CN115134948A

CN115134948A - Method and device for recovering load, core network element and storage medium

Info

Publication number: CN115134948A
Application number: CN202110315006.8A
Authority: CN
Inventors: 由县卫
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2021-03-24
Filing date: 2021-03-24
Publication date: 2022-09-30

Abstract

The embodiment of the application provides a method and a device for recovering a bearer, a core network element and a storage medium, and relates to the technical field of communication. The method for recovering the bearer is executed by a core network element, and the method includes: receiving an initial User Equipment (UE) message sent by a base station, and determining a UE context according to a non-access stratum (NAS) message in the initial UE message; if the UE context indicates that the connection state of the UE is an abnormal access state, initiating a UE context release process to the base station; and when the NAS message indicates that the session type of the UE is not a first type, executing a bearer recovery process, wherein the first type is used for indicating that the UE does not have uplink service in a request state and no bearer is established between the UE and the core network. The embodiment of the application solves the problem that the downlink service is interrupted due to the fact that the load is not recovered when the network is abnormal in the related technology.

Description

Method and device for recovering load, core network element and storage medium

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for recovering a bearer, a core network element, and a storage medium.

Background

Under the condition of network abnormality such as radio link abnormal release or NAS layer automatic chain breakage, the UE can reinitiate the registration process so as to recover the radio link.

However, in the above radio link recovery process, there may be a case where only the signaling plane link between the UE and the core network is recovered, but the user plane link between the UE and the core network is not recovered, and accordingly, the bearer is not recovered, and if there is downlink service at this time, the downlink service is interrupted, so that part of data is lost, and finally, user perception is poor.

Disclosure of Invention

Embodiments of the present application provide a method and an apparatus for recovering a bearer, a core network element, and a storage medium, which can solve the problem in the related art that a downlink service is interrupted due to the failure of bearer recovery when a network is abnormal. The technical scheme is as follows:

according to an aspect of an embodiment of the present application, a method for recovering a bearer, performed by a core network element, includes: receiving an initial User Equipment (UE) message sent by a base station, and determining a UE context according to a non-access stratum (NAS) message in the initial UE message; if the UE context indicates that the connection state of the UE is an abnormal access state, initiating a UE context release process to the base station; and when the NAS message indicates that the session type of the UE is not a first type, executing a bearer recovery process, wherein the first type is used for indicating that the UE does not have uplink service in a request state and no bearer is established between the UE and the core network.

According to an aspect of an embodiment of the present application, a core network element includes: a memory, a transceiver, and a processor; wherein the memory is used for storing the computer program; a transceiver for transceiving data under the control of the processor; a processor for reading the computer program in the memory and performing the steps of: receiving an initial User Equipment (UE) message sent by a base station, and determining a UE context according to a non-access stratum (NAS) message in the initial UE message; if the UE context indicates that the connection state of the UE is an abnormal access state, initiating a UE context release process to the base station; and when the NAS message indicates that the session type of the UE is not a first type, executing a bearer recovery process, wherein the first type is used for indicating that the UE does not have uplink service in a request state and no bearer is established between the UE and the core network.

In one possible embodiment, the NAS message comprises a registration message.

In one possible embodiment, the processor is further configured to perform the steps of: extracting a registration message from the initial UE message; if the registration message indicates that the UE is initially registered, creating a UE context; otherwise, obtaining the UE context.

In one possible embodiment, the NAS message comprises a service request message.

In one possible embodiment, the processor is further configured to perform the steps of: extracting a service request message from the initial UE message; in response to the service request message, a UE context is acquired.

In one possible embodiment, the processor is further configured to perform the steps of: initiating an authentication security procedure to the UE; and when the UE authentication is successful, determining whether the connection state of the UE is an abnormal access state or not according to the context of the UE.

In one possible embodiment, the processor is further configured to perform the steps of: acquiring a local context; and if the UE context indicates that the connection state of the UE is the abnormal access state and the local context indicates that the connection state of the UE is the normal access state, determining that the connection state of the UE is the abnormal access state.

In one possible embodiment, the processor is further configured to perform the steps of: and sending a UE release message to the base station, wherein the UE release message is used for indicating the base station to release the local resources but not informing the UE of releasing the resources.

In one possible embodiment, the processor is further configured to perform the steps of: and receiving a release completion message sent by the base station, wherein the release completion message is used for indicating that the base station has completed the release of the local resources according to the UE release message.

In one possible embodiment, the processor is further configured to perform the steps of: and determining the session type of the UE according to the uplink service state and the bearing state of the UE indicated by the NAS message.

In one possible embodiment, the processor is further configured to perform the steps of: determining whether the NAS message carries a first message, wherein the first message is used for indicating that the uplink service state of the UE is a request state; if not, determining whether the NAS message carries a second message, wherein the second message is used for indicating that the bearing state of the UE is an establishment state; if not, determining that the session type of the UE is the first type.

In one possible embodiment, the processor is further configured to perform the steps of: and if the NAS message carries the first message, determining that the session type of the UE is a second type, wherein the second type is used for indicating that the UE has the uplink service in the request state.

In one possible embodiment, the processor is further configured to perform the steps of: and if the NAS message does not carry the first message but carries the second message, determining that the session type of the UE is a third type, wherein the third type is used for indicating that the UE does not have the uplink service in the request state but establishes a bearer with a core network once.

In one possible embodiment, the processor is further configured to perform the steps of: acquiring a local context, and determining a local bearing state according to the local context; and if the local bearer state indicates that a bearer is established between the UE and the core network, determining that the session type of the UE is a third type.

In one possible embodiment, the first message comprises an upstream Data Status message.

In one possible embodiment, the second message comprises a protocol data unit Session Status PDU Session Status message.

In one possible embodiment, the core network element comprises an access and mobility management function AMF.

In one possible embodiment, the processor is further configured to perform the steps of: and the AMF initiates a bearer update request to a Session Management Function (SMF) so that the SMF performs session management on the recovered session bearer.

According to an aspect of an embodiment of the present application, an apparatus for recovering a bearer, applied to a network element of a core network, includes: the message receiving module is used for receiving an initial User Equipment (UE) message sent by a base station and determining a UE context according to a non-access stratum (NAS) message in the initial UE message; a release initiating module, configured to initiate a UE context release process to the base station if the UE context indicates that the connection state of the UE is an abnormal access state; and the bearer recovery module is used for executing a bearer recovery process when the NAS message indicates that the session type of the UE is not a first type, wherein the first type is used for indicating that the UE does not have the uplink service in the request state and no bearer is established between the UE and the core network.

