KR100454080B1 - A CAll PROCESSING METHOD OF AN IP MULTIMEDIA SERVICE USING A VISITED SUBSCRIBER SERVER - Google Patents

Abstract

The present invention relates to a call processing method when providing IP multimedia (IM) service in an all IP network, which is a fourth generation mobile communication network.

The call processing method of the present invention includes a PS-CSCF integrating a P-CSCF and an S-CSCF in a visited network of a calling subscriber and a called subscriber, and includes a called subscriber in the PS & CSCF (Proxy & Serving CSCF) block. Is applied to an All IP system having a Visited Subscriber Server (VSS) for determining whether a registered subscriber is registered, and searches for whether a called subscriber is registered in the Visited Subscriber Server (VSS). In case of a user, the call can be directly connected to the called subscriber without using the calling-home network, the calling-home network, and the calling-visit network, and if the called subscriber is not registered, the call is made from the calling-visit network. -Direct incoming call without going through the home network-By connecting the call to the home network can provide users with IP multimedia (IM) services.

Description

Call processing method of IP multimedia service using visiting subscriber server {A CALL PROCESSING METHOD OF AN IP MULTIMEDIA SERVICE USING A VISITED SUBSCRIBER SERVER}

The present invention relates to a call processing method of an IP multimedia (IM) service applied to an all IP (Internet Protocol) network, which is a fourth generation mobile communication network, and more specifically, a visited subscriber server (VSS). The IP multimedia service using the visited subscriber server that can reduce the load of the network by allowing the call to be connected without going through the calling home network or the called home network according to whether or not the called subscriber is registered in the visited subscriber server using It relates to a call processing method.

As the commercialization of the IMT-2000 system, which is the third generation network that provides voice and Internet services, has been completed, interest in the All IP network, the fourth generation network, is increasing.

In the All IP network, a voice service that communicates through a circuit is implemented using Voice over Internet Protocol (VoIP), which results in a network structure in which an existing exchange is lost in the entire network. It is characterized by the fact that traffic is handled by Internet Protocol (IP).

1 illustrates a structure of an all IP network, which is a fourth generation mobile communication network.

The All IP network shown in FIG. 1 is composed of a radio network part, a general packet radio service (GPRS) network part, a mobility management part, a call control part, and an interface part with an external network.

The wireless network portion is composed of mobile subscriber and equipment that performs network related functions such as wireless link, wireless access, and the like, and includes an end terminal equipment (TE), a mobile terminal (MT), and an EDGN of 200 kHz. ERAN (EDGE Radio Access Netwok) for performing a modulation function and responsible for the real-time packet transmission, and UTRAN (UMTS Terrestrial Radio Access Network) for the wireless access interval.

The GPRS network portion includes a Serving GPRS Support Node (SGSN), a Gateway GPRS Support Register (GGSN), and an Equipment Identity Register (EIR). The SGSN is responsible for security with an external network and performs a tunneling function with the GGSN for mobility of mobile IP. In addition, it performs mutual information function with HLR, MSC / VLR. The GGSN performs a function for interconnecting an external network such as a wireless network and the Internet. The EIR stores and manages GPRS software and key functions that are processed in real time.

The mobility management part includes a home subscriber server (HSS). The home subscriber server stores all data on subscriber data, and performs information management functions such as user profile management and mobility management, authorization verification, and authentication for security.

The call control part performs a function of call control and signaling to support real-time wireless service in an All IP network, and includes a signaling signaling gateway (R-SGW), a call state control function (CSCF), and a multimedia resource function (MRF). It consists of. The R-SGW performs interworking with the legacy mobile signal network. The CSCF performs multimedia call control based on Session Initiated Protocol (SIP), which is a protocol, and the MRF performs a conversion or generation function for mixing and multiplexing multimedia.

