KR100666959B1 - System and method providing multiple session in push to talk system - Google Patents

Abstract

A multi-session service system in a PTT(Push To Talk) system and a method thereof are provided to execute a PTT call by the selection of a special key mapped to a call waiting function as a subscriber, who is in the middle of telephone conversation, receives an invite message from another subscriber and opens a plurality of talk sessions. A PTT system comprises an originating proxy server(20), a PTT server(30), and a terminating proxy server(40). The originating proxy server(20) receives an invite message transmitted from the first UE(User Equipment)(10a) and transmits it to the PTT server(30). The PTT server(30) delivers the invite message, transmitted from the originating proxy server(20), to the terminating proxy server(40). The terminating proxy server(40), receiving the invite message from the PTT server(30), checks whether the second UE(10b) is in a log-on state. In case that the second UE(10b) is in the log-on state, the terminating proxy server(40) transmits the invite message to the second UE(10b). Also the terminating proxy server(40) checks whether the second UE(10b) is in a busy state as the second UE(10b) has participated in an existing talk session.

Description

Multi-session service system and its method in a fitness system {SYSTEM AND METHOD PROVIDING MULTIPLE SESSION IN PUSH TO TALK SYSTEM}

1 is a view showing the configuration of a multi-session service system in a PTT system according to the present invention.

FIG. 2 is a diagram for one example of creating a multi talk session when the basic setting of user terminal A (UE A) of FIG. 1 is set to manual mode; FIG.

3 is a diagram illustrating a configuration of a PTT server of FIG. 1.

4 is a diagram illustrating a multi-session service process in a PTT system according to the present invention.

Explanation of symbols on the main parts of the drawings

10a, 10b, 10c: user terminal 20, 40: proxy server

30: PTT server 31: session generator

32: control unit 33: talk session list management unit

The present invention relates to a multi-session service system and a method thereof in a fitness system.

PTT (Push To Talk) service is an instant messenger service such as a kind of walkie-talkie service, and the convenience is doubled because PTT immediately shows whether the other party can receive on the terminal screen.

Such a PTT service is a service that allows a subscriber to simply communicate by pressing the switch of the terminal as the word means, and thus can provide a relatively very fast communication service when compared to the standby time of a general mobile phone.

In addition, the PTT service allows a group of subscribers to listen to what one PTT service subscriber is saying in case of targeting a group, and overcomes the limitation of one-to-one communication that a telephone has. . Here, the PTT service subscriber may designate a small and medium sized group conversationally or make a one-to-one radio call.

PTT is based on SIP (Session Initiation Protocol), which is a text-based application level protocol. SIP has been adopted by many systems recently because its structure is simpler and more scalable than the existing protocol. . SIP is a signaling protocol used to literally connect sessions. SIP can be used for video telephony, multimedia, and online game connectivity, as well as Internet telephony. Adopted as a standard RFC, starting with RFC 2543, it is now updated to RFC 3261.

When a PTT service subscriber (Subscriber) wants to talk with the other party, the subscriber selects a party to invite to the call and selects a call button or a service start button of the PTT terminal to generate an SIP-type invitation message and transmits the message to the PTT server.

Accordingly, when a session is created by the PTT server and the PTT service subscriber joins the PTT talk session, the status icon is displayed to inform the session participation and the call status. ], The buddy participating in the session can update the contact list with the server in real time to recognize the changed state.

However, if a subscriber outside the PTT talk session requests another PTT talk session to the called subscriber in the PTT Busy state already participating in the PTT session, other PTT talk session requests requested to the called subscriber in the PTT Busy state are allowed. Will not be. In this case, from the point of view of another buddy, the called party is marked as busy, and the called party cannot know that an additional PTT incoming request has been requested.

That is, when an incoming subscriber already participates in a talk session and receives INVITE from another subscriber while busy, the following phenomenon occurs depending on the talk type.

First, when the call type is Instant Personal Talk, the PTT server generates a "486 Busy here" reject code when the SIP INVITE message is busy in the talk session. The "486 Busy here" generated in this way is set to DnD for INVITE and rejects the invitation when the called subscriber operates in manual mode, or the called subscriber is already busy belonging to another talk session. Is returned, the warning code is followed by "too many simultaneous PoC sessions". In this case, the user equipment (hereinafter referred to as "UE") from the standpoint of the status of the PTT called subscriber who is already talking with the other subscriber through a status code setting such as [away] or [conversing] You will know. At this time, if INVITE is sent to the called subscriber, the result is that the session cannot be connected.