According to an aspect of embodiments of the present application, a storage medium has a computer program stored thereon, and the computer program, when executed by a processor, implements a method of restoring a bearer as described above.

The beneficial effect that technical scheme that this application provided brought is:

in the above technical solution, after receiving an initial UE message sent by a base station, a core network element determines a UE context according to an NAS message in the initial UE message, and when the UE context indicates that a connection state of the UE is an abnormal access state, initiates a UE context release process to the base station, and when the NAS message indicates that a session type of the UE is not a first type, executes a bearer recovery procedure, that is, comprehensively determines whether to recover a bearer between the UE and the core network in combination with the connection state and the session type of the UE, so as to ensure that the bearer can be recovered to continue transmitting uplink and downlink services when an uplink service and/or a downlink service in a request state exist between the UE and the base station, thereby effectively solving a problem of downlink service interruption caused by bearer non-recovery when a network is abnormal in the related art.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the description of the embodiments of the present application will be briefly described below.

FIG. 1 is a schematic illustration of an implementation environment according to the present application;

fig. 2 is a flow diagram illustrating a method of recovering a bearer in accordance with an example embodiment;

FIG. 3 is a flow chart of one embodiment of step 21 in the corresponding embodiment of FIG. 2;

FIG. 4 is a flow chart of step 21 in another embodiment of the corresponding embodiment of FIG. 2;

FIG. 5 is a flow chart for one embodiment of step 22 in the corresponding embodiment of FIG. 2;

fig. 6 is a flow diagram illustrating another method of recovering a bearer in accordance with an example embodiment;

FIG. 7 is a flowchart of one embodiment of step 24 of the corresponding embodiment of FIG. 6;

FIG. 8 is a flow diagram illustrating another method of recovering a bearer in accordance with an example embodiment;

fig. 9 is a flow diagram illustrating another method of recovering a bearer in accordance with an example embodiment;

FIG. 10 is a flow diagram illustrating another method of recovering a bearer in accordance with an example embodiment;

fig. 11 is a block diagram illustrating an apparatus for recovering a bearer in accordance with an exemplary embodiment;

fig. 12 is a block diagram illustrating a core network element in accordance with an example embodiment.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present application and are not construed as limiting the present application.

As used herein, the singular forms "a", "an", "the" and "the" include the plural forms as well, and the plural forms "a", "an" and "the" refer to two or more, and other words of similar import, unless expressly stated otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. The term "and/or" as used herein describes an association relationship that associates objects, meaning that there may be three relationships, e.g., A and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

The following is a description and explanation of several terms involved in the present application:

RAN, English spelling is Radio Access Network, and Chinese meaning is wireless Access Network. For example, the method is applied to a Radio access network of a 5G New Radio (NR) system.

NAS, english full spelling is Non-Access Stratum, chinese means Non-Access Stratum, and as (Access Stratum) refers to Access Stratum.

AMF, English full spelling is Access and Mobility Management Function, Chinese meaning is Access and Mobility Management Function, and is responsible for terminal equipment Access core network and Mobility Management.

SMF, English spelling is Session Management Function, and Chinese meaning is Session Management Function, and is responsible for interacting with separated data plane, creating, updating and deleting PDU Session.

PDU, English full spelling is Protocol Data Unit, Chinese meaning is Protocol Data Unit.

PDU Session Status, which is a chinese meaning of a protocol data unit Session state, is used to indicate that a bearer is established between the UE and the core network, and optionally included in a registration message or a service request message.

Uplink Data Status, in chinese meaning, is an Uplink Data state, used to indicate that there is Uplink traffic to be transmitted, and optionally included in a registration message or a service request message.

UDM, English spelling is Unified Data Management, Chinese meaning is Unified Data Management function, and is responsible for user identification, signing Data, authentication Data Management, and user service network element registration Management. For example, assuming that the AMF, SMF, etc. currently providing services for the terminal device, when the user switches the currently accessed AMF, the UDM may initiate a logout message to the old AMF, and request the old AMF to delete the user-related information.

The NEF, the English full spelling is the Network Exposure Function, and is responsible for the collection, analysis and recombination of Network capacity and the opening of the Network capacity.

NRF, an english spelling of all is NF replication Function, is responsible for service discovery, receives NF discovery requests from NF instances, and provides information of discovered NF instances to NF instances.

UPF, English spelling is User Plane Function, and Chinese meaning is User Plane Function.

AUSF, English is fully assembled as Authentication Server Function, Chinese means Authentication service Function, and is used for receiving AMF request for terminal equipment identity verification, requesting key to UDM, and transmitting the key issued by UDM to AMF for Authentication processing.

PCF, English full spelling is Policy Control function, Chinese meaning is Policy Control function, which is used to support unified Policy framework to manage network behavior, provide Policy rules to network entity to implement execution, and access subscription information of Unified Data Repository (UDR).

UDR, English spelling is Unified Data replication, and Chinese meaning is Unified Data warehouse function, used for UDM to store subscription Data or read subscription Data, and PCF to store strategy Data or read strategy Data.

NG interface refers to the interface between the radio access network and the core network. The N1 interface refers to a signaling plane interface between the terminal device and the AMF. The N2 interface refers to the signaling plane interface between the RAN and the AMF. The N3 interface refers to the signaling plane interface between the RAN and the UPF. The N4 interface refers to the signaling plane interface between the SMF and the UPF.

In the related art, when the network is normal, for the normal release of the wireless link, the problem of uplink and downlink service interruption does not occur. After the old uplink and downlink services are finished, the wireless link can be released, and after the wireless link is normally released, if new uplink and downlink services exist, the wireless link is reestablished. Specifically, on one hand, if there is a new uplink service, the UE side initiates the uplink service, that is, the UE re-initiates the registration process to recover the signaling plane link or the user plane link; on the other hand, if there is a new downlink service, the network side initiates the downlink service, that is, the core network initiates a paging process to request the UE to recover the signaling plane link or the user plane link.

However, when the network is abnormal, for example, when the UE detects the network abnormality, the radio link between the UE and the core network is abnormally released, or when the NAS layer between the UE and the core network is abnormal, the NAS layer automatically breaks the link by starting the self-detection protection, and at this time, if the old downlink service is not completed, the problem of downlink service interruption may occur.

Specifically, to recover the radio link, the UE re-initiates the registration procedure by means of registration or service request, and the signaling plane link is recovered, and further, the radio link recovery procedure further includes recovering the user plane link:

on one hand, if the old Uplink service is not completed, the UE initiates the Uplink service, that is, the Uplink Data Status message is carried in the registration message or the service request message to recover the user plane link.

