CN101742693B - IMS core network system supporting network selection of different field general terminal and calling method - Google Patents

Abstract

The invention discloses an IMS core network system that supports network selection by a general-purpose terminal in a different domain, including a core network in a CS domain, an IMS domain core network connected to the CS domain through an MGCF, and a general-purpose terminal in a different domain. The ENUM module of the IMS domain is connected with the HSS and the HLR respectively. Interaction, which is used to obtain the registration status information and network selection policy information of the general terminal in the foreign region, and determine whether to return the SIP URI number according to the registration status information and network selection policy information. The invention also discloses the calling method of the corresponding foreign general terminal. Through the system and method disclosed in the invention, the network can be selected according to the user's registration state, which improves the accuracy of network selection hit; avoids the repeated state change of the user, and reduces the requirement for system performance.

Description

IMS Core Network System and Calling Method Supporting Network Selection for Universal Terminals in Different Regions

technical field

The present invention relates to an IMS core network system and a calling method that supports network selection by a general-purpose terminal in a foreign domain, in particular to an IMS core network system and a calling method that realizes user registration in the IMS domain by transforming the existing IP Multimedia Subsystem (IP Multimedia Subsystem, referred to as IMS). The network is selected according to the state, and belongs to the technical field of mobile communication.

Background technique

The traditional core network system is the CS domain, which mainly provides basic services such as end-to-end voice, videophone and short message. With the intensification of competition in the field of mobile communications, operators need to attract users through new differentiated services, and for this reason, they have introduced a packet switching (Packet Switch, PS) domain in the core network, providing new data transmission through IP services, such as Multimedia Messaging Service (MMS for short), content browsing, etc., but these IP-based data services have not been successful due to factors such as network bandwidth, terminal restrictions, poor user experience, and unclear billing. application.

In order to overcome the above problems, the 3rd Generation Partnership Project (3rd Generation Partnership Project, referred to as 3GPP) proposed the IMS core network in Release 5, which is superimposed on the PS domain and uses the PS domain to carry and transmit multimedia signals. The introduction of IMS has established a softswitch platform for call/session control, and realized real-time, end-to-end communication services through session negotiation and management, QoS management, mobility management and other technologies; IMS also provides operators with: Real-time end-to-end services, such as Chat and Instant Message (IM) services; multi-party services, such as Multimedia Conferencing, ChatRooms, and Push to talk over Cellular (POC for short); and some server-to-user services, such as Dynamic Push Services, Click to Dial, etc. It can be said that IMS is a core network technology that can really improve user experience and increase operator revenue.

In the prior art, the network architecture between the CS domain and the IMS domain of the core network is shown in Figure 1. When a terminal in the CS domain calls a terminal in the IMS domain, the HLR identifies and instructs a mobile switching center , referred to as MSC), transfers the call to the Media Gateway Control Function (MGCF for short)/Media Gateway (MGW for short) unit, and realizes further in the IMS domain, by the service-call session control function (Service -Call Session Control Function, referred to as S-CSCF) module, electronic number (Electronic Numbering, referred to as Enum) module that realizes the mapping of terminal number to universal location connection (URL), and home subscriber server (Home Subscriber Server, referred to as HSS) for processing ; When a terminal in the IMS domain makes a call, the HSS identifies and instructs the S-CSCF module to transfer the call to the MGCF unit, and the MSC further implements call processing in the CS domain. For the situation that the IMS terminal and the CS terminal are independent of each other, the above network can meet the requirement of accurate calling.

However, with the continuous advancement of terminal technology, terminals that are compatible with CS, GPRS and IMS domain services and compatible with 3rd generation CS, GPRS and IMS domain services have appeared. Business, using a unified E.164 number, can be referred to as a general terminal. Although a general-purpose terminal can independently select a network when initiating a service, when the general-purpose terminal is used as a receiving terminal, the existing network architecture cannot determine which core network is used to provide support for the service.

In order to deal with the above-mentioned problem that the network cannot be selected, a simple technical solution is to provide service support through the core network where the calling terminal initiates the call; another simple technical solution is that the system selects the core network at random. to provide support for the business. However, since the general-purpose terminal may not be registered in different core networks at the same time, the above two methods may cause the selected core network to fail to find the called general-purpose terminal, thus resulting in failure or delay of the call service.

