WO2016037365A1

WO2016037365A1 - Ps/cs coordination method and system, and mobile interaction centre

Info

Publication number: WO2016037365A1
Application number: PCT/CN2014/086436
Authority: WO
Inventors: 崇卫微; 吴晓波; 舒林
Original assignee: 华为技术有限公司
Priority date: 2014-09-12
Filing date: 2014-09-12
Publication date: 2016-03-17
Also published as: CN105594250A; CN105594250B

Abstract

Provided are a PS/CS coordination method and system, and a mobile interaction centre. The method comprises: determining, by an MSC, that a voice call of a UE is caused by SRVCC switching; and when determining that the voice call caused by the SRVCC switching is finished, sending, by the MSC, a first TMSI reallocation message to the UE, the first TMSI reallocation message comprising a TMSI network element, wherein the TMSI network element comprises an NRI, and the NRI is not allocated by any MSC in all MSC resource pools in a shared network in which the MSC is located, so that the TMSI network element is carried when the UE sends an LAU request message, and further, the MSC which has received the LAU request message is made to trigger a PS/CS coordination flow according to the NRI included in the TMSI network element in the LAU request message, so as to reselect an operator of a CS domain for the UE, thereby solving the problem of PS/CS non-coordination which easily exists when an SRVCC is switched to the shared network.

Description

PS/CS coordination method and system and mobile interaction center

Technical field

The present invention relates to a wireless communication technology, and in particular, to a PS/CS coordination method and system and a mobile interaction center suitable for Single Radio Voice Call Continuity (SRVCC).

Background technique

In the second generation mobile communication technology (2nd Generation, 2G) or the third generation mobile communication technology (3G) network, the user equipment (User Equipment, UE for short) is circuit switched in the network (Circuit Switched, After the CS) domain and the Packet Switched (PS) domain are registered, the Mobile Switching Center (MSC) allocates the CS Domain Temporary Mobile Subscriber Identity (TMSI) to the UE. The Serving GPRS Support Node (SGSN) allocates a Packet Temporary Mobile Subscriber Identity (P-TMSI) to the UE. In Long Term Evolution (LTE), the UE is in LTE. After being registered in the network, the Mobility Management Entity (MME) allocates the Globally Unique Temporary Identity (GUTI) of the Evolved Packet System (EPS) domain to the UE.

In a traditional network, an operator can provide CS domain and PS domain services to users at the same time, that is, the CS domain operators serving the users and the PS domain operators are always the same. After the UE registers the CS domain and the PS domain in the network, the network side will allocate the CS domain temporary identifier TMSI and the PS domain temporary identifier P-TMSI to the UE, both of which always point to the same carrier. However, this may not always be the case in the shared network. If the resources of the two domains are different due to lack of resources or network selection policies, if the PS and CS registration messages of the UE are accepted by different sharing operators, The UE will receive a TMSI pointing to a shared carrier, and one P-TMSI will point to another shared carrier. The access network base station will route subsequent service request messages or control messages to different operators based on these temporary identifiers. The network, that is, the so-called CS/PS inconsistency problem.

SRVCC is a widely used technology for interoperability of LTE voice services. When a user equipment (User Equipment, UE for short) uses LTE network for VOIP voice calls, the mobile to LTE signal is weak and the 2G/3G network signal coverage is relatively high. In a good area, the VoIP voice service carried on the source network is smoothly switched to the CS domain of the target network to ensure voice call continuity. With the emergence of the shared network, including: multiple operators only share the access network and the core network is independent of the Multi-operator Core Network (MOCN) architecture and multiple operators share the access network and core The gateway core network (GWCN) architecture of the network element. In the above-mentioned SRVCC handover process, if the UE is switched from the LTE network to a shared 2G/3G network, and the UE needs to be switched from the EPS domain to the CS domain and the PS domain, the CS domain operator and the PS carrier selected for the UE are likely to appear. Different, CS/PS uncoordinated, easily lead to uncertain network name display, double billing standards, and the uncertainty of the registered Public Land Mobile Network (RPLMN).

In order to avoid the problem of CS/PS uncoordination in the SRVCC process, in the prior art, a pool-centric network-side triggered PS/CS coordination scheme is generally adopted, that is, if the core network node receives the If the TMSI or P-TMSI carried in the registration message of the user is not allocated by any MSC or SGSN in the resource pool in which the user is located, the CS/PS coordination process is triggered, so that the core network node or the base station controller (Base Station Controller, referred to as The BSC)/Radio Network Controller (RNC) selects a CS/PS domain operator for the UE according to its own policy. The specific process is: when the UE performs the Location Area Update (LAU) process after the SRVCC is switched to the target 2G/3G network, the UE sends a LAU request message carrying the TMSI to the core network element MSC, if the carried TMSI If not allocated by any MSC in the resource pool, the MSC triggers the CS/PS coordination process; when the UE performs the Routing Area Update (RAU) process after the SRVCC switches to the target 2G/3G network, The core network element SGSN sends a RAU request message carrying the P-TMSI. If the carried P-TMSI is not allocated by any SGSN in the resource pool, the SGSN triggers the CS/PS coordination process.

The resource pool-centric network-side triggering PS/CS coordination scheme requires the PS domain and the CS domain to simultaneously trigger the CS/PS coordination process to ensure that the coordinated CS domain and the PS domain point to the same carrier. Since the PS domain core network device switches from the MME of the EPS domain to the SGSN in the SRVCC process, the resource pool change must occur, and the GUTI allocated in the EPS domain is mapped to the P-TMSI of the PS domain, and the P-TMSI is not Belong to any SGSN allocated in the resource pool, so in the RAU process, one The SGSN will be triggered to perform the CS/PS coordination process. However, in the CS domain, the MSC resource pool is likely to be unchanged. The TMSI carried in the LAU process is likely to belong to the MSC in the target network CS domain resource pool. The MSC is triggered to perform the CS/PS coordination process, so that the problem of CS/PS uncoupling is easy to exist after the SRVCC is switched.

Summary of the invention

In view of this, the embodiment of the present invention provides a PS/CS coordination method and system and a mobile interaction center, so as to overcome the problem that the CS and the PS are not coordinated when the UE switches to the shared network in the SRVCC handover process in the prior art.

