CN101217694B - A method, system and device of called resumption in the mobile transferring pool - Google Patents

Abstract

The invention discloses a method, system and equipment for called recovery in a pool of a mobile switching center, belonging to the communication field. The method includes: receiving a routing request message forwarded by a signaling transfer point or a media gateway; selecting an effective mobile switching center in a mobile switching center pool according to the called user information in the received routing request message; Center; connecting the call to the active mobile switching center by means of an intersystem message, and the called user is connected by the active mobile switching center. The system includes: a home location register, a signaling switching device, a backup center, an active mobile switching center and a base station controller. The device includes a setting module, an acquiring module and a call connecting module. The invention ensures that the called user can be successfully connected to the called user when a faulty MSC occurs by selecting an effective MSC as the called party by the backup center.

Description

Method, system and device for called recovery in mobile switching center pool

technical field

The invention relates to the communication field, in particular to a method, system and equipment for called recovery in a mobile switching center pool. the

Background technique

With the development of mobile communications, softswitches have been put into use on a large scale. Refer to the network structure of the MSC (Mobile Switch Center, Mobile Switching Center) pool in the mobile communication system provided in Figure 1, wherein, BSC (Base Station Control, base station Controller)/RNC (Radio Network Control, radio network controller) is connected to multiple MSCs at the same time, and the BSC distributes services to each MSC, and each MSC performs load sharing and redundant backup. the

When the control layer and the bearer layer of the mobile communication system are separate architectures, the MSC pool in the mobile communication system can also be realized through the networking structure provided in Figure 2. In this networking structure, BSC or RNC and multiple MSC Servers (servers) ) intercommunication, each MSC Server uses the same signaling point to interact with BSC/RNC; BSC/RNC signaling is transferred through MGW (MediaGateway, media gateway), one BSC/RNC can connect to one or more MGWs, and MGW uses virtual MGW technology, each virtual MGW in the MGW is connected to one MSC Server. Among them, MSC Server is called MSCe (Mobile Switching Center emulation, mobile soft switching center) under the CDMA2000 system. the

For the networking structure provided in Figure 2, the call message is distributed to each MSC Server by the MGW according to the IMSI (International Mobile Subscriber Identity)/TMSI (Temporary Mobile Station Identity, temporary mobile station identity), so that all services are distributed in each Load sharing between MSC Servers; when one MSC Server fails, the business will be distributed to other MSC Servers for processing, realizing redundant backup among MSC Servers. the

Referring to Figure 3, when the calling party initiates a call, if the MSC corresponding to the called party fails, the call to the called party will fail, and the specific processing process of the message is as follows: 

1) The calling party initiates a call, and sends a LOCREQ (Location Request, location request) message to HLR (Home Location Register, home location register) to request routing information. the

2) After the HLR receives the LOCREQ message of the calling party, it obtains the corresponding MSC of the called party according to the recorded MSC of the mobile phone as MSC1, sends a ROUTREQ (Routing Request, routing request) message to MSC1, and obtains the roaming number of the called party;

3) When MSC1 is faulty, MSC1 will fail to obtain the roaming number, which will lead to failure of the calling party. the

4) If MSC1 fails to resolve the fault within a period of time, the calling party can only call the called party when the called party re-registers or initiates a call, and the BSC or MGW distributes the called party to other normal MSCs. success. The longest duration is the periodic location duration, which is generally about 1 hour. That is to say, within one hour, the user corresponding to the faulty MSC cannot be called. the

In the process of realizing the present invention, the inventor finds that when an MSC in the MSC pool fails, if a user under the MSC is called, the user cannot be connected. the

Contents of the invention

In order to make the call succeed when the subscriber of the MSC belonging to the failed MSC in the MSC pool is called as the called party, the embodiment of the present invention provides a method, system and equipment for recovering the called party in the mobile switching center pool. Described technical scheme is as follows:

A method for called recovery in a mobile switching center pool, said method comprising:

When the signaling transfer point or media gateway finds that the called mobile switching center is unreachable, use the backup sub-routing or signaling control part load sharing function to select the backup center as the new called office;

The backup center receives the routing request message to the called user forwarded by the signaling transfer point or the media gateway;

The backup center selects an effective mobile switching center in the mobile switching center pool according to the IMSID of the called user in the received routing request message and the distribution algorithm and adjustment principle of the IMSID saved by itself;

The call is connected to the active mobile switching center by means of an intersystem message, and the called user is connected by the active mobile switching center. the

Further, the embodiment of the present invention also provides a system for recovering the called party in the mobile switching center pool, the system includes: a home location register, a signaling transfer device, a backup center, an active mobile switching center and a base station controller;

The home location register is used to send a routing request message to the called user to the original home mobile switching center of the called user after receiving the location request message to the called user;

The signaling transfer device is used to determine that the mobile switching center corresponding to the routing request message is faulty when the routing request message sent by the home location register passes through it, and then use the backup sub-routing or signaling to control part of the load sharing function Selecting the backup center as the new called office; forwarding the routing request message to the backup center according to the backup sub-routing configured by itself or the load sharing function of the signaling control part;

The backup center is used to receive the routing request message to the called user forwarded by the signaling transfer device, and select an effective mobile switching center in the mobile switching center pool according to the called user information in the received routing request message. Center, utilizing intersystem message to connect the call to said active mobile switching center;

