CN104837183A - PLMN selection method of PS domain and CS domain, and device - Google Patents

Abstract

The invention provides a PLMN selection method of a PS domain and a CS domain, and a device. The selection method comprises obtaining first PLMN information registered in the PS domain or second PLMN information registered in the CS domain through first core-network network elements, and selecting a first PLMN registered in the CS domain for user equipment through the first core-network network elements according to the first PLMN information, or selecting a second PLMN registered in the PS domain for the user equipment through the first core-network network elements according to the second PLMN information. Through adoption of the technical scheme provided by the invention, the technical problems that an existing PLMN selecting scheme may result in different PLMNs selected by the CS domain and the PS domain and then telephone charge differences are generated or terminal displayed operator names are different in the prior art are solved, the fact that the CS domain and the PS domain select the same PLMN can be guaranteed, the telephone charge differences and terminal displayed operator name differences are prevented, and user experience is improved.

Description

PLMN selection method and device for PS domain and CS domain

Technical Field

The present invention relates to the field of communications, and in particular, to a Public Land Mobile Network (PLMN) selection method in a Packet Switched (PS) domain and a Circuit Switched (CS) domain.

Background

A currently deployed third Generation Partnership Project (3 rd Generation Partnership Project, 3 GPP) network includes the following network devices, as shown in fig. 1.

User Equipment (User Equipment, abbreviated as UE) has the capability of accessing a global Mobile communication System Radio Access Network (Universal Mobile telecommunications System Radio Access Network/GSM EDGE Radio Access Network, abbreviated as UTRAN/GERAN), and in addition, the UE may also have the capability of accessing two wireless networks of Long Term Evolution (LTE). When the UE accesses the network from GERAN/UTRAN, it can access either the CS domain or the PS domain. The so-called CS domain, namely, the access Mobile Switching Center (MSC); a so-called PS domain, i.e. a General Packet Radio Service (GPRS) support Node (SGSN). Whether the UE can access both domains simultaneously is related to the capabilities of the UE and the capabilities of the network. In GERAN/UTRAN, a Base Station Controller (BSC) or a Radio Network Controller (RNC) is responsible for controlling and managing the Radio activities of users, respectively.

The core network element of the CS domain comprises: the MSC and the Visitor Location Register (VLR) are physically and generally combined together, and are responsible for managing Location information of a subscriber and call connection. A Gateway Mobile Switching Center (GMSC) is arranged to route calls to the MSC where the subscriber is located. When there is a call to a Mobile Subscriber, the GMSC obtains a Mobile Roaming Number (MSRN) of the Subscriber through a Home Location Register (HLR), and then routes the call according to the MSRN.

The PS domain core network has a general Packet SGSN, which is a control network element of the GPRS network, and is mainly used to record location information of the UE, and complete sending and receiving of mobile Packet data between the UE and a GPRS Gateway Support Node (GGSN) or between the UE and a Serving Gateway (S-GW)/Packet data Gateway (P-GW).

Both the MSC/VLR and the SGSN need to be connected to an HLR or a Home Subscriber Server (HSS), which stores the subscription information of the Subscriber and the address of the VLR. In a called call, the HLR/HSS can obtain the MSRN of the subscriber from the VLR. As shown in fig. 1, the HLR and HSS are served by one physical network element.

In the actual deployment of the network, the operator may adopt a way of establishing a shared network in order to save investment cost, and the shared network has two co-establishment modes, as shown in fig. 2 and fig. 3 respectively:

in the network shown in fig. 2, the operator's network is fully co-established, including the radio network and the core network control elements (MSC and SGSN). In the network shown in fig. 3, the operator only adopts the mode of co-building the wireless network, and the control network elements of the core network are still separately built.

If the user equipment is accessed to the shared network and the user equipment supports selecting one of the multiple PLMNs, the network determines the PLMN for the user equipment according to the selection of the user equipment. For some conventional terminals, i.e. terminals without PLMN selection capability, the BSS/RNC can only select the default PLMN for the terminal. When the user accesses the CS domain and the PS domain simultaneously, it is desirable that the PLMNs selected by the CS domain and the PS domain are identical in order to avoid the difference of telephone charges or the difference of operator names displayed by the terminal.

But when the user switches from other BSS/RNC to GERAN/UTRAN supporting shared network, the PLMN of the target cell is selected by the source radio side network element. When PS handover occurs and the target network does not support simultaneous PS and CS services, the registration of the CS domain needs to be performed after the PS handover is completed. That is, after the PS service is completed by the user handover to the target network, the registration of the CS domain is performed. This results in that the PLMN of the PS domain is selected by the source radio side network element and the PLMN of the CS domain is selected by the target radio side network element. It may cause the selected PLMNs of the CS domain and the PS domain to be different, resulting in a difference in charges or a difference in terminal display operator names.

