection. In this scenario, the first user unit corresponding to the terminal (i.e., used to serve the terminal) can directly restore the RRC connection with the terminal upon receiving a request from an inactive terminal to restore the RRC connection. This eliminates the need for complex signaling procedures between the user unit and the control unit, reducing the RRC restoration latency and thereby improving the user's service QoE.

[0175] At the same time, the control unit can interact with the user unit to establish or modify the terminal context and establish a data channel between the user unit and the core network, thus ensuring accurate data transmission between the core network and the user unit.

[0176] The following description, with reference to application examples, will provide a more detailed description of this disclosure.

[0177] Based on the network architecture shown in Figure 6, this disclosure presents an application example of a fast activation method for the RRC inactive state, as shown in Figure 9, including the following steps:

[0178] Step 901: The UPF (i.e., the core network mentioned above) transmits downlink data to the eDU (i.e., the first user unit mentioned above);

[0179] Step 902: After receiving downlink data, the eDU determines that the UE (which can also be understood as the user, i.e. the terminal mentioned above) corresponding to the downlink data is in an inactive state, caches the downlink data, and triggers the state transition process (i.e., the RRC recovery process), i.e., executes step 902.

[0180] Specifically, when the eDU receives downlink data through the service link with the core network, it can buffer the received downlink data and trigger a UE paging process to switch the UE from the inactive state to the connection state.

[0181] Step 903: eDU paging of UE in inactive state;

[0182] Step 904: After receiving a paging message, the UE in inactive state sends an RRC Resume Request message to the eDU to request the restoration of the RRC connection;

[0183] The RRCResumeRequest message may carry identification information such as the UE's I-RNTI, and the I-RNTI message contains the identification information of the eDU;

[0184] Step 905: After receiving the RRCResumeRequest message, the eDU uses the carried I-RNTI to determine the UE's context information in the current eDU, generates an RRCResume message using the UE's context information, and sends the RRCResume message to the UE to trigger the recovery of SRB and DRB.

[0185] In practical applications, after the eDU generates the RRCResume message, it first performs integrity protection and encryption processing before sending the RRCResume message to the UE.

[0186] Step 906: The eDU transmits the buffered downlink data to the UE.

[0187] In practical applications, step 906 can be executed without waiting for the UE to send an RRCResumeComplete message to the eDU. It can also be understood that step 905 can be executed in parallel with step 906, thereby restoring the transmission of uplink and downlink data more quickly.

[0188] Of course, a UE in an inactive state may move, which could cause the I-RNTI message to contain eDU identification information that differs from the current eDU identification information. In this case, this disclosure application example also proposes a fast activation method for RRC inactive state, as shown in Figure 10, including the following steps:

[0189] Step 1001: The UE in the inactive state sends an RRREsumeRequest message to the current eDU to request the restoration of the RRC connection; wherein, the RRREsumeRequest message carries the I-RNTI assigned to the UE by the last service eDU, and the I-RNTI contains the identifier of the last service eDU.

[0190] In practical applications, if the current eDU determines that the eDU identifier contained in the I-RNTI is different from its own eDU identifier, it will execute step 1002 to obtain the UE's context information.

[0191] Step 1002: The current eDU sends a DU RETRIVE UE CONTEXT REQUEST message to the previous serving eDU to request the UE's context information; wherein, the DU RETRIVE UE CONTEXT REQUEST message contains the UE's I-RNTI;

[0192] Step 1003: After the previous serving eDU receives the DU RETRIVE UE CONTEXT REQUEST message, it looks up the context information of the UE corresponding to the I-RNTI and sends a DU RETRIVE UE CONTEXT RESPONSE message to the current eDU. The DU RETRIVE UE CONTEXT RESPONSE message carries the context information of the found UE.

[0193] Step 1004: After receiving the context information from the UE, the current eDU generates an RRC Resume message using the UE's context information and sends the RRC Resume message to the UE to trigger the recovery of SRB and DRB; and receives the RRC Resume Complete message sent by the UE to inform the current eDU that the RRC connection recovery is complete; then proceed to step 1005.

