WO2007045138A1

WO2007045138A1 - A method and system for preventing failure of mobile-terminated call

Info

Publication number: WO2007045138A1
Application number: PCT/CN2006/001579
Authority: WO
Inventors: Jie Li; Ying Tang; Yunxia Cai
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2005-10-21
Filing date: 2006-07-05
Publication date: 2007-04-26
Also published as: CN1819699A; CN1332584C

Abstract

A method for preventing failure of mobile-terminated call comprises the steps: a network device selecting a second MSC to substitute a first MSC from a MSC pool where the first MSC is located when learning that the first MSC where a called subscriber is located currently has failed; the second MSC allocating a roaming number for the called subscriber according to roaming number request, and obtaining subscriber data of the called subscriber; originating a call to the second MSC according to the roaming number, and the second MSC paging the called subscriber according to the subscriber data of the called subscriber and establishing the call after obtaining a response. At the same time, the present invention also discloses a communication system.

Description

Method and system for preventing mobile terminated call failure

The present invention relates to mobile communication technologies in the field of communications, and more particularly to a method and system for preventing a mobile terminated call from failing. Background technique

In 3GPP TS 23.236, IU FLEX (Intra-domain comiection of RAN nodes to multiple CN nodes) technology is described, the purpose of which is to implement one RAN node and multiple core networks in the same domain (CS/PS) ( CN) Networking mode of node connection. The networking example is shown in Figure 1. In the CS pool-areal, the mobile switching centers MSC1, MSC2 and MSC3 form a mobile switching center pool MSC POOL1, and the mobile switching centers MSC4, MSC5 and MSC6 form another mobile switching center pool MSC POOL2.

As can be seen from the figure, if one of the MSCs in MSC POOL1, for example, MSC1/VLR1, fails (for convenience of description, it is assumed that the MSC and the VLR are integrated and the MSC number and its associated VLR number are the same), then MSC1/VLR1 Dynamic user data will be lost. As shown in Figure 2: A mobile terminated call occurs, that is, a call is made to the user B; the home location register (HLR) of the user B takes the roaming number PRN to the mobile switching center MSC1; but because the MSC1 fails, the HLR B will The response is not received or a failure response is received; the HLRB returns a failure response to the gateway mobile switching center GMSC, which ultimately results in a call loss. Summary of the invention

The present invention provides a method and system for preventing a mobile terminated call from failing to solve the problem that the prior art fails to terminate the call when a mobile switching center in the mobile switching center pool fails.

The invention provides the following technical solutions:

A method for preventing a mobile terminated call from failing includes the following steps:

When the network device learns that the first mobile switching center where the called user is currently inactive, it moves from the first one. The second mobile switching center is selected in the mobile switching center pool (MSC POOL) where the mobile switching center is located instead of the first mobile switching center;

The second mobile switching center allocates a roaming number to the called user according to the roaming number request, and acquires user data of the called user from a home location register (HLR);

A call is initiated to the second mobile switching center according to the roaming number, and the second mobile switching center pages the called user according to the user data of the called user, and establishes a call after obtaining the response.

among them:

The network device learns that the mobile switching center fails in a manual setting manner, an automatic sensing manner, or a semi-automatic manner.

The network device selects the second mobile switching center from the pool of mobile switching centers using the same algorithm as the selected radio network controller (RNC).

The second mobile switching center acquires user data from the HLR through one or more interactions. The network device is a home location register (HLR), and the mobile switching center information included in the mobile switching center pool and each mobile switching center pool is configured on the HLR.

The network device is a signaling switching point (STP), and the mobile switching center pool and the mobile switching center information included in each mobile switching center pool are configured on the STP.

The home location register accesses the second mobile switching center through the STP.

A network device, including:

a storage unit, configured to store information of a mobile switching center pool (MSC POOL) and a mobile switching center included therein;

The selecting unit selects the second mobile switching center from the pool of the corresponding mobile switching center when it is known that the first mobile switching center where the user is currently located fails;

a connection unit, configured to send a call addressed to the first mobile switching center to the second mobile switching center for processing.

A communication system comprising:

Mobile switching center for controlling calls; a network device, configured to save information of a mobile switching center pool (MSC POOL) and a mobile switching center included therein, and the network device is in the pool of the corresponding mobile switching center when it knows that the first mobile switching center where the user is currently inactive The second mobile switching center is selected to replace the failed mobile switching center for subsequent call processing.