The interface part with the external network performs a function for interfacing with an external network such as PSTN, PLMN, PDSN, VoIP, GSM, etc., and includes a Media Gateway Control Function (MGCF), a Media Gateway (MGW), and a T-SGW ( Transport signaling gateway). The MGCF performs control of some IP multimedia calls such as protocol conversion between ISUP and SIP, selection of an incoming CSCF, and connection and resource control of the MGW. The T-SGW performs interworking with a public switched telephone network (PSTN).

FIG. 2 shows the interworking relationship between a home subscriber server (HSS, hereinafter referred to as 'HSS') and a call state control function (CSCF) block according to a user's location. It is shown. Basically, the user of IP multimedia (IM: IP) service uses an existing GPRS network to use IM service. That is, the GPRS network is used as a transport layer and an IM service call processing message is transmitted and received using a GPRS bearer. If the user moves to any visited network, the procedure of registering the current location on the user's home network for the call of IM service is performed. After performing this procedure, the IM service is performed. If you want to perform the call procedure. In the 4th generation communication network, CSCF is classified into the following three types to perform this procedure, and each function is as follows.

P-CSCF (Proxy-CSCF): Performs the function of registering registration and origination call request from user's visiting network to home network.

S-CSCF (Serving-CSCF): Performs a function of handling a user's call request in an actual home network, and may configure a plurality of S-CSCFs to exist.

Interrogating-CSCF (I-CSCF): A function to select an S-CSCF suitable for a user's call request from a plurality of S-CSCFs, and the configuration information of the S-CSCF located in a home network to other networks for security purposes. Perform a function not shown.

Each CSCF transmits and receives a message using an extended SIP protocol (SIP +), and uses a diameter protocol with the HSS.

3 illustrates a conventional user location registration procedure. User equipment (UE) that has moved to the visited network sends a registration request message (SIP-Register) to the visited network's P-CSCF to register its location (1), and the received P-CSCF receives the domain name. It receives the address of the I-CSCF located in the home network of the user UE using the Domain Name System (DNS) (2, 3) and relays the registration request of the user (4). Upon receiving this, the I-CSCF queries the HSS to authorize whether the visited network in which the subscriber is located is a restricted visited network and to select an S-CSCF to handle IM call processing of the subscriber (5). . Next, the HSS performs subscriber authority verification and, if passed, transmits a list of available S-CSCFs (6). The I-CSCF selects the most suitable S-CSCF from this list and requests registration with the corresponding S-CSCF (7). The S-CSCF checks the subscriber's authentication information to determine whether the subscriber is a legitimate subscriber or not. (8) When the HSS delivers the subscriber's authentication information (9), the subscriber requests an authentication parameter (10). The subscriber delivers the authentication parameters that the subscriber has through the procedures 1 to 7 above. At this time, the S-CSCF performs subscriber authentication based on the subscriber authentication information received from the HSS and the authentication information transmitted by the subscriber, and in case of a legitimate subscriber, the S-CSCF is the S-CSCF of the subscriber. Register with the HSS (11), and receives the information of the subscriber from the HSS and stores in the S-CSCF (12).

Figure 4 shows a conventional subscriber call destination procedure. When a subscriber moves to a visited network and sends a call to a called party for IM service, an INVITE delivered from the subscriber is placed in the home network of the calling subscriber through a P-CSCF located in the calling subscriber's visited network. The I-CSCF receives the address of the S-CSCF of the registered subscriber from the HSS and transmits an outgoing request message to the S-CSCF (3, 4, 5). The S-CSCF forwards the call request message to the I-CSCF located in the home network of the called party using the called party's number and address information (6). The I-CSCF receives the corresponding S-CSCF information of the called subscriber from the HSS located at the home heart of the called subscriber and transmits it (7, 8, 9). The corresponding S-CSCF of the called party sends a call request to the P-CSCF located in the visited subscriber's visited network during the registration process of the called party (10), and the P-CSCF transmits it to the corresponding subscriber (11). ). The response is sent to the calling subscriber via the opposite paths 12, 13, 14, 15, 16, 17, 18 so far. When this call processing procedure is completed, a Realtime Transport Protocol (RTP) connection is established for transmitting IM media traffic between the calling user and the called user and a call is made (19).