On the other hand, if there is no old uplink service that is not completed, the UE only restores the signaling plane link, and at this time, since the UE cannot know whether there is a downlink service and does not initiate the downlink service, the user plane link is not restored, that is, the bearer is not restored, and then, when there is an old downlink service that is not completed, the old downlink service cannot be normally transmitted, and an interruption phenomenon occurs, which further causes a part of data to be lost, and finally causes poor user perception.

As can be seen from the above, the related art still has the defect that the downlink service is interrupted due to the failure of bearer recovery when the network is abnormal.

In view of this, the present application provides a method, an apparatus, a core network element, and a storage medium for recovering a bearer, which are intended to solve the above technical problems in the related art.

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 1 is a schematic diagram of an implementation environment related to a method for recovering a bearer. The implementation environment includes a wireless communication system 100, where the wireless communication system 100 may be a global system for mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS) system, a Long Term Evolution (LTE) system, an LTE frequency Division duplex (frequency Division duplex, FDD) system, an LTE Time Division Duplex (TDD) system, a long term evolution (long term evolution advanced, LTE-a) system, a universal mobile telecommunications system (universal mobile telecommunications system, UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) system, or a New Radio Network (NR) system, and the like.

The wireless communication System 100 includes a user equipment 110 and a network device, which may include an access network device 130 (e.g., a base station) and may further include various core network elements 150, such as an Evolved Packet System (EPS), an AMF, an SMF, a UDM, a NEF, an NRF, a UPF, an AUSF, a PCF, a UDR, and so on.

In particular, the user equipment 110, abbreviated as ue (user equipment), also referred to as a terminal or a terminal device, refers to an electronic device providing voice and/or data connectivity to a user, a handheld device having a wireless connection function, or other processing device connected to a wireless modem, for example, the user equipment 110 may be a mobile terminal device, such as a mobile phone (or referred to as a "cellular" phone), and may also be a computer having a mobile terminal device, such as a portable, pocket, handheld, computer-included, or vehicle-mounted mobile apparatus. In different systems, the names of the user equipments 110 may be different, and may be Personal Communication Service (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), and other devices. The user equipment 110 may also be referred to as a system, a subscriber unit (subscriber unit), a subscriber station (subscriber station), a mobile station (mobile station), a remote station (remote station), an access point (access point), a remote terminal (remote terminal), an access terminal (access terminal), a user terminal (user terminal), a user agent (user agent), and a user device (user device), which are not limited herein.

Access network device 130, which may be referred to as an access point, e.g., a base station, or an electronic device in an access network that communicates over the air-interface, through one or more sectors, with user device 110, or by other names, depending on the particular application. The base station 130 may be configured to exchange received air frames with Internet Protocol (IP) packets as a router between the user equipment 110 and the rest of the access network, which may include an Internet Protocol network. The base station 130 may also coordinate management of attributes for the air interface. For example, the Base Station 130 may be a Base Transceiver Station (BTS) in a Global System for Mobile communications (GSM) or Code Division Multiple Access (CDMA), may be a Base Station (NodeB) in a Wide-band Code Division Multiple Access (WCDMA), may be an evolved Node B (eNB or e-nb) in a Long Term Evolution (LTE) System, may be a 5G Base Station (gbb) in a 5G network architecture (next evolution System), may be a Home evolved Node B (HeNB), a relay Node (relay Node), a Home Base Station (femto), a pico Base Station (pico) and the like, which are not limited herein.

After RRC (Radio Resource Control) connection is established between the ue 110 and the base station 130, the base station 130 can send a Radio bearer setup message to the ue 110 based on the RRC connection, so that the ue 110 completes Radio bearer setup with the base station 130 according to the Radio bearer setup message, and thus the ue 110 can perform uplink and downlink service transmission with the base station 130 based on the currently established Radio bearer.

Referring to fig. 2, an embodiment of the present application provides a method for recovering a bearer, where the method is performed by a core network element. For example, the network element of the core network is an AMF.

As shown in fig. 2, the method may include the steps of:

step 21, receiving an initial UE message sent by the base station, and determining a UE context according to an NAS message in the initial UE message.

First, an initial UE message is used to notify the core network that the UE requests registration.

For a UE, initial attachment (attach) to a base station, or reattachment to another base station as the UE moves, or a need to restore the radio link between the UE and the core network, initiates a registration process with the core network.

In order to initiate a registration process to a core network, a UE first initiates a registration request or a service request to a base station, specifically: a registration message or a service request message is transmitted to the base station.

Correspondingly, after receiving the registration message or the service request message sent by the UE, the base station sends an initial UE message carrying the registration message or the service request message to the core network, so that the core network knows that the UE requests registration according to the received initial UE message.

Based on this, in one possible embodiment, the NAS message in the initial UE message comprises a registration message. In one possible embodiment, the NAS message in the initial UE message comprises a service request message.

As described above, when the network is normal, for the normal release of the wireless link, the problem of uplink and downlink service interruption does not occur, and when the network is abnormal, the problem of downlink service interruption may occur. For this reason, in this embodiment, after determining the NAS message according to the initial UE message, the UE context is further determined according to the NAS message, so as to determine the connection status of the UE.

Wherein the connection state of the UE at least comprises: normal access state, abnormal access state, and unaccessed state. For example, when the radio link between the UE and the core network is released abnormally, or when the NAS layer automatically breaks the link due to the self-detection protection being turned on, the connection status of the UE may be regarded as an abnormal access status.

If the connection state of the UE is a normal access state or a non-access state, which indicates that the radio link does not need to be recovered, the core network executes a relevant processing procedure following the processing procedure described in the specified protocol specification.

On the contrary, if the connection status of the UE is an abnormal access status, which indicates that the radio link between the UE and the core network needs to be recovered, the core network element executes steps 22 to 23, so that the downlink service can be prevented from being interrupted during the radio link recovery process.

It should be noted that the UE context in the embodiments of the present application refers to a radio link established between the UE and the core network, and therefore, the connection state of the UE can be reflected through the UE context.

Now, the following description is made for the UE context determination process with reference to different NAS messages:

fig. 3 illustrates a flowchart for determining UE context based on a registration message. In one possible embodiment, when the NAS message is a registration message, as shown in fig. 3, the UE context determination process may include the following steps:

step 211, extracting the registration message from the initial UE message.

If the registration message indicates that the UE is initially registered, a UE context is created, step 212.

In step 213, if the registration message indicates that the UE is re-registered, the UE context is acquired.

That is, the UE initiates a registration procedure through the registration message, and if the registration procedure is considered as an initial registration procedure of the UE, at this time, since the core network does not store the UE context related to the UE, the core network may create the UE context for the UE.