If the call type is Instant Group Talk, the PTT server writes " 486 Busy here " in SIP NOTIFY and returns it to the IMS Core, which then forwards it to the inviting UE.

If the call type is Ad-hoc Group Talk, the same result as in the Instant Personal Talk described above is obtained.

In addition, when the call type is Chat Group Talk, when INVITE is sent after setting the talk type to chat group talk due to the nature of the chat group talk, the chat group does not fall within the scope of the present invention. When a chat group session receives an INVITE, it adds an inviting subscriber to the chat session and notifies the participants of the chat session that a new subscriber has arrived. However, if it exceeds the max-participant-count, it returns "486 Busy here" with "Too many participants" warning header.

As such, the UE receives the above Reject code and notifies the user of a session creation error, so that the PTT recipient who is already talking with another person cannot open another PTT session.

Accordingly, an object of the present invention is to solve the above problems, and when an INVITE message is received to a subscriber who is already in a busy state with another subscriber, the called subscriber recognizes an invitation from another subscriber and multiple talks. The present invention provides a multi-session service system and a method in a PITTI system capable of making a PTT call while switching a plurality of talk sessions by selecting a special key mapped with a call waiting function when accepting a session. .

According to an aspect of a multi-session service system in a fitness system according to the present invention for achieving the above object, a new call connection request message of the PTT calling terminal to the PTT called terminal in a call by participating in a preset session; Transmitting and receiving a multi talk session grant message from the PTT called terminal, and generating a new session and then updating the multi talk session list.

The controller may be configured to receive an INVITE message from the PTT originating terminal, a PTT server receiving an INVITE message transmitted from the originating proxy server, and an INVITE message transmitted from the PTT server. It includes a destination proxy server for determining whether to create a new session according to the configuration mode of the PTT called terminal.

When the PTT server receives a multi talk session grant message from the PTT called terminal, the PTT server transmits a session connection message to the PTT calling terminal and establishes a new session under the control of the call controller. And a session list manager to manage a session list of the multi talk session subscriber.

The called proxy server transmits a multi-talk session allowance message to the PTT server when the setting mode of the PTT called terminal is an auto multi-session mode.

The called proxy server transmits a multitalk session rejection message to the PTT server when the configuration mode of the PTT called terminal is Auto non multi-session mode.

The called proxy server transmits a response message transmitted from the PTT called terminal to the PTT server when the setting mode of the PTT called terminal is manual mode.

The response message includes at least one of a multitalk session allow message and a multitalk session reject message.

In addition, according to an aspect of a multi-session service system in a fitness system according to the present invention for achieving the above object, from the source proxy server and the source proxy server for receiving the INVITE message from the PTT originating terminal; And a PTT server for receiving the transmitted INVITE message and a destination proxy server for determining whether to create a new session according to a setting mode of the PTT receiving terminal when receiving an INVITE message transmitted from the PTT server.

On the other hand, according to an aspect of the multi-session service method in the fitness system according to the present invention for achieving the above object, requesting a new call connection to the terminal in the call by participating in a predetermined session, and the new call And determining whether to create a new session according to the setting mode of the terminal in a call according to the connection request.

In the step of determining whether to create a new session, if the configuration mode of the terminal in the call is Auto multi-session mode, a multi-talk session allowance message is transmitted to generate a PTT multi-session.

When the PTT multi-session is generated and displayed on the user terminal, the PTT multi-session is switched to the selected session through the user interface to perform a real time call.

The user interface uses a touch pad to select an arbitrary session directly on the screen of the user terminal.

The user interface uses a keypad to select the unique number of the PTT multi-session displayed on the user terminal.

In a step of determining whether to create a new session, when the configuration mode of the mobile terminal in the call is Auto non multi-session mode, a multi-talk session rejection message is transmitted.

In the step of determining whether to create a new session, if the setting mode of the terminal in the call is manual mode, a response message transmitted from the terminal in the call is transmitted.

If the response message is a multi-talk session allow message, the multi-talk session allow message is transmitted to generate a PTT multi-session.

