KR20050103048A - Internet protocal multimedia subsystem and method for establishing session in internet protocal multimedia subsystem - Google Patents

Abstract

The present invention provides a method for establishing a session for an originating terminal to support a session-based message when the service-based regional policy is not used in an internet protocol multimedia subsystem for providing a multimedia service. The first and second call session control function blocks of networks respectively transmit intermediate messages to the receiving terminal by serving intermediate nodes, and the originating message is received as the receiving terminal receives the invite message. And transmitting and receiving messages for a message session relay protocol session (MSRP) with the terminal.

Description

Internet protocol multimedia subsystem and method for establishing session in internet protocal multimedia subsystem}

 The present invention relates to a method and apparatus for providing a multimedia service in an internet protocol multimedia subsystem, and more particularly, to a method and apparatus for establishing a session by a calling terminal for providing a multimedia service.

In addition to the proliferation of Internet services and the rapid increase in Internet traffic, data traffic has recently surpassed voice traffic. As a result, the service is switched from a circuit switched service to a packet switched service. In addition, 3G mobile communication networks, which are being standardized around 3GPP and 3GPP2, are gradually evolving to All IP networks. Accordingly, future communication services based on wired and wireless are being integrated based on IP protocol. As one of the technologies for this purpose, a voice data integration technology (Voice over IP, VoIP) is used.

The VoIP technology is a technology for integrating voice and data into a packet form using IP technology to transmit in real time. Recently, VoIP technology has been developed to integrate and transmit video information. This VoIP technology implements a variety of next generation Internet application services such as Internet telephony services and multimedia messaging services. In order to implement such a next-generation Internet application service, a connection establishment protocol (hereinafter, referred to as SIP) technology is used among protocol technologies. The SIP is a protocol developed by the Internet Engineering Task Force (IETF), an Internet standard development organization, for the purpose of replacing the H.323 standard technology. The SIP is a call signaling protocol of an application layer in which terminals to communicate on the Internet identify each other to find a location, establish a multimedia communication session, and provide session information exchange and termination functions.

An example of a system for providing a multimedia service using such a protocol is an Internet protocol multimedia subsystem (hereinafter referred to as an IMS). The IMS is a core network for providing a multimedia service. It consists of (Core Network) elements.

The Internet Protocol Multimedia Core Network System (IM CN subsystem) provides a multimedia service location based service in a convenient, commercially available, and standardized way. Such IMS can be provided by a 3rd party, and can simultaneously provide various types of packet-based services to mobile subscribers based on IP transport protocol. In addition, IMS uses the SIP as a call establishment protocol for various services, and important functional elements include a call session control function (CSCF) and a home subscriber server (HSS).

For session-based multimedia messaging services, MSRP is used using a session description protocol (hereinafter, abbreviated as SDP) transmitted by SIP. This MSRP is a protocol used to send a series of instant messages.

The IMS uses a method in which an originating terminal forms a session based message in an environment where an intermediate node is mainly used to establish a session for the multimedia messaging service. That is, in the case where the intermediate node is a sequential service determined by the user profile of the HSS in the environment where the intermediate node is located or maintains a recording path for future transactions, the calling terminal may be configured in an environment where there is no session based local policy. Form a session-based message. The intermediate node may be an application server (AS), a multimedia resource function controller (MRFC), or a multimedia resource function processor (MRFP).

However, in addition to the above methods, there are realistic cases in which services are not organized by a single profile by their order or list, so a solution for such a case is required.

Accordingly, an object of the present invention is to provide a method and apparatus for hosting a session by a calling terminal when providing a session-based messaging service for providing a multimedia service.

Another object of the present invention is to propose a method and apparatus for initiating a session by attracting a session by actively engaging a series of intermediate nodes, which are not managed in a single profile, without using a service-based regional policy. .

The method for achieving the above object of the present invention is a method for establishing a session for the originating terminal to support the session-based message when the service-based regional policy is not used in the Internet protocol multimedia subsystem for providing a multimedia service, Transmitting, by the originating terminal, an invite message for a SIP session to the receiving terminal by first and second call session control function blocks of the first and second home networks respectively encoding intermediate nodes; And transmitting and receiving messages for a message session relay protocol session (MSRP) with the originating terminal in response to receiving the invite message.