Disclosure of Invention

Aiming at the technical problems that the prior PLMN selection scheme may cause different PLMNs selected by a CS domain and a PS domain in the related art, the invention provides a PLMN selection method and a PLMN selection device of the PS domain and the CS domain, so as to at least solve the problems.

To achieve the above object, according to an aspect of the present invention, there is provided a PLMN selection method for a packet switched PS domain and a circuit switched CS domain, comprising: a first core network element acquires first PLMN information registered in a PS domain or second PLMN information registered in a CS domain; and the first core network element selects a first PLMN registered in a CS domain for the user equipment according to the first PLMN information, or selects a second PLMN registered in a PS domain for the user equipment according to the second PLMN information.

Preferably, the acquiring, by the first core network element, the first PLMN information registered in the PS domain or the second PLMN information registered in the CS domain includes: the first core network element sends a location update request to a home location register; the first core network element receives a user data inserting message and a response message of the position updating request; and the first core network element acquires the first PLMN information or the second PLMN information from the response message or the user data inserting message.

Preferably, the acquiring, by the first core network element, the first PLMN information registered in the PS domain or the second PLMN information registered in the CS domain includes: the first core network element sends an authentication data request to a home location register; the first core network element receives an authentication data response from the home location register; and the first core network element acquires the first PLMN information or the second PLMN information from the authentication data response.

Preferably, before the sending, by the first core network element, the location update request to the home location register, the method includes: when the first core network element is a mobile switching center MSC or a visitor location register VLR, the home location register receives a location update request from a general packet radio service support node SGSN, wherein the location update request carries the first PLMN information; and when the first core network element is the SGSN, the home location register receives a location update request from the MSC or VLR, wherein the location update request carries the second PLMN information.

Preferably, before the sending, by the first core network element, the authentication data request to the home location register, the method includes: when the first core network element is a mobile switching center MSC or a visitor location register VLR, the home location register receives an authentication data request from a general packet radio service support node SGSN, wherein the authentication data request carries the first PLMN information; and when the first core network element is the SGSN, the home location register receives an authentication data request from the MSC or the VLR, wherein the authentication data request carries the information of the second PLMN.

Preferably, the sending, by the first core network element, the location update request to the home location register includes: the first core network element sends the location updating request to the home location register every time a user accesses the first core network element; or, when a user accesses a first core network element from a base station subsystem BSS or a radio network controller RNC, the first core network element receives a first notification message from the BSS or the RNC; wherein, the BSS or the RNC is indicated in the first notification message not to perform PLMN co-selection for the PS domain and the CS domain, and the first core network element sends the location update request to the home location register.

Preferably, the sending, by the first core network element, the authentication data request to the home location register includes: the first core network element sends the authentication data request to the home location register every time a user accesses the first core network element; or, when a user accesses a first core network element from a base station subsystem BSS or a radio network controller RNC, the first core network element receives a fourth notification message from the BSS or the RNC; wherein, the fourth notification message indicates that the BSS or the RNC does not perform PLMN collaborative selection for the PS domain and the CS domain, and the first core network element sends the authentication data request to the home location register.

Preferably, the acquiring, by the first core network element, the first PLMN information registered in the PS domain or the second PLMN information registered in the CS domain includes: when a home location register detects that the PLMN registered in the PS domain or the CS domain of the user equipment changes, or that the stored PLMN registered in the CS domain of the user equipment is different from the PLMN registered in the PS domain, the first core network element receives a second notification message from the home location register, where the second notification message carries the first PLMN information or the second PLMN information.

Preferably, the selecting, by the first core network element, a first PLMN registered in a CS domain for the user equipment according to the first PLMN information, or selecting a second PLMN registered in a PS domain for the user equipment according to the second PLMN information includes:

judging whether the first core network element supports the first PLMN or the second PLMN;

if the first PLMN or the second PLMN is supported, taking the first PLMN or the second PLMN as a final selection result;

if the first PLMN or the second PLMN is not supported, the first core network element redirects a location update LAU flow to a second core network element supporting the first PLMN or the second PLMN in the same CS domain or PS domain; selecting the first PLMN or the second PLMN for the user equipment through the second core network element.

Preferably, the redirecting, by the first core network element, the location update LAU procedure to a second core network element supporting the first PLMN or the second PLMN in the same CS domain or PS domain includes: the first core network element sends a third notification message to a BSS or an RNC accessed by a user, wherein the third notification message carries the first PLMN information or the second PLMN information, and the first PLMN information or the second PLMN information carried in the third notification message is used for selecting the second core network element for the BSS or the RNC.