When the PTT multi-session is generated and displayed on the user terminal, the PTT multi-session is switched to the selected session through the user interface to perform a real time call.

The user interface uses a touch pad to select an arbitrary session directly on the screen of the user terminal.

The user interface uses a keypad to select the unique number of the PTT multi-session displayed on the user terminal.

If the response message is a multitalk session rejection message, the multitalk session rejection message is transmitted.

Hereinafter, a detailed description of a preferred embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different 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.

FIG. 1 is a diagram illustrating a configuration of a multi-session service system in a PTT system according to the present invention, and FIG. 2 illustrates a method for generating a multi talk session when a basic setting of user terminal A (UE A) of FIG. 1 is set to manual mode. A diagram showing an example.

As shown in FIG. 1, the multi-session service system in the PTT system of the present invention includes a PTT system and a plurality of UEs.

First, a user terminal (UE) of the present invention is a PTT terminal for accessing a PTT system to perform a voice call. In particular, the user terminal (UE) allows a user to set basic settings through a user interface in an auto multi-session mode. It supports to set one of three modes, Auto non multi-session mode and manual mode.

That is, in FIG. 1, user terminal A (UE A, 10b) is a PTT terminal in communication with user terminal B (UE B, 10c) through a talk session that has already been created, and is called originating user terminal C (UE C, 10a). ), The INVITE message is sent through the PTT system.

At this time, when the basic setting of the user terminal A (UE A, 10b) is set to the manual mode among the three modes, the called party A accepts or rejects the multi talk session request from the PTT system. You can do it.

That is, when the called party A accepts the multi-talk session request from the PTT system, a new talk session is generated according to the invitation of the calling party C other than the existing talk session by transmitting an allow message for the multi talk session to the PTT system. It is done.

As described above, the plurality of talk sessions generated by the PTT system are numbered by the serial number of the sessions in the order in which the talk sessions are allowed and displayed on the talk group screen of the user terminal. Accordingly, a user terminal (UE) belonging to a multi-talk session displays a plurality of talk session information on a group talk screen of the terminal to perform a plurality of sessions through touch pad or special key selection. As you switch, you will be able to make calls in real time.

However, when the called party A rejects the multi-talk session request from the PTT system, a new talk session is generated according to the invitation of the calling party C other than the existing talk session by transmitting only a permission message for the single talk session to the PTT system. Will not be.

The PTT system includes a source proxy server 20, a PTT server 30, and a destination proxy server 40.

The originating proxy server 20 receives the INVITE message transmitted from the user terminal C (UE C) 10a and transmits it to the PTT server 30.

The PTT server 30 receives the INVITE message transmitted from the source proxy server 20 and transmits the message to the destination proxy server 40.

When the receiving proxy server 40 receives the INVITE message transmitted from the PTT server 30, first, the receiving party proxy server 40 (UE A, 10b) is in a log on state. Check whether or not.

As a result of the check, if the Log on state, the INVITE message transmitted from the PTT server 30 is transmitted to the user terminal A (UE C, 10b), and if it is determined that the state is not logged on (Log on), the PTT server The INVITE message transmitted from 30 is not transmitted to the user terminal A (UE A, 10b).

In addition, the called proxy server 40 checks whether the user terminal A (UE A, 10b), which is the called subscriber, is in a busy state in which the user terminal A (UE A, 10b) has already participated in an existing talk session in a log on state.

As a result of the check, if the user terminal A (UE A, 10b), which is the called subscriber, is determined to be in a Log on Busy state, the proxy server 40 of the called party receives the user terminal A (UE A, which is the called subscriber). Check the basic setting of 10b), otherwise, if the called user terminal A (UE A, 10b) is confirmed to be in the Log on Idle state not participating in the existing talk session, the incoming call UE A (UE A, 10b), which is a subscriber, follows a general session initialization procedure.

The destination proxy server 40 checks the basic setting of the user terminal A (UE A, 10b), which is the called subscriber, and as a result, the basic setting (Basic A) of the user terminal A (UE A, 10b) is checked. When the setting is set to Auto multi-session mode, the destination proxy server 40 voices that a plurality of talk session configuration requests for user terminal A (UE A, 10b), which are called subscribers, are allowed. Alternatively, an event message (text) of the text (Event) is transmitted to the PTT server 30 to notify.