In a first aspect, an embodiment of the present invention provides a PS/CS coordination method, including:

The mobile switching center MSC determines that the voice call of the user equipment UE is caused by a single wireless voice call continuity SRVCC handover;

The MSC, when the determined voice call caused by the SRVCC handover ends, sends a first temporary mobile subscriber identity TMSI re-allocation message to the UE, where the first TMSI re-allocation message includes a TMSI network element, where The TMSI network element includes a Network Resource Identifier (NRI), and the NRI is not allocated by any MSC in all MSC resource pools in the shared network where the MSC is located, so that the UE sends the location. The area update LAU request message carries the TMSI network element, so that the MSC that receives the LAU request message is the UE according to the NRI trigger PS/CS coordination procedure included in the TMSI network element in the LAU request message. Re-select the operator of a CS domain.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the first TMSI re-allocation message further includes a first location area identifier (LAI), where the first The LAI is a non-broadcast LAI, so that after receiving the first TMSI reallocation message, the UE saves the first LAI and triggers an LAU procedure.

With reference to the first aspect or the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the method further includes:

The MSC, in the determined voice call caused by the SRVCC handover, sends a second TMSI re-allocation message to the UE, where the second TMSI re-allocation message includes a second LAI, so that the UE After receiving the second TMSI reallocation message, saving the second LAI, and acquiring a public land mobile network PLMN identity as a registered one according to the second LAI PLMN.

With reference to the first aspect and any one of the first to the second possible implementation manners of the first aspect, in a third possible implementation manner of the first aspect, the method further includes:

Receiving, by the MSC, a LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

Determining, by the MSC, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs according to the NRI included in the TMSI network element;

The MSC triggers a PS/CS coordination procedure to reselect an operator of the CS domain for the UE that sends the LAU request message.

In conjunction with the third possible implementation of the first aspect, in a fourth possible implementation manner of the first aspect, the MSC triggers a PS/CS coordination process, and reselects a CS for the UE that sends the LAU request message. The operator of the domain, including:

The MSC triggers the PS/CS coordination process, and reselects a CS domain operator for the UE that sends the LAU request message according to the configuration policy, and sends the LAU request message to the operator of the selected CS domain. One of the MSCs.

In conjunction with the third possible implementation of the first aspect, in a fifth possible implementation manner of the first aspect, the MSC triggers a PS/CS coordination process, and reselects a CS for the UE that sends the LAU request message. The operator of the domain, including:

The MSC sends a re-routing command to the base station controller BSC or the radio control center RNC, where the re-routing command includes an International Mobile Subscriber Identifier (IMSI) and a weight of the UE that sends the LAU request message. Directional indication information, after the BSC or the RNC receives the rerouting command, reselecting a CS domain operator for the UE that sends the LAU request message according to the BSC or the RNC's own policy. And sending the LAU request message to an MSC corresponding to the operator of the selected CS domain.

In a second aspect, an embodiment of the present invention provides an MSC, including:

a first determining module, configured to determine that the ongoing voice call of the user equipment UE is caused by a single wireless voice call continuity SRVCC handover;

a sending module, configured to send, by the first determining module, a first temporary mobile subscriber identity TMSI reallocation message to the UE when the voice call caused by the SRVCC handover ends, The first TMSI re-allocation message includes a TMSI network element, where the TMSI network element includes a network resource identifier NRI, and the NRI is not allocated by any MSC in all MSC resource pools in the shared network in which it resides, And causing the UE to send the location area update LAU request message to carry the TMSI network element, so that the MSC that receives the LAU request message according to the NRI trigger PS/CS coordination included in the TMSI network element in the LAU request message The process is to reselect an operator of the CS domain for the UE.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the first TSI re-allocation message further includes a first LAI, where the first LAI is a non-broadcast LAI, After receiving the first TMSI reallocation message, the UE saves the first LAI and triggers an LAU procedure.

With the second aspect or the first possible implementation of the second aspect, in a second possible implementation manner of the second aspect, the sending module is further configured to:

And sending, by the first determining module, a second TMSI re-allocation message to the UE during a voice call caused by the SRVCC handover, where the second TMSI re-allocation message includes a second LAI, so that After the determined UE receives the second TMSI re-allocation message, the second LAI is saved, and a public land mobile network PLMN identity is acquired as the registered PLMN according to the second LAI.

With reference to the second aspect and any one of the first to the second possible implementation manners of the second aspect, in a third possible implementation manner of the second aspect, the method further includes:

a receiving module, configured to receive a LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

a second determining module, configured to determine, according to the NRI included in the TMSI network element, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs;

The triggering module is configured to trigger a PS/CS coordination process, and reselect an operator of the CS domain for the UE that sends the LAU request message.

In conjunction with the third possible implementation of the second aspect, in a fourth possible implementation of the second aspect, the triggering module is specifically configured to:

Triggering the PS/CS coordination process, reselecting a CS domain operator for the UE that sends the LAU request message according to the configuration policy, and sending the LAU request message to the selected CS An MSC corresponding to the operator of the domain.

With reference to the third possible implementation of the second aspect, in a fifth possible implementation manner of the second aspect, the triggering module is specifically configured to:

Sending a rerouting command to the base station controller BSC or the radio control center RNC, where the rerouting command includes an international mobile subscriber identifier IMSI and redirection indication information for transmitting the LAU request message UE, so that the BSC or the After receiving the rerouting command, the RNC reselects a CS domain operator according to the BSC or the RNC's own policy to send the LAU request message, and sends the LAU request message to the selected one. An MSC corresponding to the operator.

In a third aspect, an embodiment of the present invention provides an MSC, including:

a memory, a processor and a transceiver connected via a bus;

The memory stores program code, and the processor executes the program code to perform the following steps:

Determining that the voice call of the user equipment UE is caused by a single wireless voice call continuity SRVCC handover;

Invoking the transceiver, when the determined voice call caused by the SRVCC handover ends, sending a first temporary mobile subscriber identity TMSI re-allocation message to the UE, where the first TMSI re-allocation message includes a TMSI network element The TMSI network element includes a network resource identifier NRI, and the NRI is not allocated by any MSC in all MSC resource pools in the shared network in which the UE is located, so that the UE carries the location area update LAU request message when carrying And the MSC that receives the LAU request message, according to the NRI triggering PS/CS coordination procedure included in the TMSI network element in the LAU request message, to reselect a CS domain operation for the UE. Business.