Preferably, the first PLMN information and the second PLMN information each include one of: and the SGSN number, the MSC number or the VLR number and the PLMN number are used for representing the PLMN where the user equipment is located.

In order to achieve the above object, according to another aspect of the present invention, there is provided a PLMN selection apparatus for a packet switched PS domain and a circuit switched CS domain, applied to a network element of a core network, including: an obtaining module, configured to obtain first PLMN information registered in a PS domain or second PLMN information registered in a CS domain; and the selection module is used for selecting a first PLMN registered in a CS domain for the user equipment according to the first PLMN information, or selecting a second PLMN registered in a PS domain for the user equipment according to the second PLMN information.

Preferably, the obtaining module includes: a sending unit, configured to send a location update request to a home location register; a first receiving unit, configured to receive a response message of the location update request and an insert subscriber data message; an obtaining unit, configured to obtain the first PLMN information or the second PLMN information from the response message or the insert user data message.

Preferably, the sending unit is further configured to send an authentication data request to a home location register; the first receiving unit is further configured to receive an authentication data response returned by the home location register according to the authentication data request; the obtaining unit is further configured to obtain the first PLMN information or the second PLMN information from the authentication data response.

Preferably, the obtaining module includes: a second receiving unit, configured to receive a second notification message from the home location register when the home location register detects that the PLMN registered in the PS domain or the CS domain of the user equipment changes, or that the stored PLMN registered in the CS domain and the stored PLMN registered in the PS domain are different, where the second notification message carries the first PLMN information or the second PLMN information.

According to the invention, the technical means that the first core network element selects the PLMN registered in the PS domain or the CS domain for the user equipment according to the acquired first PLMN information registered in the PS domain or the second PLMN information registered in the CS domain according to the first PLMN information or the second PLMN information is adopted, so that the technical problems that the PLMNs selected in the CS domain and the PS domain are different possibly caused by the existing PLMN selection scheme, and further the telephone charge difference or the operator name displayed by the terminal is different in the related technology are solved, the CS domain and the PS domain can be ensured to be selected to the same PLMN, the telephone charge difference or the operator name displayed by the terminal is avoided, and the user experience is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a diagram of a 3GPP network architecture according to the related art;

fig. 2 is a schematic diagram of both a core network and a wireless network according to the related art;

fig. 3 is a schematic diagram of a shared-only wireless network according to the related art;

fig. 4 is a flowchart of a PLMN selection method for a PS domain and a CS domain according to an embodiment of the present invention;

fig. 5 is a flowchart illustrating a PLMN selection method for PS domain and CS domain according to embodiment 1 of the present invention;

fig. 6 is a flowchart illustrating a PLMN selection method for PS domain and CS domain according to embodiment 2 of the present invention;

fig. 7 is a block diagram of a PLMN selection apparatus for PS domain and CS domain according to an embodiment of the present invention;

fig. 8 is another block diagram of a PLMN selection apparatus for PS domain and CS domain according to an embodiment of the present invention.

Detailed Description

The invention will be described in detail hereinafter with reference to the accompanying drawings in conjunction with embodiments. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

Fig. 4 is a flowchart of a PLMN selection method for a PS domain and a CS domain according to an embodiment of the present invention. As shown in fig. 4, the method includes steps S402-S404:

step S402, a first core network element acquires first PLMN information registered in a PS domain or second PLMN information registered in a CS domain;

step S404, the first core network element selects a first PLMN registered in the CS domain for the user equipment according to the first PLMN information, or selects a second PLMN registered in the PS domain for the user equipment according to the second PLMN information.

Through the processing steps, the first PLMN of the CS domain can be selected according to the first PLMN information of the PS domain, or the second PLMN of the PS domain can be selected according to the second PLMN information of the CS domain, so that the PLMNs selected by the PS domain and the CS domain can be prevented from being different, and the CS domain and the PS domain can be ensured to be selected to the same PLMN.

The implementation manner of step S402 is various, for example, a network element (the network element knows and stores the first PLMN information or the second PLMN information) may be set, and the first core network element obtains from the network element. In a preferred embodiment of this embodiment, the first PLMN information or the second PLMN information may be acquired in the following manner: a first core network element sends a location update request to a home location register; under the trigger of the location updating request, the first core network element receives the response message of the location updating request and the message of inserting user data; and the first core network element acquires the first PLMN information or the second PLMN information from the response message or the user data inserting message. Alternatively, the acquisition is performed by:

a first core network element sends an authentication data request to a home location register; under the trigger of the authentication data request, the first core network element receives an authentication data response returned by the home location register according to the authentication data request; and the first core network element acquires the first PLMN information or the second PLMN information from the authentication data response.