[0194] Step 1005: The current eDU sends a DU UE CONTEXT RELEASE message to the previous serving eDU to release the context of the UE in the previous serving eDU;

[0195] Step 1006: After receiving the UE's context information, the current eDU sends a DU UE CONTEXT SETUP REQUST message to the eCU to request the eCU to establish the UE's context, and receives a DU UE CONTEXT SETUP RESPONSE message from the eCU to confirm that the eCU has completed the UE's context establishment; or, the current eDU sends a DU UE CONTEXT MODIFY REQUST message to the eCU to request the eCU to modify the UE's context, and receives a DU UE CONTEXT MODIFY RESPONSE message from the eCU to confirm that the eCU has completed the UE's context modification.

[0196] In practical applications, the DU UE CONTEXT SETUP REQUST message or the DU UE CONTEXT MODIFY REQUST message carries the DL TEID corresponding to the data channel between the current eDU and UPF; simultaneously, the DU UE CONTEXT SETUP RESPONSE message or the DU UE CONTEXT MODIFY RESPONSE message carries the UL TEID corresponding to the data channel between the current eDU and UPF. Thus, by executing step 105, after the current eDU and eCU interact, on the one hand, the current eCU can establish or modify the UE context; on the other hand, a data channel between the current eDU and UPF can be established.

[0197] In practical applications, steps 1004 and 1006 can be executed simultaneously (or in a parallel manner) or sequentially. When steps 1004 and 1006 are executed sequentially, the specific execution order can be set according to actual needs.

[0198] The solution provided in this application example proposes a conversion process for a terminal from RRC Inactive state (i.e., inactive state) to RRC Connected state (i.e., connection state), which has the following three major advantages compared with related technical solutions:

[0199] Lower signaling latency and fewer signaling messages reduce the latency of the terminal transitioning from RRC Inactive to RRC Connected state (i.e., RRC connection recovery latency);

[0200] Lower user plane latency: Downlink data for inactive UEs is cached in the eDU instead of the CU-UP. Therefore, after the RRC connection is restored, the eDU can directly activate the data link and send downlink data to the UE, achieving extremely simplified data processing. This reduces the data link establishment process between the DU and CU-UP, lowers data plane latency, and improves the user's service QOE.

[0201] The eDU can send downlink data to the UE without waiting to receive the RRRCResumeComplete message, meaning that data and signaling can be processed concurrently, thereby reducing user plane latency.

[0202] To implement the method provided by the first user unit side in the embodiments of this disclosure, this disclosure also provides a connection restoration device, disposed on the first user unit of an access network. The access network includes a control unit and one or more user units, the one or more user units including the first user unit. The user unit is at least used to maintain the user plane connection between the access network and the core network. There are control plane connections and user plane connections between the user units. The control unit is at least used to maintain the control plane connection between the access network and the core network. There is a control plane connection between the control unit and the user units, but no data plane connection. As shown in FIG11, the device includes:

[0203] The first receiving unit 1101 is used to receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection;

[0204] The connection unit 1102 is used to complete the RRC connection restoration with the terminal.

[0205] In one embodiment, the first information includes I-RNTI, and the connection unit 1102 is specifically used for:

[0206] Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the first user unit;

[0207] The context information of the terminal is retrieved locally.

[0208] In one embodiment, the first information includes I-RNTI; the one or more user units further include a second user unit, and the connection unit 1102 is specifically used for:

[0209] Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the second user unit;

[0210] Send third information to the second user unit, the third information being used to request the acquisition of the terminal's context information;

[0211] Receive the context information of the terminal sent by the second user unit.

[0212] In one embodiment, the device may further include:

[0213] The first sending unit is used to send fourth information to the control unit, the fourth information being used to request the control unit to establish or modify the context of the terminal;

[0214] The first receiving unit 1101 is further configured to:

[0215] The system receives a fifth message sent by the control unit. The fifth message is used to indicate that the context of the terminal has been established or modified. The fourth and fifth messages are also used to establish a data channel between the first user unit and the core network.

[0216] In an embodiment, the first transmitting unit is further configured to:

[0217] A sixth message is sent to the second user unit, the sixth message being used to instruct the second user unit to release the context information of the terminal.

[0218] In an embodiment, the first transmitting unit is further configured to:

[0219] Upon detecting downlink traffic from the core network targeting the terminal, the downlink traffic is buffered and the terminal is paged to trigger the terminal to send the first information.

