KR20060097260A - Method for supporting of push to talk group call in a mobile communication system - Google Patents

Abstract

The present invention relates to a method for providing a group call in a mobile communication system, and more particularly, to a method for providing a push to talk (PTT) group call.

The present invention provides a PTT service method that can reduce call instances, reduce overhead, and efficiently use limited resources when providing a group call of a PTT service in a mobile communication system.

According to the first embodiment of the present invention, a method for providing a PTT service to a terminal of a preset group in a mobile communication system, the PTT server communicates with the terminals in the group from a predetermined terminal of the preset group Transmitting a call announcement message to a called party PCF / RAN where the remaining terminals of the group are located when a request call request message is received; and each called party PCF / RAN receiving the call announcement message is located within its own area. Transmitting a call guide message indicating a group to the terminals in the preset group and transmitting the call guide message to the PTT server upon receiving the response; and the PTT server receiving the response message from the called PCF / RANs. Calling PCF / RAN where the calling terminal is located by generating a call status message for each terminal in the preset group Transmitting the call setup completion to the calling terminal by using the shared traffic channel assignment message; and the called PCF / RAN are connected to the terminals. Allocating a shared traffic channel assignment message to terminals located in the called PCF / RAN when a call request / route update message is received.

PTT service, group call, mobile communication system, 1x EV-DO.

Description

METHOD FOR SUPPORTING OF PUSH TO TALK GROUP CALL IN A MOBILE COMMUNICATION SYSTEM}

1 is a signal flow diagram when supporting a predefined group call in a cdma2000 1xEV-DO network;

2 is a signal flow diagram for an ad hoc group call in a cdma2000 1xEV-DO network;

3 is a signal flow diagram when a predefined group call is supported in a cdma2000 1xEV-DO network according to the present invention;

4 is a signal flow diagram for an ad hoc group call in a cdma2000 1xEV-DO network according to another embodiment of the present invention;

5 is a signal flow diagram for an ad hoc group call in a cdma2000 1xEV-DO network in accordance with another embodiment of the present invention.

The present invention relates to a method for providing a group call in a mobile communication system, and more particularly, to a method for providing a push to talk (PTT) group call.

In general, mobile communication systems have been developed for the purpose of providing voice services to users, have a very high penetration rate, and are rapidly spreading around the world. Such mobile communication systems continue to evolve and are currently being developed to provide relatively high speed data as well as providing voice services and simple data services.

Such mobile communication systems are classified into synchronous and asynchronous methods. The asynchronous scheme is being developed in Europe, and standardization is actively underway in the 3GPP camp. Motives are also being developed at the forefront in North America, and standardization is nearing completion in the 3GPP2 camp. The ultimate goal of both the mobile communication system being developed in the 3GPP camp and the mobile communication system being developed in the 3GPP2 camp is to provide high-speed data service efficiently. In other words, development is being made to provide a packet type data service at a higher speed than development of a voice service that was basically provided.

The first commercialized system among these standardized systems is the 1x EV-DO system developed by 3GPP2. The 1x EV-DO system is widely known as a system capable of transmitting only high speed data. In other words, it is known as a service that cannot provide real-time services such as voice services. Therefore, various attempts have been made to provide a voice service even in a 1x EV-DO system. As described above, in order to provide a voice service in a 1x EV-DO system, since voice service data is basically provided in a packet form, it is provided in a VoIP form. Therefore, it takes a little time delay.

As such, when a time delay occurs in the voice service, the quality of service (QoS) is greatly degraded. As a result, it has come to provide services that put more emphasis on multilateral communication services than on general voice services. This multi-party communication service is a 1: N service method or a N: M service method, which is not a 1: 1 service method, which combines specific users into at least one group and simultaneously provides voice services to users included in the group. Form. In other words, it is a service that provides a voice service like a radio system. This type of service is a PTT service. In addition, the group call can be extended to 1: 1 communication as well as 1: N communication.

Next, the case in which the PTT service is performed will be described.

1 is a signal flow diagram when a predefined group call is supported in a cdma2000 1xEV-DO network. Hereinafter, a signal flow when a predefined group call is supported in the cdma2000 1xEV-DO network will be described with reference to FIG. 1.