In another preferred embodiment of step S402, the first PLMN information or the second PLMN information may be further acquired by:

when the home location register detects that the PLMN registered in the PS domain or the CS domain of the user equipment changes, or the stored PLMN registered in the CS domain of the user equipment is different from the PLMN registered in the PS domain, the first core network element receives a second notification message from the home location register, where the second notification message carries the first PLMN information or the second PLMN information.

In the above processing procedure, the processing step of the first core network element sending the location update request to the home location register may be represented by the following implementation procedures, but is not limited thereto:

the first core network element sends the location updating request to the home location register every time a user accesses the first core network element; or,

when a user accesses a first core network element from a BSS or an RNC, the first core network element receives a first notification message from the BSS or the RNC; wherein, the first notification message indicates that the BSS or the RNC does not perform PLMN reselection for a PS domain and a CS domain, and the first core network element sends the location update request to the home location register. Here, "co-selection" means that the same PLMN is selected in the PS domain and the CS domain.

In the above processing procedure, the processing step of the first core network element sending the authentication data request to the home location register may be expressed as the following implementation procedures, but is not limited thereto:

the first core network element sends the authentication data request to a home location register when a user accesses each time; or,

when a user accesses a first core network element from a base station subsystem BSS or a radio network controller RNC, the first core network element receives a fourth notification message from the BSS or the RNC; wherein, the fourth notification message indicates that the BSS or the RNC does not perform PLMN collaborative selection for the PS domain and the CS domain, and the first core network element sends the authentication data request to the home location register.

It should be noted that, in this embodiment, the first notification message and the fourth notification message may be the same notification message or may be two independent notification messages, and the description is not limited herein.

Before a first core network element sends a location update request or an authentication data request to a home location register, the home location register needs to acquire and store the first PLMN information or the second PLMN information, which is specifically implemented as follows:

when the first core network element is an MSC or VLR, the home location register receives a location update request or an authentication data request from an SGSN, wherein the location update request or the authentication data request carries the first PLMN information;

and when the first core network element is the SGSN, the hlr receives a location update request or an authentication data request from the MSC or the VLR, wherein the location update request or the authentication data request carries the information of the second PLMN.

There are various implementation manners of step S404, and in a preferred implementation manner of this embodiment, the following implementation manners may be implemented: judging whether a first core network element supports the first PLMN or the second PLMN; if the first PLMN or the second PLMN is supported, the first PLMN or the second PLMN is used as a final selection result; if the first PLMN or the second PLMN is not supported, the first core network element redirects the LAU flow to a second core network element which supports the first PLMN or the second PLMN in the same CS domain or PS domain; the first PLMN or the second PLMN is selected for the user equipment through the second core network element, wherein the main body that determines whether the first core network element supports the first PLMN or the second PLMN may be the first core network element.

In the above processing procedure, the first core network element redirects the LAU flow to the second core network element supporting the first PLMN or the second PLMN in the same CS domain or PS domain, which may be implemented by, but is not limited to, the following manners:

the first core network element sends a third notification message to a BSS or an RNC accessed by a user, wherein the third notification message carries the first PLMN information or the second PLMN information, and the first PLMN information or the second PLMN information carried in the third notification message is used for providing the BSS or the RNC with a basis for selecting the second core network element, i.e., the BSS or the RNC selects the second core network element according to the first PLMN information or the second PLMN information carried in the third notification message.

The first PLMN information and the second PLMN information each include one of: and the SGSN number, the MSC number or the VLR number and the PLMN number are used for indicating the PLMN where the user equipment is located.

The home location register mentioned in the above embodiments may be an HLR, or an HSS supporting a similar function as the HLR, or another network element storing subscriber subscription data, or information for registering a subscriber in a PS domain or a CS domain.

For a better understanding of the above embodiments, reference is made to the following detailed description of the preferred embodiments.

Example 1

The embodiment may be applicable to a process that after the UE is handed over in the PS domain and performs a Routing Area Update (RAU) to the target side, a Location Area Update (LAU) is performed after the PS service is finished (that is, the target side does not support simultaneous connection of the PS service and the CS service). The embodiment may also be applicable to the handover of the UE in the PS domain, and the RAU procedure is not performed but a separate LAU procedure is performed when the UE arrives at the target side. Steps S502 to S510 may be considered to be completed on the source side at this time, i.e., before the handover. Therefore, there is no strict time limit requirement after steps S502 to S510 and the subsequent step S512.

Step S502, the UE initiates an RAU procedure.