Accordingly, the PTT server 30 creates a new talk session other than the existing talk session and then joins the called subscriber to the newly created talk session. At this time, the called subscriber is a called subscriber who is already logged on (Log On), so that the time can be shortened by immediately participating in the newly created talk session without having to query the GLMS (Group List Management Server) again. .

In addition, the PTT server 30 manages the talk session list by keeping a list of subscribers belonging to each talk session each time a new talk session is created.

Then, the called proxy server 40 checks the basic setting of the user terminal A (UE A, 10b) that is the called subscriber, and as a result, the basic setting of the user terminal A (UE A, 10b) is checked. When the (Basic setting) is set to Auto non multi-session mode, the destination proxy server 40 returns a "486 Busy here" message to the PTT server 30 to determine the destination subscriber. Notify that multiple talk session configurations for UE A (UE A, 10b) are not allowed.

Then, the called proxy server 40 checks the basic setting of the user terminal A (UE A, 10b) that is the called subscriber, and as a result, the basic setting of the user terminal A (UE A, 10b) is checked. When (Basic setting) is set to manual mode, a permission message for a multi talk session is transmitted from user terminal A (UE A, 10b), which is a called subscriber who recognizes a talk session request as an event-message according to the reception of an INVITE message. If so, the proxy server 40 of the called party indicates that a plurality of talk session establishment requests for the user terminal A (UE A, 10b), which are called subscribers, are allowed. ) Is sent to the PTT server 30 to notify.

Accordingly, the PTT server 30 creates a new talk session other than the existing talk session and then joins the called subscriber to the newly created talk session. At this time, the called subscriber is a called subscriber who is already logged on (Log On), so that the time can be shortened by immediately participating in the newly created talk session without having to query the GLMS (Group List Management Server) again. .

That is, as shown in FIG. 2, the called party A, who is busy with the subscriber B in the already created session, receives an INVITE message from the PTT system. In other words, called party A sends a message from the PTT system that caller C invited you. Do you want to open a multi session? In case of receiving an SMS message, the PTT server creates a new session when the INVITE message is recognized and the allow message for the multi talk session is transmitted to the PTT system.

Accordingly, the calling party C can make a voice call with the called party A, which is already in a call, through the newly created session (voice conference 2).

In addition, the PTT server 30 manages the talk session list by keeping a list of subscribers belonging to each talk session each time a new talk session is created.

However, when a permission message for a single talk session is transmitted from UE A (UE A, 10b), the destination proxy server 40 returns a "486 Busy here" message to the PTT server 30 ( return) to inform the user that the configuration of multiple talk sessions for the user terminal A (UE A, 10b) is not allowed.

As a result, a user terminal (UE) belonging to a multi-talk session displays a plurality of talk session information on a group talk screen of the terminal, and switches a plurality of sessions through a touch pad or special key selection. As you go, you will be able to make calls in real time.

In more detail, selecting a multi-talk session by a user belonging to a multi-talk session can be switched by long-clicking the corresponding numeric key using '#' as a delimiter. have. Once the session is switched, the normal PTT call process is followed.

In particular, a user belonging to a multi-talk session can deliver a pre-set voice message or short message (SMS) to the meeting participants before the session switch. It is removed from the display screen.

3 is a diagram illustrating a configuration of the PTT server of FIG. 1.

As shown in FIG. 3, the PTT server 30 of the present invention includes a session generator 31, a controller 32, and a talk session list manager 33.

The session generator 31 generates a new session in response to a request from the controller 32. That is, the session generator 31 generates a requested session when the controller 32 receives a multi talk session permission message for an INVITE message from a called subscriber in a call state and requests to create a new session. .

The control unit 32 transmits the invitation message received according to the new call connection request from the calling subscriber to the called subscriber who is already in a call with another subscriber.

As a result of transmission, when the control unit 32 receives an event message in voice or text indicating that a plurality of talk session configuration requests are allowed from the called party, the controller 32 sends a session connection success message to the calling party. If receiving a rejection message for a plurality of talk session establishment request from the called party, the session connection failure message is notified to the calling party.

The talk session list manager 33 updates and manages the talk session list to which each subscriber belongs whenever a new session is generated from the session generator 31 under the control of the controller 32.