[0220] In practical applications, the first receiving unit 1101 and the first sending unit can be implemented by the communication interface in the connection restoration device, and the connection unit 1102 can be implemented by the processor in the connection restoration device in combination with the communication interface.

[0221] To implement the control unit side method of this disclosure embodiment, this disclosure embodiment also provides a connection restoration device, disposed on the control unit of an access network. The access network further includes one or more user units, each user unit including a first user unit. Each user unit is at least used to maintain the user plane connection between the access network and the core network. There are control plane connections and user plane connections between the user units. The control unit is at least used to maintain the control plane connection between the access network and the core network. There is a control plane connection between the control unit and the user units, but no data plane connection. As shown in FIG12, the device includes:

[0222] The second receiving unit 1201 is used to receive fourth information sent by the first user unit. The fourth information is used to request the establishment or modification of the context information of the terminal in the control unit. The terminal includes a terminal requesting the restoration of the RRC connection.

[0223] The second sending unit 1202 is used to send fifth information to the first user unit. The fifth information indicates that the control unit has completed the establishment or modification of the terminal's context information. The fourth and fifth information are also used to establish a data channel between the first user unit and the core network.

[0224] In one embodiment, the fifth information includes first related information for establishing a data channel between the first user unit and the core network, and the second sending unit 1202 is further configured to:

[0225] Send the first relevant information to the core network;

[0226] The second receiving unit 1201 is further configured to:

[0227] The system receives second relevant information sent by the core network for establishing a data channel between the first user unit and the core network, and the second relevant information is included in the fifth information sent to the first user unit.

[0228] In practical applications, the second receiving unit 1201 and the second sending unit 1202 can be implemented by the processor in the connection recovery device combined with the communication interface.

[0229] It should be noted that the connection restoration device provided in the above embodiments is only illustrated by the division of the above-described program units. In practical applications, the above processing can be assigned to different program units as needed, that is, the internal structure of the device can be divided into different program units to complete all or part of the processing described above. In addition, the connection restoration device and the connection restoration method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0230] Based on the hardware implementation of the above program modules, and in order to implement the method on the first user unit side of this disclosure embodiment, this disclosure embodiment also provides a first user unit. The first user unit belongs to an access network, the access network includes a control unit and one or more user units, the one or more user units include the first user unit, the user unit is at least used to maintain the user plane connection between the access network and the core network, there is a control plane connection and a user plane connection between the user units, the control unit is at least used to maintain the control plane connection between the access network and the core network, there is a control plane connection between the control unit and the user unit but no data plane connection, as shown in FIG13, the first user unit 1300 includes:

[0231] The first communication interface 1301 is capable of exchanging information with other devices (such as the control unit of the access network);

[0232] The first processor 1302 is connected to the first communication interface 1301 to enable information interaction with the control unit of the access network, and to execute the methods provided by one or more technical solutions on the first user unit side when running a computer program;

[0233] The computer program is stored in the first memory 1303.

[0234] Specifically, the first communication interface 1301 is used for:

[0235] Receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection;

[0236] The first processor 1302 is used for:

[0237] The RRC connection is restored with the terminal through the first communication interface.

[0238] In one embodiment, the first processor 1302 is specifically used for:

[0239] Using the first information, the context information of the terminal is obtained;

[0240] Using the context information of the terminal, the RRC connection is restored with the terminal through the first communication interface.

[0241] In one embodiment, the first information includes I-RNTI; the first processor 1302 is specifically used for:

[0242] Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the first user unit;

[0243] The context information of the terminal is retrieved locally.

[0244] In one embodiment, the first information includes I-RNTI; the one or more user units further include a second user unit, and the first processor 1302 is specifically used for:

[0245] Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the second user unit;

[0246] Send third information to the second user unit, the third information being used to request the acquisition of the terminal's context information;

[0247] Receive the context information of the terminal sent by the second user unit.

[0248] In one embodiment, the first communication interface 1301 is further configured to:

[0249] Send a fourth message to the control unit, the fourth message being used to request the control unit to establish or modify the context of the terminal;

[0250] The system receives a fifth message sent by the control unit. The fifth message is used to indicate that the context of the terminal has been established or modified. The fourth and fifth messages are also used to establish a data channel between the first user unit and the core network.