Step S504, SGSN sends position updating request to HLR/HSS after UE confirms PLMN. When the procedure occurs after handover, the PLMN is selected by the source BSS/RNC and notified to the target SGSN through a Routing Area Identity (RAI). When the procedure is completed before handover, the PLMN is the source BSS/RNC selection and is notified to the SGSN via the RAI. The location update request carries the identity of the UE and the SGSN number. When the number can represent the PLMN of the UE, there is no need to additionally carry a new PLMN id indication. In some networks, the SGSN number may not accurately indicate the PLMN where the UE is located, and an Information Element (IE) may need to be added to notify the HLR/HSS, so that the UE registers PLMN information in the PS domain.

In step S506, the HLR/HSS records the PLMN information registered in the PS domain by the UE. The HLR/HSS inserts Subscriber Data (Insert Subscriber Data) to the SGSN.

Step S508, HLR/HSS returns location update response message to SGSN.

In step S510, the SGSN returns an RAU accept message to the UE. If this procedure allocates PTMSI, the UE also needs to return an RAU complete message to the network.

Other procedures such as authentication, bearer establishment, HLR/HSS cancellation to the old SGSN, etc. may be also performed in the above procedure, and these procedures are well known to those skilled in the art and will not be described herein again.

Step S512, the UE initiates LAU, and the BSS/RNC selects MSC/VLR1 for the UE.

At step S514, MSC/VLR1 initiates a location update request to HLR/HSS. The location update request carries the identity of the UE and the SGSN number.

Step S516, HLR/HSS inserts user data into MSC/VLR1 according to the recorded PLMN information registered by UE in PS domain. The user data may contain PLMN information for the PS domain the UE is registered with.

At step S518, the HLR/HSS returns a location update response message to MSC/VLR1. If the PLMN information of the PS domain registered by the UE is not provided in step S516. Then the message contains PLMN information for the PS domain the UE is registered with.

Step S520, the MSC/VLR1 selects the PLMN information registered in the CS domain for the UE according to the PLMN information of the PS domain registered by the UE. If the MSC/VLR1 supports the PLMN, the MSC completes the remaining flow of LAUs. Otherwise MSC/VLR1 redirects the LAU to the MSC/VLR of the other PLMN. In this embodiment, the subsequent steps are performed assuming that they are not supported.

Other procedures such as authentication, UE ID acquisition, HLR/HSS location cancellation to the old MSC/VLR may be included in the above procedures, which are well known to those skilled in the art, and on the other hand, the steps themselves have little relation to the present embodiment, and are not described.

Step S522, the MSC/VLR1 sends a redirection message, wherein the PLMN ID, LAU message, which needs to be redirected, to the BSS/RNC. If the BSS/RNC is able to buffer the previous LAU message, the message may not include the LAU message, but include the relevant identifier of the LAU message, so as to instruct the BSS/RNC to forward the previously buffered LAU message.

Step S524, the BSS/RNC selects an appropriate MSC/VLR2 for the UE according to the PLMN ID. The BSS/RNC returns a redirect response message to the MSC/VLR1.

In step S526, the BSS/RNC sends LAU message to MSC/VLR 2.

Step S528 to step S532, the MSC/VLR2 initiates location update and subscription data acquisition procedures to the HLR/HSS. Similar to steps S514-S518, the description is omitted here.

At step S534, the MSC/VLR2 determines the selected PLMN for the UE.

And step S536-S538, the MSC/VLR sends an LAU receiving message to the UE, and if the message contains TMSI distributed by the MSC/VLR2, the UE sends an LAU completing message to the MSC/VLR 2.

If the MSC/VLR is not changed during the execution of the LAU by the UE, the MSC/VLR may not initiate a location update request to the HLR/HSS, and thus cannot obtain the PLMN registered in the PS domain, so this embodiment further includes the following manner to ensure that the MSC/VLR obtains the parameter:

1. it is required that the MSC/VLR always initiates a location update request to the HSS/HLR.

2. The BSS/RNC is required to notify the MSC/VLR in step X06 when no PS/CS domain coordinated network selection is performed, and always initiate a location update request to the HSS/HLR when the MSC/VLR knows this information.

3. The procedure used in example 2 was followed. For details, refer to embodiment 2, which is not described herein.

Example 2

The embodiment can be applied to the process that the UE is switched in the PS domain, and after the RAU is executed to the target side, the LAU is executed after the PS service is finished (namely, the target side does not support the connection of the PS service and the CS service at the same time). The embodiment may also be applicable to the handover of the UE in the PS domain, and the RAU procedure is not performed but a separate LAU procedure is performed when the UE arrives at the target side. Steps S602 to S614 at this time may be considered to be completed on the source side, i.e., before the handover. Therefore, there is no strict time limit requirement after steps S602 to S614 and the subsequent step S616.