First, a method for supporting a pre-defined group call is performed by exchanging group information belonging to a subscriber when establishing / registering a session between a PTT server and a user terminal. This is the case with group information such as).

First, in step 100, the subscriber selects a desired group to attempt a group call, and then requests a call attempt by pressing a PTT button provided in the terminal. Then, in step 102, the terminal generates a call request message including the group information previously generated by the PTT server and the group creation / update and the like, and transmits the call request message on the access channel. The call request then takes the form of a DOS message. Accordingly, the RAN / PCF 20 that receives the DOS message from the terminal 10 sends a call request message to the PTT server 30 via the PDSN 40 through the A10 connection established for the terminal in step 104. ). Accordingly, the PTT server 30 receiving the call request message from the terminal 10 analyzes the message received in step 106b and transmits a call announcement message (CallAnnounce message) for requesting an incoming call to subscribers belonging to the group. Via 40, transmission is made to the destination RAN / PCF 50 in the form of a packet.

Meanwhile, in step 106b, the originating terminal 10 which has transmitted the call request message transmits a connection request / route update message on the access channel to establish a call.

In step 108, the PTT server 30 transmits a call announcement message to the called party RAN / PCF 50 via the PDSN 40 to the third terminal AT3 70 included in the group information. Step 108 may occur with step 106b described above. In addition, the PCF / RAN 50 of the third terminal 70 may be a different PCF / RAN than the second terminal 60. The receiving side RAN / PCF 50 which has received the call announcement message for the second terminal 60 from the PTT server 30 through the above process is controlled by the control channel (Control Channel) to the second terminal 60 in step 110a. Send the message via).

On the other hand, the originating side RAN / PCF 20 that receives the CR / RU message from the originating terminal 10 allocates resources for establishing a connection and includes the corresponding information in the traffic channel assignment message in step 110b. The solution is transmitted to the calling terminal 10. In this case, it is assumed that the originating terminal 10 is assigned MACIndex1.

On the other hand, the called party RAN / PCF 50 receiving the call announcement message for the third terminal 70 from the PTT server 30 sends the corresponding message on the control channel to the third terminal 70 in step 112. send.

Through the above process, an attempt is made for a call connection from the calling party to the called party. Next, the process after the attempt for call connection is made will be described below. Upon receiving the call announcement message, the second terminal 60 transmits a CallAnnAck message to the PCF / RAN 50 through an access channel in response to the message. In step 116, the RAN / PCF 50 receiving the call announcement response message from the second terminal 60 transmits the message to the PTT server 30 via the PDSN 40. In addition, in step 118a, the third terminal 70 receiving the call announcement message transmits the call announcement response message to the corresponding PCF / RAN 50 through the access channel in step 118a.

Meanwhile, the PTT server 30 receiving the call announcement response message from the second terminal 60 sends a call status message in step 118b to inform the calling terminal 10 that the called terminal has received / answered the call request. It transmits to the calling party RAN / PCF 20 via the PDSN 40. In addition, the RAN / PCF 50 receiving the call announcement response message from the third terminal 70 transmits the message to the PTT server 30 via the PDSN 40 in step 120a.

Meanwhile, the RAN / PCF 20 receiving the call status message from the PTT server 30 transmits the message to the first terminal 10. In this case, the call status message may be transmitted on a forward traffic channel or a control channel if a connection is established. If the message is transmitted on the traffic channel, it may have the form of RLP or DOS. On the other hand, when the message is transmitted on the control channel, it has a form of DOS.

In operation 130, the second terminal 60 transmits a CR / RU message for establishing a call to the RAN / PCF 50 on the access channel. In addition, the third terminal 70 transmits a CR / RU message for establishing a call to the RAN / PCF 50 through the access channel in the same manner as the second terminal 60. In this way, the RAN / PCF 50 that receives the CR / RU message from the second terminal 60 allocates resources for the connection in step 134a, and includes the corresponding information in a TCA message. To send). In this case, it is assumed that the second terminal 60 is assigned MACIndex2.

On the other hand, the subscriber of the calling terminal 10 receives a message indicating that the called party has answered and starts speaking when receiving a voice. In FIG. 1, the PTT server 30 does not show separate signaling for permission to speak to the calling terminal 10. Such permission to speak may be delivered using embedded signaling or embedded in a call status message. Then, the calling terminal 10 transmits a speech signal from the subscriber to the PTT server 30 through the RAN / PCF 20.

