CN109548094B

CN109548094B - Connection recovery method and device and computer storage medium

Info

Publication number: CN109548094B
Application number: CN201710681666.1A
Authority: CN
Inventors: 李文婷
Original assignee: Sanechips Technology Co Ltd
Current assignee: Sanechips Technology Co Ltd
Priority date: 2017-08-10
Filing date: 2017-08-10
Publication date: 2021-04-06
Anticipated expiration: 2037-08-10
Also published as: CN109548094A

Abstract

The invention discloses a connection recovery method and device and computer storage equipment, wherein the method comprises the following steps: a first access network element determines whether a second core network element can be accessed according to context information of a terminal, which is acquired from or reported by the second access network element or the terminal, and the state of the core network element which can be connected with the first access network element, wherein the second core network element is connected with the second access network element; when the first access network element cannot access the second core network element, sending an indication message to the terminal; and when receiving the response message sent by the terminal, the first access network element accesses to a first core network element and transmits the message based on the first core network element.

Description

Connection recovery method and device and computer storage medium

Technical Field

The invention relates to the fifth generation (5G, 5)^thGeneration) mobile communication technology, and in particular, to a connection recovery method and apparatus, and a computer storage medium.

Background

To reduce the latency of data transmission, 5G is in the fourth generation (4G, 4G)^thGeneration) an inactive state is introduced on the basis of an idle state and a connected state of mobile communication.

The inactive state is equivalent to the connected state for the Non-Access Stratum (NAS) layer, so in the inactive state, the network can only initiate paging of the radio area, and for a user moving in the inactive state, when the user moves from one radio area to another radio area, the user should report to the network through the radio area update process, so that the network end updates the radio area maintained by the user, and the core network can conveniently initiate paging in the correct real-time radio area.

As described above, in the inactive state, when a User Equipment (UE) moves to a new radio area, a radio area update procedure is to be initiated. However, the problem is how the UE should operate when it moves to a new radio area, which in turn belongs to a new core network area. According to the core network Area rule, the UE should initiate a Tracking Area Update (TAU) procedure, so that there is a procedure in which a radio Area Update overlaps with a core network Area Update. Since sending the TAU message inevitably causes the establishment or recovery of the radio link, the Access Stratum (AS) may be triggered to initiate a radio link establishment recovery message by using the TAU request message triggered by the core network area update, so that the core network area update and the radio area update process are executed simultaneously. However, if the new base station (gNB) where the UE resides cannot be connected to the source core network element, although the radio area update procedure can be completed, the core network area update procedure cannot be performed normally. Namely: once the radio area update procedure is performed in the inactive state, but at this time, the new gNB cannot connect to the old Access and Mobility management network element (AMF), a series of problems across the AMF occur.

Disclosure of Invention

In order to solve the foregoing technical problems, embodiments of the present invention provide a connection recovery method and apparatus, and a computer storage medium.

The connection recovery method provided by the invention comprises the following steps:

a first access network element determines whether a second core network element can be accessed according to context information of a terminal, which is acquired from or reported by the second access network element or the terminal, and the state of the core network element which can be connected with the first access network element, wherein the second core network element is connected with the second access network element;

when the first access network element cannot access the second core network element, sending an indication message to the terminal;

and when receiving the response message sent by the terminal, the first access network element accesses to a first core network element and transmits the message based on the first core network element.

In the embodiment of the present invention, the method further includes:

the first access network element receives a connection recovery request message sent by a terminal, wherein the connection recovery request message carries indication information of the second core network element;

and the first access network element judges whether the second core network element can be accessed according to the indication information in the connection recovery request message.

In the embodiment of the present invention, the method further includes:

the first access network element receives a connection recovery request message sent by a terminal, wherein the connection recovery request message carries an identifier of the terminal;

the first access network element acquires the context information of the terminal from the second core network element according to the identifier of the terminal in the connection recovery request message;

and the first access network element judges whether the second core network element can be accessed or not according to the context information of the terminal.

In the embodiment of the present invention, the method further includes:

and if the first access network element can access the second core network element, transmitting a message based on the second core network element, and sending a non-access stratum message sent by the terminal to the second core network element.

In this embodiment of the present invention, the indication message sent by the first access network element to the terminal is used to control the terminal to perform the following operations: and when receiving the indication message, the access layer of the terminal sends the indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be sent according to an idle-state coding mode and a safety protection algorithm.

In this embodiment of the present invention, the sending, by the first access network element, the indication message to the terminal includes at least one of:

the first access network element sends a Radio Resource Control (RRC) connection establishment message, wherein the RRC connection establishment message carries the indication message;

the first access network element sends an RRC connection rejection message, wherein the RRC connection rejection message carries the indication message;

and the first access network element sends an RRC connection release message, wherein the RRC connection release message is used for indicating to return to an idle state.