4 is a diagram illustrating a multi-session service process in a PTT system according to the present invention.

As shown in FIG. 4, first, the PTT server checks whether an INVITE message is received from the subscriber station (S10).

As a result of the check, when the INVITE message is received from the subscriber station, the received INVITE message is transmitted to the destination proxy server (S20).

Accordingly, the called proxy server first checks whether the called subscriber is logged on (S30) and transmits an INVITE message transmitted from the PTT server to the called subscriber when the logged on is logged on (S30). And, if it is confirmed that the log on (Log On) state does not transmit the INVITE message transmitted from the PTT server to the called subscriber (S40).

Subsequently, the called proxy server checks whether the called subscriber is in a busy state that is already participating in an existing talk session (S50).

If it is confirmed that the called party is in the Log on Busy state, the basic setting of the called party is checked. Otherwise, if it is determined that the called party is in the Log on Idle state not participating in the existing talk session, it is called. The subscriber performs a general session initialization process (S60).

Subsequently, in the process of checking the basic setting of the called subscriber, it is first checked whether the basic setting of the called subscriber terminal is set to the auto multi-session mode (S70).

As a result, when the basic setting of the called party terminal is set to Auto multi-session mode, an event message (voice or text) indicating that a plurality of talk session configuration requests for the called party is allowed ( Event Message) is transmitted to the PTT server (S80).

Accordingly, the PTT server creates a new talk session other than the existing talk session (S90) and then joins the called subscriber to the newly created talk session. At this time, the called subscriber is a called subscriber who is already logged on (Log On), so that the time can be shortened by immediately participating in the newly created talk session without having to query the GLMS (Group List Management Server) again. .

Subsequently, since a new talk session is generated, the subscriber manages the talk session list to which the subscriber belongs (S100).

On the other hand, in the step S70, if the basic setting (basic setting) of the terminating subscriber station is not set to the auto multi-session mode, it is checked whether the auto non-multi-session mode is set (S110).

As a result, when the basic setting of the called subscriber terminal is set to Auto non multi-session mode, a plurality of talk sessions are configured for the called subscriber by transmitting a "486 Busy here" message to the PTT server (S120). Notify this is not allowed.

On the other hand, in step S110, if the basic setting (basic setting) of the terminating subscriber station is not set to Auto non multi-session mode, it is checked whether the manual mode is set (S130).

As a result of the check, when the basic setting of the called subscriber station is set to manual mode, the called subscriber station receives an INVITE message (S140), and a permission message for a multi talk session is transmitted from the called subscriber station. Check whether it is (S150).

As a result of the check, when the permission message for the multi talk session is transmitted from the called subscriber station, the same process (S80 to S100) as in the case of Auto multi-session mode is performed.

However, if a grant message for a single talk session is transmitted from the called subscriber station, as in the case where the called subscriber terminal is in auto non multi-session mode, a message of "486 Busy here" is transmitted to the PTT server to talk to the called subscribers. Signals that session configuration is not allowed.

That is, when a multi talk session is created, a user terminal (UE) belonging to the multi talk session displays a plurality of talk session information on the group talk screen of the terminal and selects a plurality of talk sessions through a touch pad or special key selection. You will be able to make calls in real time as you switch sessions.

In the present invention has been shown and described only with respect to the embodiment of the multi-session service system in the PTT system, the present invention is not limited to the above-described embodiment, it is applicable to any system for performing a voice call.

According to the present invention, a subscriber who is already in a busy state with another subscriber receives an invitation message from another subscriber to open a plurality of talk sessions, whereby a call waiting function is mapped through a special key selection. There is an effect that you can make a PTT call while switching.

In addition, even if a new talk session is opened, since the called subscriber is already registered in GLMS, the time required for call setup can be shortened by immediately joining the session without querying the subscriber information in GLMS.