The effective mobile switching center is configured to, after receiving the call forwarded by the backup center, send a paging request to the base station controller and receive the paging request response message of the called user, and then connect the call to the Describe the called user;

The base station controller is used for paging the called user after receiving the paging request from the effective mobile switching center, and after the called user responds to the paging of the base station controller, the called user The paging response message sent to the active mobile switching center. the

Furthermore, the embodiment of the present invention also provides a backup center device, when the signaling transfer point or the media gateway finds that the signaling point of the called mobile switching center is unreachable, it uses the backup sub-routes or signaling to control part of the load sharing The function selects the backup center as the new called office; the backup center equipment includes:

The setting module is used to store the user's location area identification, the international mobile station identification and the information of the user's call state under the mobile switching center in the backup mobile switching center pool, as well as the distribution algorithm and adjustment principle of the mobile switching center;

The obtaining module is used to receive the routing request message to the called user forwarded by the signaling transfer point or the media gateway, according to the received routing request message The called user's international mobile station identity and the backup of the setting module information, select an effective mobile switching center in the mobile switching center pool;

The call connecting module is used to connect the call to the active mobile switching center obtained by the obtaining module by using an inter-system message, and the active mobile switching center connects the called user. the

The embodiment of the present invention is a kind of backup central equipment, and described backup central equipment comprises:

The new mobile switching center acquisition module is used to obtain the new mobile switching center corresponding to the called party according to the same distribution algorithm as the base station controller or media gateway stored in advance after receiving the routing request message; the routing request message is a signaling forwarded by the transfer point after discovering that the original mobile switching center corresponding to the called party is faulty;

The call connecting module is configured to connect the call to the new mobile switching center obtained by the new mobile switching center obtaining module by using an intersystem message, and the new mobile switching center connects the called party. the

In the embodiment of the present invention, the backup center in the MSC pool selects other non-faulty MSCs in the MSC pool as the called office, and can successfully call users belonging to the faulty MSC. the

Description of drawings

Fig. 1 is a schematic diagram of a network structure of an MSC pool in a mobile communication system provided by the prior art;

Fig. 2 is a schematic diagram of the network structure of the MSC pool in another mobile communication system provided by the prior art;

Fig. 3 is a schematic diagram of message interaction when the MSC failure provided by the prior art;

Fig. 4 is a schematic diagram of the networking structure provided by the embodiment of the present invention;

Fig. 5 is the method flow chart of called recovery in the mobile switching center pool that the embodiment of the present invention 1 provides;

Fig. 6 is the method information interaction schematic diagram of called recovery in the mobile switching center pool that embodiment 1 of the present invention provides;

Fig. 7 is a schematic diagram of information interaction of another method for called recovery in the mobile switching center pool provided by Embodiment 1 of the present invention;

Fig. 8 is the method flow chart of called recovery in the mobile switching center pool that the embodiment of the present invention 2 provides;

Fig. 9 is a schematic diagram of the information interaction of the called recovery method in the mobile switching center pool provided by Embodiment 2 of the present invention;

Fig. 10 is the system schematic diagram of called recovery in the mobile switching center pool that the embodiment of the present invention 3 provides;

FIG. 11 is a schematic structural diagram of a backup center device provided by Embodiment 4 of the present invention. the

Detailed ways

The embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. the

The embodiment of the present invention pre-sets the backup center in the MSC pool. When the MSC fails and the user belonging to the faulty MSC is called, the backup center will select other MSCs that have not failed to perform call processing, thereby realizing disaster recovery for the called party. The successful recovery of the MSC and the load balance of each MSC in the MSC pool are guaranteed. In the embodiment of the present invention, the MSCs in the MSC pool that have not failed are called valid MSCs. the

Referring to Fig. 4, a backup center is preset in the MSC pool in this networking structure, and is used for backing up LAI (Location Area Identification, location area identification), IMSI, user status (on/off status or Call status), time slot index and other information are shared by all MSCs in the MSC pool, and the backup center itself does not undertake business, and each MSC updates user information to the backup center independently, and the distribution algorithm and adjustment principle of the mobile switching center are also set in the backup center. Among them, the distribution algorithm and adjustment principle of the mobile switching center are consistent with the distribution algorithm and adjustment principle of the mobile switching center configured by the base station controllers or media gateways that are connected to each mobile switching center in the mobile switching center pool. Generally speaking, the base station controller Or the mobile switching center distribution algorithm configured by the media gateway is the IMSI distribution algorithm, so the backup center also configures the IMSI distribution algorithm;

After a certain MSC failure is configured on the STP (Signaling Transfer Point, signaling transfer point) or MGW, the corresponding backup sub-route to the backup center, or the STP or MGW uses the backup center as the SCCP (SignalingConnection Control Part) of the failed MSC. , signaling control part) mutual assistance signaling point, the backup center selects an effective MSC as the called office, and the effective MSC performs call connection. the

At the same time, when the backup center detects the MSC state change (failure or recovery) in the MSC pool, it updates the mobile switching center distribution algorithm (IMSI distribution algorithm) according to the adjustment principle. the

The MSC mentioned in the embodiment of the present invention may be a traditional MSC, or a combination of an MSC Server and an MGW under a control and bearer separation architecture. the