On the contrary, if the registration process considers that the UE is re-registered, for example, re-attached to another base station as the UE moves, the core network stores the UE context corresponding to the UE, and at this time, the core network can directly obtain the UE context.

Fig. 4 illustrates a flowchart for determining UE context based on a service request message. In one possible embodiment, when the NAS message is a service request message, as shown in fig. 4, the UE context determination process may include the following steps:

step 214, the service request message is extracted from the initial UE message.

Step 215, in response to the service request message, the UE context is acquired.

That is to say, the UE initiates the registration process through the service request message, and at this time, the registration process is not the initial registration process of the UE, so that the core network stores the UE context corresponding to the UE, and the UE context can be directly obtained.

Step 22, if the UE context indicates that the connection status of the UE is an abnormal access status, initiating a UE context release procedure to the base station.

As described above, when the connection state of the UE is an abnormal access state, the connection state may be caused by abnormal release of a radio link between the UE and the core network, or may be caused by automatic disconnection of the NAS layer due to the self-detection protection being turned on. At this time, the core network initiates a UE context release procedure to the base station.

Fig. 5 illustrates a flowchart of a UE context release procedure, and in one possible embodiment, as shown in fig. 5, step 22 may include the following steps:

step 221, sending the UE release message to the base station.

The UE release message is used for instructing the base station to release the local resources but not notifying the UE to release the resources. The local resources include, but are not limited to: radio resources, storage resources, etc. in the base station relating to the UE.

In the process, only the base station notifies the release of the resources, but the UE does not notify the release of the resources, so that the recovery of the user interface link in the recovery process of the wireless link is greatly facilitated, the timely recovery of the load is further fully ensured, and the problem of interruption of the downlink service caused by the untimely recovery of the load is further avoided.

Further, with continued reference to fig. 5, in one possible implementation, step 22 may further include the steps of:

step 222, receiving a release completion message sent by the base station.

The release completion message is used for indicating that the base station has completed the release of the local resources according to the UE release message.

Therefore, the completeness of the bearing recovery flow is fully ensured.

And step 23, when the NAS message indicates that the session type of the UE is not the first type, executing a bearer recovery procedure.

The session type is used for indicating a session state of a session established between the UE and the core network.

As described above, when a network is abnormal, if only a signaling plane link is recovered and a user plane link is not recovered, assuming that an old downlink service exists between a UE and a base station, the old downlink service cannot be completed because the user plane is not connected, the inventor realizes that, in the related art, only consideration is given to whether there is a technical vulnerability of the old uplink service between the UE and the base station, and therefore, the inventor designs to introduce whether to establish a bearer between the UE and a core network as a basis for whether to recover the bearer between the UE and the core network, that is, if a bearer is established between the UE and the core network, which indicates that the old downlink service may exist between the UE and the base station, the bearer between the UE and the core network needs to be recovered. In view of this, in one possible implementation, the session state includes at least: an uplink traffic state and a bearer state.

In one possible implementation, the uplink traffic state at least includes: a request state and an idle state. The request state refers to that the UE has uplink service in the request state; the idle state refers to the absence of uplink traffic in the UE in the request state. It should be noted that the uplink service/downlink service in the request state related to each embodiment of the present application may refer to an uplink service/downlink service being transmitted between the UE and the base station, and may also be an uplink service to be transmitted in the UE or a downlink service to be transmitted in the base station.

In a possible embodiment, the bearer state includes at least: an established state and an unestablished state. The establishment state refers to that a bearer is established between the UE and a core network once, and indicates that downlink service in a request state possibly exists between the UE and the base station; the non-establishment state refers to that no bearer is established between the UE and the core network, which means that there is no downlink service in the request state between the UE and the base station. It should be noted that once a bearer is established between the UE and the core network, the bearer is established between the UE and the core network before the radio link is abnormally released, and then is interrupted due to the abnormal release of the radio link.

It should be noted that the service includes an uplink service and a downlink service. Of course, in other embodiments, the uplink service/downlink service may be further divided into an uplink/downlink voice service and an uplink/downlink data service, which is not limited herein.

Based on this, in one possible implementation, the session types include at least a first type, a second type, and a third type. The first type is used for indicating that the UE does not have uplink service in a request state and no bearer is established between the UE and a core network; the second type is used for indicating that the UE has uplink service in a request state; the third type is used for indicating that the UE does not have uplink service in a request state but once establishes a bearer with a core network.

Then, after determining that the session type of the UE is not the first type, the core network knows that the UE has the uplink service in the request state or that a bearer has been established between the UE and the core network (at this time, a downlink service in the request state may exist between the UE and the base station), and executes a bearer recovery procedure by a network element of the core network in order to avoid interruption of the uplink service and the downlink service, so as to ensure that the uplink service and the downlink service in the request state can be continuously transmitted depending on the recovered bearer.

Compared with the related art, on the one hand, if the UE has the Uplink service in the request state, the method is similar to the radio link recovery process when the network is normal, that is, when the UE re-initiates the registration process to recover the signaling plane link, the Uplink Data Status message is carried in the registration message or the service request message to recover the user plane link, so as to recover the bearer.

On the other hand, if the UE does not have the uplink service in the request state but establishes the bearer with the core network once, at this time, the downlink service in the request state may exist between the UE and the base station, and different from the radio link recovery process when the network is abnormal, the UE will continue to recover the user plane link and further recover the bearer, thereby avoiding downlink service interruption caused by the UE only recovering the signaling plane link when the uplink service does not exist.

Through the process, whether the bearer between the UE and the core network needs to be recovered or not is comprehensively judged by combining the connection state and the session type of the UE, so that the situation that the bearer continues to transmit the uplink service and the downlink service when the uplink service and/or the downlink service in the request state exist between the UE and the base station can be timely recovered, and the problem that the downlink service is interrupted due to the fact that the bearer is not recovered when the network is abnormal in the related technology is effectively solved.

Referring to fig. 6, an embodiment of the present application provides a method for recovering a bearer, where the method is performed by a core network element. For example, the network element of the core network is an AMF.

As shown in fig. 6, the method may include the steps of:

And step 24, determining the session type of the UE according to the uplink service state and the bearing state of the UE indicated by the NAS message.

The uplink service state is used for indicating whether the UE has an uplink service in a request state. The bearer status is used to indicate whether a bearer is established between the UE and the core network, or may be considered to indicate whether there is a possibility that a downlink service in a request state may exist between the UE and the base station. In one possible implementation, the uplink traffic state at least includes: a request state and an idle state. In one possible embodiment, the loading state includes at least: an established state and an unestablished state.