In conjunction with the third aspect, in a first possible implementation of the third aspect, the processor executes the program code, and is further configured to perform the following steps:

Also included in the first TMSI reassignment message is a first location area identifier LAI, wherein the first LAI is a non-broadcast LAI, so that the UE saves after receiving the first TMSI reallocation message. The first LAI triggers a LAU flow.

With reference to the third aspect, or the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, the processor executes the program code, and is further configured to perform the following steps:

In the determined voice call caused by the SRVCC handover, the transceiver is invoked to send a second TMSI re-allocation message to the UE, where the second TMSI redistribution message includes a second LAI, so that After receiving the second TMSI re-allocation message, the UE saves the second LAI, and acquires a public land mobile network PLMN identity as a registered PLMN according to the second LAI.

In conjunction with the third aspect and any one of the first to second possible implementations of the third aspect, in a third possible implementation of the third aspect, the processor executes the program code, Used to perform the following steps:

Invoking the transceiver to receive a LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

Determining, according to the NRI included in the TMSI network element, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs;

The PS/CS coordination process is triggered to reselect an operator of the CS domain for the UE that sends the LAU request message.

In conjunction with the third possible implementation of the third aspect, in a fourth possible implementation of the third aspect, the processor executes the program code, and is specifically configured to perform the following steps:

The PS/CS coordination process is triggered, and the UE that sends the LAU request message reselects an operator of the CS domain according to the configuration policy, and sends the LAU request message to an MSC corresponding to the operator of the selected CS domain. .

In conjunction with the third possible implementation of the third aspect, in a fifth possible implementation manner of the third aspect, the processor is configured to execute the program code, and is specifically configured to perform the following steps:

Sending a rerouting command to the base station controller BSC or the radio control center RNC, where the rerouting command includes an international mobile subscriber identifier IMSI and redirection indication information of the UE that sends the LAU request message, so that the BSC or the After receiving the rerouting command, the RNC reselects a CS domain operator for the UE that sends the LAU request message according to the BSC or the RNC's own policy, and sends the LAU request message to the One MSC corresponding to the operator of the selected CS domain.

In a fourth aspect, the embodiment of the present invention provides a PS/CS coordination system, including: the MSC, the user, according to any one of the first to fifth possible implementation manners of the third aspect The device UE, the base station controller BSC or the radio control center RNC, and the GPRS service support node SGSN.

With the above solution, the embodiment of the present invention provides that the first TMSI re-allocation message is sent by the MSC to the UE that performs the voice call caused by the SRVCC handover, and the TMSI cell carries none of the MSCs in all the resource pools in the shared network. The allocated NRI is such that the UE saves the NRI and carries the NRI when the LAU request message is sent, so that the MSC that receives the LAU request message determines that the TMSI reported by the UE is not the MSC in the resource pool in which the UE is located. The allocation, which in turn triggers the PS/CS coordination process, reselects a CS domain operator for the UE, and solves the problem of using the pool centric scheme for SRVCC handover to the shared network in the prior art, the MSC does not The PS/CS coordination process must be triggered, and the SGSN will definitely trigger the PS/CS coordination process, which will easily lead to the PS/CS uncoordinated problem. In the SRVCC process, the MSC will trigger the PS/CS coordination process to ensure the SRVCC process. PS/CS coordination.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention, Those skilled in the art can also obtain other drawings based on these drawings without paying for inventive labor.

FIG. 1 is a flowchart of a PS/CS coordination method according to an embodiment of the present invention;

2 is a flowchart of a PS/CS coordination method according to another embodiment of the present invention;

FIG. 3 is a signaling interaction diagram of a PS/CS coordination method according to still another embodiment of the present invention; FIG.

4 is a schematic structural diagram of an MSC according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of an MSC according to another embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an MSC according to another embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a PS/CS coordination system according to an embodiment of the present invention.

detailed description

The present invention will be further described in detail with reference to the accompanying drawings, in which FIG. For example, not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In the SRVCC handover process, the voice and data services are switched from the EPS domain of the LTE network to the CS domain and the PS domain of the 2G/3G network, that is, to the Global System for Mobile Communications (GSM). /Enhanced Data Rates for GSM Evolution (EDGE) Radio Access Network (GSM/EDGE Radio Access Network, GERAN)/Universal Terrestrial Radio Access Network (UTRAN) CS domain And PS domain. When the UE that is performing the VOIP voice service enters a shared 2G/3G network signal coverage area from the LTE signal coverage area, the source network side triggers the SRVCC handover procedure to the target network side to ensure that the voice service is not interrupted, thereby The handover of the voice session from the EPS domain of the LTE network to the CS domain of the 2G/3G network is continued by the target MSC.

FIG. 1 is a flowchart of a PS/CS coordination method according to an embodiment of the present invention. As shown in FIG. 1, the method includes the following steps:

Step 101: The MSC determines that the voice call of the UE is caused by the SRVCC handover.

Generally, the shared network includes one or more operators, each of which includes one or more MSC resource pools, each of which includes multiple MSCs, and the foregoing MSCs that provide voice services for the UE may be shared networks. One of the MSCs in any of the resource pools of any of the operators.

Step 102: The MSC sends a first TMSI re-allocation message to the UE when the determined voice call caused by the SRVCC handover ends, where the first TMSI re-allocation message includes a TMSI network element, where the TMSI network element includes an NRI, and The NRI is not allocated to any MSC in the MSC resource pool in the shared network where the MSC is located, so that the UE carries the NRI when the LAU request message is sent, so that the MSC that receives the LAU request message is included in the LAU request message. The above NRI triggers the PS/CS coordination process to reselect a CS domain operator for the UE.