Example 1

Referring to Fig. 5 and Fig. 6, present embodiment provides a kind of method that the called party recovers in the mobile switching center pool, and this method comprises:

Step 101: After the HLR receives the LOCREQ message sent by the calling office, it sends a ROUTREQ message to the called original home MSC1 to obtain the called roaming number, wherein the ROUTREQ message carries the MSC1's signaling point or other routing information;

Step 102: After receiving the ROUTREQ message, the STP or MGW adjacent to the original home MSC of the called party finds that the MSC1 signaling point of the called office is unreachable, and uses the backup sub-routing or SCCP load sharing function to select the backup center as the new called party. Make an office call and send the ROUTREQ message to the backup center;

When MSC1 fails, the physical link will notify the MSC1 of the failure, so that the STP or MGW adjacent to MSC1 can know that the signaling point of MSC1 is unreachable;

Step 103: After the backup center receives the ROUTREQ message, according to the IMSI of the called user in the ROUTREQ message and the IMSI distribution algorithm and adjustment principle saved by itself, it is found that the control node to which the called user is distributed after MSC1 fails is MSC2, and sends the message to MSC2 ROUTREQ or ISPAGE (Inter System Page, inter-system paging) message, carrying information such as LAI and time slot index of the called user with pre-backup;

Step 104: After receiving the ROUTREQ or ISPAGE message, MSC2 obtains the paging range according to the LAI, sends a paging request message to the BSC, that is, a Paging REQ message, and notifies the BSC or MGW of the called party, wherein the Paging REQ message carries TAG (tag ) parameter and paging range, TAG parameter is used to identify MSC2, for example: the number of MSC2 in the MSC pool;

Wherein, the BSC is located in the RAN (Radio Access Network, radio access network), and is connected with the called user terminal through a wireless signal. When MSC2 obtains the paging range according to the LAI, it can obtain the corresponding relationship between the pre-stored LAI identifier and the paging range, and the paging request message sent by MSC2 to the BSC can be forwarded through the media gateway;

Step 105: After receiving the Paging REQ message, the BSC or MGW sends a paging message to the called user according to the paging range in the Paging REQ message, and the called user reports a paging response message after receiving the paging message; BSC or After the MGW receives the paging response message from the called user, it obtains MSC2 according to the same IMSI distribution algorithm as that saved by it and the backup center, or obtains the MSC2 according to the TAG parameter in the paging request, and sends the paging response message (Paging RSP message) to MSC2 requesting paging;

Step 106: After MSC2 receives the paging response message, it interacts with HLR through the location registration process or qualification request process, and restores the user data of the called user in the VLR of MSC2;

Among them, the location registration process or the qualification request process is a prior art, which is realized by sending a REGNOT or QUALREQ message to HLR through MSC2, and HLR returns regnot or qualreq message to MSC2, and will not be described in detail here;

Step 107: MSC2 assigns a roaming number TLDN to the called user, and sends a routreq or ispage response message to the backup center, carrying the roaming number TLDN;

Step 108: After receiving the routreq or ispage response message, the backup center sends a routreq response message to the STP or MGW, carrying the roaming number TLDN;

Step 109: After receiving the routreq response message, the STP or MGW forwards it to the HLR;

Step 110: After the HLR receives the routreq response message, the roaming number TLDN is forwarded to the originating office, and the originating office uses the roaming number TLDN to connect the call to MSC2, and sends an IAM (Initial Address Management, initial address management) message. the

Step 111: MSC2 connects the called user after receiving the IAM message;

Wherein, above-mentioned step 104-step 105 is the process that MSC2 paging called user, and step 106 is the process that MSC2 recovers the process of called user data, and step 107 to step 111 is the process that MSC2 distributes roaming number; The process of assigning roaming number can be by MSC2 flexible control, that is: the process of assigning roaming numbers can be executed in sequence according to the above steps, or you can assign roaming numbers first, and then restore the called user data; or, assign roaming numbers first, then page the called user, and then restore called user data;

If the roaming number is assigned before the called party is paged or the called party data is restored, the originating office will use the roaming number TLDN to connect the call to MSC2 after receiving the roaming number, and send an IAM initial address message to MSC2, which can reduce The connection time of the call. the

Referring to Fig. 7, taking MSC2 to allocate roaming numbers first, then page the called user, and then restore the sequence of the called user data as an example, the message interaction process in the method for called recovery in the mobile switching center pool is briefly described as follows:

1) After the HLR receives the LOCREQ message sent by the calling office, it sends a ROUTREQ message to the original MSC1 of the called user to obtain the called roaming number request, wherein the ROUTREQ message carries the signaling point of MSC1 or other routing information; the ROUTREQ When the message is transferred through the STP or MGW adjacent to the original home MSC1 of the called user, and the MSC1 signaling point of the called office is found to be unreachable, the backup sub-routing or SCCP load sharing function is used to select the backup center as the new called office. Send a ROUTREQ message to the backup center. the

2) After the backup center receives the ROUTREQ message, according to the IMSI of the called user in the ROUTREQ message and the IMSI distribution algorithm and adjustment principle saved by itself, it is found that the control node distributed to the called user after MSC1 fails is MSC2, and sends ROUTREQ to MSC2 Or an ISPAGE message, carrying information such as the backup called user's LAI, time slot index, etc. the