In this embodiment of the present invention, when the first access network element cannot access the second core network element, an indication message is sent to the terminal; when receiving the response message sent by the terminal, the first access network element accesses to a first core network element and transmits the message based on the first core network element, including:

when the first access network element cannot access the second core network element, the first access network element sends an RRC connection establishment message to the terminal, where the RRC connection establishment message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

and when receiving an RRC connection establishment completion message sent by the terminal, the first access network element accesses a first core network element, wherein the RRC connection establishment completion message carries a non-access layer message, and the non-access layer message in the RRC connection establishment completion message is sent to the first core network element through an initial terminal message.

when the first access network element cannot access the second core network element, the first access network element sends an RRC connection reject message or an RRC connection release message to the terminal, where the RRC connection reject message or the RRC connection release message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

when the first access network element receives the RRC connection request message sent by the terminal, sending an RRC connection establishment message to the terminal;

Another embodiment of the present invention provides a connection recovery method, including:

when a terminal is in an inactive state, determining whether a non-access stratum of the terminal has a message to be transmitted;

when the non-access layer of the terminal has a message to be transmitted and receives an indication message sent by a first access network element through the access layer of the terminal, the access layer of the terminal sends the indication message to the non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be transmitted according to an idle-state coding mode and a security protection algorithm.

In this embodiment of the present invention, the access layer of the terminal receives the indication message sent by the first access network element, where the indication message at least includes one of the following:

an access layer of the terminal receives an RRC connection establishment message sent by a first access network element, wherein the RRC connection establishment message carries the indication message;

an access layer of the terminal receives an RRC connection rejection message sent by a first access network element, wherein the RRC connection rejection message carries the indication message;

and the access layer of the terminal receives an RRC connection release message sent by the network element of the first access network, wherein the RRC connection release message is used for indicating to return to an idle state.

The connection recovery device provided by the embodiment of the invention comprises:

a determining unit, configured to determine whether a second core network element can be accessed according to context information of a terminal, which is acquired from or reported by a second access network element or a terminal, and a state of the core network element to which a first access network element can be connected, where the second core network element is connected to the second access network element;

an indicating unit, configured to send an indication message to the terminal when the first access network element cannot access the second core network element;

and the access unit is used for accessing the first core network element when receiving the response message sent by the terminal and transmitting the message based on the first core network element.

In an embodiment of the present invention, the determining unit is specifically configured to: receiving a connection recovery request message sent by a terminal, wherein the connection recovery request message carries indication information of the second core network element; and judging whether the second core network element can be accessed according to the indication information in the connection recovery request message.

In an embodiment of the present invention, the determining unit is specifically configured to: receiving a connection recovery request message sent by a terminal, wherein the connection recovery request message carries an identifier of the terminal; acquiring context information of the terminal from the second core network element according to the identifier of the terminal in the connection recovery request message; and judging whether the second core network element can be accessed according to the context information of the terminal.

In the embodiment of the present invention, the apparatus further includes:

and a recovery unit, configured to, if the first access network element can access the second core network element, perform message transmission based on the second core network element, and send a non-access stratum message sent by the terminal to the second core network element.

In this embodiment of the present invention, the indication message sent by the indication unit to the terminal is used to control the terminal to perform the following operations: and when receiving the indication message, the access layer of the terminal sends the indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be sent according to an idle-state coding mode and a safety protection algorithm.

In an embodiment of the present invention, the indication unit is specifically configured to:

sending an RRC connection establishment message, wherein the indication message is carried in the RRC connection establishment message; or,

sending an RRC connection rejection message, wherein the indication message is carried in the RRC connection rejection message; or,

and sending an RRC connection release message, wherein the RRC connection release message is used for indicating to return to an idle state.

In an embodiment of the present invention, the indication unit is specifically configured to: when the first access network element cannot access the second core network element, sending an RRC connection establishment message to the terminal, where the RRC connection establishment message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

the access unit is specifically configured to: and accessing to a first core network element when receiving an RRC connection establishment completion message sent by the terminal, wherein the RRC connection establishment completion message carries a non-access layer message, and the non-access layer message in the RRC connection establishment completion message is sent to the first core network element through an initial terminal message.

In an embodiment of the present invention, the indication unit is specifically configured to: when the first access network element cannot access the second core network element, sending an RRC connection reject message or an RRC connection release message to the terminal, where the RRC connection reject message or the RRC connection release message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

the access unit is specifically configured to: when receiving an RRC connection request message sent by the terminal, sending an RRC connection establishment message to the terminal; and accessing to a first core network element when receiving an RRC connection establishment completion message sent by the terminal, wherein the RRC connection establishment completion message carries a non-access layer message, and the non-access layer message in the RRC connection establishment completion message is sent to the first core network element through an initial terminal message.

Another embodiment of the present invention provides a connection recovery apparatus, including:

a determining unit, configured to determine, when a terminal is in an inactive state, whether a non-access stratum of the terminal has a message to be transmitted;

and the execution unit is used for sending an indication message to the non-access stratum of the terminal to trigger the non-access stratum to locally return to an idle state and process the message to be sent according to an idle-state coding mode and a safety protection algorithm when the non-access stratum of the terminal has the message to be transmitted and the indication message sent by the first access network element is received through the access stratum of the terminal.

The computer storage medium provided by the embodiment of the present invention stores computer executable instructions, and the computer executable instructions are used for implementing any step in the connection recovery method when executed.

