CN107864496B

CN107864496B - Method for recording backfill user identification by SRVCC/eSRVCC A interface

Info

Publication number: CN107864496B
Application number: CN201710977632.7A
Authority: CN
Inventors: 牛玲玲; 席革勇
Original assignee: Beijing Zhongchuang Telecom Test Co Ltd
Current assignee: Beijing Zhongchuang Telecom Test Co Ltd
Priority date: 2017-10-19
Filing date: 2017-10-19
Publication date: 2020-12-25
Anticipated expiration: 2037-10-19
Also published as: CN107864496A

Abstract

The invention relates to the field of communication networks, and discloses a method for backfilling a user identifier by an SRVCC/eSRVCC A interface record, which comprises the following steps: step a: decoding and synthesizing the Sv interface message, and extracting corresponding parameters according to different information; step b: establishing a node according to the key switching parameters for the correlation search of the interface A, and filling user identity identification information in the node; step c: decoding and synthesizing the A interface message, and extracting corresponding parameters according to different information; step d: and after receiving the switching completion message, searching the node according to the key switching parameter, finding the user identity identification information in the node, taking out the user identity identification information, and putting the user identity identification information into the current interface A record. The invention carries out the association processing of the Sv interface and the A interface through the key switching parameter, and backfills the user identity identification of the Sv interface into the switching record of the A interface, thereby carrying out the user level analysis on the switching record of the A interface.

Description

Method for recording backfill user identification by SRVCC/eSRVCC A interface

Technical Field

The invention relates to the field of communication networks, in particular to a method for backfilling a user identifier by an SRVCC/eSRVCC A interface record.

Background

SRVCC (Single Radio Voice Call Continuity) is a Voice over LTE (Voice over LTE) Voice service Continuity scheme proposed by 3GPP (3 rd Generation Partnership Project), and mainly aims to solve the problem of how to ensure Voice Call Continuity when a Single Radio frequency handset moves between an LTE (Long Term Evolution) network and a 2G/3G network.

The eSRVCC (Enhanced Single Radio Voice Call Continuity) is an upgrade solution of SRVCC, and reduces handover delay as much as possible while ensuring Voice Call Continuity.

Fig. 1 is a schematic diagram of related network interfaces and devices in SRVCC/eSRVCC technology, where an Sv interface is an interface between an MME (Mobility Management Entity) and an MSC Server (Mobile Switching Center Server), which is an interface added by the SRVCC/eSRVCC technical solution. The a interface is an interface between the MSC Server and a BSC (Base Station Controller), which is an interface in a 2G network.

In the prior art, the Sv interface and the a interface are processed separately, and the a interface switching record has no user identification, so that the a interface switching cannot be analyzed at the user level, and the detailed service condition of the a interface cannot be obtained when the whole SRVCC/eSRVCC service is analyzed.

The invention carries out the association processing of the Sv interface and the A interface, and backfills the user identification of the Sv interface into the A interface switching record, thereby carrying out the user level analysis on the A interface switching record, and further expanding the association analysis of the SRVCC/eSRVCC service to the A interface.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for backfilling a user identifier of an SRVCC/eSRVCC A interface record, wherein an Sv interface and an A interface can be associated through key switching parameters, and the user identifier of the Sv interface is backfilled into the A interface switching record, so that the A interface switching record can be analyzed at a user level.

The specific technical scheme of the invention is as follows:

a method for backfilling user identification of an SRVCC/eSRVCC A interface record comprises the following steps:

step a: decoding and synthesizing the Sv interface message, and extracting corresponding parameters according to different information;

step b: establishing a node according to the key switching parameters for the correlation search of the interface A, and filling user identity identification information in the node;

step c: decoding and synthesizing the A interface message, and extracting corresponding parameters according to different information;

step d: and after receiving the switching completion message, searching the node according to the key switching parameter, finding the user identity identification information in the node, taking out the user identity identification information, and putting the user identity identification information into the current interface A record.

Further, the Sv interface is an interface between the mobility management entity MME and the mobile switching center Server MSC Server, and the Sv interface is a newly added interface of SRVCC/eSRVCC.

Further, the a interface is an interface between the mobile switching center Server MSC Server and the base station controller BSC, and the a interface is an interface in a 2G network.

Preferably, before the step a is executed, the method further includes decoding a message of a bottom layer, and determining an interface type of a current message.

Further, the key handover parameters include a target cell identity and a handover reference.

Preferably, the different information of step a includes an SRVCC PS to CS request message and an SRVCC PS to CS response message.