The network device is a home location register; or the network device is a signaling transfer point. According to the present invention, when an MSC in the MSC POOL fails (such as a failure), an alternative MSC is selected from the MSC POOL for the called user, and the MSC acquires user data and pages the user, thereby making the user Mobile terminated calls can still be successful, thus avoiding call loss. DRAWINGS

1 is a schematic diagram of a configuration of an existing MSC POOL;

2 is a flow chart of a mobile terminated call after an MSC failure in an existing MSC POOL; FIG. 3 is a schematic structural diagram of a network device according to an embodiment of the present invention;

4 and FIG. 5 are flowcharts showing a mobile terminated call after an MSC failure occurs in an MSC POOL according to an embodiment of the present invention. detailed description

In order to avoid the loss of the mobile terminated call when the MSC fails in the mobile switching center pool (MSC POOL), when the network device learns that an MSC fails, another normal MSC is selected from the MSC POOL where the MSC is located instead of the invalidation. The MSC, in normal processing, terminates the call.

Referring to FIG. 3, the network device 30 in this embodiment includes a storage unit 300, a selection unit 310, and a connection unit 320. The storage unit 300 stores the information of the mobile switching center pool (MSC POOL) and the information of the mobile switching center included therein. The selecting unit 310 has a connection relationship with the storage unit for knowing that the mobile switching center where the user is currently located is invalid. And selecting another normal mobile switching center from the pool of mobile switching centers according to the information stored in the storage unit 300; the connecting unit 320 transmits the call addressed to the failed mobile switching center to the selected another mobile switching The heart is processed.

The network device 30 may be a home location register (HLR), which is more suitable for a local network user; the network device 30 may also be a signaling transfer point (STP), which is more suitable for non-local network users and Roaming users.

The HLR and STP learn about the failure of the mobile switching center, including: manual setting, automatic sensing mode or semi-automatic mode, where:

A. Manual setting means that after the MSC fails, the MSC is manually set to the invalid state on the HLR or STP.

B. The automatic sensing mode refers to interacting with the MSC through the HLR or STP. When the HLR or STP finds that the MSC does not respond correctly, the MSC is automatically set to a failure state.

C. The semi-automatic mode refers to interacting with the MSC through the HLR or STP. When the HLR or STP finds that the MSC does not respond correctly, it generates an alarm, which is manually determined and sets the MSC to a failed state.

The MSC is selected from the MSC POOL. The preferred method is to use the same algorithm as the Radio Network Controller (RNC). Of course, other algorithms can be used for selection.

The following is a detailed description with reference to the accompanying drawings:

The MSC POOL is configured in the HLR database, and when the MSC fails, the HLR selects an alternate MSC from the corresponding MSC POOL.

Taking the network structure of Fig. 1 as an example, the HLR is configured with two MSC POOLs, one for POOL1, including mobile switching centers MSC1, MSC2 and MSC3, and the other for MSC POOL2, including mobile switching centers MSC4, MSC5 and MSC6. If the current home MSC of mobile subscriber B is MSC1 and MSC1 fails, the mobile terminated call processing process for user B is as shown in FIG. 4:

1. A call from user A to mobile user B is initiated on the GMSC.

2. The GMSC sends a routing information request SRI (Send Routing Information) to the HLR of the user B.

3. The HLR finds that the current VLR of the user B is MSC1/VLR1 from the user database, and the HLR finds that the MSC1/VLR1 has failed, and the HLR obtains the MSC from the MSC1/VLR1. Another normal working MSC is selected in POOL1, for example, MSC2/VLR2 is selected instead of MSC1, and the HLR sends a PRN (Prov. Roaming Number) to MSC2/VLR2 to obtain the roaming number of User B.

4. After receiving the PRN request from the HLR, MSC2/VLR2 assigns the roaming number to the HLR (PRNAck); meanwhile, since MSC2/VLR2 does not have the data of User B, the data is restored to the HLR.

5. The HLR inserts User Data (Insert Subscriber Data) into MSC2/VLR2, and responds with MSC2/VLR.

Inserting user data between the HLR and MSC2/VLR2 may be done in one interaction or through multiple interactions.

6. The HLR responds to the MSC2/VLR2 response data recovery (Restore DataAck).

7. After obtaining the PRNAck of MSC2/VLR2, the HLR returns SRI_ACK to the GMSC;

8. The GMSC initiates a call to MSC2 based on the MSRN.

9. The MSC2 obtains the incoming call request of the MSRN and waits for the recovery data to be completed, and has obtained the user information of the user B. Since the MSC2/VLR2 does not have the current location area of the user B, it searches for the coverage of the MSC2 (ie, PoolAreal). Call (using the subscriber's IMSI as the paging identifier).

10. Since User B is actually within the scope of PoolAreal, it can receive the paging and give the paging response; RNC BSC sends the paging response to MSC2 according to IMSI.

11. After MSC2, the call is established according to the normal procedure.

In order to modify the HLR as little as possible, MSC POOL is configured in the STP database. When the MSC fails, an alternative MSC is selected by the STP MSC POOL; the HLR to MSC signaling is transferred through STP.