3) After MSC2 receives the ROUTREQ or ISPAGE message, it allocates a roaming number TLDN for the called user, and sends a routreq or ispage response message to the backup center, carrying the roaming number TLDN; MSC2 also needs to save the LAI and time in the ROUTREQ or ISPAGE message. The slot index and other information are ready to be used when paging the called party after TLDN incoming. the

4) After receiving the routreq or ispage response message, the backup center forwards the roaming number TLDN to the originating office through the HLR, and the originating office uses the roaming number TLDN to connect the call to MSC2 and send an IAM message. the

5) After MSC2 receives the IAM message, it obtains the paging range according to the LAI, and sends a paging request message to the BSC or MGW, that is, the PagingREQ message, carrying the paging range in the paging message, and notifying the BSC of the called party; the BSC receives After the Paging REQ message, send a paging message to the called user according to the paging range in the Paging REQ message. After receiving the paging message, the called user reports a paging response message to the BSC; the BSC receives the paging message from the called user After calling the response message, the BSC obtains MSC2 itself, or notifies the MGW to obtain MSC2. When BSC or MGW obtains MSC2, it can obtain MSC2 according to the IMSI distribution algorithm saved by it and the same IMSI distribution algorithm as the backup center, or according to the TAG parameter in the paging request message. Then the paging response message (Paging RSP message) is sent to MSC2;

Among them, the Paging REQ message carries the TAG parameter and LIA, and the TAG parameter is used to indicate the identification information of MSC2 in the MSC pool, for example: number. the

6) After MSC2 receives the paging response message, it interacts with the HLR through the location registration process or the qualification request process, and restores the user data of the called user in the VLR (Visited Location Registor, Visited Location Register) of MSC2; user. the

Wherein, the location registration process or the qualification request process is the prior art, which is implemented by MSC2 sending REGNOT or QUALREQ message to HLR, and HLR returning regnot or qualreq message to MSC2, which will not be described in detail here. the

In this embodiment, when a failure occurs in an MSC and the user belonging to the failure MSC is used as the called party, the backup center in the MSC pool selects the MSC that has not failed in the MSC pool as the called office, and the user can successfully call the user belonging to the failure MSC. In addition, the selected MSC is obtained according to the distribution algorithm, so it is guaranteed that when a faulty MSC occurs, the calls under the faulty MSC will not be connected to a certain MSC, causing a business load impact on a certain MSC. To balance the load; at the same time, use the backup center to restore the callee for disaster recovery, which simplifies the backup process, facilitates maintenance, and enhances the practicability of callee recovery for disaster recovery. the

Example 2

Referring to Fig. 8 and Fig. 9, present embodiment provides a kind of method that the called party recovers in the mobile switching center pool, and this method comprises:

Step 201: After receiving the LOCREQ message sent by the calling office, the HLR sends a ROUTREQ message to the called user's original home MSC1 to obtain a roaming number request; the ROUTREQ message is transferred through the STP or MGW adjacent to the called user's original home MSC1 When the STP or MGW finds that the MSC1 signaling point of the called office is unreachable, it uses the backup sub-routing or SCCP load sharing function to select the backup center device as the new called office, and sends the ROUTREQ message to the backup center;

Step 202: After receiving the ROUTREQ message, the backup center allocates the roaming number TLDN, and sends the roaming number TLDN to the HLR through the routreq message, and the HLR forwards the roaming number TLDN to the originating office, and the originating office uses the roaming number TLDN to connect the call To the backup center, send an IAM message;

Step 203: After the backup center receives the IAM message, according to the IMSI of the called user in the ROUTREQ message and the IMSI distribution algorithm and adjustment principle saved by itself, it is known that the control node distributed to the called user after MSC1 fails is MSC2, and the IMSI is sent to MSC2 Send an ISPAGE2 message, and the ISPAGE2 message carries information such as the LAI and time slot index of the called user backed up in advance;

Step 204: After receiving the ISPAGE2 message, MSC2 notifies the BSC to page the called party, the scope of the BSC sending the paging request message can be determined according to the LAI in the Paging REQ message, and the paging response message (Paging RSP) sent by the called user is received. message), the BSC or MGW sends the paging response message to the MSC2 requesting paging according to the same IMSI distribution algorithm saved by it and the backup center, or according to the TAG parameter in the paging request;

Wherein, the paging response message is the same as the paging response message in the prior art, carrying information such as user identification and authentication parameters, and the user identification can be IMSI or ESN (Enterprise Storage Network, enterprise storage network) identification, and authentication parameters Including authentication random numbers and authentication calculation results, etc.;

Step 205: MSC2 sends an ispage2 response message to the backup center after receiving the paging response message, carrying the information in the paging response message sent by the BSC or MGW;

Step 206: After receiving the ispage2 response message, the backup center interacts with the HLR through the location registration process or the qualification request process, and the obtained called user data is only used for this call connection, and the MAP circuit number of this call is allocated according to the user data, Then the backup center sends an ISSETUP message to MSC2, instructing MSC2 to connect to the called user, and the message carries the allocated MAP circuit number;

Wherein, the MAP circuit in this embodiment is used for the voice channel connection between the backup center and MSC2, but the backup center in Embodiment 1 does not participate in the final call, so the MAP circuit is not needed. The backup center and MSC2 determine which channel is the used channel through the MAP circuit number. the