Further, the extracting of the corresponding parameters in the step a includes extracting a target cell identifier and user identity identifier information in a SRVCC PS to CS request message, and extracting a handover reference in a SRVCC PS to CS response message.

Preferably, the subscriber identity information includes an international mobile subscriber identity IMSI and a mobile subscriber ISDN number MSISDN.

Further, the different information of step c includes a handover request message and a handover request response message.

Preferably, the extracting of the corresponding parameter in step c includes extracting a target cell identifier in a handover request message, and extracting a handover reference in a handover request response message.

Further, in the step d, if the handover completion message is not received, it is determined whether the interface a receives the end message or the handover record timeout timer expires, if so, the node is searched according to the key handover parameter, the user identity identification information is found and taken out, and the user identity identification information is put into the current interface a record; otherwise, processing other interfaces A.

The embodiment of the invention has the following beneficial effects:

the invention backfills the user identification (IMSI and MSISDN) to the A interface switching record, thereby analyzing the user level of the A interface switching record without user identification originally, and further expanding the correlation analysis of SRVCC/eSRVCC service to the A interface.

Drawings

FIG. 1 is a diagram of the relevant network interfaces and equipment in SRVCC/eSRVCC technology;

fig. 2 is a schematic message flow diagram of an Sv interface and an a interface when SRVCC/eSRVCC occurs according to an embodiment of the present invention;

fig. 3 is a flowchart of a method for backfilling a subscriber identity of an SRVCC/eSRVCC a interface record according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

SRVCC, i.e., single channel continuous service, by which a terminal can be handed over from LTE to CS (Circuit switched) domain in single channel mode. SRVCC establishes a CS domain call branch when a UE (User Equipment) moves from LTE to CS, and connects the CS branch and a source IMS (IP Multimedia Subsystem) to a call-side branch through an SCC AS (Service Centralization and Continuity Application Server) anchor point, thereby forming a complete call chain and maintaining that IMS domain calls can continue after handover. In the SRVCC handover process, the SCC AS in the IMS network is required to organize the handover method and the media handover of the participants, which results in a long delay.

The SRVCC networking contains three domains, EPC (Evolved Packet Core), CS and IMS. Before switching, the terminal user resides in EPC domain, and communicates with the opposite terminal user through IMS domain. After the handover, the terminal user accesses in the CS domain. The switching branch goes through Enhanced MSC to MGCF (Media Gateway Control Function), and continues to communicate with the opposite end user.

On the basis of SRVCC, the eSRVCC adds an ATCF (Access Transfer Control Function) network element AS a pre-network element of the SCC AS a signaling plane anchor point instead of the SCC AS. The ATCF is located in a service network, the SCC AS is located in a home network, and the ATCF is closer to the terminal, so that the bearing establishment time from the MSC to the IMS is reduced. The eRVCC can shorten the interruption time of the switching process and optimize the performance. Under any scenes such as roaming or operator intercommunication, the eSRVCC can ensure that the switching interruption time delay is less than 300 ms.

The overall architecture of the eSRVCC is basically consistent with that of SRVCC, and the following two network elements are added on the basis of SRVCC:

an ATCF (Access Transfer Control Function) network element serves AS a pre-network element of the SCC AS, and replaces the SCC AS a signaling plane anchor point.

The ATGW (Access Transfer Gateway) network element is used as a media plane anchor point and is matched with the ATCF network element to work.

Example 1

Fig. 2 is a message flow diagram of an Sv interface and an a interface when SRVCC/eSRVCC occurs, where a SRVCC PS to CS request message of the Sv interface includes a User identity of a UE (User Equipment): IMSI (International Mobile Subscriber identity) and MSISDN (Mobile Station ISDN number). The a interface is a standard handover procedure, and all messages do not contain user identification.

Typically, the association between the interfaces of a communication network is by user identification: TMSI (Temporary Mobile Subscriber Identity), IMSI (International Mobile Subscriber Identity), etc., but the a interface cannot be used because it does not have such information when SRVCC/esvcc occurs.

When SRVCC/eSRVCC occurs, a cross-system handover procedure actually occurs, and in the handover procedure, some resource information for handover is inevitably interacted between the source and the target, and in this embodiment, some key handover parameters (target cell identity and handover reference) are adopted, and the Sv interface and the a interface are recorded and associated together.

(1) Target cell identification

The SRVCC PS to CS request message on the Sv interface contains the Target Cell Global identity (Target Global Cell ID) to which handover is desired, and this parameter is passed to the Target BSC in the handover request message on the a interface.