In the technical solution of the embodiment of the present invention, a first access network element determines whether a second core network element can be accessed according to context information of a terminal, which is acquired from or reported by a second access network element or a terminal, and a state of the core network element to which the first access network element can be connected, wherein the second core network element is connected with the second access network element; when the first access network element cannot access the second core network element, sending an indication message to the terminal; and when receiving the response message sent by the terminal, the first access network element accesses to a first core network element and transmits the message based on the first core network element. By adopting the technical scheme of the embodiment of the invention, the abnormal flow of RRC connection recovery can be effectively solved.

Drawings

The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed herein.

Fig. 1 is a schematic diagram of a UE mobility scenario;

fig. 2 is a schematic diagram of a radio area update process performed in an inactive state;

fig. 3 is a first flowchart illustrating a connection recovery method according to an embodiment of the present invention;

fig. 4 is a second flowchart illustrating a connection recovery method according to an embodiment of the present invention;

fig. 5 is a third flowchart illustrating a connection recovery method according to an embodiment of the present invention;

fig. 6 is a fourth schematic flowchart of a connection recovery method according to an embodiment of the present invention;

fig. 7 is a fifth flowchart illustrating a connection recovery method according to an embodiment of the present invention;

fig. 8 is a sixth flowchart illustrating a connection recovery method according to an embodiment of the present invention;

fig. 9 is a seventh flowchart illustrating a connection recovery method according to an embodiment of the present invention;

FIG. 10 is a first schematic view illustrating a first exemplary embodiment of a connection recovery apparatus;

FIG. 11 is a schematic structural diagram of a connection recovery apparatus according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of an electronic device according to an embodiment of the present invention.

Detailed Description

So that the manner in which the features and aspects of the embodiments of the present invention can be understood in detail, a more particular description of the embodiments of the invention, briefly summarized above, may be had by reference to the embodiments, some of which are illustrated in the appended drawings.

The following is an explanation of key terms associated with embodiments of the present invention:

AS: access Stratum, Access Stratum

NAS: Non-Access Stratum, Non-Access Stratum

TgNB: target base station, Target gNB

SgNB: source base station, Source gNB

TAMF: target Access and Mobility management function

SAMF: source Access and Mobility management network element, Source Access and Mobility management function

CN: core Network, Core Network

UE: user Equipment, User Equipment

SRB: message Bearer, Signal Radio Bearer

DRB: data Radio Bearer

TAU: tracking area update, Tracking area update

RLAU: radio location area update, Ran location area update

RRC: radio resource control

Rcconnectionrelease: RRC connection release message indicating whether to enter inactive or idle state

Rcconnectionreject: RRC connection rejection, which may be used to reject RrcconnectionRequest and RrcconnectionResumeRequest

Rcconnectionresponse Request: RRC connection resume request message for UE to resume connection in inactive state

rcconnectionResume: RRC connection resume request response

Rcconnectionresummemplete: RRC connection resume request completion

Rcconnectionrequest: RRC connection setup request message for UE to establish connection in idle state

Rcconnectionsetup: RRC connection setup request response

Rcconnectionsetupcomp: RRC connection establishment request completion

Retrieveueconcontextrequest: UE context acquisition message request, request for acquiring UE context information between two base stations

Retrieveueconcontexttresnse: UE context acquisition message response, response for acquiring UE context information between two base stations

Initial UE msg: initial message of UE, used for sending initial message to core network element at wireless network element of network side

UlNasMsg: the uplink direct transmission message of the UE is used for sending the uplink NAS cancellation of the UE to the core network element by the wireless network element at the network side

PathSwithRequest: a path switching message for the access network element to inform the core network element that the UE has accessed to a new access network element

PathSwithResponse: a path switching message for the access network element to inform the core network element that the UE has been accessed to a new access network element

The inactive state is a new state introduced on the basis of 4G by 5G, and is different from the idle state and the connected state. In an inactive state, the UE and the network side maintain the context information of the SRB and the DRB, and when there is data or a message to be sent subsequently, the UE may directly send an rcconnneconresume message, and then the network side obtains the context information of the SRB and the DRB of the UE across the base station or at the base station according to the UE identifier in the rcconnneconresume message and directly resumes the UE connection according to the context information, that is, switches the UE from the inactive state to the connected state. The inactive state eliminates the need for special security and SRB2/DRB establishment procedures as compared to establishing a connection in the idle state, thereby reducing latency for connection recovery. In addition to this, the inactive state is not aware of the NAS layer, i.e. the inactive state is equivalent to the connected state for the NAS layer.

In the inactive state, if there is downlink data or downlink message to be sent, the network should first initiate a paging procedure. In order to reduce the delay, in 5G, paging of a radio area is defined, and a paging cycle of the radio area is smaller than a paging cycle of a core network area, and to be precise, the paging cycle of the core network area is an integral multiple of the paging cycle of the radio area. In addition, in order to reduce the paging load of the entire system, the paging range of the radio area is smaller than or equal to that of the core network area because its paging cycle is shorter. Also because in the inactive state the network will only initiate paging of radio zones (since in the inactive state is equal to the connected state for NAS layer, so no paging in connected state will be initiated), a user moving in the inactive state should report to the network through a radio zone update procedure when moving from one radio zone to another radio zone, so that the network side updates the radio zone it maintains, facilitating the core network to initiate paging in the correct real-time radio zone.