Now, the following description is made on the process of determining the session type of the UE with reference to the uplink service state and the bearer state of the UE:

as shown in fig. 7, in one possible implementation, step 24 may include the steps of:

step 241, determining whether the NAS message carries the first message.

The first message is used for indicating that the uplink service state of the UE is a request state.

In one possible embodiment, the first message comprises an Uplink Data Status message or any other suitable message.

If the NAS message carries the first message, which indicates that the uplink service status of the UE is in the request status, or it can be considered that there is an uplink service in the request status in the UE, step 242 is executed.

Otherwise, if the NAS message does not carry the first message, indicating that the uplink service state of the UE is an idle state, it may also be considered that the UE does not have the uplink service in the request state, and then further determine whether a bearer is established between the UE and the core network, i.e., perform step 243.

In step 242, the session type of the UE is determined to be a second type.

The second type is used for indicating that the UE has uplink service in a request state.

Step 243, determine whether the NAS message carries the second message.

And the second message is used for indicating that the bearing state of the UE is an establishment state.

In one possible embodiment, the second message comprises a PDU Session Status message or any other suitable message.

If the NAS message carries the second message, which indicates that the bearer status of the UE is the establishment status, it may also be considered that the bearer is established between the UE and the core network, and also indicates that there may be downlink traffic in the request status between the UE and the base station, then step 244 is executed.

Otherwise, if the NAS message does not carry the second message, which indicates that the bearer status of the UE is an unrecognized status, it may also be considered that no bearer is established between the UE and the core network, which also indicates that there is no downlink service in the requested status between the UE and the base station, then step 245 is executed.

It should be noted that, without being limited to the above, the NAS message optionally carries the first message/the second message to indicate the uplink service state/bearer state of the UE, in other embodiments, the NAS message optionally carries the first message/the second message to indicate the uplink service state/bearer state of the UE, which is not limited herein.

In step 244, the session type of the UE is determined to be a third type.

And the third type is used for indicating that the UE does not have uplink service in a request state but once establishes a bearer between the UE and the core network.

In order to ensure the necessity of executing the bearer recovery procedure, in a possible embodiment, step 244 may further include the following steps:

and acquiring a local context, and determining a local bearing state according to the local context.

The local context is a UE context stored in the core network. Correspondingly, the local bearer state refers to the bearer state of the UE stored in the core network. The local bearer state at least comprises an established state and an unestablished state, wherein the established state is used for indicating that the bearer is established between the UE and the core network once, and the unestablished state indicates that the bearer is not established between the UE and the core network.

In step 243, the NAS message carries the second message to indicate that the bearer has been established between the UE and the core network, and based on this, if the local bearer status also indicates that the bearer has been established between the UE and the core network, which indicates that both the UE and the core network determine that the bearer has been established between the UE and the core network before the radio link is abnormally released, the session type of the UE is determined to be the third type, so as to avoid misjudgment on whether the bearer has been established between the UE and the core network before the radio link is abnormally released, thereby effectively ensuring the necessity of executing the bearer recovery procedure.

Step 245, determining the session type of the UE as a first type.

As can be seen from the above, when the session type of the UE is determined to be the first type, that is, it indicates that the UE does not have the uplink service in the request state and does not have a bearer established with the core network (or there is no downlink service that may exist in the request state), at this time, the core network element does not need to execute the bearer recovery procedure, and the relevant processing procedure is executed according to the processing procedure described in the specified protocol specification.

Correspondingly, when it is determined that the session type of the UE is the second type or the third type, that is, the UE has the uplink service in the request state, or a bearer has been established between the UE and the core network (there may be the downlink service in the request state between the UE and the base station), the core network element needs to execute a bearer recovery procedure, that is, step 23 is executed.

In the process, the session type of the UE is determined by combining the Uplink service state and the bearer state of the UE, and the session type is used as one of the bases for judging whether the bearer between the UE and the core network needs to be restored, so that the technical loophole of wireless link restoration only through an Uplink Data Status message in the related technology is avoided.

Fig. 8 illustrates a flow chart of a method performed by the AMF to recover a bearer. A method for recovering a bearer according to an embodiment of the present application is now described with reference to fig. 8 as follows:

as shown in fig. 8, the method may include the steps of:

in step 401, after receiving the initial UE message, the AMF determines a NAS message in the initial UE message.

Wherein the NAS message at least comprises: registration messages, service request messages.

Step 402, determining the UE context according to the NAS message.

Specifically, on one hand, when the NAS message is a registration message, if the registration message indicates that the UE is initially registered, the UE context is created; otherwise, when the registration message indicates that the UE is re-registered, the UE context is acquired.

On the other hand, when the NAS message is a service request message, the UE context is acquired in response to the service request message.

In step 403, the AMF determines whether the connection status of the UE is an abnormal access status.

Specifically, if the connection state of the UE is a normal access state or a non-access state, the AMF performs a relevant process flow following a process flow described in a specified protocol specification.

Otherwise, if the connection status of the UE is the abnormal access status, step 404 is executed.

Step 404, initiating a UE context release procedure to the base station.

Specifically, the AMF sends the UE release message to the base station, and correspondingly, after receiving the UE release message, the base station releases only the local resource and does not notify the UE to release the resource according to the indication of the UE release message.

After the base station completes the local resource release, step 405 is performed.

In step 405, the AMF determines whether the NAS message carries an Uplink Data Status message.

Specifically, if the NAS message carries an Uplink Data Status message indicating that the UE has an Uplink service in a request state, it is determined that bearer needs to be restored, that is, step 407 is executed.

Otherwise, if the NAS message does not carry the Uplink Data Status message, which indicates that the UE does not have the Uplink service in the request state, step 406 is executed.

In step 406, the AMF determines whether the NAS message carries a PDU Session Status message.

Specifically, if the NAS message carries a PDU Session Status message indicating that a bearer has been established between the UE and the core network, it may also be understood that a downlink service in a request state may exist between the UE and the base station, and it is determined that the bearer needs to be restored, that is, step 407 is executed.

Otherwise, if the NAS message does not carry the PDU Session Status message, which indicates that no bearer is established between the UE and the core network, that is, there is no downlink service in the request state between the UE and the base station, it is determined that the bearer does not need to be restored. At this time, the AMF executes the relevant process flow following the process flow described in the specified protocol specification.

Step 407, execute the bearer recovery procedure.

Therefore, the bearer recovery between the UE and the core network is realized through the AMF when the network is abnormal, so that the uplink service and/or the downlink service in a request state between the UE and the base station can be fully ensured to be continuously transmitted depending on the recovered bearer, and the problem of downlink service interruption caused by the fact that the bearer is not recovered when the network is abnormal in the related technology is effectively solved.