[0251] In one embodiment, the first communication interface 1301 is further configured to:

[0252] A sixth message is sent to the second user unit, the sixth message being used to instruct the second user unit to release the context information of the terminal.

[0253] In one embodiment, the first communication interface 1301 is further configured to:

[0254] Upon detecting downlink traffic from the core network targeting the terminal, the downlink traffic is buffered and the terminal is paged to trigger the terminal to send the first information.

[0255] It should be noted that the specific processing procedures of the first processor 1302 and the first communication interface 1301 can be understood by referring to the above method.

[0256] Of course, in practical applications, the various components in the first user unit 1300 are coupled together through the bus system 1304. It can be understood that the bus system 1304 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 1304 also includes a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as bus system 1304 in Figure 13.

[0257] The first memory 1303 in this embodiment is used to store various types of data to support the operation of the first user unit 1300. Examples of such data include any computer program used to operate on the first user unit 1300.

[0258] The methods disclosed in the above embodiments of this disclosure can be applied to the first processor 1302, or implemented by the first processor 1302. The first processor 1302 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the integrated logic circuit of the hardware or by instructions in the form of software in the first processor 1302. The first processor 1302 may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The first processor 1302 can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this disclosure. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the methods disclosed in the embodiments of this disclosure can be directly manifested as being executed by a hardware decoding processor, or being executed by a combination of hardware and software modules in the decoding processor. The software modules may be located in a storage medium, which is located in the first memory 1303. The first processor 1302 reads the information in the first memory 1303 and completes the steps of the aforementioned method in conjunction with its hardware.

[0259] In an exemplary embodiment, the first user unit 1300 may be implemented by one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components to perform the aforementioned method.

[0260] Based on the hardware implementation of the above program modules, and in order to implement the method on the control unit side of this disclosure embodiment, this disclosure embodiment also provides a control unit, the control unit belonging to an access network, the access network further including one or more user units, the one or more user units including a first user unit, the user unit being at least used to maintain the user plane connection between the access network and the core network, the user units having control plane connection and user plane connection, the control unit being at least used to maintain the control plane connection between the access network and the core network, the control unit having control plane connection and no data plane connection with the user units, as shown in FIG14, the control unit 1400 includes:

[0261] The second communication interface 1401 is capable of exchanging information with other devices (such as the first user unit of the access network);

[0262] The second processor 1402 is connected to the second communication interface 1401 to enable information interaction with the first user unit of the access network, and to execute the methods provided by one or more technical solutions on the control unit side when running a computer program.

[0263] The computer program is stored in the second memory 1403.

[0264] Specifically, the second processor 1402 is used for:

[0265] The second communication interface 1401 receives fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including a terminal requesting the restoration of the RRC connection; and sends fifth information to the first user unit, the fifth information indicating that the control unit has completed the establishment or modification of the terminal's context information, the fourth and fifth information also being used to establish a data channel between the first user unit and the core network.

[0266] In one embodiment, the fifth information includes first related information for establishing a data channel between the first user unit and the core network, and the second processor 1402 is used for:

[0267] The system sends the first relevant information to the core network through the second communication interface 1401; and receives the second relevant information sent by the core network for establishing a data channel between the first user unit and the core network, wherein the second relevant information is included in the fifth information sent to the first user unit.

[0268] It should be noted that the specific processing procedures of the second processor 1402 and the second communication interface 1401 can be understood by referring to the above method.

[0269] Of course, in practical applications, the various components in the control unit 1400 are coupled together through the bus system 1404. It can be understood that the bus system 1404 is used to achieve communication between these components. In addition to the data bus, the bus system 1404 also includes a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as bus system 1404 in Figure 14.

[0270] The second memory 1403 in this embodiment of the present disclosure is used to store various types of data to support the operation of the control unit 1400. Examples of such data include any computer programs used to operate on the control unit 1400.

[0271] The methods disclosed in the above embodiments of this disclosure can be applied to, or implemented by, the second processor 1402. The second processor 1402 may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by the integrated logic circuitry of the hardware or by instructions in the form of software within the second processor 1402. The second processor 1402 may be a general-purpose processor, a DSP, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The second processor 1402 can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this disclosure. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the methods disclosed in the embodiments of this disclosure can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software modules may be located in a storage medium, specifically a second memory 1403. The second processor 1402 reads information from the second memory 1403 and, in conjunction with its hardware, completes the steps of the aforementioned method.