Step S602, the UE initiates an RAU procedure.

Step S604, SGSN initiates location update request to HLR/HSS after determining PLMN for UE. When the procedure occurs after handover, the PLMN is selected by the source BSS/RNC and notified to the target SGSN via the RAI. When the procedure is completed before handover, the PLMN is the source BSS/RNC selection and is notified to the SGSN via the RAI. The location update request carries the identity of the UE and the SGSN number. When the number can represent the PLMN of the UE, there is no need to additionally carry a new PLMN id indication. In some networks, the SGSN number may not accurately indicate the PLMN where the UE is located, and an additional IE may be required to notify the HLR/HSS, so that the UE registers PLMN information in the PS domain.

In step S606, the HLR/HSS records PLMN information registered by the UE in the PS domain. The HLR/HSS inserts the subscriber data to the SGSN.

In step S608, the HLR/HSS returns a location update response message to the SGSN.

In step S610, the SGSN returns an RAU accept message to the UE. If this procedure allocates PTMSI, the UE also needs to return an RAU complete message to the network.

Step S612, when the HLR/HSS finds that the PLMN registered in the PS domain is changed, or the HLR/HSS can record the PLMN registered in the CS domain and the PLMN registered in the PS domain at the same time, it finds that the two are different, and notifies the other domain. HLR/HSS sends PLMN change notification message to UE registration old (old) MSC/VLR, which carries PLMN information of PS domain registration. The message can be reused with the existing position cancellation message or other available messages, or can be realized by adding a message. It is within the scope of the present embodiment as long as the notification function is implemented.

Step S614, the old MSC/VLR compares the PLMN currently registered by the UE with the PLMN information registered by the PS domain, and if not, the subsequent process is not executed. If a change has occurred, the subsequent steps are performed.

Step S616, old MSC/VLR returns notification response message to HLR/HSS.

Other procedures such as authentication, bearer establishment, HLR/HSS cancellation to the old SGSN, etc. may be also performed in the above procedure, and these procedures are well known to those skilled in the art and will not be described herein again.

The UE initiates LAU, and the BSS/RNC selects MSC/VLR1 for the UE.

If it is registered in the MSC/VLR1, i.e. the old MSC/VLR and the MSC/VLR1 are the same network element, step S618 is directly performed. If the UE has not been registered with the MSC/VLR1 before, it is possible to perform steps S616 a-S616 b or perform steps 407-419 as in embodiment 1.

In step S616a, the MSC/VLR1 sends an ID acquisition request to the old MSC/VLR.

In step S616b, the old MSC/VLR returns an acquisition identifier response to the MSC/VLR1, where the acquisition identifier response carries the PLMN id of the PS domain registered by the UE.

In step S618, the MSC/VLR1 selects PLMN information registered in the CS domain for the UE according to the PLMN information of the PS domain registered by the UE obtained in step S614. If the MSC/VLR1 supports the PLMN, the MSC/VLR1 completes the remaining flow of LAUs. Otherwise MSC/VLR1 redirects the LAU to the MSC/VLR of the other PLMN. In this embodiment, the subsequent steps are performed assuming that they are not supported.

Steps S620 to S636 are similar to steps S522 to S538, and are not described herein.

In both embodiment 1 and embodiment 2, the PS domain is selected first, and then the CS domain is selected as an example. In a practical deployment network, the possibility of selecting the CS domain first and then the PS domain is not excluded. Therefore, when such a scenario occurs, the newly added functions of the CS domain and the PS domain in the above procedure are similar, that is, the HSS/HLR is required to notify the PLMN of the CS domain registered by the UE to the SGSN in the above manner, and to trigger reselection of the SGSN.

Example 3

The application range of this embodiment is similar to that of fig. 5, and the execution flow is also similar, except that step S514 to step S518 do not need to be executed at this time, but rather, the MSC/VLR1 sends an authentication data request to the HLR, and the HSS returns an authentication data response to the MSC after receiving the authentication data request, where the authentication data response carries the PLMN information of the PS domain registered by the UE. And the MSC/VLR1 selects PLMN information registered in the CS domain for the UE according to the PLMN information in the PS domain. If the MSC/VLR1 supports the PLMN, the MSC completes the remaining flow of LAUs. Otherwise the MSC/VLR1 redirects the LAU to the MSC/VLR of the other PLMN, performing the remaining steps after step S522 in fig. 5.

In addition, the steps S528 to S532 may obtain PLMN information of the PS domain through an authentication data request procedure.