Referring to fig. 9, a method for recovering a bearer in a wireless communication system 100 in the environment shown in fig. 1 is provided.

In this embodiment, the wireless communication system includes at least: user equipment UE (i.e. terminal), access network equipment RAN (i.e. base station), core network elements AMF and SMF.

As shown in fig. 9, the method may include the steps of:

in step 501, the UE sends a registration message to the RAN.

In step 502, after receiving the registration message, the RAN sends an initial UE message carrying the registration message to the AMF.

In step 503, the AMF initiates an authentication security procedure to the UE after receiving the initial UE message.

It is described herein that the authentication security procedure aims to verify whether the UE has the right to use the relevant resources of the core network.

Step 504, when the UE is successfully authenticated, the AMF determines whether the connection state of the UE is an abnormal access state.

Specifically, if the registration message indicates that the UE is initially registered, a UE context is created; and if the registration message indicates that the UE is re-registered, acquiring the context of the UE, determining the context of the UE in such a way, and further determining the connection state of the UE according to the context of the UE.

If the connection state of the UE is a normal access state or a non-access state, the AMF performs a related process flow following a process flow described in a specified protocol specification.

Otherwise, if the connection status of the UE is an abnormal access status, step 505 is executed.

Further, in order to ensure the necessity of executing the bearer recovery procedure, the determining procedure of the connection status of the UE may include the following steps:

and acquiring a local context, and determining the connection state of the UE in the local according to the local context.

The local context is a UE context stored in the AMF. Correspondingly, the connection status of the UE locally refers to the connection status of the UE stored in the AMF. The connection state of the UE locally at least comprises the following steps: a normal access state, an abnormal access state, and a non-access state.

Based on this, if the connection state of the UE in the local area indicates that the connection state of the UE is the normal access state, and the connection state of the UE determined by the UE context is the abnormal access state, that is, the radio link between the UE and the core network is abnormally released, the connection state of the UE is determined to be the abnormal access state, and then step 505 is executed, so as to avoid misjudgment on whether the connection state of the UE is the abnormal access state, thereby effectively ensuring the necessity of executing the bearer recovery procedure.

Step 505, a UE context release procedure is initiated to the RAN.

Specifically, the AMF sends the UE release message to the RAN, and correspondingly, after receiving the UE release message, the RAN releases only the local resource and does not notify the UE to release the resource according to the indication of the UE release message.

After the RAN completes the local resource release, step 506 is performed.

At step 506, a release complete message is sent to the AMF to notify the AMF that the RAN has completed releasing the local resources.

Step 507, the AMF determines whether to resume the bearer by combining the Uplink Data Status message and the PDU Session Status message.

Specifically, if the registration message carries an Uplink Data Status message indicating that the UE has an Uplink service in the request state, it is determined that bearer needs to be restored, that is, step 508 is executed.

If the registration message does not carry the Uplink Data Status message but carries the PDU Session Status message, which indicates that the UE does not have the Uplink service in the requested state but has established a bearer with the core network, it is determined that the bearer needs to be restored, i.e., step 508 is performed.

Here, in order to ensure the accuracy of the bearer recovery determination process, after determining that the registration message carries the PDU Session Status message, the UE may further determine whether to recover the bearer jointly in combination with the local bearer state indicated by the local context, so as to avoid misjudgment on whether the bearer is established between the UE and the core network before the radio link is abnormally released, thereby effectively ensuring the necessity of executing the bearer recovery procedure.

And if the registration message does not carry the Uplink Data Status message or the PDU Session Status message, which indicates that the UE does not have the Uplink service in the request state and does not establish the bearer with the core network, determining that the bearer does not need to be recovered. At this time, the AMF executes the relevant process flow following the process flow described in the specified protocol specification.

Step 508, a bearer recovery procedure is performed.

The method specifically comprises the following steps: step 5081, the AMF initiates a bearer update request to the SMF to enable the SMF to perform session management on a subsequently recovered session bearer; step 5082, the SMF returns a bearer update response message to the AMF; at step 5083, the relevant process flow is executed following the bearer recovery flow described in the specified protocol specification.

Therefore, the recovery of the bearer is realized, so that the uplink service and/or the downlink service existing between the UE and the RAN in the request state can be continuously transmitted depending on the recovered bearer.

In the above process, the wireless link is restored through the registration message when the network is abnormal, and then the bearer is restored, so that the uplink and downlink services in the request state between the UE and the base station can be sufficiently ensured to be continuously transmitted, and the problem of downlink service interruption caused by the unrecoverable bearer when the network is abnormal in the related art is effectively solved.

Referring to fig. 10, a method for recovering a bearer in a wireless communication system 100 in the environment shown in fig. 1 is provided.

As shown in fig. 10, the method may include the steps of:

in step 601, the UE sends a service request message to the RAN.

In step 602, after receiving the service request message, the RAN sends an initial UE message carrying the service request message to the AMF.

Step 603, the AMF initiates an authentication security procedure to the UE after receiving the initial UE message.

It is described herein that the authentication security procedure aims to verify whether the UE has the right to use the radio resources associated with the core network.

Step 604, when the UE is successfully authenticated, the AMF determines whether the connection state of the UE is an abnormal access state.

Specifically, the UE context is acquired in response to the service request message, and the UE context is determined in this way, so that the connection state of the UE is determined according to the UE context.

Otherwise, if the connection status of the UE is the abnormal access status, step 605 is executed.

The local context is a UE context stored in the AMF. Correspondingly, the connection status of the UE locally refers to the connection status of the UE stored in the AMF.

Based on this, if the connection status of the UE in the local area indicates that the connection status of the UE is the normal access status, and the connection status of the UE determined by the UE context is the abnormal access status, that is, the radio link between the UE and the core network is released abnormally, it is determined that the connection status of the UE is the abnormal access status, and step 605 is further executed.

Step 605, initiate UE context release procedure to RAN.

After the RAN completes the local resource release, step 606 is performed.

Step 606, a release complete message is sent to the AMF to inform the AMF RAN that the release of local resources has been completed.

Step 607, the AMF determines whether to resume the bearer by combining the Uplink Data Status message and the PDU Session Status message.

If the service request message carries an Uplink Data Status message indicating that the UE has an Uplink service in the request state, it is determined that bearer needs to be restored, i.e., step 508 is performed.

If the service request message does not carry the Uplink Data Status message but carries the PDU Session Status message, which indicates that the UE does not have the Uplink service in the requested state but has established a bearer with the core network, it is determined that the bearer needs to be restored, i.e., step 508 is performed.