In addition, in step 138, the RAN / PCF 50 that receives the CR / RU message from the third terminal 70 allocates a resource for a connection and includes the corresponding information in a traffic channel assignment (TCA) message to transmit the third resource. Transmit to the terminal 70. In this case, it is assumed that the third terminal 70 is assigned an MACIndex.

On the other hand, the PTT server 30 that receives the chat signal from the calling terminal 10 transmits the chat signal to another terminal belonging to the group and sending a call guide response message to participate in the call. At this time, the PTT server 30 transmits through a call path set individually for each terminal. That is, the PTT server 30 transmits a media, which is a conversation signal, to the second terminal 60 in step 140, and transmits the media, which is a conversation signal, to the third terminal 70 in step 142. Such media transmission may be simultaneously transmitted even from different terminals. The media transmitted as described above is delivered to the PCF / RAN 50 in which the terminals are located. In FIG. 1, the media is illustrated in steps 144 and 146. In this case, the media delivered to each terminal is transmitted using the connection and MACIndex allocated to each terminal in the RAN / PCF of the terminal.

2 is a signal flow diagram for an ad hoc group call in a cdma2000 1 × EV-DO network. Hereinafter, a signal flow for an ed hog group call in the cdma2000 1xEV-DO network will be described with reference to FIG. 2. The ad hoc group call is a case where a user temporarily sets subscribers from a plurality of groups or not belonging to a specific group as a member of a group.

First, in step 200, the subscriber selects random subscribers and attempts to call the group by pressing the PTT button provided in the terminal 10. Then, in step 202, the originating terminal 10 transmits a call request message including information (e.g., User ID) of each of the called subscribers selected by the PTT server 30 and the user on the access channel. The call request message then takes the form of a DOS. In this way, the RAN / PCF 20 that has received the DOS message from the calling terminal 10 transmits to the PTT server 30 via the PDSN (not shown in FIG. 2) through the A10 connection established for the corresponding terminal in step 204. Send a call request message.

Through this process, the PTT server 30 receiving the call request message from the calling terminal 10 analyzes the message received in step 206b and sends a call announcement message (CallAnnounce message) for requesting an incoming call to each subscriber. The packet is transmitted to the destination RAN / PCF 50 in the form of a packet via 40). Meanwhile, in step 206a, the originating terminal 10 which has transmitted the call request message transmits a CR / RU message on the access channel to establish a call. After that, the PTT server 30 sends a call announcement message to the third terminal 70 included in the user information received from the originating terminal 10 via the PDSN 40 in step 208 through the destination side RAN / PCF ( 50). The process of transmitting a call announcement message to the called party RAN / PCF 50 to the third terminal 70 may occur simultaneously with step 206b. In addition, in FIG. 2, for convenience of description, it is assumed that the second terminal 60 and the third terminal 70, which are called terminals, are connected to the lower part of the same PCF / RAN 50.

As such, the called party RAN / PCF 50 that receives the call announcement message for the second terminal 60 from the PTT server 30 transmits the message to the second terminal 60 through the control channel in step 210a. . On the other hand, the originating side RAN / PCF 20 that receives the CR / RU from the originating terminal 10 allocates resources for connection establishment in step 210b and includes the corresponding information in a traffic channel assignment message to send the originating terminal ( To 10). In this case, it is assumed that the originating terminal 10 is assigned MACIndex1. The receiving side RAN / PCF 50 that receives the call announcement message for the third terminal 70 from the PTT server 30 transmits the corresponding message on the control channel to the third terminal 70 in step 212. In operation 214, the second terminal 60 receiving the call announcement message transmits a CallAnnAck message on the access channel in response to the corresponding message.