(2) Handover reference

The handover request confirmation message sent by the side of the a interface BSC carries a complete rr (radio resource) layer handover command message, which includes air interface resource information allocated in the target BSC, and these information will be transmitted to the MME by using the SRVCC PS to CS response of the Sv interface. Of these information, the present embodiment selects a handover reference for association, the handover reference being an integer of one byte, identifying a handover within a cell.

Example 2

Fig. 3 is a flowchart of a method for backfilling an SRVCC/eSRVCC a interface record into a subscriber identity, which is provided by an embodiment of the present invention, and the method for backfilling the SRVCC/eSRVCC a interface record into the subscriber identity first performs message decoding on a bottom layer, and determines an interface type of a current message, and further includes the following steps:

step a: and decoding and synthesizing the Sv interface message, and extracting corresponding parameters according to different information.

Specifically, extracting target cell identification and user identity identification (IMSI and MSISDN) from SRVCC PS to CS request message; the handover reference is extracted from the SRVCC PS to CS response message.

Step b: and establishing a node according to the key switching parameters for the A interface correlation search, and filling user identity identification information in the node.

Specifically, whether a response message from the SRVCC PS to the CS is received is judged, if yes, step b is executed, otherwise, other Sv interface processing is performed.

Step c: decoding and synthesizing the A interface message, and extracting corresponding parameters according to different information.

Specifically, extracting a target cell identifier from a handover request message; a handover reference is extracted from the handover request response message.

Specifically, due to reasons such as handover failure and message loss, there may be a situation that no handover completion message is received at the a interface, and in order to enable the handover record to be normally associated with the Sv interface, when the handover record of the a interface receives an end message or the handover record timeout timer expires, the association processing of the Sv interface is performed.

For the time of the association of the interface a, if the interface a obtains the handover request confirmation messages of all the parameters used for association, the information of the Sv interface is disassociated, and since the Sv interface at this time is likely not to receive the SRVCC PS to CS response message yet and cannot obtain the corresponding user identification information, the association fails, so that the present embodiment delays to receive the handover completion message and then disassociates the Sv interface.

Example 3

The embodiment provides a C language description of an association data structure of an Sv interface and an a interface, and the code is as follows:

struct sv_a_asso_info{

short dst_lac;

short dst_ci;

unsigned char dst_mcc;

unsigned char dst_mnc;

unsigned char hd_ref;

unsigned char reserved;

char imsi[MAX_IMSI_LEN];

char msisdn[MAX_ISDN_LEN];

};

wherein, the target cell identification is filled in dst _ mcc, dst _ mnc, dst _ lac and dst _ ci, and the handover reference is filled in hd _ ref.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, therefore, the present invention is not limited by the appended claims.

Claims

1. A method for backfilling user identification of an SRVCC/eSRVCC A interface record is characterized by comprising the following steps:

step a: decoding and synthesizing the Sv interface message, and extracting corresponding parameters according to different information; the different information comprises SRVCC PS to CS request information and SRVCC PS to CS response information, the extracting of the corresponding parameters comprises extracting target cell identification and user identity identification information in the SRVCC PS to CS request information, and extracting switching reference in the SRVCC PS to CS response information;

step c: decoding and synthesizing the A interface message, and extracting corresponding parameters according to different information; the different information comprises a switching request message and a switching request response message, and the extracting of the corresponding parameter comprises extracting a target cell identifier in the switching request message and extracting a switching reference in the switching request response message;

step d: after receiving the switching completion message, searching the node according to the key switching parameter, finding the user identity identification information in the node, taking out the user identity identification information, and putting the user identity identification information into the current interface A record;

the key handover parameters in all steps include a target cell identity and a handover reference.

2. The method of claim 1, wherein the Sv interface is an interface between a mobility management entity MME and a mobile switching center Server MSC Server, and the Sv interface is a newly added interface of SRVCC/eSRVCC.

3. The method of claim 1, wherein the a interface is an interface between a mobile switching center Server MSC Server and a base station controller BSC, and the a interface is an interface in a 2G network.

4. The method as claimed in claim 1, wherein the step a is further performed by performing a bottom layer message decoding to determine the interface type of the current message.

5. The method of claim 1, wherein the subscriber identity information comprises an International Mobile Subscriber Identity (IMSI) and a mobile subscriber ISDN number (MSISDN).

6. The method according to claim 1, wherein in step d, if no handover complete message is received, it is determined whether the a interface receives end information or a handover record timeout timer expires, and if so, the node is searched according to a key handover parameter, and the user identity information is found and taken out to be placed in the current a interface record; otherwise, processing other A interfaces.