Specifically, the MSC determines that the ongoing voice call of the UE is caused by the SRVCC handover. When the voice call ends, the signaling connection of the CS domain is not immediately released, but the first TMSI re-allocation message is sent to the UE. The TMSI redistribution message includes a TMSI cell, and the NRI included in the TMSI cell is set to a special NRI, and the special NRI may be a special number sequence or a special character, which is not limited by the present invention. The special NRI is not To share all resource pools in the network Any MSC in the allocation, in other words, the NRI is not recognized by any MSC in the resource pool.

In a specific implementation, the MSC may use the coding mode different from the NRI of all the MSCs to generate the special NRI, or assign a garbled code to the special NRI, or leave the special NRI blank, which is not limited by the present invention.

After receiving the first TMSI re-allocation message sent by the MSC, the UE saves the TMSI including the special NRI as its own temporary identifier. When the LCA process is initiated by the BSC or the RNC to the core network MSC, the UE carries the NRI in the TMSI network element of the LAU request message. After receiving the LAU request message sent by the UE, the BSC or the RNC acquires the NRI included in the TMSI network element, and queries the operator corresponding to the NRI in its configuration. Since the NRI included in the foregoing TMSI is a special NRI and is not allocated by any MSC in the shared network, the BSC or the RNC cannot find a matching operator according to the configuration relationship, and randomly selects a CS domain operator for the UE according to a certain rule. And forwarding the LAU request message sent by the UE to an MSC of the selected operator.

It should be noted that the MSC that receives the LAU request message sent by the UE forwarded by the BSC or the RNC may be the foregoing MSC that provides voice service for the UE, or may be any other MSC in the shared network.

After the NRI included in the TMSI network element of the LAU request message is not allocated by any MSC in the shared network, the MSC that receives the LAU request message determines the NRI that is included in the TMSI network element, and determines the reported by the UE according to the NRI. If the TMSI is not allocated by any MSC in its own resource pool, the PS/CS coordination process is triggered to reselect a CS domain operator for the UE.

In this embodiment, the first TMSI re-allocation message is sent by the MSC to the UE that performs the voice call caused by the SRVCC handover, and the NSI that is not allocated by any MSC in all resource pools in the shared network is carried in the TMSI cell, so that the UE The NRI is saved and carried in the subsequent transmission of the LAU request message, so that the MSC that receives the LAU request message determines that the TMSI reported by the UE is not allocated by any MSC in the resource pool in which the UE is located according to the foregoing NRI, thereby triggering the PS/CS. Coordinating the process, re-selecting a CS domain operator for the UE, and solving the prior art adopting a pool centric scheme for SRVCC handover to the shared network, the MSC does not necessarily trigger the PS/CS coordination process. The SGSN will definitely trigger the PS/CS coordination process, which will easily lead to PS/CS uncoordinated problems. In the SRVCC process, the MSC will trigger the PS/CS coordination process to ensure PS/CS coordination in the SRVCC process.

In a preferred embodiment of the present invention, the first TMSI reassignment message further includes a first LAI, where the first LAI is a non-broadcast LAI, so that the UE receives the first TMSI reallocation. After the message, the first LAI is saved, and the LAU trigger condition is created, thereby initiating the LAU process.

Generally, after receiving the broadcast LAI message sent by the base station of the radio access network in which the UE is located, the UE sends the broadcast LAI included in the broadcast LAI message and the core network MSC saved by the core network MSC in the process of LAU process or attaching. If the LAI is different, if the LAU request is different, the LAU request needs to wait until the location of the UE (Location Area, LA for short) changes, and the broadcast LAI and the LAI stored by the UE are different, and there is a certain Delay.

In a preferred embodiment, by including a first LAI in the first TMSI reassignment message, the UE receives the first TMSI reassignment message, receives a non-broadcast LAI and stores it, and compares the stored non-broadcast LAI with The LAI in the broadcast message is sent to the MSC as soon as the two are different, so that the UE can quickly initiate the LAU request after the CS voice session ends, thereby improving the efficiency of the PS/CS coordination.

In another preferred embodiment of the present invention, the MSC sends a second TMSI re-allocation message to the UE during the determined voice call caused by the SRVCC handover, where the second TMSI re-allocation message includes a second LAI. The second LAI may be a broadcast or non-broadcast LAI, so that after receiving the second TMSI reallocation message, the UE saves the second LAI and acquires a public land mobile network according to the second LAI (Public Land Mobile Network) , referred to as PLMN), as a registered PLMN, ie RPLMN.

It should be noted that the second TMSI re-allocation message in this embodiment may also be sent by the MSC to the UE in the process of the SRVCC, and the implementation process is similar, and details are not described herein.

Generally, the UE may not be registered on any MSC before the SRVCC handover, or is not registered on the target network MSC. In the handover process or during the CS domain call, the UE does not have an RPLMN, resulting in no UE. The network name shows anomalies, and subsequent network reselection and cell reselection processes may also be affected.

In the preferred embodiment, the MSC sends a second TMSI re-allocation message to the UE in the SRVCC handover process, so that the UE can acquire the RPLMN according to a second LAI carried in the UE, thereby resolving the non-RPLMN triggered by the UE in the SRVCC process. No problems such as network name display.

2 is a flowchart of a PS/CS coordination method according to another embodiment of the present invention. The embodiment is an extension of the method embodiment shown in FIG. 1. The embodiment is that the MSC receives a message according to the first TMSI re-allocation message. The specific implementation process of the sent LAU request message is as shown in FIG. 2, and the method embodiment includes:

Step 201: The MSC receives the LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE.

The TMSI network element is the same as the TMSI network element in the first embodiment of the present invention, and is a TMSI network element carried by the first TMSI re-allocation message sent by the MSC to the UE, and includes an NRI in the TMSI network element. The NRI is not allocated to any MSC in all resource pools in the shared network, and details are not described herein.

Step 202: The MSC determines, according to the NRI included in the TMSI network element, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which the MSC belongs.

Step 203: The MSC triggers a PS/CS coordination process to reselect an operator of the CS domain for the UE that sends the LAU request message.

In step 203, the MSC re-selects a CS domain operator for the UE that sends the LAU request message, and may include the following two possible implementation manners:

The MSC re-selects an available CS carrier for the UE that sends the LAU request message according to its own configuration policy, and forwards the LAU request message to an MSC corresponding to the operator of the selected CS domain.