Taking the network structure of FIG. 1 as an example, STP configures two MSC POOLs, one for POQL1, including mobile switching centers MSC1, MSC2 and MSC3, and the other for MSC POOL2, including mobile switching centers MSC4, MSC5 and MSC6. If the current home MSC of mobile subscriber B is MSC1 and MSC1 fails, the mobile terminated call processing process for user B is as shown in FIG. 5: 1. A call from user A to mobile user B is initiated on the GMSC.

3. The HLR finds that the current LR of the user B is MSCl/VLR1 from the user database, and sends a PRN (Prov. Roaming Number) to obtain the roaming number of the user B. The CdPA (Called Party Address) of the SCCP of the message is MSC1/VLR1. The message was relayed via STP.

4. STP obtains MSCl/VLR1 from the SCCP CldPA of the MAP message PRN, and finds that MSCl/VLR1 has failed; then STP selects another normal working MSC from MSC POOL1 where MSCl/VLR1 is located, for example, MSC2/VLR2 is selected instead. MSC1, STP forwards the CldPA of the SCCP of the PRN to MSC2 VLR2 and then forwards it.

5. After receiving the PRN request, MSC2/VLR2 assigns the roaming number to the HLR (PRN Ack), and at the same time, since MSC2 VLR2 does not have the data of User B, it recovers the data to the HLR.

( Restore Data ).

6. The HLR inserts user data (Insert Subscriber Data) into MSC2/VLR2, and responds with MSC2/VLR.

7. The HLR responds to the MSC2 VLR2 with a Restore Data Ack.

8, 11 in getting ^^2€2 \^1 2? After 1^8 01^, reply SRI-ACK to GMSC.

9. The GMSC initiates a call to MSC2 based on the MSRN.

10. The MSC2 obtains the incoming call request of the MSRN and waits for the recovery data to be completed, and has obtained the user information of the user B. Since the MSC2/VLR2 does not have the current location area of the user B, it searches for the coverage of the MSC2 (ie, PoolAreal). Call (using the subscriber's IMSI as the paging identifier).

11. Since User B is actually within the scope of PoolAreal, it can receive the page and give a page response. The RNC/BSC sends a paging response to MSC2 based on IMSI.

12. After MSC2, the call is established according to the normal procedure. ' In FIG. 4, although MSC2 acquires user data from the HLR through STP, it is not limited thereto, and MSC2 can directly acquire data by interacting with the HLR.

It can be seen from the above that after an MSC/VLR failure in the MSC POOL, the user on the mobile terminal can still succeed in the mobile termination call, thereby avoiding call loss.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Therefore, it is intended that the present invention cover the modifications and variations of the invention as claimed.

Claims

Rights request

A method for preventing a mobile terminated call from failing, comprising the steps of: when the network device learns that the first mobile switching center where the called user is currently inactive, from the mobile switching center pool where the first mobile switching center is located ( MSC POOL) selects the second mobile switching center instead of the first mobile switching center;

2. The method according to claim 1, wherein the network device learns that the mobile switching center fails in a manually set manner, an automatic sensing manner, or a semi-automatic manner.

3. The method of claim 1 wherein the network device selects the second mobile switching center from the pool of mobile switching centers using the same algorithm as the selected radio network controller (RNC).

4. The method of claim 1 wherein the second mobile switching center acquires user data from the HLR by one or more interactions.

The method according to any one of claims 1 to 4, wherein the network device is a home location register (HLR), and the mobile switching center pool and each mobile switching center pool are configured on the HLR. Mobile switching center information.

The method according to any one of claims 1 to 4, wherein the network device is a signaling transfer point (STP), and the mobile switching center pool and each mobile switching center pool are configured on the STP. Contains mobile switching center information.

7. The method of claim 6, wherein the home location register accesses the second mobile switching center via the STP.

8. A network device, comprising:

a storage unit, configured to store information of a mobile switching center pool (MSC POOL) and a mobile switching center included therein; The selecting unit selects the second mobile switching center from the pool of the corresponding mobile switching center when it is known that the first mobile switching center where the user is currently located fails;

9. The network device according to claim 8, wherein the network device is a home location register or a signaling transfer point.

10. A communication system, comprising:

Mobile switching center, used to control calls;

a network device, configured to save information of a mobile switching center pool (MSC POOL) and a mobile switching center included therein, and the network device is in the pool of the corresponding mobile switching center when it knows that the first mobile switching center where the user is currently inactive The second mobile switching center is selected to replace the failed mobile switching center for subsequent call processing.

The communication system according to claim 10, wherein the network device comprises: a storage unit, configured to store information of a mobile switching center pool (MSC POOL) and a mobile switching center included therein;

The communication system according to claim 11, wherein the network device is a home location register or a signaling transfer point.