In the inactive state, as described above, the UE is to initiate a radio area update procedure when moving to a new radio area. However, the problem is how the UE should operate when it moves to a new radio area, which in turn belongs to a new core network area. According to the core network area rule, the UE should initiate a TAU procedure, so that there is a procedure where the radio area update overlaps with the core network area update. Since sending the TAU message inevitably causes the establishment or recovery of the radio link, the AS layer may be triggered to initiate a radio link establishment recovery message by using the TAU request message triggered by the core network area update, so that the core network area update and the radio area update process are executed simultaneously. However, if the new gNB where the UE resides cannot be connected to the old core network element, although the radio area update procedure can be completed, the core network area update procedure cannot be performed normally. As shown in fig. 1, the UE selects AMF1 when registering with gNB3, and then moves to gNB2, but N2 port is not established between gNB2 and AMF1, and the UE side does not know that the new gNB2 cannot be connected to the original AMF (i.e., AMF1) before sending the TAU request message, so that the UE side performs processing according to the flow of the connection state (it is considered that the core network side has completed synchronization as if the connection state handover (handover) occurs at the bottom layer), so that if no special processing is performed, as can be seen from fig. 2, for the NAS message in the connection state sent by the UE, the gNB only serves as an initial message and sends the initial message to the TAMF, and obviously, a NAS message with encryption cannot be processed at the TAMF side, and therefore, only the NAS message is directly discarded. It is clear that once the radio area update procedure is performed in the inactive state, but at this time the new gNB cannot connect to the old AMF, a series of problems across AMFs occur, which are not limited to TAU messages only.

Fig. 3 is a first flowchart of a connection recovery method according to an embodiment of the present invention, and as shown in fig. 3, the connection recovery method includes the following steps:

step 301: the first access network element determines whether a second core network element can be accessed according to context information of the terminal, which is acquired from or reported by the second access network element or the terminal, and the state of the core network element which can be connected with the first access network element, wherein the second core network element is connected with the second access network element.

When a first access network element receives a connection recovery message sent by a terminal, context information of the terminal is obtained from a second access network element according to a terminal identifier in the connection recovery message, and the second access network element is connected with a second core network element.

In this embodiment, the first access network element refers to a new access network element (also referred to as a target access network element), the second access network element refers to an old access network element (also referred to as a source access network element), and correspondingly, the first core network element refers to a new core network element (also referred to as a target core network element), and the second core network element refers to an old core network element (also referred to as a source core network element). Here, the access network element may be, for example, a base station, and accordingly, the first access network element is also referred to as a target base station, and the second access network element is also referred to as a source base station. The core network elements may be, for example, AMFs, and accordingly the first core network element is also referred to as a target AMF and the second core network element is also referred to as a source AMF.

In this embodiment, after the terminal moves from the area corresponding to the second access network element to the area corresponding to the first access network element, when the first access network element receives a connection recovery message sent by the terminal, the context information of the terminal is obtained from the second access network element according to a terminal identifier in the connection recovery message, where the second access network element is connected to the second core network element.

In an embodiment of the present invention, the first access network element receives a connection recovery request message sent by a terminal, where the connection recovery request message carries indication information of the second core network element; and the first access network element judges whether the second core network element can be accessed according to the indication information in the connection recovery request message.

In another embodiment of the present invention, the first access network element receives a connection recovery request message sent by a terminal, where the connection recovery request message carries an identifier of the terminal; the first access network element acquires the context information of the terminal from the second core network element according to the identifier of the terminal in the connection recovery request message; and the first access network element judges whether the second core network element can be accessed or not according to the context information of the terminal.

Step 302: when the first access network element cannot access the second core network element, sending an indication message to the terminal; and when receiving the response message sent by the terminal, the first access network element accesses to a first core network element and transmits the message based on the first core network element.

In this embodiment, if the first access network element can access the second core network element, the message is transmitted based on the second core network element, and the non-access stratum message sent by the terminal is sent to the second core network element.

In this embodiment, the indication message sent by the first access network element to the terminal is used to control the terminal to perform the following operations: and when receiving the indication message, the access layer of the terminal sends the indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be sent according to an idle-state coding mode and a safety protection algorithm.

In the foregoing solution, the sending, by the first access network element, the indication message to the terminal includes at least one of the following:

the first access network element sends Rrcconnectionsetup, and the RRC connection establishment message carries the indication message;

the first access network element sends RrcconnectionReject, and the RRC connection rejection message carries the indication message;

and the first access network element sends RrcconnectionRelease, and the RRC connection release message is used for indicating to return to an idle state.

In an embodiment of the present invention, when the first access network element cannot access the second core network element, the first access network element sends an RRC connection establishment message to the terminal, where the RRC connection establishment message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm; and when receiving an RRC connection establishment completion message sent by the terminal, the first access network element accesses a first core network element, wherein the RRC connection establishment completion message carries a non-access layer message, and the non-access layer message in the RRC connection establishment completion message is sent to the first core network element through an initial terminal message.

In another embodiment of the present invention, when the first access network element cannot access the second core network element, the first access network element sends an RRC connection reject message or an RRC connection release message to the terminal, where the RRC connection reject message or the RRC connection release message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm; when the first access network element receives the RRC connection request message sent by the terminal, sending an RRC connection establishment message to the terminal; and when receiving an RRC connection establishment completion message sent by the terminal, the first access network element accesses a first core network element, wherein the RRC connection establishment completion message carries a non-access layer message, and the non-access layer message in the RRC connection establishment completion message is sent to the first core network element through an initial terminal message.