As described above, when all the called and receiving subscribers are in their respective visited networks, in the conventional call processing method, the calling home network and the called home network are used in the calling visited network by using the location information of the subscriber registered in the HSS. The call processing procedure proceeded to the incoming visit network. However, when the call processing method is applied to the All IP network which is the fourth generation system, there is a problem of generating a large amount of network load.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described technical problem, and in order to reduce a large amount of network load generated when providing an Internet Protocol Multimedia (IM) service based on the Internet Protocol to a user, According to whether or not a subscriber is registered, a call processing method is provided to connect a call with a called party directly from an outgoing visited network or to connect directly to a called home network without going through an outgoing home network. For the purpose of

Another object of the present invention is to provide a user location registration method for IP multimedia service to be preceded before applying this call processing method.

1 is a diagram showing the structure of an All IP network that is a fourth generation mobile communication network;

2 is a diagram illustrating an interworking relationship between a home subscriber server and a call state control function block;

3 is a diagram illustrating a conventional user location registration procedure.

4 is a diagram illustrating a conventional subscriber originator call procedure.

5 is a diagram illustrating a procedure for registering a user of an IP multimedia service using a visited subscriber server according to an embodiment of the present invention.

6 is a diagram illustrating an incoming and outgoing procedure of an IP multimedia service user registered in a visited subscriber server according to an embodiment of the present invention.

7 is a diagram illustrating an incoming / outgoing procedure of an IP multimedia service user not registered in a visited subscriber server according to an embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

HSS: Home Subscriber Server DNS: Domain Name System

I-CSCF: Interrogating-CSF

PS-CSCF: PS-CSCF VSS: Visiting Subscriber Server

UE: subscriber station

In order to achieve the above object, a user location registration method for IP multimedia service using a visited subscriber server according to an aspect of the present invention includes a home subscriber server and an interrogating-call state control function (I-CSCF) in a home network. : Inter-gate-Call State Control Function (hereinafter referred to as 'I-CSCF') block, and the proxy-call state control function (P-CSCF: Proxy-Call State Control Function, hereinafter referred to as 'P-CSCF') PS-CSCF (hereinafter referred to as PS-CSCF) incorporating a block and Serving-Call State Control Function (S-CSCF) block , A 'PS-CSCF') block, a domain name system (DNS: Domain Name System, hereinafter referred to as 'DNS'), and a fourth generation communication network having a visitor subscriber server.

The PS-CSCF informs the I-CSCF located in the user's home network according to the user's location registration request of the user who has moved to the visited network, and requests the I-CSCF to select itself as the S-CSCF of the subscriber. Stage 1;

The I-CSCF of the home network verifies the subscriber's authority through the home subscriber server and verifies whether the PS-CSCF is authorized to the S-CSCF for the corresponding subscriber, and if the authorization is made, notifies the visited network. Step 2;

In accordance with the permission of the second step, the PS-CSCF of the visited network compares the subscriber's authentication parameters with the subscriber's authentication information from the home subscriber server to determine whether the subscriber is a legitimate subscriber; And,

In case of the legal subscriber in the third step, a fourth step of performing a registration procedure for the home subscriber server and the visited subscriber server is included.

In addition, the method for processing call-in / out of the IP multimedia service using a visitor subscriber server according to another aspect of the present invention is an interrogateing-call state control function (I-CSCF) with a home subscriber server in a home network. (Hereinafter, referred to as 'I-CSCF') block, and a proxy-call state control function (P-CSCF: Proxy-Call State Control Function (P-CSCF)) block and serving in the visited network. PS-CSCF (hereinafter referred to as 'PS-CSCF') incorporating a Block-Call State Control Function (S-CSCF) block 4th generation communication network having a block, a domain name system (DNS: hereinafter referred to as 'DNS'), and a visited subscriber server.