In step 216, the RAN / PCF 50 that receives the call announcement response message from the second terminal 60 transmits the message to the PTT server 30 via the PDSN 40. In addition, in operation 218a, the third terminal 70 receiving the call announcement message transmits a call announcement response message on the access channel in response to the corresponding message. Meanwhile, the PTT server 30 receiving the call announcement response message from the second terminal 60 sends a call status message to notify the calling terminal 10 that the called terminal has received / answered the call request in step 218b. It transmits to the calling party RAN / PCF 20 via the PDSN 40. In addition, the RAN / PCF 50 receiving the call announcement response message from the third terminal 70 transmits the message to the PTT server 30 via the PDSN 40 in step 220a. Meanwhile, the called side RAN / PCF 20 that receives the call status message from the PTT server 30 transmits the message to the calling terminal 10 in step 220b. The call status message can then be sent on the forward traffic channel or on the control channel if the connection was not established. In this case, when the message is transmitted on the traffic channel, it may have a form of RLP or DOS. On the other hand, when transmitted over the control channel, it has a form of DOS.

In operation 230, the second terminal 60 transmits a CR / RU message for establishing a call to the RAN / PCF 50 on the access channel. In operation 232, the third terminal 70 transmits a CR / RU message for establishing a call to the RAN / PCF 50 on the access channel.

In this way, the RAN / PCF 50 that receives the CR / RU message from the second terminal 60 allocates resources for the connection in step 234a, and includes the corresponding information in a traffic channel assignment (TCA) message. Transmit to two terminals (60). In this case, it is assumed that the second terminal 60 is assigned MACIndex2. On the other hand, the originating subscriber receives a message that the called party has answered and starts speaking when receiving a voice. In FIG. 2, the PTT server 30 does not show separate signaling for permission to speak to the calling terminal 10. In this way, the permission to speak may be delivered by using separate signaling or embedded in a call status message.

As such, when the caller obtains the right to speak, the subscriber of the calling terminal 10 may speak in step 234b. Accordingly, the originating terminal 10 transmits a speech signal from the subscriber to the PTT server 30 via the RAN / PCF 20 in step 236.

On the other hand, the RAN / PCF 50 that receives the CR / RU from the third terminal 70 allocates resources for the connection in step 238 and includes the corresponding information in the TCA message to transmit to the third terminal 70. . In this case, it is assumed that the third terminal 70 is assigned an MACIndex.

The PTT server 30 receiving the conversation signal from the first terminal 10 transmits the conversation signal to other terminals participating in the call by transmitting a call guide response message belonging to the group in step 240. At this time, the PTT server 30 transmits through a call path set individually for each terminal. At this point, the PTT server 30 transmits media to the second terminal 60. In addition, the PTT server 30 transmits the media to the third terminal 70 in step 242. This step may occur simultaneously with step 240 described above. However, the PTT server 30 is shown in different stages to show that the media is individually transmitted to each terminal.

For the media received from the PTT server 30 for the second terminal 60, the RAN / PCF 50 uses the MACIndex and the connection assigned to the second terminal 60 in step 244 to the second terminal 60. Transfer media to In addition, for the media received from the PTT server 30 with respect to the third terminal 70, the RAN / PCF 50 uses the MACIndex and the connection allocated to the third terminal 70 in step 246. Transfer media to Steps 244 and 246 may occur simultaneously.

As described above, the method for supporting a group call for a PTT subscriber in the cdma2000 1xEV-DO network may be provided by setting N 1: 1 calls. In other words, if a number of 1: 1 subscribers are connected in groups, PTT service is provided. When providing a PTT service in this way, N call instances are required to provide one group call to N subscribers. That is, there is one call instance for every N subscribers. And since each subscriber transmits voice signals in VoIP format, each terminal should have an IP address and a port. In addition, an over-the-air traffic channel must be individually allocated to each subscriber station for communication in the wireless channel.

As such, call instances, IP addresses, and ports assigned to each individual become resources of the network, and the radio traffic channel becomes radio resources allocated by the base station. In addition, when one radio traffic channel is allocated, signaling resources for call control must be allocated. Therefore, when supporting a group call, the amount of data actually transmitted is small, but communication is only possible when wired resources and radio resources are allocated to all terminals in the same manner as a terminal receiving a high capacity data service.

However, when wired resources and wireless resources are allocated as described above, a problem arises in that many subscribers cannot be accommodated due to limited resources. In addition, when a large amount of resources are allocated to a PTT service that transmits a very small amount of data, the overall throughput of the system is degraded. In addition, media copy operation increases according to the size of a group, which requires additional processing resources, thus limiting the number of subscribers that can participate in the group call, signaling overhead and media processing. System limitations may occur due to performance and the like. That is, the biggest disadvantage of the PTT group call of the proposed method up to now is that the individual call instances are aggregated and serviced, so that the efficient use of resources is not possible, and the control and traffic overheads for generating multiple independent call instances ( is a lot of control / traffic overhead).

