CN1332584C - Method and system for preventing mobile terminal calling fault - Google Patents

Abstract

The present invention discloses a method and a system for preventing mobile terminal calling failure. In the method, when network equipment knows a first mobile switching center which called subscribers currently are placed in fails, a second mobile switching center is selected from a mobile switching center pool (MSC POOL) which the first mobile switching center is placed in to replace the first mobile switching center; the second mobile switching center distributes roaming numbers for the called subscribers according to a request of the roaming numbers, and subscriber data of the called subscribers can be obtained from an HLR; calling is initiated towards the second mobile switching center according to the roaming numbers, the second mobile switching center pages the called subscribers according to the subscriber data of the called subscribers, and the calling is established after response is obtained. The present invention also discloses a communication system simultaneously.

Description

Method and system for preventing mobile termination call failure

technical field

The invention relates to mobile communication technology in the field of communication, in particular to a method and system for preventing mobile termination call failure.

Background technique

In 3GPP TS 23.236, the IU FLEX (Intra-domain connection of RANnodes to multiple CN nodes) technology is described. The purpose of this technology is to realize that one RAN node in the same domain (CS/PS) can communicate with multiple core networks (CN ) node connection networking mode, 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 a certain MSC in MSC POOL1, such as MSC1/VLR1, breaks down (for convenience of description, it is assumed that MSC and VLR are integrated and the MSC number is the same as its associated VLR number), then in MSC1/VLR1 Dynamic user data for will be lost. As shown in Figure 2: a user’s mobile termination call occurs, that is, a phone dials the user B; the home location register (HLR) of user B will obtain the roaming number PRN from the mobile switching center MSC1; but due to the failure of MSC1, HLR B will No response or failure response is received; HLR B returns a failure response to the gateway mobile switching center GMSC, resulting in call loss.

Contents of the invention

The invention provides a method and system for preventing mobile termination call failure to solve the problem in the prior art that a mobile switching center in the mobile switching center pool fails to cause call termination failure.

The invention provides the following technical solutions:

A method for preventing mobile termination call failure, comprising the steps of:

When the signaling transfer point receives the roaming number request sent to the first mobile switching center and determines that the first mobile switching center is invalid, it selects the second mobile switching center from the mobile switching center pool where the first mobile switching center is located, and Sending the roaming number request to the second mobile switching center, the signaling transfer point is configured with information about mobile switching center pools and mobile switching centers included in each mobile switching center pool;

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

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

in:

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

The network device selects the second MSC from the MSC pool using the same algorithm as that used for selecting a Radio Network Controller (RNC).

The second mobile switching center acquires subscriber data from the HLR through one or more interactions.

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

A communication system comprising:

Mobile Switching Center for controlling calls;

a home location register, used for storing user data, and obtaining a roaming number after receiving the routing information request from the mobile switching center;

The signaling transfer point stores the information of the mobile switching center pool (MSC POOL) and the mobile switching center it contains. When receiving the request for obtaining the roaming number from the home location register and knowing that the mobile switching center where the user is currently located is invalid , select another MSC from the corresponding MSC pool to replace the failed MSC for subsequent call processing.

By adopting the present invention, when a certain MSC in the MSC POOL fails (such as failure), an alternative MSC is selected for the called user from the MSC POOL again, and the MSC obtains user data and pages the user, so that the user's Mobile terminated calls can still succeed, avoiding call loss.

Description of drawings

Figure 1 is a schematic diagram of the configuration of the existing MSC POOL;

Fig. 2 is the flowchart of mobile termination call after certain MSC failure in existing MSC POOL;

Fig. 3, Fig. 4 are the flow chart of mobile termination call after certain MSC failure in MSC POOL of the present invention.

Detailed ways

In order to avoid the loss of mobile termination calls when a certain MSC in the mobile switching center pool (MSC POOL) fails, when the network device learns that a certain MSC has failed, select another normal MSC from the MSC POOL where the MSC is located to replace the failed one. MSC to handle mobile terminated calls normally.

The network device may be a home location register (HLR), and this solution is more suitable for local network users; the network device may also be a signaling transfer point (STP), and this solution is more suitable for local network users and roaming users.

The ways for HLR and STP to learn about the failure of the mobile switching center include: manual setting, automatic sensing or semi-automatic, wherein:

A. The way of manual setting means that after the MSC is found to be invalid, the MSC is manually set to the invalid state on the HLR or STP.

B. The automatic sensing method 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 automatically sets the MSC to an invalid state.

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

To select MSC from MSC POOL, the better way is to use the same algorithm as selecting the radio network controller (RNC), and of course other algorithms can also be used for selection.

Describe in detail below in conjunction with accompanying drawing:

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

Taking the network structure in Figure 1 as an example, HLR configures two MSC POOLs, one is POOL1, including mobile switching centers MSC1, MSC2 and MSC3; the other is MSC POOL2, including mobile switching centers MSC4, MSC5 and MSC6. If the current home MSC of mobile user B is MSC1, and MSC1 fails, the mobile termination call processing of user B is as follows:

1. Initiate a call from user A to mobile user B on the GMSC.

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

3. HLR finds out from the user database that the current VLR of user B is MSC1/VLR1, and at the same time, HLR finds that MSC1/VLR1 has failed, so HLR selects another MSC that works normally from MSC POOL1 where MSC1/VLR1 is located, for example, select MSC2/VLR2 replaces MSC1, and HLR sends PRN (Provide Roaming Number) to MSC2/VLR2 to obtain user B's roaming number.