Step 207: MSC2 assigns the called user after receiving the ISSETUP message. After the assignment is successful, it occupies the MAP circuit allocated by the backup center, and then sends an issetup response message to the backup center;

Among them, assigning the called user refers to MSC2 notifying BSC or MGW to perform the following two operations:

(1) Establish an air traffic channel for the called user. After the air traffic channel is established, the terminal of the called user will start ringing, and the called user will answer after pressing the answer button;

(2) Establish a voice channel between MSC2 and BSC or MGW;

Step 208: After the backup center receives the issetup response message, it sends an ACM (Address CompleteMessage, address complete message) to the originating office, indicating that the called number in the IAM is enough for number analysis and routing, and the called user ( The called party is ringing);

Step 209: After the called user answers, MSC2 receives the CONNECT message from the BSC, then sends an ISANSWER message to the backup center, and the backup center sends an ANM response message to the originating office; so far the call is connected, and the backup center is in this call. the status of the gateway;

Among them, the answer means that the called party presses the connect key to connect the call after hearing the ringing, and at this time, there will be an answer message notified from the BSC or MGW to the MSC2. the

Step 210: After the call is over, the called user initiates a location registration request, and the BSC or MGW can send the location registration request message to MSC2 according to the same IMSI distribution algorithm saved by the BSC or MGW, and MSC2 interacts with the HLR through the location registration process, Recover the called user data in the VLR of MSC2;

Wherein, recovering the called user data refers to the user data normally stored in the VLR. After the general location registration, the VLR can download some user subscription data from the HLR and save them in the VLR. the

The solution provided in this embodiment is a late paging solution, and the backup center directly allocates roaming numbers, so the backup center needs to have the functions of roaming number TLDN allocation, tandem call, trunk circuit and MAP circuit management. the

In this embodiment, when the MSC fails and the user belonging to the failure MSC is called, the backup center in the MSC pool selects the effective MSC as the called office, and can successfully call the called user belonging to the failure MSC. Moreover, the selected MSC is obtained according to the distribution algorithm, so it is guaranteed that when a faulty MSC occurs, the calls under the faulty MSC will not be connected to a certain MSC, causing a business load impact on a certain MSC and balancing the load; at the same time , use the backup center to restore the callee for disaster recovery, which simplifies the backup process, facilitates maintenance, and enhances the practicability of callee recovery for disaster recovery. the

In the above embodiment, for a network with a separate architecture, an MGW is set between each BSC and MSC, and the signaling interaction between the BSC and MSC needs to be forwarded by the MGW. At the same time, when the distribution algorithm is not saved on the BSC, the BSC needs to notify the MGW according to The distribution algorithm saved by itself obtains the MSC corresponding to the called party; for a network with a traditional architecture (circuit domain), the BSC and the MSC can directly exchange information. the

Example 3

Referring to FIG. 10 , the present embodiment provides a system for called recovery in a mobile switching center pool, including: a home location register 201, a signaling transfer device 202, a backup center 203, an active mobile switching center 204 and a base station controller 205 ;

Wherein, the home location register 201 is used for sending the routing request message to the called user to the former home mobile switching center of the called user after receiving the location request message to the called user;

The signaling switching device 202 is used to determine that the mobile switching center corresponding to the routing request message is faulty when the routing request message sent by the home location register 201 passes through it, and according to the backup sub-routing configured by itself or the load sharing of the signaling control part The function forwards the routing request message to the backup center 203;

The backup center 203 is used to receive the routing request message to the called user forwarded by the signaling transfer device 202, and select an effective mobile switching center 204 in the mobile switching center pool according to the called user information in the received routing request message , using the intersystem message to connect the call to an active mobile switching center 204;

Effective mobile switching center 204 is used to receive the call forwarded by backup center 203, and after sending a paging request to base station controller 205 and receiving the paging request response message of the called user, the call is connected to the called user;

The base station controller 205 is used to page the called user after receiving the paging request from the active mobile switching center 204, and after the called user responds to the paging request, send the paging response message of the called user to the active mobile switching center 204 . the

Further, backup center 203 includes:

The setting module is used to store the information of the user's location area identification, the international mobile station identification and the user's call state under the mobile switching center in the backup mobile switching center pool;

The acquisition module is configured to receive the routing request message to the called user forwarded by the signaling transfer device 202, and select the mobile station according to the called user information in the received routing request message and the information backed up by the above-mentioned setting module. an active mobile switching center 204 in the switching center pool;

The call connecting module is used to connect the call to the active mobile switching center 204 obtained by the above-mentioned obtaining module by using the inter-system message, and the active mobile switching center 204 will connect the called user. the

Further, backup center 203 also includes:

A roaming number distribution module is configured to distribute a roaming number for the called user after receiving the routing request message, and send the roaming number to the originating mobile switching center that initiates the call;

Correspondingly, the above-mentioned call connection module is specifically used to notify the effective mobile switching center 204 to page the called user after receiving the call from the originating mobile switching center; after the called user responds, obtain the user data of the called user, and according to the user data The circuit number of this call is allocated, and the active mobile switching center 204 is notified to use the circuit corresponding to the circuit number to connect to the called user. the

The signaling transfer device 202 is a signaling transfer point or a media gateway. the