Accordingly, an object of the present invention is to provide a method for reducing a call instance when providing a group call of a PTT service in a mobile communication system.

Another object of the present invention is to provide a method for reducing the overhead of a PTT service in a mobile communication system.

It is another object of the present invention to provide a PTT service method that can efficiently use limited resources in a mobile communication system.

A method according to the first embodiment of the present invention for achieving the above object is a method for providing a PTT service to a terminal of a preset group in a mobile communication system, the PTT server from a predetermined terminal of the preset group Transmitting a call announcement message to a called party PCF / RAN where the remaining terminals of the group are located when a call request message requesting communication with the terminals in the group is received, and each called party PCF receiving the call announcement message; / RANs transmits a call announcement message indicating a group to the terminals in the preset group located in its area, and forwards it to the PTT server upon receiving a response thereto, and the PTT server transmits the called party PCF / When the response message is received from the RANs, the call status message is generated by generating a call status message for each terminal in the preset group. Transmitting to the calling PCF / RAN where the terminal is located; and sending, by the calling PCF / RAN, a call setup completion to the calling terminal by using a shared traffic channel assignment message, providing the PTT service; The side PCF / RANs include a process of allocating a shared traffic channel assignment message to terminals located in the called party PCF / RAN when receiving a call request / route update message with the terminals.

A method according to a second embodiment of the present invention for achieving the above object, as a method for providing a PTT service to the calling terminal requesting communication with a group of terminals not preset in the mobile communication system, PTT server When a call request message requesting communication with predetermined terminals of the group requested by the originating terminal is received, the call guide message is transmitted to the called party PCF / RAN where the terminals of the requested group are located; Each called party PCF / RAN receiving the message transmits a call guide message indicating a group to the terminals designated by the calling terminal among the terminals located within its own area, and transmits it to the PTT server upon receiving the response. Process and the PTT server generates a call status message for each terminal upon receiving a response message from the called party PCF / RANs. Transmitting to the calling PCF / RAN where the calling terminal is located; and sending the completion of call setup to the calling terminal by using a shared traffic channel assignment message and notifying call status of other terminals; The receiving PCF / RANs allocate and notify the multiple access terminal identifiers to the corresponding terminals when receiving the Multiple Access Terminal Identifier (MATI) request message from the terminals, and the destination PCF / RANs receive information from the receiving terminals. And allocating a shared traffic channel assignment message to terminals located in the called party's PCF / RAN when a call request / route update message is received.

The method according to the third embodiment of the present invention for achieving the above objects is a method for providing a PTT service to a calling terminal requesting communication with a group of terminals not preset in the mobile communication system. When the server receives a call request message requesting communication with predetermined terminals of the group requested by the calling terminal, the server transmits a call announcement message to the called PDSN using multiple IP addresses of the PDSN where the terminals of the requested group are located. And the called PDSN transmits a call announcement message to a called party PCF / RAN, and each called PCF / RAN receiving the call announcement message by the calling terminal among terminals located within its own area. Transmitting a call announcement message indicating a group to designated terminals and transmitting the call announcement message to the PTT server when a response is received; The PDSN generates and transmits a group assignment message to the calling PCF / RAN, and the PTT server generates a call status message for each terminal when receiving a response message from the called PCF / RAN. Transmitting to a calling party PCF / RAN located, the calling party PCF / RAN using the shared traffic channel assignment message to transmit a call setup completion to the calling terminal and informing the call status of other terminals; When PCF / RANs receive a Multiple Access Terminal Identifier (MATI) request message from the terminals, the PCF / RANs allocate and notify the multiple access terminal identifiers to the corresponding terminals, and the called PCF / RANs make a call request / Allocating a shared channel by allocating a shared traffic channel assignment message to terminals located in the called party's PCF / RAN when a route update message is received. Includes chisels.

Hereinafter, the detailed operation and structure of the present invention will be described in detail 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.