Transmitting a call request of the subscriber who has moved to the visited network to the PS-CSCF of the visited network;

The PS-CSCF searching for the visited subscriber server to determine whether the called party targeted for the originating request is a registered called party;

A third step of informing the caller if the called party is registered in the second step and establishing a transmission line connection between the calling party and the called party;

If the called party is not the called party registered in the second step, the PS-CSCF receives the PS-CSCF information of the called party by sending an outgoing request message to the I-CSCF located in the home network of the called party. -Sending a call request message to the CSCF; And,

And transmitting a response of the called party to the calling party to establish a transmission line connection between the calling party and the called party.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is composed of a user registration procedure of an IP multimedia service using a visited subscriber server and an origination call processing procedure using a visited subscriber server. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

5 illustrates a procedure of registering a user of an IP multimedia service using a visited subscriber server according to an embodiment of the present invention, and FIG. 6 illustrates an IP multimedia service user registered to a visited subscriber server according to an embodiment of the present invention. The call procedure of FIG. 7 is shown, and FIG. 7 shows the call procedure of the IP multimedia service user who is not registered in the visited subscriber server according to the embodiment of the present invention.

Referring to FIG. 5, in the present invention, a visited subscriber server (VSS) is provided in a PS & CSCF (Proxy & Serving CSCF) of a visited network. The visited subscriber server (VSS) temporarily stores the subscriber information in the PS-CSCF (Proxy & Serving CSCF) of the calling-visiting network when the calling subscriber located in the calling visited network completes the location registration, and re-registers or departs the location. It is not necessary to transmit to the home subscriber server (HSS) of the home network again at the time of registration. In addition, the PS-CSCF that integrates the P-CSCF and the S-CSCF in the outgoing-visit network enables the call processing without the outgoing-home network in the outgoing-visit network, thereby applying the concept of VSS more flexibly. It was. Since I-CSCF is used for security purposes of each network operator, it is excluded from the present invention.

Specifically, when the user location registration procedure is examined, a user (UE) who has moved to the visited network transmits a registration request message (SIP-Register) to the PS-CSCF of the visited network for registering his location (1). The PS-CSCF receives the address of the I-CSCF located in the user's home network using the Domain Name System (DNS) (2, 3), and transmits itself (PS-CSCF) with the relay of the registration request message. It asks for selection by S-CSCF of (4). Upon receiving this, the I-CSCF determines whether the S-CSCF is authorized to handle authorization verification and call processing of the subscriber's IP multimedia (IM) service. Inquire the server (HSS) (5). In response, the HSS verifies subscriber authority and, if passed, verifies the permission of the S-CSCF. If permission is granted, the authentication information of the user is transmitted to the I-CSCF with this result (6). The I-CSCF notifies the PS-CSCF of the visited network that the authorization has been made (7), and the PS-CSCF requests an authentication parameter to the corresponding UE (UE) to know whether the subscriber is a legitimate subscriber. (8). The subscriber forwards the authentication parameters he has to the PS-CSCF (9). At this time, the PS-CSCF performs subscriber authentication based on the subscriber authentication information received from the home subscriber server (HSS) and the authentication information transmitted by the subscriber (Authentication), and if the corresponding PS-CSCF is a valid subscriber, S-CSCF is registered in the home subscriber server (HSS) of the home network (10, 11, 12, 13), and receives the subscriber's information from the home subscriber server (HSS) visited subscriber server (PS-CSCF) VSS).

Fig. 6 shows an incoming / outgoing call processing procedure when the called party is a user registered in the visited subscriber server. Referring to FIG. 6, the visited network of the calling subscriber and the called subscriber have a PS-CSCF integrating the P-CSCF and the S-CSCF, and the PS-CSCF (Proxy & Serving CSCF) block has a visited subscriber. A server (VSS: Visited Subscriber Server) is provided.