[0272] In an exemplary embodiment, the control unit 1400 may be implemented by one or more ASICs, DSPs, PLDs, CPLDs, FPGAs, general-purpose processors, controllers, MCUs, microprocessors, or other electronic components to perform the aforementioned method.

[0273] It is understood that the memories (first memory 1303, second memory 1403) in the embodiments of this disclosure can be volatile memory or non-volatile memory, or both. Specifically, the non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM); the magnetic surface memory can be disk storage or magnetic tape storage. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Synchronous Static Random Access Memory (SSRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), SyncLink Dynamic Random Access Memory (SLDRAM), and Direct Rambus Random Access Memory (DRRAM).The memories described in the embodiments of this disclosure are intended to include, but are not limited to, these and any other suitable types of memories.

[0274] In exemplary embodiments, this disclosure also provides a storage medium, namely a computer storage medium, specifically a computer-readable storage medium. For example, it may include a first memory 1303 storing a computer program, which can be executed by a first processor 1302 of a first user unit 1300 to complete the steps described in the aforementioned first user unit-side method. Another example is a second memory 1403 storing a computer program, which can be executed by a second processor 1402 of a control unit 1400 to complete the steps described in the aforementioned control unit-side method. The computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, Flash Memory, magnetic surface memory, optical disc, or CD-ROM.

[0275] In an exemplary embodiment, this disclosure also provides a computer program product, including a computer program that can be executed by a first processor 1302 of a first user unit 1300 to complete the steps described in the aforementioned first user unit-side method, or the computer program can be executed by a second processor 1402 of a control unit 1400 to complete the steps described in the aforementioned control unit-side method.

[0276] To implement the method provided in this disclosure, this disclosure also provides a connection restoration system, as shown in FIG15. The system includes: a user unit 1501 of the access network, a control unit 1502 of the access network, and a core network 1503. The user unit 1501 of the access network includes at least a first user unit 15011.

[0277] It should be noted that the specific processing procedures of the user unit 1501, the control unit 1502, and the core network 1503 of the access network have been described in detail above and will not be repeated here.

[0278] It should be noted that terms such as "first" and "second" are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0279] Furthermore, the technical solutions described in the embodiments of this disclosure can be combined arbitrarily without conflict.

[0280] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the scope of protection of this disclosure.

Claims

1. A connection restoration method applied to a first user unit of an access network, the access network comprising a control unit and one or more user units, the one or more user units including the first user unit, the user units being at least used to maintain a user plane connection between the access network and a core network, the user units having a control plane connection and a user plane connection, the control unit being at least used to maintain a control plane connection between the access network and the core network, the control unit having a control plane connection and the user units having no data plane connection, the method comprising: Receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the Radio Resource Control (RRC) connection; The RRC connection was restored with the terminal.

2. The method of claim 1, wherein, The step of restoring the RRC connection with the terminal includes: Using the first information, the context information of the terminal is obtained; Using the context information of the terminal, the RRC connection is restored with the terminal.

3. The method of claim 2, wherein, The first information includes an inactive wireless network temporary identifier (I-RNTI); obtaining the terminal's context information using the first information includes: Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the first user unit; The context information of the terminal is retrieved locally.

4. The method of claim 2, wherein, The first information includes I-RNTI; the one or more user units further include a second user unit, and obtaining the context information of the terminal using the first information includes: Using the I-RNTI, it is determined that the user unit that allocated the I-RNTI includes the second user unit; Send third information to the second user unit, the third information being used to request the acquisition of the terminal's context information; Receive the context information of the terminal sent by the second user unit.

5. The method of claim 4, wherein, The method further includes: Send a fourth message to the control unit, the fourth message being used to request the control unit to establish or modify the context of the terminal; The system receives a fifth message sent by the control unit. The fifth message is used to indicate that the context of the terminal has been established or modified. The fourth and fifth messages are also used to establish a data channel between the first user unit and the core network.

6. The method of claim 4, wherein, The method further includes: A sixth message is sent to the second user unit, the sixth message being used to instruct the second user unit to release the context information of the terminal.