And a system for achieving the object of the present invention, in the Internet protocol multimedia subsystem for providing a multimedia service, a system for establishing a session for the originating terminal to support the session-based message when the service-based regional policy is not used And the originating terminal for transmitting an invite message for a SIP session to a first home network and, when receiving a visit message from a receiving terminal, sending a dispatch message for establishing a message session transfer protocol session (MSRP); A first serving call session control function block located in a home network and transmitting the invite message received from the first end call session control function block and the invite message from the first serving call session control function block; Receive and generate new part-time messages A first intermediate node transmitting to a first serving call session control function block and a second serving call session control located in the second home network and transmitting the invite message received from the first serving call session control function block; A third intermediate node for receiving a function block, an invite message generated at the first intermediate node and generating a new invite message to the second serving call session control function block; and generating from the third intermediate node And a receiving terminal for receiving the received invite message through the second serving call session control function block, transmitting the visit message to the calling terminal, and receiving a sending message for establishing an MSRP session from the calling terminal. Said system, characterized in that.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention described below will be described by taking an Internet multimedia core network subsystem (hereinafter, abbreviated as IMS) for providing a multimedia service. In addition, it is assumed that intermediate nodes (AS, MRFC, MRFP) are actively involved in session establishment without using a session-based local policy in establishing a session in session-based messaging. An apparatus and method for establishing (hosting) a session by a calling terminal will be described. First, with reference to the accompanying drawings, a configuration of an IMS for an originating terminal to form a SIP session and a message session transfer protocol (hereinafter referred to as MSRP) session in an environment in which an intermediate node is actively involved in session establishment will be described. Let's do it.

1 is a diagram illustrating the configuration of a SIP session and an MSRP session in an internet protocol multimedia subsystem according to a preferred embodiment of the present invention.

The IMS is largely divided into visited networks 110a and 110b and home networks 120a and 120b for the respective mobile terminals UE # 1 and UE # 2.

The IMS communicates with call session control function blocks (CSCFs) 112a, 112b, 121a, 121b, and 122b that are logically divided according to functions performed according to the network in which the subscriber is located. UEs (UE # 1, UE # 2) (111a, 111b), and an application server (hereinafter referred to as AS, 124, 125, 126) serving as an intermediate node, MRFC, MRFP .

Referring to FIG. 1, when the mobile terminal (UE # 1) 111a moves from its home network 120a to the external network 110b in the overall network of the configured IMS, S- It can be seen that CSCF # 1 121a processes the intermediate node INVITE. The message used for session establishment in the IMS is divided into three types, one of which is a SIP message, the other is a transport protocol message, and the other is an MSRP message.

The CSCF is divided into P-CSCFs 112a and 112b, S-CSCFs 121a and 121b, and I-CSCF 122b, and each may perform the function of an objectized exchange.

The P-CSCFs 112a and 112b are blocks located in the respective visited networks 110a and 110b, respectively, and are the first contact blocks when the mobile stations 111a and 111b receive IMS services as proxy CSCFs. The S-CSCFs 122a and 122b are serving CSCFs respectively located in the corresponding home networks 120a and 120b to process SIP sessions of the mobile stations 111a and 111b. The I-CSCF 122b is an interrogating CSCF, which is located at the point of contact between different operator networks. Here, the S-CSCF # 1 121a located in the mobile terminal 111a is invite to the AS # 1 123, and the AS # 1 123 is in the record route for future transactions. Add your location.

 The AS # 2 124 located in the home network 120b for the mobile terminal 111b actively participates in the establishment of a SIP session by ingesting the AS # 3 125. However, it is not involved in MSRP sessions. That is, AS # 2 124 transmits the SIP invite message to AS # 3 125 and does not perform any other processing. On the other hand, AS # 3 125 is involved in both SIP session and MSRP session, and acts as a parsing server.

The message transmission process for the bytes in the overall network of the IMS having such a configuration is shown in 11 to 31, as shown in Figure 1, this process will be described in detail with reference to Figure 2 below. . The MSRP session establishment is illustrated in steps 51 through 53, and an MSRP session for transmitting the actual message is established between the mobile station UE and the application server AS. This MSRP session establishment is always negotiated through the Session Description Protocol (hereinafter abbreviated as SDP) with SIP. The SIP message is independent of the underlying transport protocol and uses SDP as a message body for negotiating session information.