Fig. 4 is a second flowchart illustrating a connection recovery method according to an embodiment of the present invention, and as shown in fig. 4, the connection recovery method includes the following steps:

step 401: when a terminal is in an inactive state, determining whether a non-access stratum of the terminal has a message to be transmitted.

Step 402: when the non-access layer of the terminal has a message to be transmitted and receives an indication message sent by a first access network element through the access layer of the terminal, the access layer of the terminal sends the indication message to the non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be transmitted according to an idle-state coding mode and a security protection algorithm.

In this embodiment, the receiving, by the access layer of the terminal, the indication message sent by the first access network element includes at least one of the following:

Here, when the terminal receives the indication message, the access stratum of the terminal sends an indication message to a non-access stratum to trigger the non-access stratum to locally return to an idle state. After the non-access layer returns to the idle state locally, the relevant flow is reinitiated, and at this time, the message of the non-access layer should be encoded in the idle state, that is, without encryption.

The following further describes the technical solution of the embodiment of the present invention with reference to a specific application example, for convenience of description, a NAS message is taken as an example of a TAU message in the following example, and it should be understood by those skilled in the art that all NAS messages are applicable to the technical solution of the embodiment of the present invention, and are not limited to the TAU message.

Fig. 5 is a third flowchart illustrating a connection recovery method according to an embodiment of the present invention, AS shown in fig. 5, in this example, the AS layers of the UE and the UE are collectively represented by a UE AS, where the connection recovery method includes the following steps:

step 501: the SgNB issues an RrcnnecitonRelease message to the UE to enable the UE to enter an inactive state; then the UE moves to a new core network area in the inactive state, and initiates a TAU procedure in the connected state.

Step 502: and the UE AS triggers an RrcconneceonResume flow under the TgNB and sends an RrcconneceonResumRequest to the TgNB.

Step 503: and after receiving the RrcconneceResumRequest, the TgNB sends a RenoveContextRequest message to the SgNB according to the identity of the UE to acquire the context information of the UE.

Step 504: the SgNB feeds back the UE context information to the TgNB through a RetiveUEContextResponse message; the TgNB determines a previously connected SAMF according to the UE context information, but finds that it cannot connect to the SAMF.

Step 505: and the TgNB issues a corresponding RrcnnecitonSetup message, reestablishes AS connection, indicates the UE in the message, allows the AS layer of the UE to notify the NAS layer of locally entering an idle state, and carries the NAS message according to the security rule of the idle state.

Step 506: and the UE receives the AS layer Rrcconnectionsetup message and performs related operation according to the content and the instruction of the Rrcconnectionsetup.

Specifically, the AS layer should notify the NAS layer and inform the NAS layer of the relevant operations. After receiving the indication from the AS layer, the NAS layer may clear 0, locally return to the Idle state, and then re-initiate the relevant flow, at this time, the first message of the NAS should use the encoding mode in the Idle state, that is, there is no encryption. The NAS message is carried to the network side in a subsequent rcconnectionseupcomplete message.

Step 507: the network side receives the Rrccon connection Seupcomplete, completes the RRC connection establishment process, and simultaneously sends the NAS message in the Rrccon connection Seupcomplete message to the TAMF through InitialUEMsg.

Fig. 6 is a fourth flowchart illustrating a connection recovery method according to an embodiment of the present invention, as shown in fig. 6, in this example, the connection recovery method includes the following steps:

step 601: the SgNB issues an RrcnnecitonRelease message to the UE to enable the UE to enter an inactive state; then the UE moves to a new core network area in the inactive state, and initiates a TAU procedure in the connected state.

Step 602: and the UE AS triggers an RrconneceonResume flow under the TgNB and sends the RRCConneceonResumRequest to the TgNB.

Step 603: after receiving the RrcconneceReumRequest, the SgNB sends a RenoveContextRequest message to the SgNB according to the identity of the UE to acquire the context information of the UE.

Step 604: the SgNB feeds back the UE context information to the TgNB through a RetiveUEContextResponse message; the TgNB determines a previously connected SAMF according to the UE context information, but finds that it cannot connect to the SAMF.

Step 605: and the TgNB issues a corresponding RrcnnecitonReject message, indicates the UE in the message, allows the AS layer of the UE to notify the NAS layer of locally entering an idle state, and carries the NAS message according to the security rule of the idle state.

Step 606: after receiving the RrcconnneconReject, the UE returns to an idle state, and re-initiates a random access process to establish RRC connection and sends a RrcconnneconRequest message.

Step 607: the TgNB sends a normal rcconnectionsetup message.

Step 608: and the UE receives the AS layer Rrcconnectionsetup message and performs related operation according to the content and the instruction of the Rrcconnectionsetup.

Step 609: the network side receives the Rrccon connection Seupcomplete, completes the RRC connection establishment process, and simultaneously sends the NAS message in the Rrccon connection Seupcomplete message to the TAMF through InitialUEMsg.