If a subscriber (UE) who has moved to the visited network sends to the called party for IP multimedia (IM) service, the calling request (INVITE) delivered from the subscriber is delivered to the PS-CSCF located in the calling subscriber's visited network (1). The PS-CSCF searches for the VSS, and if the called party is registered, the PS-CSCF transmits it to the subscriber (2). The response is sent to the calling subscriber via the opposite paths 3 and 4 so far. When the call processing procedure is completed, a Realtime Transport Protocol (RTP) connection is established and a call is made between the calling subscriber and the called subscriber for the media traffic of the IP multimedia service (5).

7 shows an incoming / outgoing call processing procedure when the called party is a user who is not registered in the visited subscriber server. Referring to FIG. 7, the visited network of the calling subscriber and the called subscriber have a PS-CSCF integrating the P-CSCF and the S-CSCF, and the PS-CSCF (Proxy & Serving CSCF) block has a visited subscriber. A server (VSS: Visited Subscriber Server) is provided.

When a subscriber who has moved to the visited network sends to the called party for the IP multimedia (IM) service, the calling request (INVITE) transmitted from the subscriber is delivered to the PS-CSCF in the calling subscriber's visited network (1), and the PS The CSCF searches the visited subscriber server (VSS) to determine whether the called party is a registered user. If the called party is not registered, the CSCF uses the number and address information of the called party to locate the I subscriber in the home network. -Forward the outgoing request message to the CSCF (2). The I-CSCF receives the PS-CSCF information of the called subscriber from the HSS in the home network of the called subscriber (3, 4), and sends a call request to the PS-CSCF (5). The PS-CSCF sends it to the subscriber (6). The response is sent to the calling subscriber via the opposite paths 7, 8, 9, 10 so far. When the call processing procedure is completed, a Realtime Transport Protocol (RTP) connection is established and a call is made between the calling user and the called user for media traffic of an IP multimedia service (11).

The embodiment of the present invention is only one embodiment, and many variations and modifications are possible to the call processing method of the components of the network and the IP multimedia service without departing from the gist of the present invention. It is not limited only to an Example.

As described above, the call processing method of the present invention includes a PS-CSCF integrating a P-CSCF and an S-CSCF in a visited network of a calling party and a called subscriber, and the PS-CSCF (Proxy & Serving CSCF). ) Block is applied to an All IP system having a visited subscriber server (VSS) for determining whether a called subscriber is registered, and depending on whether the called subscriber is registered in the visited subscriber server (VSS). The call can be connected to the called subscriber without passing through the calling home network or the calling home network.

Therefore, in order to solve a large amount of traffic generation and performance degradation that may be a serious problem in providing IP multimedia service in the fourth generation mobile communication network, the call processing procedure is simplified and essential functions are integrated to solve the problem. Can be reduced.

Claims (9)