Example 4

The application range of this embodiment is similar to that of fig. 6, and the execution flow is similar, except that steps S626 to S630 do not need to be executed at this time, but rather the MSC/VLR2 sends an authentication data request to the HLR, and the HSS returns an authentication data response to the MSC after receiving the authentication data request, where the authentication data response carries the PLMN information of the PS domain registered by the UE. And the MSC/VLR2 selects PLMN information registered in the CS domain for the UE according to the PLMN information in the PS domain.

In order to implement the foregoing method, in this embodiment, a PLMN selection apparatus for a PS domain and a CS domain is further provided, where the apparatus is applied to a core network element, and is used to implement the foregoing embodiment and the preferred embodiment, which have already been described and are not described again, and a module related in the apparatus is described below. As used below, the term "module" may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Fig. 7 is a block diagram of a PLMN selection apparatus for PS domain and CS domain according to an embodiment of the present invention. As shown in fig. 7, the apparatus includes:

an obtaining module 70, configured to obtain first PLMN information registered in a PS domain or second PLMN information registered in a CS domain;

a selecting module 72, connected to the obtaining module 70, is configured to select a first PLMN registered in the CS domain for the user equipment according to the first PLMN information, or select a second PLMN registered in the PS domain for the user equipment according to the second PLMN information.

The functions realized by the modules can also ensure that the CS domain and the PS domain are selected to the same PLMN.

In this embodiment, the obtaining module 70, as shown in fig. 8, includes the following processing units: a sending unit 700, configured to send a location update request to a home location register; a first receiving unit 702, connected to the sending unit 700, for receiving the response message of the location update request and the inserted user data message; an obtaining unit 704, connected to the first receiving unit 702, is configured to obtain the first PLMN information or the second PLMN information from the response message or the insert subscriber data message.

Optionally, as shown in fig. 8, the obtaining module 70 may further include: a second receiving unit 706, configured to receive a second notification message from the home location register when the home location register detects that the PLMN registered in the PS domain or the CS domain of the user equipment changes, or that the stored PLMN registered in the CS domain of the user equipment is different from the PLMN registered in the PS domain, where the second notification message carries the first PLMN information or the second PLMN information.

In this embodiment, the sending unit 700 is further configured to send an authentication data request to the home location register; a first receiving unit 702, further configured to receive an authentication data response returned by the home location register according to the authentication data request; an obtaining unit 704, configured to obtain the first PLMN information or the second PLMN information from the authentication data response.

As described above, the modules described above in this embodiment can be implemented by software, or by hardware accordingly. For example, each of the above modules may be in a processor, for example: the modules are all in one processor: a processor, comprising: an acquisition module 70 and a selection module 72; or, the modules are respectively located in a corresponding processor: the acquisition module 70 is located in the first processor and the selection module 72 is located in the second processor.

In another embodiment, a software is provided, which is used to execute the technical solutions described in the above embodiments and preferred embodiments.

In another embodiment, a storage medium is provided, in which the software is stored, and the storage medium includes but is not limited to: optical disks, floppy disks, hard disks, erasable memory, etc.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described may be performed in an order different than that described herein, or they may be separately fabricated into individual integrated circuit modules, or multiple ones of them may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (15)

1. A method for PLMN selection in a packet switched PS domain and a circuit switched CS domain, comprising:

a first core network element acquires first PLMN information registered in a PS domain or second PLMN information registered in a CS domain;

and the first core network element selects a first PLMN registered in a CS domain for the user equipment according to the first PLMN information, or selects a second PLMN registered in a PS domain for the user equipment according to the second PLMN information.

2. The method of claim 1, wherein the obtaining, by the first core network element, the first PLMN information registered in the PS domain or the second PLMN information registered in the CS domain comprises:

the first core network element sends a location update request to a home location register;

the first core network element receives a user data inserting message and a response message of the position updating request;

and the first core network element acquires the first PLMN information or the second PLMN information from the response message or the user data inserting message.

3. The method of claim 1, wherein the obtaining, by the first core network element, the first PLMN information registered in the PS domain or the second PLMN information registered in the CS domain comprises:

the first core network element sends an authentication data request to a home location register;

the first core network element receives an authentication data response returned by the home location register according to the authentication data request;

and the first core network element acquires the first PLMN information or the second PLMN information from the authentication data response.

4. The method of claim 3, wherein before the first core network element sends the authentication data request to the home location register, the method comprises:

when the first core network element is a mobile switching center MSC or a visitor location register VLR, the home location register receives an authentication data request from a general packet radio service support node SGSN, wherein the authentication data request carries the first PLMN information;

and when the first core network element is the SGSN, the home location register receives an authentication data request from the MSC or the VLR, wherein the authentication data request carries the information of the second PLMN.