Another technical solution is that the general-purpose terminal continuously registers and switches in various core network domains to ensure that only one domain is valid at a certain moment to realize accurate and instant network selection of the core network. However, this technical solution requires the network to continuously switch the status of users and configure status information repeatedly, resulting in a decrease in efficiency and an increase in network performance requirements; at the same time, it cannot take advantage of the universal terminal's ability to support foreign services at the same time.

Contents of the invention

The purpose of the present invention is to overcome the defects of the above-mentioned prior art, provide an IMS core network system and a calling method that support network selection for general-purpose terminals in different regions, and realize network selection for call services in the IMS network through user registration status.

In order to achieve the above purpose, the present invention provides an IMS core network system that supports network selection for general-purpose terminals in foreign domains, including a core network in CS domain, an IMS domain core network connected to CS domain through MGCF/MGW, and general-purpose terminals in foreign domains. The HSS of the domain is used to save the network selection policy information and the registration status information of the IMS domain terminal;

The HLR of the CS domain is used to save the registration status information of the CS domain terminal;

The ENUM module of the IMS domain interacts with the HSS and the HLR respectively to obtain the registration status information and network selection policy information of the foreign general terminal, and determine whether to return the SIP URI number according to the registration status information and the network selection policy information .

Wherein, the interaction between the ENUM and the HLR and the HSS is specifically: the ENUM communicates with the HLR and the HSS respectively. The ENUM communicates with the HLR through a MAP interface.

Alternatively, the HLR and the HSS are co-established; the ENUM interacts with the HLR and the HSS respectively, specifically, the ENUM communicates with the co-established HLR and HSS.

Alternatively, the HLR is connected to the HSS in communication, and the HLR updates the registration status information of the CS domain terminal to the HSS; the ENUM interacts with the HLR and the HSS respectively, specifically, the ENUM is connected to the HSS in communication.

The MGCF/MGW are respectively connected to the MSC and the SMS/MMS for distinguishing between real-time services and non-real-time services, and sending real-time services to the MSC and sending the non-real-time services to the SMS/MMS.

Based on the above-mentioned IMS core network system that supports network selection for foreign general terminals, the present invention also provides a calling method for foreign general terminals. When an IMS domain terminal initiates a call service to a foreign general terminal, the following steps are included:

Step 1, the S-CSCF of the IMS domain requests ENUM to resolve the called number;

Step 2. The ENUM inquires whether the foreign-region universal terminal is registered in the IMS domain, if yes, execute step 3, otherwise execute step 5;

Step 3. The ENUM inquires whether the foreign-region universal terminal is registered in the CS domain, if yes, execute step 4, otherwise execute step 7;

Step 4, the ENUM queries the preset network selection policy information in the HSS, and when it is the CS domain network selection mode, perform step 5, otherwise perform step 7;

Step 5, the ENUM returns a parsing failure instruction to the S-CSCF;

Step 6. The S-CSCF connects the call service to the foreign general terminal in the CS domain through the MGCF/MGW, and ends the call after completing the call;

Step 7, the ENUM returns the resolved SIP URI number to the S-CSCF;

Step 8: The S-CSCF directly connects the call service to the foreign general terminal.

Wherein, in order to realize business connection more accurately, described step 6 can specifically be:

Step 61, the S-CSCF connects the call service to the MGCF/MGW;

Step 62, the MGCF/MGW judges whether the call service is a real-time service, if yes, execute step 63, otherwise execute step 64;

Step 63, the MGCF/MGW connects the call service to the MSC, and executes step 65;

Step 64, the MGCF/MGW connects the call service to SMS/MMS;

Step 65, the MSC or SMS/MMS connects the call service to the general-purpose terminal in the foreign area, and ends the call after completing the call.

It can be seen from the above technical solution that the present invention obtains the registration status of the general-purpose terminal in a different region through ENUM, and adopts the method of presetting the whole network strategy, which has the following beneficial effects:

1. It can select the network according to the user's registration status, which improves the accuracy of the network selection hit;

2. It avoids repeated state changes by users and reduces the requirements for system performance.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

FIG. 1 is a system block diagram of communication between a CS domain and an IMS domain in the prior art of the present invention;

FIG. 2 is a block diagram of Embodiment 1 of an IMS core network system that supports network selection for a general-purpose terminal in a different region provided by the present invention;

FIG. 3 is a block diagram of Embodiment 2 of an IMS core network system that supports network selection for a general-purpose terminal in a different region provided by the present invention;

FIG. 4 is a block diagram of Embodiment 3 of an IMS core network system that supports network selection for a general-purpose terminal in a different region provided by the present invention;

FIG. 5 is a schematic flow chart of a calling method for a foreign universal terminal provided by the present invention;

FIG. 6 is a flowchart of an embodiment of the method shown in FIG. 5 .