The system provided by this embodiment connects the call to the backup center when the original mobile switching center (MSC) fails, and the backup center selects an effective mobile switching center according to the same distribution algorithm as the base station controller or media gateway stored in advance, and the effective mobile switching center is selected by the backup center. The mobile switching center connects the called party to achieve the purpose of successfully calling the called party; moreover, the selected MSC is obtained according to the distribution algorithm, thus ensuring that when a faulty MSC occurs, all calls under the faulty MSC will not be connected to a certain MSC , causing a business load impact on a certain MSC to balance the load; at the same time, using the backup center to restore the disaster recovery callee simplifies the backup process, facilitates maintenance, and enhances the practicability of the disaster recovery callee recovery. the

Example 4

Referring to Figure 11, the present embodiment provides a backup center device, including:

The setting module 301 is used to store the location area identification of the user under the mobile switching center in the backup mobile switching center pool, the information of the international mobile station identification and the call state of the user;

The obtaining module 302 is configured to receive the routing request message to the called user forwarded by the signaling transfer point or the media gateway, and select the an active MSC in the MSC pool;

The call connecting module 303 is configured to use the inter-system message to connect the call to the active mobile switching center obtained by the obtaining module 302, and the active mobile switching center connects the called user. the

Call continuing module 303 comprises:

The paging range notification unit is used to send a routing request message or an intersystem paging request message carrying the location area identifier of the called user to the effective mobile switching center obtained by the obtaining module 302;

The roaming number forwarding unit is used to return the roaming number to the originating mobile switching center that initiates the call after receiving the routing request response message or the inter-system paging request response message carrying the assigned roaming number returned by the effective mobile switching center , so that the originating mobile switching center connects the call to the active mobile switching center according to the roaming number. the

Further, the backup center equipment also includes:

The roaming number distribution module is used to allocate a roaming number for the called user after receiving the routing request message, and send the roaming number to the originating mobile switching center that initiates the call;

Correspondingly, the call connection module 303 specifically includes:

An inter-system paging request sending unit, configured to send an inter-system paging request to the effective mobile switching center acquired by the acquisition module 302 after receiving the call from the originating mobile switching center, requesting the effective mobile switching center to page the called user;

The circuit number allocation and sending unit is used for obtaining the user data of the called user after the called user responds, assigning the circuit number of this call according to the user data, sending the circuit number to the effective mobile switching center, and notifying the effective mobile switching center according to the circuit number. The circuit corresponding to the number is connected to the called user. the

In order to make the effective mobile switching center selected by the acquisition module 302 more reasonable, the setting module 301 is also used to set the distribution algorithm and modulation principle information of the mobile switching center consistent with the base station controller or media gateway, and accordingly, the backup center equipment also includes :

The distribution algorithm update module is used for updating the distribution algorithm of the MSC according to the adjustment principle set by the setting module after detecting the status change of the MSCs in the MSC pool. the

The backup center equipment provided by this embodiment selects an effective mobile switching center in the mobile switching center pool according to the information backed up in advance by the setting module; the effective mobile switching center connects the called party to achieve the purpose of successfully calling the called party; and, the selected effective mobile switching center The mobile switching center is obtained according to the distribution algorithm, so it is guaranteed that when there is a faulty mobile switching center, the calls under the faulty mobile switching center will not be connected to a certain mobile switching center, causing a business load impact on a certain mobile switching center. Balance the load; at the same time, use the backup center equipment to restore the callee for disaster recovery, which simplifies the backup process, facilitates maintenance, and enhances the practicability of callee recovery for disaster recovery. the

All or part of the technical solutions provided by the above embodiments can be realized by software programming, and the software program is stored in a readable storage medium, such as a hard disk, an optical disk or a floppy disk in a computer. the

The above description is only an embodiment of the present invention, and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention Inside. the

Claims (20)