The MSC sends a re-routing command to the BSC or the RNC, where the re-routing command includes the IMSI and the redirection indication information of the UE that sends the LAU request message, so that the BSC or the RNC receives the re-routing command, according to the BSC or The RNC's own policy is to reselect the operator of a CS domain for the UE transmitting the LAU request message, and forward the LAU request message to an MSC corresponding to the operator of the selected CS domain.

For the shared network of the GWCN architecture, the first possible implementation manner may be adopted. The MSC selects a CS domain operator for the UE through the configured policy. The SGSN will trigger the PS/CS coordination process, SGSN. The eNB and the SGSN can be re-assigned to the UE. The MSC and the SGSN can be re-assigned to the UE. The selected CS domain operator and PS domain operator will point to the same carrier, so that the UE is in the same carrier. PS domain and CS domain registration, thereby ensuring PS/CS coordination of UEs performing SRVCC handover;

For the shared network of the MOCN architecture, the second possible implementation manner may be adopted. The MSC returns a re-routing command including the IMSI and the redirection indication information of the UE to the BSC or the RNC, and informs the BSC or the RNC of the command by using the redirection indication information. The purpose is to use PS/CS coordination, and the BSC or the RNC is required to re-select a CS domain operator for the user. After receiving the rerouting command, the BSC or the RNC reselects a CS domain for the UE according to its own policy (such as the IMSI hash method). The carrier network is registered. For the PS domain, after receiving the RAU request message, the SGSN also sends a re-routing command including the IMSI and the redirection indication information of the UE to the BSC or the RNC because the P-TMSI in the RAU cannot be identified. The BSC or the RNC re-selects the carrier network of the PS domain for the UE to register according to its own policy. As long as the BSC or the RNC ensures the policy consistency of the same UE, the BSC or the RNC can be guaranteed to re-select the CS operator. The PS domain operator is directed to the same carrier, so that the UE is registered in the PS domain and the CS domain of the same carrier, thereby ensuring PS/CS coordination of the UE performing the SRVCC handover.

The MSC, the BSC, or the RNC is a specific implementation process for the UE to re-select a CS domain. The same as the prior art, details are not described herein.

In this embodiment, the MSC receives the LAU request message sent by the UE, where the UE carries the TMSI network element included in the first TMSI re-allocation message received by the UE in the LAU request message, where the TMSI network element includes For the NRI allocated by any MSC in the resource pool of the shared network, the MSC determines that the TMSI reported by the UE is not allocated by any MSC in the resource pool in which the UE is located according to the NRI carried in the LAU request message, thereby triggering the PS/CS coordination process. Re-selecting a CS domain operator for the UE, and forwarding the LAU request message to an MSC corresponding to the operator of the selected CS domain, thereby solving the MSC that is easy to exist in the prior art does not necessarily trigger the PS/CS coordination process. However, the SGSN will definitely trigger the PS/CS coordination process, which will easily lead to PS/CS uncoordinated problems.

The following takes the MOCN architecture shared network as an example to specifically describe the signaling interaction process between the network nodes involved in the embodiment of the present invention. The implementation manner of the GWCN architecture shared network is similar, and details are not described herein.

FIG. 3 is a signaling interaction diagram of a PS/CS coordination method according to another embodiment of the present invention. The shared network on the 2G/3G network side includes an operator A and an operator B, and each operator has 1 The MSC resource pools are respectively MSC pool A and MSC pool B. MSC pool A includes two MSCs, which are respectively recorded as MSC _A1 , MSC _A2 and MSC pool B, which include two MSCs, which are respectively recorded as MSC _B1. MSC _B2 , and each operator has at least one SGSN, which is denoted as SGSN _A and SGSN _{B respectively} as an example to illustrate the specific implementation process of this embodiment. For other numbers of operators, resource pools and each resource pool The implementation process of the MSC is similar, and is not described here. The embodiment further includes signaling interaction between the UE and the source network side MME, and the BSC/RNC in the access network, as shown in FIG. This embodiment includes the following steps:

Step 301: The MME on the source network side selects one MSC as the target MSC in the MSC _A1 , the MSC _A2, and the MSC _B1 and the MSC _B2 , and initiates an SRVCC handover to the target MSC.

Specifically, the MME initiates a PS to CS (ps to cs) handover request to an MSC server on the target network side according to the logical interface Sv for the SRVCC and the self-selection policy between the MME and the MSC, where the request requires the MSC to be the UE. The arrival of the corresponding do the preparation and session switching operations. In this embodiment, the MME selects the MSC _A1 as the target MSC as an example. The implementation process of the MSC is similar to that of the other MSCs in the shared network, and details are not described herein.

Step 302: The MSC _A1 sends a second TMSI re-allocation message to the UE during the voice call caused by the SRVCC process or the subsequent SRVCC handover, and carries a TMSI and a MSC _A1 allocated to the UE in the message. Second LAI.

Step 303: The UE receives the second TMSI re-allocation message, saves the TMSI as its own temporary identifier, and acquires the RPLMN according to the second LAI.

Step 304: When the voice call caused by the SRVCC handover ends, the MSC _A1 does not immediately release the CS domain signaling connection of the UE, and sends a first TMSI re-allocation message to the UE, where the message carries the TMSI cell and a first LAI. The first LAI is a non-broadcast LAI, wherein an NRI is included in the TMSI cell, the NRI may be a special sequence of numbers or special characters, and the NRI is not any one of all resource pools in the shared network. The assigned, that is, the NRI included in the TMSI network element cannot be identified by any one of the MSCs. Specifically, the NRI is the same as the first embodiment, and details are not described herein.

Step 305: After receiving the first TMSI re-allocation message, the UE saves the first LAI, and compares the first LAI with the LAI received in the broadcast message, because the LAI received in the first LAI and the broadcast message Certainly, the UE determines that the condition for triggering the LAU procedure is met, and sends a LAU request message to the BSC/RNC of the access network, and the LAU request message carries the TMSI cell included in the first TMSI re-allocation message, wherein the TMSI letter The above includes the above NRI.