Claims (25)

In the PTT multi-session service system, PTT called party terminal with a participation in a preset session, A PTT calling terminal for transmitting a new call connection request message to the PTT called terminal; And a controller for generating a new session and updating a multi talk session list when receiving a multi talk session grant message from the PTT called terminal. The method of claim 1, The control unit, An originating proxy server for receiving an INVITE message from the PTT originating terminal; A PTT server receiving an INVITE message transmitted from the originating proxy server; And When receiving the INVITE message transmitted from the PTT server, PTT multi-session service system including a destination proxy server for determining whether to create a new session according to the configuration mode of the PTT called terminal. The method of claim 2, The PTT server, A call controller for transmitting a session connection message to the PTT calling terminal when receiving a multi talk session grant message from the PTT called terminal; A session generator for generating a new session under the control of the call controller; And And a session list manager configured to manage a session list of the multi talk session subscriber. The method of claim 2, The called party proxy server, PTT multi-session service system for transmitting a multi-talk session allowance message to the PTT server, if the configuration mode of the PTT called party terminal is Auto multi-session mode. The method of claim 2, The called party proxy server, PTT multi-session service system for transmitting a multi-talk session rejection message to the PTT server when the configuration mode of the PTT called party terminal is Auto non multi-session mode. The method of claim 2, The called party proxy server, PTT multi-session service system for transmitting a response message transmitted from the PTT called terminal to the PTT server when the setting mode of the PTT called terminal. The method of claim 6, The response message includes at least one of a multi-talk session allow message and a multi-talk session reject message. In the PTT multi-session service system, A source proxy server for receiving an INVITE message from a PTT source terminal; A PTT server receiving an INVITE message transmitted from the originating proxy server; And When receiving the INVITE message transmitted from the PTT server, PTT multi-session service system including a destination proxy server for determining whether to create a new session according to the configuration mode of the PTT destination terminal. The method of claim 8, The PTT server, A call controller for transmitting a session connection message to the PTT calling terminal when receiving a multi talk session grant message from the PTT called terminal; A session generator for generating a new session under the control of the call controller; And And a session list manager configured to manage a session list of the multi talk session subscriber. The method of claim 8, The called party proxy server, PTT multi-session service system for transmitting a multi-talk session allowance message to the PTT server, if the configuration mode of the PTT called party terminal is Auto multi-session mode. The method of claim 8, The called party proxy server, PTT multi-session service system for transmitting a multi-talk session rejection message to the PTT server, when the configuration mode of the PTT called party terminal is Auto non multi-session mode. The method of claim 8, The called party proxy server, PTT multi-session service system for transmitting a response message transmitted from the PTT called terminal to the PTT server when the setting mode of the PTT called terminal. The method of claim 12, The response message includes at least one of a multi-talk session allow message and a multi-talk session reject message. In the PTT multi-session service method, Requesting a new call connection to a terminal in a call by participating in a preset session; PTT multi-session service method comprising the step of determining whether to create a new session according to the setting mode of the terminal in the call according to the new call connection request. The method of claim 14, In the step of determining whether to create a new session, PTT multi-session service method for generating a PTT multi-session by transmitting a multi-talk session allowance message, when the configuration mode of the terminal in the call is Auto multi-session mode. The method of claim 15, PTT multi-session service method for performing a real-time call by switching to the session selected through the user interface when the PTT multi-session is generated and displayed on the user terminal. The method of claim 16, The user interface is a PTT multi-session service method using a touch pad (touch pad) for selecting an arbitrary session directly on the screen of the user terminal. The method of claim 16, The user interface is a PTT multi-session service method using a keypad for selecting a unique number of the PTT multi-session displayed on the user terminal. The method of claim 14, In the step of determining whether to create a new session, PTT multi-session service method for transmitting a multi-talk session rejection message when the configuration mode of the terminal in the call is Auto non multi-session mode. The method of claim 14, In the step of determining whether to create a new session, PTT multi-session service method for transmitting a response message transmitted from the mobile terminal when the setting mode of the mobile terminal in the call. The method of claim 20, If the response message is a multi-talk session allow message, transmitting the multi-talk session allow message to generate a PTT multi-session. The method of claim 21, PTT multi-session service method for performing a real-time call by switching to the session selected through the user interface when the PTT multi-session is generated and displayed on the user terminal. The method of claim 22, The user interface is a PTT multi-session service method using a touch pad (touch pad) for selecting an arbitrary session directly on the screen of the user terminal. The method of claim 22, The user interface is a PTT multi-session service method using a keypad for selecting a unique number of the PTT multi-session displayed on the user terminal. The method of claim 20, If the response message is a multitalk session rejection message, transmitting the multitalk session rejection message.

Images