7. The method according to any one of claims 1 to 6, wherein, Upon detecting downlink traffic from the core network targeting the terminal, the downlink traffic is buffered and the terminal is paged to trigger the terminal to send the first information.

8. A connection restoration method applied to a control unit of an access network, the access network further comprising one or more user units, the one or more user units comprising a first user unit, the user units being at least used to maintain a user plane connection between the access network and a core network, the user units having a control plane connection and a user plane connection, the control unit being at least used to maintain a control plane connection between the access network and the core network, the control unit having a control plane connection and the user units having no data plane connection, the method comprising: The system receives fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including a terminal requesting the restoration of the RRC connection; The control unit sends a fifth message to the first user unit, the fifth message indicating that the control unit has completed the establishment or modification of the terminal's context information, and the fourth and fifth messages are also used to establish a data channel between the first user unit and the core network.

9. The method of claim 8, wherein, The fifth information includes first relevant information for establishing a data channel between the first user unit and the core network, and the method further includes: Send the first relevant information to the core network; The system receives second related information sent by the core network for establishing a data channel between the first user unit and the core network, and the second related information is included in the fifth information sent to the first user unit.

10. A connection restoration apparatus, disposed in a first user unit of an access network, the access network comprising a control unit and one or more user units, the one or more user units including the first user unit, the user units being at least used to maintain a user plane connection between the access network and a core network, the user units having a control plane connection and a user plane connection, the control unit being at least used to maintain a control plane connection between the access network and the core network, the control unit having a control plane connection and no data plane connection with the user units, comprising: The first receiving unit is configured to receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection; A connection unit is used to restore the RRC connection with the terminal.

11. A connection restoration device, disposed in a control unit of an access network, the access network further comprising one or more user units, the one or more user units comprising a first user unit, the user units being at least used to maintain a user plane connection between the access network and a core network, the user units having a control plane connection and a user plane connection, the control unit being at least used to maintain a control plane connection between the access network and the core network, the control unit having a control plane connection with the user units but no data plane connection, comprising: The second receiving unit is configured to receive fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the terminal's context information in the control unit, the terminal including a terminal requesting the restoration of the RRC connection; The sending unit is used to send fifth information to the first user unit. The fifth information indicates that the control unit has completed the establishment or modification of the terminal's context information. The fourth and fifth information are also used to establish a data channel between the first user unit and the core network.

12. A first user unit, the first user unit belonging to an access network, the access network including a control unit and one or more user units, the one or more user units including the first user unit, the user unit being at least used to maintain a user plane connection between the access network and a core network, the user units having a control plane connection and a user plane connection, the control unit being at least used to maintain a control plane connection between the access network and the core network, the control unit having a control plane connection and no data plane connection with the user units, comprising: The first communication interface is used to receive first information sent by a terminal in an inactive state, the first information being used to request the restoration of the RRC connection; A first processor is configured to restore the RRC connection with the terminal via the first communication interface.

13. A control unit, the control unit belonging to an access network, the access network further comprising one or more user units, the one or more user units including a first user unit, the user units being at least used to maintain a user plane connection between the access network and a core network, the user units having a control plane connection and a user plane connection, the control unit being at least used to maintain a control plane connection between the access network and the core network, the control unit having a control plane connection with the user units but no data plane connection, comprising: A second processor and a second communication interface; wherein... The second communication interface is used to receive fourth information sent by the first user unit, the fourth information being used to request the establishment or modification of the context information of a terminal in the control unit, the terminal including a terminal requesting the restoration of an RRC connection; and to send fifth information to the first user unit, the fifth information indicating that the control unit has completed the establishment or modification of the context information of the terminal, the fourth information and the fifth information also being used to establish a data channel between the first user unit and the core network.

14. A subscriber unit comprising: A first processor and a first memory for storing computer programs capable of running on the processor. Wherein, when the first processor is used to run the computer program, it performs the steps of the method according to any one of claims 1 to 7.

15. A control unit comprising: A second processor and a second memory for storing computer programs that can run on the processor. Wherein, when the second processor is used to run the computer program, it performs the steps of the method according to any one of claims 8 to 9.

16. A storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 7, or implements the steps of the method according to any one of claims 8 to 9.

17. A computer program product comprising a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 7, or implements the steps of the method according to any one of claims 8 to 9.

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