2A and 2D are flowcharts illustrating a process in which an originating terminal attracts an MSRP session and forms an MSRP session according to a preferred embodiment of the present invention.

Here, the procedure for inducing the MSRP session by the calling terminal is performed when the intermediate node is involved in session formation without using the precondition or service based local policy (SBLP) proposed in the present invention. It is a process.

Referring to FIGS. 2A and 2D, the UE # 1 111a allocates an IP Connectivity Access Network (IP CAN) bearer in step 201, and a SIP invite (INVITE) in step 202. ) Is sent to the P-CSCF 112a. In the SDP transmitted along with the SIP INVITE message, the directionality of the MSRP is set to both. At this time, the TCP port number and the URL for the MSRP session are set between the calling terminal 111a and the P-CSCF 112a. In this case, when the receiving terminal (UE # 2) 111b wants to host a session, it may be set to active.

In step 203, the originating terminal 111a receives a 100 attempting message for the invite message from the P-CSCF 112a. At this time, in steps 204 and 205, the P-CSCF 112a sends an invite message to the S-CSCF 121a located in the home network 120a, and receives a 100 challenge response in response thereto. This process is the same as the general SIP proxying method. In step 206, the S-CSCF 121a transmits the SIP invite message to another CSCF or an application server according to an initial filtering criterion. Here, the S-CSCF 121a sets the transmission to the AS # 1 123. Accordingly, in steps 207 to 208, the S-CSCF # 1 121a transmits an invite message to the AS # 1 123, and receives 100 attempting responses in response thereto. This process is the same as the general SIP proxying method.

Then, in step 209, the calling terminal (UE # 1) 111a performs a TCP setup with the AS # 1 123. When this TCP setup is made, in step 210 and 211, the AS # 1 123 generates a new invite message and transmits it to the S-CSCF # 1 121a and receives a 100 Trying response thereto. This is the same as SIP Proxying. Then, the S-CSCF 121a transmits an invite message to the I-CSCF # 2 122b located in the home network 120b for the receiving terminal 111b, and receives a 100 Trying response.

In step 214, the I-CSCF # 2 122b sends a query to a home subscriber server (HSS) to find the S-CSCF # 2 121b located in the home network 120b. If the S-CSCF # 2 121b is found, in steps 215 and 216, the I-CSCF # 2 122b transmits a SIP invite message to the S-CSCF # 2 121b, and sends a response (100 Trying). Receive.

Then, in step 217, the S-CSCF # 2 121b transmits the SIP invite message to another CSCF or an application server according to an initial filtering criterion, which is set to be transmitted to the AS # 2 124. Accordingly, in steps 218 and 219, S-CSCF # 2 121b transmits a SIP invite message to AS # 2 124, and receives a response (100 trying).

In step 220 and step 221, the AS # 2 124 proxys and sends a SIP invite message to the AS # 3 125, and receives a response (100 trying). In step 222, the AS # 3 125 performs a TCP setup with the AS # 1 123. Subsequently, in step 223 and step 224, the AS # 3 125 generates a SIP invite message, transmits it to the S-CSCF # 2 121b, and receives a response (100 Trying). Then, in step 225 and step 228, the S-CSCF # 2 121b receives the received invite message again from the P-CSCF # 2 112b and the receiving terminal UE located in the UE # 2 Visited Network 110b. # 2) 111b, and receives a response from the receiving terminal 111b through the P-CSCF # 2 112b.

Thereafter, in step 229, the receiving terminal 111b allocates an IP-CAN Bearer (IP-CAN Bearer) using the received session URL, and performs TCP setup with the AS # 3 125 in step 230. do. Then, in step 231, the receiving terminal 111b sends a VISIT message for the MSRP session to the calling terminal 111a through the AS # 3 125 and the AS # 1 123, that is, through a TCP set-up path. In step 232, a 200 OK message is received from the originating terminal 111a in response to the visit message through the path.