Fig. 7 is a fifth flowchart illustrating a connection recovery method according to an embodiment of the present invention, as shown in fig. 7, in this example, the connection recovery method includes the following steps:

step 701: the SgNB issues an RrcnnecitonRelease message to the UE to enable the UE to enter an inactive state; then the UE moves to a new core network area in the inactive state, and initiates a TAU procedure in the connected state.

Step 702: and the UE AS triggers an RrconneceonResume flow under the TgNB and sends the RRCConneceonResumRequest to the TgNB.

Step 703: after receiving the RrcconneceReumRequest, the SgNB sends a RenoveContextRequest message to the SgNB according to the identity of the UE to acquire the context information of the UE.

Step 704: the SgNB feeds back the UE context information to the TgNB through a RetiveUEContextResponse message; the TgNB determines a previously connected SAMF according to the UE context information, but finds that it cannot connect to the SAMF.

Step 705: and the TgNB issues a corresponding RrcnnecitonRelease message, indicates the UE in the message, and allows the AS layer of the UE to notify the NAS layer of locally entering an idle state and carry the NAS message according to the safety rule of the idle state.

Step 706: after the UE receives the RrcconnecionRelease, the UE returns to an idle state, and re-initiates a random access process to establish RRC connection and sends an RrcconnecionRequest message.

Step 707: the TgNB sends a normal rcconnectionsetup message.

Step 708: and the UE receives the AS layer Rrcconnectionsetup message and performs related operation according to the content and the instruction of the Rrcconnectionsetup.

Step 709: the network side receives the Rrccon connection Seupcomplete, completes the RRC connection establishment process, and simultaneously sends the NAS message in the Rrccon connection Seupcomplete message to the TAMF through InitialUEMsg.

Fig. 8 is a sixth flowchart of a connection recovery method according to an embodiment of the present invention, AS shown in fig. 8, in this example, the AS layers of the UE and the UE are collectively represented by a UE AS, where the connection recovery method includes the following steps:

step 801: the SgNB issues an RrcnnecitonRelease message to the UE to enable the UE to enter an inactive state; then the UEAS layer informs the NAS layer of the inactive state, the NAS layer moves to a new core network area in the inactive state, a TAU process in the connection state is initiated, and the NAS layer informs the AS layer of the original AMF identification.

Step 802: and the UE AS triggers an RrconneceonResume flow under the TgNB, sends an RRCConneceonResumRequest to the TgNB, and the RRCConneceonResumRequest message carries the source AMF identifier. And after receiving the RrcconnnectionResumRequest, the TgNB finds that the source AMF cannot be connected to the SAMF according to the source AMF identifier carried in the RRCConnecencionResumRequest message.

Step 803: and the TgNB issues a corresponding RrcnnecitonSetup message, reestablishes AS connection, indicates the UE in the message, allows the AS layer of the UE to notify the NAS layer of locally entering an idle state, and carries the NAS message according to the security rule of the idle state.

Step 804: and the UE receives the AS layer Rrcconnectionsetup message and performs related operation according to the content and the instruction of the Rrcconnectionsetup.

Step 805: the network side receives the Rrccon connection Seupcomplete, completes the RRC connection establishment process, and simultaneously sends the NAS message in the Rrccon connection Seupcomplete message to the TAMF through InitialUEMsg.

Fig. 9 is a seventh flowchart illustrating a connection recovery method according to an embodiment of the present invention, as shown in fig. 9, in this example, the connection recovery method includes the following steps:

step 901: the SgNB issues an RrcnnecitonRelease message to the UE to enable the UE to enter an inactive state; then the UEAS layer informs the NAS layer of the inactive state, the NAS layer moves to a new core network area in the inactive state, a TAU process in the connection state is initiated, and the NAS layer informs the AS layer of the original AMF identification.

Step 902: and the UE AS triggers an RrconneceonResume flow under the TgNB, sends an RRCConneceonResumRequest to the TgNB, and the RRCConneceonResumRequest message carries the source AMF identifier. And after receiving the RrcconnnectionResumRequest, the TgNB finds that the source AMF cannot be connected to the SAMF according to the source AMF identifier carried in the RRCConnecencionResumRequest message.

Step 903: and the TgNB issues a corresponding RrcnnectionReject/RRCConnectionRelease message, indicates the UE in the message, allows the AS layer of the UE to notify the NAS layer of locally entering an idle state, and carries the NAS message according to the safety rule of the idle state.

Step 904: after the UE receives the RrcconnnectionReject/RRCConnectionRelease, the UE returns to an idle state, and re-initiates a random access process to establish RRC connection and send an RrconnectionRequest message.

Step 905: the TgNB sends a normal rcconnectionsetup message.

Step 906: and the UE receives the AS layer Rrcconnectionsetup message and performs related operation according to the content and the instruction of the Rrcconnectionsetup.

Step 907: the network side receives the Rrccon connection Seupcomplete, completes the RRC connection establishment process, and simultaneously sends the NAS message in the Rrccon connection Seupcomplete message to the TAMF through InitialUEMsg.