1. a method for called recovery in a mobile switching center pool, is characterized in that, said method comprises: When the signaling transfer point or the media gateway finds that the called mobile switching center is unreachable, use the backup sub-routing or signaling control part load sharing function to select the backup center as the new called office; The backup center receives the routing request message to the called user forwarded by the signaling transfer point or the media gateway; The backup center selects an effective mobile switching center in the mobile switching center pool according to the IMSID of the called user in the received routing request message and the IMSID distribution algorithm and adjustment principle saved by itself; The call is connected to the active mobile switching center by means of an intersystem message, and the called user is connected by the active mobile switching center. 2. the method for called recovery in the mobile switching center pool as claimed in claim 1, is characterized in that, also comprises before described receiving the routing request message to called user forwarded by signaling transfer point or media gateway: A backup center is pre-configured in the mobile switching center pool, and the location area identification, international mobile station identification and call status information of the user under the mobile switching center in the mobile switching center pool is backed up in the backup center ; Then the backup center receives the routing request message for the called user forwarded by the signaling transfer point or the media gateway. 3. the method for called recovery in the mobile switching center pool as claimed in claim 2, is characterized in that, before described backup center receives the routing request message to called user forwarded by signaling transfer point or media gateway include: After receiving the location request message to the called user, the home location register of the called user sends a routing request message to the original home mobile switching center of the called user; When the route request message passes through the adjacent signaling transfer point or media gateway of the mobile switching center where the called user originally belongs to, the signaling transfer point or media gateway will control Part of the load sharing function forwards the routing request message to the backup center. 4. the method for called recovery in the mobile switching center pool as claimed in claim 2, is characterized in that, in described mobile switching center pool, pre-configuring backup center also comprises: The mobile switching center distribution algorithm and adjustment principle are also set in the backup center, and the mobile switching center distribution algorithm and adjustment principle are configured by the base station controllers or media gateways that are communicatively connected to each mobile switching center in the mobile switching center pool The distribution algorithm and adjustment principle of the mobile switching center are consistent. 5. the method for called recovery in the mobile switching center pool as claimed in claim 4, is characterized in that, the mobile switching center distribution algorithm that is provided with in the backup center is the algorithm that carries out mobile switching center distribution according to the international mobile station identification; According to the International Mobile Station Identity of the called user in the route request message received and the distribution algorithm and adjustment principle of the International Mobile Station Identity preserved by itself, selecting an effective Mobile Switching Center in the Mobile Switching Center pool specifically includes: Said backup center selects the IMS in the MSC pool according to the IMSID of the called user in the route request message received, and the algorithm and adjustment principle for the distribution of the MSC according to the IMSID set by itself. Effective mobile switching center. 6. The method for called recovery in the mobile switching center pool as claimed in claim 2, wherein said utilizing intersystem message to connect the call to the effective mobile switching center specifically comprises: The backup center sends a routing request message or an inter-system paging request message carrying the location area identifier of the called user to the active mobile switching center; The backup center receives the routing request response message or the intersystem paging request response message carrying the assigned roaming number returned by the active mobile switching center, and returns the roaming number to the originating mobile switching center that initiated the call; The originating mobile switching center connects the call to the active mobile switching center based on the roaming number. 7. the method for called recovery in the mobile switching center pool as claimed in claim 6, is characterized in that, described backup center sends the routing request message that carries the location area identification of described called user to described valid mobile switching center Or after the intersystem paging request message also include: The active mobile switching center receives a routing request message or an intersystem paging request message carrying the location area identifier of the called user, acquires a paging range according to the location area identifier, and sends a paging request message carrying the paging request message to the base station controller. range of paging request messages; After receiving the paging request message, the base station controller pages the called user according to the paging range; After the called user responds to the paging of the base station controller, the base station controller or the media gateway sends the paging response message of the called user to the active mobile switching center; After the active mobile switching center receives the paging response message, it restores the user data of the called user by registering the location with the home location register, and assigns a roaming number to the called user, and sends the call to the backup center Return a routing request response message or an intersystem paging request response message carrying the roaming number. 8. The method for called recovery in the mobile switching center pool as claimed in claim 2, wherein said utilizing intersystem message to connect the call to the effective mobile switching center specifically comprises: The backup center sends a routing request message or an intersystem paging request message carrying the location area identifier of the called user to the active mobile switching center; the active mobile switching center receives the routing request message carrying the location area identifier After the request message or inter-system paging request message, save the location area identifier, assign a roaming number to the called user, and return a routing request response message or an inter-system paging request carrying the roaming number to the backup center response message; After receiving the routing request response message or the intersystem paging request response message, the backup center sends the roaming number to the originating mobile switching center that initiates the call; After receiving the roaming number, the originating mobile switching center connects the call to the effective mobile switching center according to the roaming number. 9. The method for called recovery in the mobile switching center pool as claimed in claim 8, characterized in that, after the originating mobile switching center receives the roaming number, the call is connected to the said roaming number according to the roaming number. After an active mobile switching center also includes: The active mobile switching center acquires a paging range according to the location area identifier, and sends a paging request message carrying the paging range to the base station controller; After receiving the paging request message, the base station controller pages the called user according to the paging range; After the called user responds to the paging of the base station controller, the base station controller or the media gateway sends the paging response message of the called user to the active mobile switching center; After receiving the paging response message, the active mobile switching center recovers the subscriber data of the called subscriber by registering the location with the home location register, and continues the call. 10. The method for called recovery in the mobile switching center pool as claimed in claim 7 or 9, characterized in that, the effective paging request message sent by the mobile switching center to the base station controller also carries the effective Label parameters of the mobile switching center; Correspondingly, sending the paging response message of the called user to the active mobile switching center by the base station controller or the media gateway includes: The base station controller or the media gateway acquires the active mobile switching center according to the tag parameter carried in the paging request message, and sends the called user's paging response message to the active mobile switching center. 