Then, in step 233, the receiving terminal 111b transmits 200 OK to the AS # 3 125 via the P-CSCF # 2 112b and the S-CSCF # 2 121b, and responds to this in step 234. The ACK message is received from the AS # 3 125 via the S-CSCF # 2 121b and the P-CSCF # 2 112b. Subsequently, in step 235, the AS # 3 125 transmits a 200 OK message to the S-CSCF # 1 121a via the AS # 2 124, the S-CSCF 2 121b, and the I-CSCF 122b. In step 236, an ACK message is received in response. In step 237 and step 238, the AS # 1 123 transmits a 200 OK message to the calling terminal 111a via the S-CSCF # 1 121a and the P-CSCF # 1 of the visited network 110a. Receive an ACK message in response.

Then, the receiving terminal 111b receives a send (SEND) message for transmitting actual data through the TCP setup path from the calling terminal 111a in steps 239 to 240, and in response thereto, the calling terminal 111a. Send a 200 OK message.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention provides another method by allowing unmanaged intermediate nodes (AS) to actively participate in session establishment when a service is not configured by a single profile by order or list. There is an effect that can enable the form of multimedia services.

1 is a diagram illustrating the configuration of a SIP session and an MSRP session in an internet protocol multimedia subsystem according to a preferred embodiment of the present invention;

2A and 2D are flowcharts illustrating a process in which an originating terminal attracts an MSRP session and forms an MSRP session according to a preferred embodiment of the present invention.

Claims (9)

In the method of establishing a session for supporting the session-based message when the calling terminal does not use the service-based regional policy in the Internet protocol multimedia subsystem for providing a multimedia service, Sending, by the originating terminal, first and second call session control function blocks of the first and second home networks to each of the intermediate nodes to transmit an invite message for a connection establishment protocol (SIP) session to the receiving terminal; , And transmitting and receiving messages for a message session transfer protocol session (MSRP) with the originating terminal as the receiving terminal receives the invite message. The method of claim 1, wherein the sending of the invite message for the SIP session comprises:  Sending, by the calling terminal, a session establishment protocol invite message to a first intermediate node through a first serving call session control function block of a first home network; The first serving call session control function block receives a response to the session establishment protocol invite message from the intermediate node and performs a transmission control protocol (TCP) setup. If the byte message is received, sending the received byte message to a second serving call session control function block of the first home network; Sending, by the second serving call session control function block, the received invite message to a third intermediate node via a second intermediate node; And generating, by the third intermediate node, a new SIP invite message to a receiving terminal through a second serving call session control function block. The method of claim 2, wherein the sending of the invite message for the SIP session comprises: Setting up, by the calling terminal, an internet protocol with the first intermediate node after performing the SIP invite; Establishing, by the first intermediate node, an internet protocol with the third intermediate node; And the third intermediate node sets up an internet protocol with the receiving terminal. The method of claim 1, wherein sending and receiving messages for a message session transfer protocol session (MSRP) comprises: Transmitting a visit message to the originating terminal through the third intermediate node and the second intermediate node in response to receiving the invite message; Receiving a response message to the visit message from the calling terminal; Receiving a sending message for establishing an MSRP session from the calling terminal; Sending a response message to the dispatch message. In the Internet protocol multimedia subsystem for providing a multimedia service, the system for establishing a session for the originating terminal to support the session-based message when the service-based regional policy is not used, The originating terminal transmitting an invite message for a session establishment protocol (SIP) session to a first home network and transmitting a dispatch message for forming a message session transfer protocol session (MSRP) upon receiving a visit message from a receiving terminal; , A first serving call session control function block located in the first home network and transmitting the invite message received from the first end call session control function block; A first intermediate node receiving the invite message from the first serving call session control function block and generating a new invite message to the first serving call session control function block; A second serving call session control function block located in the second home network and transmitting the invite message received from the first serving call session control function block; A third intermediate node receiving the invite message generated at the first intermediate node and generating a new invite message to the second serving call session control function block; Receive an invite message generated from the third intermediate node through the second serving call session control function block, send the visit message to the calling terminal, and receive a sending message for establishing an MSRP session from the calling terminal. The system, characterized in that it comprises the receiving terminal. The method of claim 5, And a second intermediate node for relaying messages for a SIP session between the second serving call session control function block and the third intermediate node. The method of claim 5, The calling terminal performs the transmission control protocol (TCP) setup with the first intermediate node. The method of claim 5, The first intermediate node is configured to perform a Transmission Control Protocol (TCP) setup with the third intermediate node. The method of claim 5, The third intermediate node is configured to perform a Transmission Control Protocol (TCP) setup with the receiving terminal.