5. The method of claim 3, wherein sending, by the first core network element, the authentication data request to the home location register comprises:

the first core network element sends the authentication data request to the home location register every time a user accesses the first core network element; or,

when a user accesses a first core network element from a BSS or an RNC, the first core network element receives a fourth notification message from the BSS or the RNC; indicating in the fourth notification message that the BSS or the RNC does not perform a collaborative selection of a PLMN for a PS domain and a CS domain, and the first core network element sending the authentication data request to the home location register.

6. The method of claim 2, wherein before the first core network element sends the location update request to the home location register, the method comprises:

when the first core network element is an MSC or VLR, the home location register receives a location update request from an SGSN, where the location update request carries the first PLMN information;

and when the first core network element is the SGSN, the home location register receives a location update request from the MSC or VLR, wherein the location update request carries the second PLMN information.

7. The method of claim 2, wherein sending, by the first core network element, the location update request to a home location register comprises:

the first core network element sends the location updating request to the home location register every time a user accesses the first core network element; or,

when a user accesses a first core network element from a Base Station Subsystem (BSS) or a Radio Network Controller (RNC), the first core network element receives a first notification message from the BSS or the RNC; wherein, the BSS or the RNC is indicated in the first notification message not to perform PLMN co-selection for the PS domain and the CS domain, and the first core network element sends the location update request to the home location register.

8. The method of claim 1, wherein the obtaining, by the first core network element, the first PLMN information registered in the PS domain or the second PLMN information registered in the CS domain comprises:

when a home location register detects that the PLMN registered in the PS domain or the CS domain of the user equipment changes, or that the stored PLMN registered in the CS domain of the user equipment is different from the PLMN registered in the PS domain, the first core network element receives a second notification message from the home location register, where the second notification message carries the first PLMN information or the second PLMN information.

9. The method according to any of claims 1 to 8, wherein the selecting, by the first core network element, a first PLMN registered in a CS domain for the user equipment according to the first PLMN information, or selecting a second PLMN registered in a PS domain for the user equipment according to the second PLMN information, comprises:

judging whether the first core network element supports the first PLMN or the second PLMN;

if the first PLMN or the second PLMN is supported, taking the first PLMN or the second PLMN as a final selection result;

if the first PLMN or the second PLMN is not supported, the first core network element redirects a location update LAU flow to a second core network element supporting the first PLMN or the second PLMN in the same CS domain or PS domain; selecting the first PLMN or the second PLMN for the user equipment through the second core network element.

10. The method of claim 9, wherein the first core network element redirecting the location update LAU procedure to a second core network element supporting the first PLMN or the second PLMN in the same CS domain or PS domain comprises:

the first core network element sends a third notification message to a BSS or an RNC accessed by a user, wherein the third notification message carries the first PLMN information or the second PLMN information, and the first PLMN information or the second PLMN information carried in the third notification message is used for selecting the second core network element for the BSS or the RNC.

11. The method of any of claims 1-8, wherein the first PLMN information and the second PLMN information each comprise one of:

and the SGSN number, the MSC number or the VLR number and the PLMN number are used for representing the PLMN where the user equipment is located.

12. A public land mobile network PLMN selection apparatus for packet switched PS domain and circuit switched CS domain, for use in a core network element, comprising:

an obtaining module, configured to obtain first PLMN information registered in a PS domain or second PLMN information registered in a CS domain;

and the selection module is used for selecting a first PLMN registered in a CS domain for the user equipment according to the first PLMN information, or selecting a second PLMN registered in a PS domain for the user equipment according to the second PLMN information.

13. The apparatus of claim 12, wherein the obtaining module comprises:

a sending unit, configured to send a location update request to a home location register;

a first receiving unit, configured to receive a response message of the location update request and an insert subscriber data message;

an obtaining unit, configured to obtain the first PLMN information or the second PLMN information from the response message or the insert user data message.

14. The apparatus of claim 12,

the sending unit is also used for sending an authentication data request to the home location register;

the first receiving unit is further configured to receive an authentication data response returned by the home location register according to the authentication data request;

the obtaining unit is further configured to obtain the first PLMN information or the second PLMN information from the authentication data response.

15. The apparatus of claim 12, wherein the obtaining module comprises:

a second receiving unit, configured to receive a second notification message from the home location register when the home location register detects that the PLMN registered in the PS domain or the CS domain of the user equipment changes, or that the stored PLMN registered in the CS domain and the stored PLMN registered in the PS domain are different, where the second notification message carries the first PLMN information or the second PLMN information.