Here, in order to ensure the accuracy of the bearer recovery determination process, after determining that the service request message carries the PDU Session Status message, the method may further jointly determine whether the bearer needs to be recovered in combination with the local bearer state indicated by the local context, so as to avoid misjudgment on whether the bearer is established between the UE and the core network before the radio link is abnormally released, thereby effectively ensuring the necessity of executing the bearer recovery procedure.

And if the service request message does not carry the Uplink Data Status message or the PDU Session Status message, which indicates that the UE does not have the Uplink service in the request state and does not establish the bearer with the core network, determining that the bearer does not need to be recovered. At this time, the AMF executes the relevant process flow following the process flow described in the specified protocol specification.

At step 608, a bearer recovery procedure is performed.

The method specifically comprises the following steps: step 6081, the AMF initiates a bearer update request to the SMF, so that the SMF can perform session management on the subsequently recovered session bearer; step 6082, the SMF returns a bearer update response message to the AMF; in step 6083, the relevant processing flow is executed following the bearer recovery flow described in the specified protocol specification.

In the process, the wireless link is restored again through the service request message when the network is abnormal, and then the bearer is restored, so that the uplink and downlink services in a request state between the UE and the base station can be sufficiently ensured to be continuously transmitted, and the problem of downlink service interruption caused by the fact that the bearer is not restored when the network is abnormal in the related technology is effectively solved.

The following is an embodiment of an apparatus of the present application, which can be used to execute a method for recovering a bearer according to the present application. For details not disclosed in the embodiments of the apparatus of the present application, please refer to the embodiments of the method for recovering a bearer referred to in the present application.

Referring to fig. 11, an apparatus 900 for recovering a bearer is provided in an embodiment of the present application, and is applied to a network element of a core network.

The apparatus 900 for recovering the bearer includes but is not limited to: a message receiving module 901, a release initiating module 902 and a bearer resuming module 903.

The message receiving module 901 is configured to receive an initial UE message sent by a base station, and determine a UE context according to a non-access stratum NAS message in the initial UE message.

A release initiating module 902, configured to initiate a UE context release process to the base station if the UE context indicates that the connection state of the UE is an abnormal access state.

A bearer recovery module 903, configured to execute a bearer recovery procedure when the NAS message indicates that the session type of the UE is not a first type, where the first type is used to indicate that the UE does not have the uplink service in the request state and no bearer is established between the UE and the core network.

It should be noted that, in the embodiment of the present application, the division of the unit and/or the module is schematic, and is only a logic function division, and another division manner may be available in actual implementation. In addition, functional units and/or modules in various embodiments of the present application may be integrated into one processing unit and/or module, or each unit and/or module may exist alone physically, or two or more units and/or modules may be integrated into one unit and/or module. The integrated units and/or modules may be implemented in the form of hardware, or may be implemented in the form of software functional units and/or modules.

The integrated units and/or modules, if implemented in the form of software functional units and/or modules and sold or used as a stand-alone product, may be stored in a processor readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed by the relevant technology or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

In addition, the apparatus for recovering a bearer and the method for recovering a bearer provided in the above embodiments are based on the same application concept, and because the principles of the method and the apparatus for solving the problem are similar, the apparatus and the method may be implemented by referring to each other, and repeated parts are not described again.

Therefore, whether the bearer between the UE and the core network needs to be restored or not is comprehensively judged by combining the connection state and the session type of the UE, so that the situation that the bearer continues to transmit the uplink service and the downlink service when the uplink service and/or the downlink service in the request state exist between the UE and the base station can be timely restored, and the problem that the downlink service is interrupted due to the fact that the bearer is not restored when the network is abnormal in the related technology is effectively solved.

Fig. 12 is a block diagram illustrating a structure of a network element of a core network according to an example embodiment. For example, the core network element is an AMF.

As shown in fig. 12, the core network element 1100 at least includes: a processor 1110, a memory 1120, and a transceiver 1130.

Among other things, the transceiver 1130 is used to receive and transmit data under the control of the processor 1110.

In FIG. 12, the bus architecture may include any number of interconnected buses and bridges, with one or more processors, represented by the processor 1110, and various circuits, represented by the memory 1120, being linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 1130 may be a number of elements including a transmitter and receiver that provide a unit and/or module for communicating with various other apparatus over a transmission medium including wireless channels, wired channels, fiber optic cables, and the like.

The processor 1110 is responsible for managing the bus architecture and general processing, and the memory 1120 may store data used by the processor 1110 in performing operations.

Alternatively, the processor 1110 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and the processor 1110 may also adopt a multi-core architecture. The processor 1110 and the memory 1120 may also be physically disposed separately.

The processor 1110, by calling the computer program stored in the memory 1120, is configured to execute any one of the methods for recovering a bearer provided by the above embodiments of the present application according to the obtained executable instructions.

Specifically, processor 1110 is configured to perform the steps of: receiving an initial User Equipment (UE) message sent by a base station, and determining a UE context according to a non-access stratum (NAS) message in the initial UE message; if the UE context indicates that the connection state of the UE is an abnormal access state, initiating a UE context release process to the base station; and when the NAS message indicates that the session type of the UE is not a first type, executing a bearer recovery process, wherein the first type is used for indicating that the UE does not have uplink service in a request state and no bearer is established between the UE and the core network.

In one possible embodiment, the NAS message comprises a registration message.

In one possible embodiment, the processor is further configured to perform the steps of: initiating an authentication security process to the UE; and when the UE authentication is successful, determining whether the connection state of the UE is an abnormal access state or not according to the context of the UE.

In one possible embodiment, the core network element comprises an access and mobility management function, AMF.

It should be noted that the apparatus provided in the embodiment of the present application can implement all the method steps implemented by the method embodiment and achieve the same technical effect, and detailed descriptions of the same parts and beneficial effects as the method embodiment in this embodiment are omitted here.

In addition, a storage medium is provided in the embodiments of the present application, where a computer program is stored on the storage medium, and when executed by a processor, the computer program implements the method for recovering a bearer in the embodiments described above. The storage medium may be any available media or data storage device that can be accessed by a processor, including but not limited to magnetic memory (e.g., floppy disks, hard disks, magnetic tape, magneto-optical disks (MOs), etc.), optical memory (e.g., CDs, DVDs, BDs, HVDs, etc.), and semiconductor memory (e.g., ROMs, EPROMs, EEPROMs, non-volatile memory (NAND FLASH), Solid State Disks (SSDs)), etc.