In the home network, a home subscriber server and an interrogating-call state control function (I-CSCF) block are called. Function (P-CSCF: Proxy-Call State Control Function, hereinafter called 'P-CSCF') Block and Serving-Call State Control Function (S-CSCF: Serving-Call State Control Function, hereinafter, 'S-CSCF' PS-call state control function (PS-CSCF, hereinafter referred to as PS-CSCF) block incorporating the block, Domain Name System (DNS) and visit A method for registering a location of a user in a fourth generation communication network having a subscriber server, The PS-CSCF informs the I-CSCF located in the user's home network according to the user's location registration request of the user who has moved to the visited network, and requests the I-CSCF to select itself as the S-CSCF of the subscriber. Stage 1; The I-CSCF of the home network verifies the subscriber's authority through the home subscriber server and verifies whether the PS-CSCF is authorized to the S-CSCF for the corresponding subscriber, and if the authorization is made, notifies the visited network. Step 2; In accordance with the permission of the second step, the PS-CSCF of the visited network compares the subscriber's authentication parameters with the subscriber's authentication information from the home subscriber server to determine whether the subscriber is a legitimate subscriber; And, And a fourth step of performing a registration procedure for the home subscriber server and the visited subscriber server when the subscriber is a legitimate subscriber in the third step. User location registration method for IP multimedia service using visited subscriber server. The method of claim 1, The first step is Transmitting, by the user moving to the visited network, a registration request message for registering his location to the PS-CSCF of the visited network; And, In response to the registration request message, the PS-CSCF receives an address of an I-CSCF located in a user's home network from the DNS, and requests to select itself as the S-CSCF of the subscriber along with the registration request message. Transmitting to the I-CSCF of the home network; User location registration method for IP multimedia service using visited subscriber server. The method of claim 1, The second step is Querying, by the I-CSCF, a home subscriber server of the home network to verify the authorization of the visited network in which the subscriber is located or not, and whether the PS-CSCF is granted to the S-CSCF by the subscriber; Verifying, by the home subscriber server, the authority of the subscriber in response to the inquiry and whether the PS-CSCF is granted to the S-CSCF of the corresponding subscriber; And If authorization is made at the home subscriber server, the I-CSCF includes notifying the corresponding PS-CSCF of the visited network; User location registration method for IP multimedia service using visited subscriber server. The method of claim 3, The home subscriber server transmits the authentication information of the subscriber to the I-CSCF with the result of the authorization when the authorization is made. User location registration method for IP multimedia service using visited subscriber server. The method of claim 1, The third step is In accordance with the permission in the second step, requesting and receiving an authentication parameter from the subscriber by the PS-CSCF; The PS-CSCF receiving subscriber authentication information from the home subscriber server through the I-CSCF; And, Comparing, by the PS-CSCF, with the subscriber authentication parameter and the subscriber authentication information to confirm whether the subscriber is a legitimate subscriber; User location registration method for IP multimedia service using visited subscriber server. The method of claim 1, The fourth step is Registering the PS-CSCF as the S-CSCF of the subscriber to a home subscriber server of a home network when the subscriber is a legitimate subscriber in the third step; And And receiving, by the PS-CSCF, the subscriber information from the home subscriber server and storing the information on the visited subscriber server. User location registration method for IP multimedia service using visited subscriber server. In the home network, a home subscriber server and an interrogating-call state control function (I-CSCF) block are called. Function (P-CSCF: Proxy-Call State Control Function, hereinafter called 'P-CSCF') Block and Serving-Call State Control Function (S-CSCF: Serving-Call State Control Function, hereinafter, 'S-CSCF' PS-call state control function (PS-CSCF, hereinafter referred to as PS-CSCF) block incorporating the block, Domain Name System (DNS) and visit A call processing method for an incoming / outgoing call for IP multimedia service of a fourth generation communication network having a subscriber server, Transmitting a call request of the subscriber who has moved to the visited network to the PS-CSCF of the visited network; The PS-CSCF searching for the visited subscriber server to determine whether the called party targeted for the originating request is a registered called party; A third step of informing the caller if the called party is registered in the second step and establishing a transmission line connection between the calling party and the called party; If the called party is not the called party registered in the second step, the PS-CSCF receives the PS-CSCF information of the called party by sending an outgoing request message to the I-CSCF located in the home network of the called party. -Sending a call request message to the CSCF; And, And transmitting a response of the called party to a calling party to establish a transmission line connection between the calling party and the called party. A call processing method for call multimedia service for IP multimedia service using visited subscriber server. The method of claim 7, wherein The establishment of the transmission line connection in the third and fifth steps is made by the real-time transmission protocol. A call processing method for call multimedia service for IP multimedia service using visited subscriber server. The method of claim 7, wherein In the fourth step, The PS-CSCF searches for an I-CSCF located in the home network of the called party using the number and address information of the called party and delivers an outgoing request message. A call processing method for call multimedia service for IP multimedia service using visited subscriber server.