Detailed ways

In order to really take advantage of the compatibility of foreign domain universal terminals with CS domain and IMS domain services, improve the hit rate of network selection, and avoid the defects of repeated registration and cancellation in the prior art, the present invention provides an IMS core network system that supports foreign domain general terminal network selection , realize calling foreign general terminals according to the terminal registration status and the preset network-wide routing policy. Describe in detail below by embodiment.

Example 1:

Referring to Figure 2, it includes CS domain core network A, IMS domain core network B, CS domain core network A and IMS domain core network B are connected through MGCF/MGW B4, and also includes foreign general terminal C. The so-called general-purpose terminal in a foreign region means that the terminal C uses a 2nd generation SIM+ISIM composite card or a 3rd generation USIM+ISIM composite card. Under the same E.164 number, it can access the IMS domain and use the IMS service , and can access the CS domain to use the CS service, and may use the services of the two domains at the same time.

For example, when using the 2nd generation SIM+ISIM composite card, you can use all the 2nd generation CS domain and PS domain services by accessing the 2nd generation network, and you can also access the IMS domain through the 2nd generation GPRS to use non-real-time IMS services ( Such as instant messaging) and real-time IMS services (such as multimedia sessions); when using a 3rd generation USIM+ISIM composite card, access to the 3rd generation network can use all 3rd generation CS domain and PS domain services, and can also pass the 3rd generation GPRS accesses the IMS domain, and uses non-real-time IMS services (such as instant messaging) and real-time IMS services (such as multimedia conversations).

In this system, IMS domain B includes S-CSCF module B1, HSS B2, ENUM module B3, and MGCF/MGW unit B4. The CS domain A includes MSC A1, HLR A2, and Short Message Service (Short Message Service, SMS for short)/Multimedia Message Service (Multimedia Message Service, MMS for short) center A3.

In the prior art, the S-CSCF module B1 directly realizes the communication with the terminal C by querying the attribution information in the HSS B2, and then obtains the analytical mapping relationship between the E.164 number and the SIP URI number through the ENUMB3, or through the MGCF/MGW B4 Realize the communication with the terminal C; the HSS saves the registration state information of the terminal in the IMS domain, and the terminal is not limited to the common terminal C in a foreign area, but also includes common IMS domain terminals.

In the system provided by the present invention, the HSS B2 of the IMS domain B is used to store the network selection strategy information, which is a kind of whole network strategy information, that is, no service distinction is performed, and the simple setting is CS Domain A bearer or IMS domain B bearer.

The ENUM module B3 of the IMS domain B interacts with the HSS B2 and the HLR A2 respectively to obtain the registration status information and network selection policy information of the foreign general terminal C, and determine whether to return the SIP URI according to the registration status information and the network selection policy information Number.

For example, when ENUM B3 recognizes that the general-purpose terminal C in a different region is registered in IMS domain B and CS domain A at the same time, according to the network selection policy obtained from HSS B2, it selects a network for the CS domain, and then returns a parsing failure instruction to the S-CSCF, then S - The CSCF automatically routes the call to the MGCF/MGW.

In the present invention, HSS B2 is used for storing the registration status information of network selection policy information and IMS domain B terminal; said HLR A2 is used for storing the registration status information of CS domain A terminal; if a foreign general terminal uses IMS domain B The service of CS domain A is also used, then the status of the terminal C is registered in HSS B2 and HLR A2 at the same time.

In this embodiment, the ENUM B3 interacts with the HLR A2 and the HSS B2 respectively, specifically, the ENUM B3 communicates with the HLR A2 and the HSS B2 respectively. Specifically, the ENUM B3 of the IMS domain B communicates with the HLR A2 through the MAP interface.

Simultaneously, in the present invention, MGCF/MGW B4 can carry out certain function improvement, promptly can distinguish real-time service and non-real-time service, real-time service is sent to MSC, non-real-time short message service is sent to SMS/MMS, then can Avoid the problem of MSC forwarding SMS/MMS, and further improve efficiency.