Step 306: The BSC/RNC receives the LAU request message sent by the UE, obtains a TMSI cell from the LAU request message, and identifies the NRI in the TMSI cell, according to a mapping table of the NRI and the carrier relationship stored by the UE. Query the operator corresponding to the NRI. Since the NRI is not allocated to any MSC in all resource pools, the BSC/RNC cannot find the corresponding operator, so select a CS domain operator randomly or according to certain rules, and The LAU request message is forwarded to an MSC corresponding to the selected operator.

Taking the selected carrier as the carrier A and forwarding the LAU request to the MSC _A1 as an example for performing the subsequent steps. For the selected MSC being the MSC _A2 or one of the operators B, the specific implementation process is similar. No longer repeat them.

Step 307: The MSC _A1 receives the LAU request message forwarded by the BSC/RNC, and determines that the TMSI reported by the UE is not allocated by any MSC in the resource pool in which the UE is located according to the foregoing NRI, triggers a PS/CS coordination process, and sends the PS/CS coordination process to the BSC/RNC. The rerouting command includes the IMSI and redirection indication information of the UE in the rerouting command.

Step 308: After receiving the rerouting command, the BSC/RNC reselects an operator of the CS domain for the UE according to the IMSI of the UE and the self-policy.

Step 309: The BSC/RNC forwards the LAU request message of the UE to an MSC corresponding to the operator of the selected CS domain, and the selected operator is the operator B. The LAU request message may be forwarded to the MSC _B1. Or the MSC _B2 , the embodiment is forwarded to the MSC _B1 as an example, and the process is similar to the other MSCs in the MSC resource pool included in the selected carrier B, and details are not described herein.

Step 310: The UE triggers a Route Area Update (RAU) process, and sends a RAU request message to the BSC/RNC, and carries the P-TMSI mapped by the GUTI allocated by the MME in the RAU request message.

Step 311: After receiving the RAU request message sent by the UE, the BSC/RNC randomly selects one SGSN and forwards the RAU request message to the SGSN because the P-TMSI is not allocated by any SGSN on the 2G/3G network side. at the selected SGSN SGSN _a as an example, for the selected SGSN is an SGSN _B, which is similar to the implementation process, not further described herein.

Step 312: After receiving the RAU request message, the SGSN _A triggers the PS/CS coordination process to send a re-routing command to the BSC/RNC after the P-TMSI is not allocated by any SGSN on the 2G/3G network side, where the re-routing is performed. The command includes the IMSI and redirection indication information of the UE.

Step 313: After receiving the rerouting command, the BSC/RNC reselects a carrier of the PS domain for the UE according to its own policy. For the same UE, the BSC/RNC uses the same policy to select the operator of the CS domain or the PS domain. It can be ensured that the operator of the PS domain selected by the UE is the same as the operator of the CS domain, and the operator of the PS domain that the BSC/RNC reselects for the UE is also the operator B.

Step 314: The BSC/RNC forwards the RAU request message to the SGSN _{B that is} reselected for the UE.

It should be noted that the execution sequence of the RAU process corresponding to the foregoing steps 305-309 and the RAU process corresponding to the foregoing steps 310-314 may be performed simultaneously with steps 305-309 and steps 310-314, or steps 305-309 may be performed at the same time. Executed after 310-314, the invention is not limited thereto.

FIG. 4 is a schematic structural diagram of an MSC according to an embodiment of the present invention. As shown in FIG. 4, the MSC 400 includes a first determining module 401 and a sending module 402.

The first determining module 401 is configured to determine that the voice call of the UE is caused by the SRVCC switch;

The sending module 402 is configured to send a first TMSI re-allocation message to the UE when the voice call caused by the SRVCC handover is determined by the first determining module 401, where the first TMSI re-allocation message includes a TMSI network element, where the TMSI The network element includes an NRI, and the NRI is not allocated by any MSC in all the MSC resource pools in the shared network, so that the UE carries the LSI request message when transmitting the LAU request message, so that the LAU request message is received. The MSC re-selects a CS domain operator for the UE according to the NRI triggering PS/CS coordination procedure included in the TMSI network element in the LAU request message.

In a preferred embodiment of the present invention, the first TMSI re-allocation message further includes a first LAI, where the first LAI is a non-broadcast LAI, so that the UE saves the first TMSI re-allocation message after receiving the first The first LAI, which manufactures the LAU trigger condition, initiates the LAU process.

In another preferred embodiment of the present invention, the sending module 402 is further configured to send a second TMSI re-allocation message to the UE, in the process of the voice call caused by the SRVCC handover determined by the first determining module 401, the second The TMSI redistribution message includes a second LAI. The second LAI may be a broadcast or non-broadcast LAI, so that after receiving the second TMSI re-allocation message, the UE saves the second LAI and acquires a PLMN identity as the registered PLMN according to the second LAI.

The MSC provided by the embodiment of the present invention may be used to implement the technical solution in the method embodiment shown in FIG. 1. The implementation principle and technical effects are similar, and details are not described herein.

FIG. 5 is a schematic structural diagram of an MSC according to another embodiment of the present invention, where The MSC 500 is an extension of the MSC shown in FIG. 4 to process the LAU request message sent by the received UE according to the first TMSI re-allocation message. As shown in FIG. 5, the MSC 500 further includes:

a receiving module 501, a second determining module 502, and a triggering module 503, wherein

The receiving module 501 is configured to receive a LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

The second determining module 502 is configured to determine, according to the NRI included in the foregoing TMSI network element, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs;

The triggering module 503 is configured to trigger a PS/CS coordination process to reselect an operator of the CS domain for the UE that sends the LAU request message.

Further, the triggering module 503 is specifically configured to:

The PS/CS coordination process is triggered, and the UE that sends the LAU request message reselects an operator of the CS domain according to the configuration policy, and sends the LAU request message to an MSC corresponding to the operator of the selected CS domain.

Optionally, the trigger module 503 is specifically configured to:

Sending a rerouting command to the BSC or the RNC, where the rerouting command includes the IMSI and the redirection indication information of the UE that sends the LAU request message, so that the BSC or the RNC receives the rerouting command, and sends the LAU according to the policy of the BSC or the RNC itself. The request message UE reselects an operator of a CS domain and sends a LAU request message to an MSC corresponding to the selected operator.