Fig. 10 is a schematic structural composition diagram of a connection recovery apparatus according to an embodiment of the present invention, as shown in fig. 10, the connection recovery apparatus includes:

a determining unit 1001, configured to determine whether a second core network element can be accessed according to context information of a terminal, which is obtained from or reported by a second access network element, and a state of the core network element to which a first access network element can be connected, where the second core network element is connected to the second access network element;

an indicating unit 1002, configured to send an indication message to the terminal when the first access network element cannot access the second core network element;

an access unit 1003, configured to access a first core network element when receiving a response message sent by the terminal, and transmit a message based on the first core network element.

In this embodiment of the present invention, the determining unit 1001 is specifically configured to: receiving a connection recovery request message sent by a terminal, wherein the connection recovery request message carries indication information of the second core network element; and judging whether the second core network element can be accessed according to the indication information in the connection recovery request message.

In this embodiment of the present invention, the determining unit 1001 is specifically configured to: receiving a connection recovery request message sent by a terminal, wherein the connection recovery request message carries an identifier of the terminal; acquiring context information of the terminal from the second core network element according to the identifier of the terminal in the connection recovery request message; and judging whether the second core network element can be accessed according to the context information of the terminal.

In the embodiment of the present invention, the apparatus further includes:

a recovering unit 1004, configured to, if the first access network element is capable of accessing the second core network element, perform message transmission based on the second core network element, and send a non-access stratum message sent by the terminal to the second core network element.

In this embodiment of the present invention, the indication message sent by the indication unit 1002 to the terminal is used to control the terminal to execute the following operations: and when receiving the indication message, the access layer of the terminal sends the indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be sent according to an idle-state coding mode and a safety protection algorithm.

In this embodiment of the present invention, the indicating unit 1002 is specifically configured to:

In an embodiment of the present invention, the indicating unit 1002 is specifically configured to: when the first access network element cannot access the second core network element, sending an RRC connection establishment message to the terminal, where the RRC connection establishment message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

the access unit 1003 is specifically configured to: and accessing to a first core network element when receiving an RRC connection establishment completion message sent by the terminal, wherein the RRC connection establishment completion message carries a non-access layer message, and the non-access layer message in the RRC connection establishment completion message is sent to the first core network element through an initial terminal message.

In another embodiment of the present invention, the indicating unit 1002 is specifically configured to: when the first access network element cannot access the second core network element, sending an RRC connection reject message or an RRC connection release message to the terminal, where the RRC connection reject message or the RRC connection release message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

the access unit 1003 is specifically configured to: when receiving an RRC connection request message sent by the terminal, sending an RRC connection establishment message to the terminal; and accessing to a first core network element when receiving an RRC connection establishment completion message sent by the terminal, wherein the RRC connection establishment completion message carries a non-access layer message, and the non-access layer message in the RRC connection establishment completion message is sent to the first core network element through an initial terminal message.

It will be understood by those skilled in the art that the functions implemented by the units in the connection restoration apparatus shown in fig. 10 can be understood by referring to the related description of the connection restoration method.

In practical applications, the functions implemented by each Unit in the connection recovery apparatus may be implemented by a Central Processing Unit (CPU), a microprocessor Unit (MPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), or the like located in the connection recovery apparatus.

Fig. 11 is a schematic structural composition diagram of a connection recovery apparatus according to an embodiment of the present invention, and as shown in fig. 11, the connection recovery apparatus includes:

a determining unit 1101, configured to determine, when a terminal is in an inactive state, whether a non-access stratum of the terminal has a message to be transmitted;

an executing unit 1102, configured to, when a non-access stratum of the terminal has a message to be transmitted and an indication message sent by a first access network element is received through an access stratum of the terminal, send the indication message to the non-access stratum by the access stratum of the terminal to trigger the non-access stratum to locally return to an idle state, and process the message to be transmitted according to an idle-state coding mode and a security protection algorithm.

In practical applications, the functions implemented by the units in the connection recovery apparatus may be implemented by a CPU, an MPU, a DSP, an FPGA, or the like located in the connection recovery apparatus.

The device for tracking the service signaling, which is provided by the embodiment of the invention, can be stored in a computer readable storage medium if the device is implemented in the form of a software functional module and sold or used as an independent product. Based on such understanding, the technical solutions of the embodiments of the present invention may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the methods described in the embodiments of the present invention. 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 magnetic disk, or an optical disk. Thus, embodiments of the invention are not limited to any specific combination of hardware and software.

Accordingly, an embodiment of the present invention further provides a computer storage medium, in which a computer program is stored, the computer program being configured to execute the connection recovery method according to the embodiment of the present invention.

An embodiment of the present invention further provides a computer device, as shown in fig. 12, where the computer device includes: at least one processor 1201, memory 1202, at least one network interface 1203. The various components in the base station are coupled together by a bus system 1204. It is understood that the bus system 1204 is used to enable connective communication between these components. The bus system 1204 includes a power bus, a control bus, and a status signal bus, in addition to a data bus. For clarity of illustration, however, the various buses are labeled as bus system 1204 in fig. 12.

It is to be understood that the memory 1202 in embodiments of the present invention may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory.

In some embodiments, memory 1202 stores the following elements, executable modules or data structures, or a subset thereof, or an expanded set thereof:

an operating system 12021 and application programs 12022.