Example 2:

Referring to Fig. 4, its constituent modules are the same as those shown in Fig. 2, the difference is that the HLR A2 and the HSS B2 are combined to form an overall device D; the ENUM B3 interacts with the HLR A2 and the HSS B2 respectively, specifically the ENUM B3 is in communicative connection with the co-established overall device D.

Since HLR A2 and HSS B2 are co-located and connected through an internal interface is the development trend of mobile communication network integration, therefore, the solution provided in this embodiment is more suitable for the integrated mobile communication system.

Example 3:

Referring to Figure 4, its constituent modules are the same as those shown in Figure 2, the difference being that the HLR A2 communicates with the HSS B2, and the HLR A2 updates the registration state information of the CS domain terminal to the HSS B2.

Then the ENUM B3 interacts with the HLR A2 and the HSS B2 respectively, specifically, the ENUM B3 communicates with the HSS B2 to indirectly know the CS domain terminal registration status information provided by the HLR A2.

The solution provided by this embodiment does not require large-scale transformation of HLR and HSS equipment, and avoids the increase of system complexity caused by multiple connections between equipment. Only by setting the MAP interface in the HSS, the HSS and HLR can be realized. connect.

In the above-mentioned embodiment, when the general-purpose terminal C in a foreign region is used as the calling party, since it can actively select a network, it can meet the requirement by continuing to use the system of the prior art. However, when the general-purpose terminal C in a different area is called, the system provided by the present invention determines that the call is routed to the IMS domain B or One of the 2/3 generation CS domain A is processed.

It can be seen that, through the core network system supporting foreign universal terminals provided by the present invention, the current registration status in different core networks can be known, thereby improving the accuracy of network selection hits; at the same time, repeated state changes by users are avoided, reducing the requirements for system performance.

Based on the above-mentioned core network system supporting network selection of a general-purpose terminal in a foreign region, the present invention also provides a calling method for a general-purpose terminal in a foreign region. Since there is no difference between the processing method of the general terminal in the foreign domain as the calling party and the terminal in the common IMS domain or the terminal in the CS domain, it will not be repeated here. The processing method of the foreign-area general-purpose terminal as the called party will be described below.

In the CS domain, there is no module that needs to convert the number, so it is difficult to formulate a strategy. The simple solution is to execute the service initiated by the CS domain caller in the CS domain; if the user is not registered in the CS domain, then the HLR will instruct Routing to the IMS domain.

When an IMS domain terminal initiates a call service to a general terminal in a foreign domain, refer to Figure 5, including the following steps:

Step 1, the S-CSCF of the IMS domain requests ENUM to resolve the called number;

Step 2. The ENUM inquires whether the foreign-region universal terminal is registered in the IMS domain, if yes, execute step 3, otherwise execute step 5;

Step 3. The ENUM inquires whether the foreign-region universal terminal is registered in the CS domain, if yes, execute step 4, otherwise execute step 7;

Step 4, the ENUM queries the preset network selection policy information in the HSS, and when it is the CS domain network selection mode, perform step 5, otherwise perform step 7;

Step 5, the ENUM returns a parsing failure instruction to the S-CSCF;

Step 6. The S-CSCF connects the call service to the foreign general terminal in the CS domain through the MGCF/MGW, and ends the call after completing the call;

Step 7, the ENUM returns the resolved SIP URI number to the S-CSCF;

Step 8. The S-CSCF directly connects the call service to the foreign general terminal, and ends the call after completing the call.

In order to further improve efficiency, when the MGCF/MGW increases the service identification function, referring to Figure 6, a specific embodiment of the present invention is:

Step 101, a terminal M in the IMS domain initiates a call to the S-CSCF, and the called party does not have the E.164 number of the terminal C with the same number in a different domain;

Step 102, the S-CSCF requests the ENUM to resolve the called E.164 number;

Step 103, the ENUM inquires whether the foreign general terminal C is registered in the IMS domain, if yes, execute step 104, otherwise execute step 106;

Step 104, the ENUM inquires whether the foreign general terminal C is registered in the CS domain, if yes, execute step 105, otherwise execute step 112;

Step 105, the ENUM queries the preset network selection policy information in the HSS, and if it is the CS domain network selection mode, perform step 106, otherwise perform step 112;

Step 106, the ENUM returns a parsing failure instruction to the S-CSCF;

Step 107, the S-CSCF connects the call service to the MGCF/MGW;

Step 108, MGCF/MGW judges whether the call service is a real-time service, if yes, execute step 109, otherwise execute step 110;