The MSC provided in this embodiment may be used to implement the technical solution in the embodiment of the method shown in FIG. 1 and the embodiment of the MSC in the embodiment shown in FIG. 3, and the implementation principle and the technical effect are similar. No longer.

FIG. 6 is a schematic structural diagram of an MSC according to another embodiment of the present invention. As shown in FIG. 6, the MSC 600 includes: a memory 601 connected by a bus (shown by a thick solid line in the figure), a processor 602, and a transceiver 602. 603, wherein

The memory 601 stores program code, and the processor 602 executes the program code for performing the following steps:

Determining that the voice call of the UE is caused by the SRVCC handover;

The calling transceiver 603, when the determined voice call caused by the SRVCC handover ends, sends a first TMSI re-allocation message to the UE, where the first TMSI re-allocation message includes a TMSI network element, The TMSI network element includes an NRI, and the NRI is not allocated by any MSC in all the MSC resource pools in the shared network, so that the UE carries the LSI request message and carries the TMSI network element, so that the MSC receives the LAU request message. The operator of the CS domain is reselected for the UE according to the NRI triggering PS/CS coordination procedure included in the TMSI network element in the LAU request message.

Preferably, the processor 602 executes the program code, and is further configured to perform the following steps:

The first LAI is further included in the first TSI re-allocation message, where the first LAI is a non-broadcast LAI, so that after receiving the first TSI re-allocation message, the UE saves the first LAI, triggering the LAU process.

In the determined voice call caused by the SRVCC handover, the transceiver 603 is invoked to send a second TMSI re-allocation message to the UE, and the second TMSI re-allocation message includes a second LAI, so that the UE receives the second TMSI reallocation. After the message, the second LAI is saved, and a PLMN identity is acquired as the registered PLMN according to the second LAI.

Further, when the UE receives the first TMSI re-allocation message and sends the LAU request message to the core network MSC, the processor 602 in this embodiment executes the program code, and is further configured to perform the following steps:

The transceiver 603 is configured to receive the LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

Determining, by the NRI included in the TMSI network element, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs;

Further, the processor 602 executes the program code, specifically for performing the following steps:

Optionally, the processor 602 executes the program code, specifically for performing the following steps:

Sending a rerouting command to the BSC or the RNC, where the rerouting command includes the IMSI and the redirection indication information of the UE that sends the LAU request message, so that the BSC or the RNC receives the rerouting command, and sends the LAU according to the policy of the BSC or the RNC itself. The UE requesting the message reselects the operator of a CS domain and sends a LAU request message to the operator of the selected CS domain. Should be an MSC.

The MSC in this embodiment may be used to perform a technical solution that can be used to implement the technical solution in the embodiment of the method shown in FIG. 2 and the MSC corresponding part in the embodiment shown in FIG. 3, and the implementation principle and technical effect are Similarly, the details will not be described again.

FIG. 7 is a schematic structural diagram of a PS/CS coordination system according to an embodiment of the present invention. As shown in FIG. 7, the PS/CS coordination system 700 includes: an MSC 701, a UE 702, a BSC 703 or an RNC 704, and an SGSN 705. The MSC 701 may be the MSC 500 or the MSC 600 provided in the embodiment shown in FIG. 5 or FIG. 6. The implementation principle and technical effects are similar, and details are not described herein.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented in hardware, firmware implementation, or a combination thereof. When implemented in software, the functions described above may be stored in or transmitted as one or more instructions or code on a computer readable medium. Computer readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A storage medium may be any available media that can be accessed by a computer. By way of example and not limitation, computer readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage media or other magnetic storage device, or can be used for carrying or storing in the form of an instruction or data structure. The desired program code and any other medium that can be accessed by the computer. Also. Any connection may suitably be a computer readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable , fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless, and microwave are included in the fixing of the associated media. As used in the present invention, a disk and a disc include a compact disc (CD), a laser disc, a compact disc, a digital versatile disc (DVD), a floppy disk, and a Blu-ray disc, wherein the disc is usually magnetically copied, and the disc is The laser is used to optically replicate the data. Combinations of the above should also be included within the scope of the computer readable media.

Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A packet switching PS/circuit switched CS coordination method, comprising:

The mobile switching center MSC determines that the voice call of the user equipment UE is caused by a single wireless voice call continuity SRVCC handover;

The MSC, when the determined voice call caused by the SRVCC handover ends, sends a first temporary mobile subscriber identity TMSI re-allocation message to the UE, where the first TMSI re-allocation message includes a TMSI network element, where The TMSI network element includes a network resource identifier NRI, and the NRI is not allocated by any MSC in all MSC resource pools in the shared network where the MSC is located, so that the UE carries the location area update LAU request message. And the MSC that receives the LAU request message, according to the NRI triggering PS/CS coordination procedure included in the TMSI network element in the LAU request message, to reselect a CS domain operation for the UE. Business.
The method according to claim 1, wherein the first TMSI reallocation message further includes a first location area identifier LAI, wherein the first LAI is a non-broadcast LAI, so that the UE is receiving After the first TMSI reallocation message, the first LAI is saved and the LAU procedure is triggered.
The method according to claim 1 or 2, further comprising:

The MSC, in the determined voice call caused by the SRVCC handover, sends a second TMSI re-allocation message to the UE, where the second TMSI re-allocation message includes a second LAI, so that the UE After receiving the second TMSI reallocation message, the second LAI is saved, and a public land mobile network PLMN identity is acquired as the registered PLMN according to the second LAI.
The method according to any one of claims 1 to 3, further comprising:

Receiving, by the MSC, a LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

Determining, by the MSC, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs according to the NRI included in the TMSI network element;

The MSC triggers a PS/CS coordination procedure to reselect an operator of the CS domain for the UE that sends the LAU request message.
The method of claim 4 wherein said MSC triggers a PS/CS protocol The process of re-selecting a CS domain operator for the UE that sends the LAU request message includes:

The MSC triggers the PS/CS coordination process, and reselects a CS domain operator for the UE that sends the LAU request message according to the configuration policy, and sends the LAU request message to the operator of the selected CS domain. One of the MSCs.
The method according to claim 4, wherein the MSC triggers a PS/CS coordination procedure, and reselects a CS domain operator for the UE that sends the LAU request message, including:

Sending, by the MSC, a rerouting command to the base station controller BSC or the radio control center RNC, where the rerouting command includes an international mobile subscriber identifier IMSI and redirection indication information of the UE that sends the LAU request message, so that the After receiving the rerouting command, the BSC or the RNC reselects a CS domain operator for the UE that sends the LAU request message according to the BSC or the RNC's own policy, and the LAU request message is sent. An MSC corresponding to the operator of the selected CS domain.
A mobile switching center MSC, comprising:

a first determining module, configured to determine that the ongoing voice call of the user equipment UE is caused by a single wireless voice call continuity SRVCC handover;

a sending module, configured to send, by the first determining module, a first temporary mobile subscriber identity TMSI re-allocation message to the UE when the voice call caused by the SRVCC handover ends, the first TMSI re-allocation message A TMSI network element is included, wherein the TMSI network element includes a network resource identifier NRI, and the NRI is not allocated by any MSC in all MSC resource pools in the shared network in which the UE is located, so that the UE sends the location area update. The LAU request message carries the TMSI network element, so that the MSC that receives the LAU request message reselects the UE according to the NRI trigger PS/CS coordination procedure included in the TMSI network element in the LAU request message. The operator of a CS domain.
The MSC according to claim 7, wherein the first TMSI reassignment message further includes a first LAI, wherein the first LAI is a non-broadcast LAI, so that the UE receives the After the first TMSI reassigns the message, the first LAI is saved and the LAU procedure is triggered.
The MSC according to claim 7 or 8, wherein the transmitting module is further used to:

And sending, by the first determining module, a second TMSI re-allocation message to the UE during a voice call caused by the SRVCC handover, where the second TMSI re-allocation message includes a second LAI, so that After the determined UE receives the second TMSI re-allocation message, the second LAI is saved, and a public land mobile network PLMN identity is acquired as the registered PLMN according to the second LAI.
The MSC according to any one of claims 7-9, further comprising:

a receiving module, configured to receive a LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

a second determining module, configured to determine, according to the NRI included in the TMSI network element, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs;

The triggering module is configured to trigger a PS/CS coordination process, and reselect an operator of the CS domain for the UE that sends the LAU request message.
The MSC according to claim 10, wherein the triggering module is specifically configured to:

The PS/CS coordination process is triggered, and the UE that sends the LAU request message reselects an operator of the CS domain according to the configuration policy, and sends the LAU request message to an MSC corresponding to the operator of the selected CS domain. .
The MSC according to claim 10, wherein the triggering module is specifically configured to:

Sending a rerouting command to the base station controller BSC or the radio control center RNC, where the rerouting command includes an international mobile subscriber identifier IMSI and redirection indication information for transmitting the LAU request message UE, so that the BSC or the After receiving the rerouting command, the RNC reselects a CS domain operator according to the BSC or the RNC's own policy to send the LAU request message, and sends the LAU request message to the selected one. An MSC corresponding to the operator.
A mobile interaction center MSC, comprising:

a memory, a processor and a transceiver connected via a bus;

The memory stores program code, and the processor executes the program code for executing as Next steps:

Determining that the voice call of the user equipment UE is caused by a single wireless voice call continuity SRVCC handover;

Invoking the transceiver, when the determined voice call caused by the SRVCC handover ends, sending a first temporary mobile subscriber identity TMSI re-allocation message to the UE, where the first TMSI re-allocation message includes a TMSI network element The TMSI network element includes a network resource identifier NRI, and the NRI is not allocated by any MSC in all MSC resource pools in the shared network in which the UE is located, so that the UE carries the location area update LAU request message when carrying And the MSC that receives the LAU request message, according to the NRI triggering PS/CS coordination procedure included in the TMSI network element in the LAU request message, to reselect a CS domain operation for the UE. Business.
The MSC according to claim 13, wherein said processor executes said program code and is further configured to perform the following steps:

Also included in the first TMSI reassignment message is a first location area identifier LAI, wherein the first LAI is a non-broadcast LAI, so that the UE saves after receiving the first TMSI reallocation message. The first LAI triggers a LAU flow.
The MSC according to claim 13 or 14, wherein the processor executes the program code and is further configured to perform the following steps:

In the determined voice call caused by the SRVCC handover, the transceiver is invoked to send a second TMSI re-allocation message to the UE, where the second TMSI redistribution message includes a second LAI, so that After receiving the second TMSI re-allocation message, the UE saves the second LAI, and acquires a public land mobile network PLMN identity as a registered PLMN according to the second LAI.
The MSC according to any one of claims 13 to 15, wherein the processor executes the program code, and is further configured to perform the following steps:

Invoking the transceiver to receive a LAU request message sent by the UE, where the LAU request message carries the TMSI network element included in the first TMSI request message received by the UE;

Determining, according to the NRI included in the TMSI network element, that the TMSI reported by the UE that sends the LAU request message is not allocated by any MSC in the resource pool to which it belongs;

The PS/CS coordination process is triggered to reselect an operator of the CS domain for the UE that sends the LAU request message.
The MSC according to claim 16, wherein the processor executes the program code, specifically for performing the following steps:

The PS/CS coordination process is triggered, and the UE that sends the LAU request message reselects an operator of the CS domain according to the configuration policy, and sends the LAU request message to an MSC corresponding to the operator of the selected CS domain. .
The MSC according to claim 16, wherein the processor executes the program code, specifically for performing the following steps:

Sending a rerouting command to the base station controller BSC or the radio control center RNC, where the rerouting command includes an international mobile subscriber identifier IMSI and redirection indication information of the UE that sends the LAU request message, so that the BSC or the After receiving the rerouting command, the RNC reselects a CS domain operator for the UE that sends the LAU request message according to the BSC or the RNC's own policy, and sends the LAU request message to the One MSC corresponding to the operator of the selected CS domain.
A packet switched PS/circuit switched CS coordination system, comprising: a mobile interaction center MSC according to any one of claims 13 to 18, a user equipment UE, a base station controller BSC or a radio control center RNC, and The GPRS service supports the node SGSN.