Wherein the processor 1201 is configured to: determining whether a second core network element can be accessed according to context information of a terminal, which is acquired from or reported by a second access network element or a terminal, and a state of the core network element which can be connected with the first access network element, wherein the second core network element is connected with the second access network element; when the first access network element cannot access the second core network element, sending an indication message to the terminal; and when receiving the response message sent by the terminal, accessing to a first core network element, and transmitting the message based on the first core network element.

Alternatively, the processor 1201 is configured to: when a terminal is in an inactive state, determining whether a non-access stratum of the terminal has a message to be transmitted; when the non-access layer of the terminal has a message to be transmitted and receives an indication message sent by a first access network element through the access layer of the terminal, the access layer of the terminal sends the indication message to the non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be transmitted according to an idle-state coding mode and a security protection algorithm.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, and the scope of the invention should not be limited to the embodiments described above.

Claims

1. A method for connection recovery, the method comprising:

2. The connection restoration method according to claim 1, further comprising:

3. The connection restoration method according to claim 1, further comprising:

4. The connection restoration method according to claim 1, further comprising:

5. The connection recovery method according to claim 1, wherein the indication message sent by the first access network element to the terminal is used to control the terminal to perform the following operations: and when receiving the indication message, the access layer of the terminal sends the indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be sent according to an idle-state coding mode and a safety protection algorithm.

6. The connection recovery method according to claim 1 or 5, wherein the first access network element sends the indication message to the terminal, and the indication message comprises at least one of the following:

7. The connection recovery method according to claim 2 or 3, wherein when the first access network element cannot access the second core network element, an indication message is sent to the terminal; when receiving the response message sent by the terminal, the first access network element accesses to a first core network element and transmits the message based on the first core network element, including:

8. The connection recovery method according to claim 2 or 3, wherein when the first access network element cannot access the second core network element, an indication message is sent to the terminal; when receiving the response message sent by the terminal, the first access network element accesses to a first core network element and transmits the message based on the first core network element, including:

9. A method for connection recovery, the method comprising:

when a message is to be transmitted in a non-access layer of the terminal and an indication message sent by a first access network element is received through the access layer of the terminal, the access layer of the terminal sends the indication message to the non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be transmitted according to an idle-state coding mode and a security protection algorithm;

the indication message is sent to the terminal when the first access network element determines that the first access network element cannot access the second core network element according to context information of the terminal, which is acquired from the second access network element or reported by the terminal, and the state of the core network element which can be connected with the first access network element; the second core network element is connected with the second access network element;

and the first access network element is used for accessing the first core network element according to the received response message sent by the terminal and transmitting the message based on the first core network element.

10. The connection recovery method according to claim 9, wherein the access layer of the terminal receives the indication message sent by the first access network element, and the indication message includes at least one of the following:

11. A connection restoration apparatus, characterized in that the apparatus comprises:

12. The connection restoration device according to claim 11, wherein the determination unit is specifically configured to: receiving a connection recovery request message sent by a terminal, wherein the connection recovery request message carries indication information of the second core network element; and judging whether the second core network element can be accessed according to the indication information in the connection recovery request message.

13. The connection restoration device according to claim 11, wherein the determination unit is specifically configured to: receiving a connection recovery request message sent by a terminal, wherein the connection recovery request message carries an identifier of the terminal; acquiring context information of the terminal from the second core network element according to the identifier of the terminal in the connection recovery request message; and judging whether the second core network element can be accessed according to the context information of the terminal.

14. The connection restoration device according to claim 11, wherein the device further comprises:

15. The apparatus according to claim 11, wherein the indication message sent by the indication unit to the terminal is used to control the terminal to perform the following operations: and when receiving the indication message, the access layer of the terminal sends the indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process the message to be sent according to an idle-state coding mode and a safety protection algorithm.

16. The connection restoration device according to claim 11 or 15, wherein the indication unit is specifically configured to:

17. The connection restoration device according to claim 12 or 13, wherein the indication unit is specifically configured to: when the first access network element cannot access the second core network element, sending an RRC connection establishment message to the terminal, where the RRC connection establishment message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

18. The connection restoration device according to claim 12 or 13, wherein the indication unit is specifically configured to: when the first access network element cannot access the second core network element, sending an RRC connection reject message or an RRC connection release message to the terminal, where the RRC connection reject message or the RRC connection release message carries indication information, and the indication information is used to indicate the terminal to perform the following operations: when receiving the RRC connection establishment message, an access layer of the terminal sends an indication message to a non-access layer to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a safety protection algorithm;

19. A connection restoration apparatus, characterized in that the apparatus comprises:

the terminal comprises an execution unit and a security protection algorithm, wherein the execution unit is used for sending an indication message to a non-access layer of the terminal to trigger the non-access layer to locally return to an idle state and process a message to be sent according to an idle-state coding mode and a security protection algorithm when the non-access layer of the terminal has the message to be transmitted and the indication message sent by a first access network element is received through the access layer of the terminal;

20. The apparatus for recovering connection according to claim 19, wherein the access layer of the terminal receives the indication message sent by the network element of the first access network, and the indication message includes at least one of:

21. A computer storage medium having computer-executable instructions stored thereon that, when executed, perform the connection restoration method of any one of claims 1-8 or the connection restoration method of any one of claims 9-10.