Step 109, MGCF/MGW connects the call service to MSC, and executes step 111;

Step 110, MGCF/MGW connects the call service to SMS/MMS;

Step 111, MSC or SMS/MMS connects the call service to the general-purpose terminal C in the foreign area, establishes a call channel between terminal M and terminal C, and ends the call after completing the call;

Step 112, the ENUM returns the resolved SIP URI number to the S-CSCF;

Step 113: The S-CSCF directly connects the call service to the foreign common terminal C, establishes a call channel between terminal M and terminal C, ends the call after completing the call, and releases resources.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be The scheme shall be modified or equivalently replaced without departing from the spirit and scope of the technical scheme of the present invention.

Claims (8)

1. IMS core network system of supporting network selection of different field general terminal; The IMS domain core net and the different field general terminal that comprise the CS domain core net, be connected through MGCF/MGW with the CS territory; Comprise service-call session control function module S-CSCF in the said IMS domain core net, it is characterized in that:

The HSS in said IMS territory is used to preserve the registration status information at network selection policy information and terminal, IMS territory;

The HLR in said CS territory is used to preserve the registration status information at terminal, CS territory;

The ENUM module in said IMS territory is mutual with said HSS and HLR respectively; Be used to obtain the registration status information and the network selection policy information of said different field general terminal, and determine whether to return SIP URI number to S-CSCF according to registration status information and network selection policy information;

Said S-CSCF is used for receiving after said ENUM module returns SIP URI number; Call business directly is routed to different field general terminal; When receiving the parsing SIP URI number failure command that said ENUM module returns, call business is routed to the different field general terminal in CS territory through MGCF/MGW.

2. IMS core network system according to claim 1 is characterized in that said ENUM is specially with HSS with HLR respectively alternately: said ENUM communicates by letter with HSS with HLR respectively and is connected.

3. IMS core network system according to claim 2 is characterized in that said ENUM is specially with HSS with HLR respectively alternately: said ENUM communicates by letter with said HLR through the MAP interface and is connected.

4. IMS core network system according to claim 1 is characterized in that said HLR and said HSS close to establish; Said ENUM is specially said ENUM alternately and closes the HLR that establishes and communicate by letter with HSS and be connected with HLR and HSS respectively.

5. IMS core network system according to claim 1 is characterized in that communication is connected said HLR with HSS, and said HLR upgrades the registration status information at terminal, CS territory to said HSS; Said ENUM is specially said ENUM alternately with HLR and HSS respectively and communicates by letter with HSS and be connected.

6. according to the arbitrary described IMS core network system of claim 1-5; It is characterized in that said MGCF/MGW communicates by letter with MSC and SMS/MMS respectively is connected; Be used to distinguish real time business and non-real-time service, and send real time business and give said MSC, send said non-real-time service and give said SMS/MMS.

7. method of calling based on the different field general terminal of the arbitrary said system of claim 1-6, it is characterized in that when terminal, IMS territory when different field general terminal makes a call business, may further comprise the steps:

The S-CSCF in step 1, said IMS territory is to ENUM request analysis called number;

Step 2, said ENUM inquire about the whether registration in the IMS territory of said different field general terminal, are execution in step 3 then, otherwise execution in step 5;

Step 3, said ENUM inquire about the whether registration in the CS territory of said different field general terminal, are execution in step 4 then, otherwise execution in step 7;

Preset network selection policy information among step 4, the said ENUM inquiry HSS, during for CS territory network selection mode, execution in step 5, otherwise execution in step 7;

Step 5, said ENUM return the parsing failure command to said S-CSCF;

Step 6, said S-CSCF through the different field general terminals that MGCF/MGW is routed to the CS territory, accomplish call business to call out the back end;

Step 7, the said ENUM SIP URI number after said S-CSCF returns parsing;

Step 8, said S-CSCF directly are routed to said different field general terminal with call business.

8. method of calling according to claim 7 is characterized in that said step 6 is specially:

Step 61, said S-CSCF are routed to MGCF/MGW with call business;

Step 62, said MGCF/MGW judge whether said call business is real time business, are execution in step 63 then, otherwise execution in step 64;

Step 63, said MGCF/MGW are routed to MSC with call business, and execution in step 65;

Step 64, said MGCF/MGW are routed to SMS/MMS with call business;

Step 65, MSC or SMS/MMS are routed to said different field general terminal with call business, accomplish and call out the back end.

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