4. After MSC2/VLR2 obtains the PRN request of HLR, it distributes the roaming number and returns to HLR (PRN Ack); meanwhile, because MSC2/VLR2 does not have the data of user B, it restores data (Restore Data) to HLR.

5. HLR inserts subscriber data (Insert Subscriber Data) into MSC2/VLR2, and MSC2/VLR responds.

The insertion of user data between HLR and MSC2/VLR2 may be completed through one interaction or through multiple interactions.

6. HLR responds to MSC2/VLR2 with Restore Data Ack.

7. After HLR gets the PRNAck from MSC2/VLR2, it replies SRI ACK to GMSC.

8. The GMSC initiates a call to MSC2 according to the MSRN.

9. MSC2 has obtained the user B's user information after receiving the incoming call request from MSRN, and at the same time after the restoration of data is completed; since MSC2/VLR2 does not have the current location area of user B, it searches for the coverage area of MSC2 (that is, PoolAreal). call (using user B's IMSI as the paging identifier).

10. Since user B is actually within the range of PoolAreal, user B can receive paging and give a paging response; RNC/BSC sends a paging response to MSC2 according to the IMSI.

11. MSC2 then establishes a call according to the normal process.

In order to change the HLR as little as possible, MSC POOL is configured in the STP database. When the MSC fails, the STP selects an alternative MSC from the corresponding MSC POOL; the signaling from the HLR to the MSC is transferred through the STP.

Taking the network structure in Figure 1 as an example, STP configures two MSC POOLs, one is POOL1, including mobile switching centers MSC1, MSC2 and MSC3; the other is MSC POOL2, including mobile switching centers MSC4, MSC5 and MSC6. If the current home MSC of mobile user B is MSC1, and MSC1 fails, the mobile termination call processing of user B is as follows:

1. Initiate a call from user A to mobile user B on the GMSC.

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

3. The HLR finds out from the user database that the current VLR of user B is MSC1/VLR1, and sends a PRN (Provide Roaming Number) to obtain the roaming number of user B. The SCCP CldPA (Called Party Address) of the message is MSC1/VLR1, The message is relayed through STP.

4. STP obtains MSC1/VLR1 from CldPA of SCCP of MAP message PRN, and finds that MSC1/VLR1 has failed; then STP selects another MSC that works normally from MSC POOL1 where MSC1/VLR1 is located, for example, selects MSC2/VLR2 instead MSC1, STP changes the CldPA of the SCCP of the PRN to MSC2/VLR2 before forwarding.

5, MSC2/VLR2, after obtaining PRN request, distribute roaming number and return to HLR (PRN Ack), simultaneously because MSC2/VLR2 does not have the data of user B, just restore data (RestoreData) to HLR.

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

The insertion of user data between HLR and MSC2/NLR2 may be completed through one interaction or through multiple interactions.

7. HLR responds to MSC2/VLR2 with Restore Data Ack.

8. After HLR gets the PRN Ack from MSC2/VLR2, it replies SRI ACK to GMSC.

9. The GMSC initiates a call to MSC2 according to the MSRN.

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

11. Since user B is actually within the range of PoolAreal, he can receive the paging and give a paging response. RNC/BSC sends the paging response to MSC2 according to the IMSI.

12. MSC2 then establishes a call according to the normal process.

In Fig. 4, although MSC2 obtains user data from HLR through STP, it is not limited to this, and MSC2 can directly interact with HLR to obtain data.

It can be seen from the above that after a certain MSC/VLR in the MSC POOL fails, the mobile termination calls of the users on it can still succeed, thereby avoiding call loss.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (6)

1, a kind of method that prevents mobile terminal calling fault is characterized in that, comprises the steps:

When Signalling Transfer Point receives the roaming number request of mailing to first mobile switching centre and determines that this first mobile switching centre lost efficacy, from the mobile switching centre pond at the first mobile switching centre place, select second mobile switching centre, and described roaming number request sent to described second mobile switching centre, dispose the information of the mobile switching centre that mobile switching centre pond and each mobile switching centre pond comprised on the described Signalling Transfer Point;

Described second mobile switching centre is that described called subscriber distributes roaming number according to the roaming number request, and obtains called subscriber's user data from attaching position register;

Make a call to second mobile switching centre according to described roaming number,, and obtaining the foundation calling of response back by the user data calling called subscriber of second mobile switching centre according to the called subscriber.

2, the method for claim 1 is characterized in that, described Signalling Transfer Point knows that the mode that mobile switching centre lost efficacy is the artificial mode that is provided with, automatic perceptive mode or semi-automatic mode.

3, the method for claim 1 is characterized in that, described Signalling Transfer Point adopts the algorithm identical with selecting radio network controller to select second mobile switching centre from the mobile switching centre pond.

4, the method for claim 1 is characterized in that, described second mobile switching centre obtains user data from described HLR alternately by one or many.

5, the method for claim 1 is characterized in that, described attaching position register is visited second mobile switching centre by described STP.

6, a kind of communication system is characterized in that, comprising:

Mobile switching centre is used for controlling call;

Attaching position register is used for storaging user data, and obtains roaming number after the routing iinformation request that receives described mobile switching centre;

Signalling Transfer Point, the information of the mobile switching centre that preserves the mobile switching centre pond and comprised, when the roaming number request of obtaining that receives described attaching position register and the mobile switching centre of knowing the current place of user lost efficacy, the mobile switching centre of selecting another mobile switching centre to replace losing efficacy from corresponding mobile switching center pond carried out subsequent voice calls and handles.

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