The embodiment of the application provides a program product, for example, the program product is an FPGA chip or a DSP chip, and the program product includes executable instructions, and the executable instructions are stored in a storage medium. The processor reads the executable instructions from the storage medium, so that the executable instructions, when executed by the processor, implement the method for recovering the bearer in the embodiments described above.

Compared with the related art, the recovery of the bearer when the network is abnormal is realized, on one hand, if the UE has the Uplink service in the request state, the same process as the recovery process of the wireless link when the network is normal is performed, that is, when the UE re-initiates the registration process to recover the signaling plane link, the Uplink Data Status message is carried in the registration message or the service request message to recover the user plane link, so as to recover the bearer. On the other hand, if the UE does not have the uplink service in the request state, but establishes a bearer with the core network once, at this time, a downlink service in the request state may exist between the UE and the base station, which is different from a radio link recovery process when the network is abnormal, the UE will continue to recover the user plane link and further recover the bearer, thereby avoiding downlink service interruption caused by the UE only recovering the signaling plane link when the uplink service does not exist, avoiding partial data loss, and effectively improving user perception.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It should be understood that, although the steps in the flowcharts of the figures are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and may be performed in other orders unless explicitly stated herein. Moreover, at least a portion of the steps in the flow chart of the figure may include multiple sub-steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed alternately or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

The foregoing is only a partial embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and decorations can be made without departing from the principle of the present application, and these modifications and decorations should also be regarded as the protection scope of the present application.

Claims

1. A method for bearer recovery, performed by a core network element, the method comprising:

receiving an initial User Equipment (UE) message sent by a base station, and determining a UE context according to a non-access stratum (NAS) message in the initial UE message;

if the UE context indicates that the connection state of the UE is an abnormal access state, initiating a UE context release process to a base station;

and when the NAS message indicates that the session type of the UE is not a first type, executing a bearer recovery process, wherein the first type is used for indicating that the UE does not have uplink service in a request state and no bearer is established between the UE and a core network.

2. The method of claim 1, wherein the NAS message comprises a registration message;

the determining a UE context according to the NAS message in the initial UE message includes:

extracting the registration message from the initial UE message;

if the registration message indicates that the UE is initially registered, creating the UE context; otherwise, obtaining the UE context.

3. The method of claim 1, wherein the NAS message comprises a service request message;

the determining the UE context according to the NAS message in the initial UE message includes:

extracting the service request message from the initial UE message;

and responding to the service request message, and acquiring the UE context.

4. The method of claim 1, wherein before initiating a UE context release procedure to a base station if the UE context indicates that the connection status of the UE is an abnormal access status, the method further comprises:

initiating an authentication security procedure to the UE;

and when the UE authentication is successful, determining whether the connection state of the UE is an abnormal access state according to the UE context.

5. The method of claim 4, wherein the determining whether the connection state of the UE is an abnormal access state according to the UE context comprises:

acquiring a local context;

and if the UE context indicates that the connection state of the UE is an abnormal access state and the local context indicates that the connection state of the UE is a normal access state, determining that the connection state of the UE is the abnormal access state.

6. The method of claim 1, wherein the initiating a UE context release procedure to a base station comprises:

and sending a UE release message to the base station, wherein the UE release message is used for indicating the base station to release the local resources but not informing the UE of releasing the resources.

7. The method of claim 6, wherein the initiating the UE context release procedure to the base station further comprises:

and receiving a release completion message sent by the base station, wherein the release completion message is used for indicating that the base station has completed the release of the local resources according to the UE release message.

8. The method of claim 1, wherein before performing the bearer recovery procedure when the NAS message indicates that the session type of the UE is not the first type, the method further comprises:

and determining the session type of the UE according to the uplink service state and the bearing state of the UE indicated by the NAS message.

9. The method of claim 8, wherein the determining the session type of the UE according to the uplink traffic state and the bearer state of the UE indicated by the NAS message comprises:

determining whether the NAS message carries a first message, wherein the first message is used for indicating that the uplink service state of the UE is a request state;

if not, determining whether the NAS message carries a second message or not, wherein the second message is used for indicating that the bearing state of the UE is an establishment state;

and if not, determining the session type of the UE as the first type.

10. The method of claim 9, wherein the determining a session type of the UE according to the uplink traffic status and the bearer status of the UE indicated by the NAS message further comprises:

and if the NAS message carries the first message, determining that the session type of the UE is a second type, wherein the second type is used for indicating that the UE has the uplink service in the request state.

11. The method of claim 9, wherein the determining the session type of the UE according to the uplink traffic state and the bearer state of the UE indicated by the NAS message further comprises:

and if the NAS message does not carry the first message but carries the second message, determining that the session type of the UE is a third type, wherein the third type is used for indicating that the UE does not have the uplink service in the request state but establishes a bearer with a core network once.

12. The method of claim 11, wherein the determining that the session type of the UE is of a third type comprises:

acquiring a local context, and determining a local bearing state according to the local context;

and if the local bearer state indicates that a bearer is established between the UE and the core network, determining that the session type of the UE is the third type.

13. The method of claim 9, wherein the first message comprises an upstream Data Status message.

14. The method of claim 9, wherein the second message comprises a protocol data unit Session Status PDU Session Status message.

15. The method according to any of claims 1 to 14, wherein said core network element comprises an access and mobility management function, AMF;

after the performing the bearer recovery procedure when the NAS message indicates that the session type of the UE is not the first type, the method further includes:

and the AMF initiates a bearer update request to a Session Management Function (SMF) so that the SMF performs session management on the recovered session bearer.

16. A core network element, comprising: a memory, a transceiver, and a processor;

wherein the memory is used for storing a computer program; the transceiver is used for transceiving data under the control of the processor; the processor for reading a computer program in the memory to implement the method of recovering a bearer of any of claims 1 to 15.

17. An apparatus for recovering a bearer, applied to a network element of a core network, the apparatus comprising:

the device comprises a message receiving module, a message sending module and a message sending module, wherein the message receiving module is used for receiving an initial User Equipment (UE) message sent by a base station and determining a UE context according to a non-access stratum (NAS) message in the initial UE message;

a release initiating module, configured to initiate a UE context release process to a base station if the UE context indicates that a connection state of the UE is an abnormal access state;

and a bearer recovery module, configured to execute a bearer recovery procedure when the NAS message indicates that the session type of the UE is not a first type, where the first type is used to indicate that the UE does not have the uplink service in the request state and no bearer is established between the UE and the core network.

18. A storage medium having stored thereon a computer program, characterized in that the computer program, when being executed by a processor, implements the method of restoring a bearer according to any one of claims 1 to 15.