11. The method for called recovery in the mobile switching center pool as claimed in claim 2, wherein the call is connected to the effective mobile switching center by using an intersystem message, and the effective mobile switching center is connected to the call. The called users specifically include: The backup center assigns a roaming number to the called user, and sends the roaming number to the originating mobile switching center that initiates the call; After receiving the roaming number, the originating mobile switching center connects the call to the backup center according to the roaming number; The backup center sends an intersystem paging request to the active mobile switching center, requesting the active mobile switching center to page the called user; The active mobile switching center pages the called user through the base station controller, and after the called user responds to the paging of the base station controller, the base station controller or the media gateway sends the paging of the called user to a call response message is sent to the active mobile switching center; After the active mobile switching center receives the paging response message, it notifies the backup center that the paging has been responded; The backup center obtains the user data of the called user, allocates the circuit number of this call according to the user data, and sends the circuit number to the active mobile switching center; After receiving the circuit number, the active mobile switching center connects the call according to the circuit number. 12. the method for called recovery in the mobile switching center pool as claimed in claim 11, is characterized in that, after described connecting call according to described circuit number, also comprises: After the called user completes the call, initiate a location registration request message; The base station controller or media gateway acquires the active mobile switching center, and forwards the location registration request message to the active mobile switching center; After the active mobile switching center receives the location registration request message, it restores the subscriber data of the called user by registering the location with the home location register. 13. A system for called recovery in a mobile switching center pool, characterized in that the system includes: a home location register, signaling switching equipment, a backup center, an effective mobile switching center and a base station controller; The home location register is used to send a routing request message to the called user to the original home mobile switching center of the called user after receiving the location request message to the called user; The signaling transfer device is used to determine that the mobile switching center corresponding to the routing request message is faulty when the routing request message sent by the home location register passes through it, and then use the backup sub-routing or signaling to control part of the load sharing function Selecting the backup center as the new called office; forwarding the route request message to the backup center according to the backup sub-routing configured by itself or the load sharing function of the signaling control part; The backup center is used to receive the routing request message to the called user forwarded by the signaling transfer device, and select an effective mobile switching center in the mobile switching center pool according to the called user information in the received routing request message. a center that connects the call to said active mobile switching center using an intersystem message; The effective mobile switching center is configured to, after receiving the call forwarded by the backup center, send a paging request to the base station controller and receive the paging request response message of the called user, and then connect the call to the Describe the called user; The base station controller is used for paging the called user after receiving the paging request from the effective mobile switching center, and after the called user responds to the paging of the base station controller, the called user The paging response message is sent to the active MSC. 14. the system that called recovery in the mobile switching center pool as claimed in claim 13 is characterized in that, described backup center comprises: The setting module is used to store the user's location area identification, international mobile station identification and user's call state information under the mobile switching center in the backup mobile switching center pool; An acquisition module, configured to receive a routing request message for the called user forwarded by the signaling transfer device, and select a mobile an active mobile switching center in the switching center pool; The call connecting module is used to connect the call to the active mobile switching center obtained by the obtaining module by using an inter-system message, and the active mobile switching center connects the called user. 15. the system that called recovery in the mobile switching center pool as claimed in claim 14 is characterized in that, described backup center also comprises: A roaming number allocation module is configured to allocate a roaming number for the called user after receiving the routing request message, and send the roaming number to the originating mobile switching center that initiates the call; Correspondingly, the call connection module is specifically configured to notify the active mobile switching center to page the called user after receiving the call from the originating mobile switching center; after the called user responds, obtain the According to the user data of the called user, assign the circuit number of this call according to the user data, and notify the active mobile switching center to use the circuit corresponding to the circuit number to connect the called user. 16. The system for recovering the called party in the mobile switching center pool according to claim 13, wherein the signaling transfer device is a signaling transfer point or a media gateway. 17. A backup center device, when the signaling transfer point or the media gateway finds that the called mobile switching center signaling point is unreachable, it uses the backup sub-routing or signaling control part load sharing function to select the backup center as the new called mobile switching center. call office; it is characterized in that, described backup center equipment comprises: The setting module is used to store location area identifiers, international mobile station identifiers and call status information of users under the mobile switching center in the backup mobile switching center pool, as well as distribution algorithms and adjustment principles of the mobile switching center; The obtaining module is used to receive the routing request message to the called user forwarded by the signaling transfer point or the media gateway, according to the received routing request message The called user's international mobile station identity and the backup of the setting module information, select an effective mobile switching center in the mobile switching center pool; The call connecting module is used to connect the call to the active mobile switching center obtained by the obtaining module by using an inter-system message, and the active mobile switching center connects the called user. 18. The backup center device according to claim 17, wherein the call connection module comprises: A paging range notification unit, configured to send a routing request message or an inter-system paging request message carrying the location area identifier of the called user to the active mobile switching center obtained by the obtaining module; The roaming number forwarding unit is configured to return the roaming number to the originator of the call after receiving the routing request response message or the inter-system paging request response message carrying the assigned roaming number returned by the effective mobile switching center An originating mobile switching center, so that the originating mobile switching center connects the call to the active mobile switching center according to the roaming number. 19. The backup center device according to claim 17, wherein the backup center device further comprises: A roaming number allocation module is configured to allocate a roaming number for the called user after receiving the routing request message, and send the roaming number to the originating mobile switching center that initiates the call; Correspondingly, the call connection module specifically includes: An inter-system paging request sending unit, configured to send an inter-system paging request to the effective mobile switching center obtained by the acquisition module after receiving the call from the originating mobile switching center, requesting the effective mobile switching center to page call the called party; The circuit number allocation and sending unit is used for obtaining the user data of the called user after the called user responds, assigning the circuit number of this call according to the user data, and sending the said call to the effective mobile switching center. circuit number, informing the active mobile switching center to continue calling the called user according to the circuit corresponding to the circuit number. 20. backup center equipment as claimed in claim 17, is characterized in that, described setting module is also used for setting the mobile switching center distribution algorithm that is consistent with base station controller or media gateway and the information of adjusting principle, correspondingly, described Backup center equipment also includes: The distribution algorithm update module is used to update the distribution algorithm of the mobile switching center according to the adjustment principle set by the setting module after detecting the state change of the mobile switching center in the mobile switching center pool.

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