First, nodes to be described according to the present invention in a mobile communication system include a PTT server, a packet data service node (hereinafter referred to as PDSN), a packet control function (hereinafter referred to as a PCF), Radio access network (hereinafter referred to as RAN) and a terminal (hereinafter referred to as AT). The configuration of such a network will be described in more detail in the following drawings.

Next, the basic concept according to the present invention will be described first, and each embodiment will be described with reference to the accompanying drawings.

The group call support method according to the present invention depends on the group type. Group types supported by the present invention are classified into two types as follows. The first group type is a predefined group in which any group member is already registered and the corresponding information is shared between the PTT server and the group member. The second group type is an ad hoc group that is created temporarily and accidentally by any subscriber.

The predefined group, which is the first group type, shares group information with a PTT server among each group member, and includes information for supporting a group call and a cell to which the subscriber belongs in a wireless network in a session. Perform additional procedures.

And for the second group type ad hoc group, we propose two methods as follows. The first scheme is to guarantee IP transparency to the RAN, but additionally requires over-the-air signaling to provide group call intelligence in the RAN. The second method of the ad hoc group does not guarantee IP transparency to the RAN, but minimizes control signaling for the group call.

3 is a signal flowchart when a predefined group call is supported in a cdma2000 1xEV-DO network according to the present invention. Hereinafter, a signal flow diagram when a predefined group call is supported in the cdma2000 1xEV-DO network according to the present invention will be described in detail.

The first terminal 310 and the second terminal 360 each of the group information they have as a result of group creation / update with the PTT server 330 negotiate an HRPD session or session with the corresponding RAN. The group information is transmitted during the session update process. The RAN allocates MATI to the first terminal 310 and the second terminal 360 belonging to the group. In this case, if the location of the first terminal 310 and the second terminal 360 is in an area (eg, subnet) in which the RAN manages the first terminal 310 in the same manner, the same MATI is used. Can be used. This process is illustrated in FIG. 3 as 400a and 400b steps. In operation 402, the third terminal 370 performs the same operation performed by the first terminal 310 and the second terminal 360 with the RAN corresponding to the third terminal 370.

Thereafter, when the user of the first terminal 310 presses the PTT button provided in the first terminal 310 in step 404 for the group call origination, the first terminal 310 receives the MATI address in step 406. The call request message including the group information is transmitted to the RAN / PCF 320 using. At this time, CallRequest uses DOS.

Then, the RAN / PCF 320 transmits the call request message received from the first terminal 310 to the PTT server 330 in step 408. In this case, the RAN / PCF 320 may use an R-P connection to the calling terminal 310 or may use a separate R-P connection for the corresponding group call. In FIG. 3, it is assumed that a separate R-P connection for the group is used. The PTT server 330 that receives the group call request from the originating terminal 310 via the PDSN (not shown in FIG. 3) receives the PDSN IP address as an area of the PDSN 340 where the called terminal is located in step 410b. A CallAnnounce message is transmitted to a destination address. In this case, the call announcement message includes multicast IP address and multicast port allocation information along with group information of the called terminal. The originating terminal 310 which transmits the call request message transmits connection request / route update messages (CC / RU) to establish a connection in step 410a.

In addition, the PDSN 340 receiving the call announcement message from the PTT server 330 transmits a group call request to the RAN / PCF 350 where the called terminal is located by using the A11-CallAnnounce message. At this time, the PDSN 340 transmits one A11-CallAnnounce message to the RAN / PCF 350 where one or more destination terminals are located. For this purpose, the PDSN 340 analyzes the call announcement message received from the PTT server 330. It should be possible to determine the position of each terminal included in the group. This is a matter that PDSN 340 is additionally provided according to the present invention. This feature of the PDSN can be used as a resource for efficient resource utilization and call setup.

In addition, the RAN / PCF 350 receiving the A11-CallAnnounce message from the PDSN 340 transmits a CallAnnounce message with the MATI address corresponding to the group in step 414b. The call announcement message uses DOS. In addition, the originating side RAN / PCF 320 receiving the CR / RU from the originating terminal 310 performs resource allocation for the terminal in step 414a and transmits the resource to the calling terminal 310. In this case, the RAN / PCF 320 may allocate a common MACIndex or assign a unicast MACIndex based on an address type received from the calling terminal 310. When the one-way MACIndex is allocated, it can be switched to public by signaling between the RAN / PCF 320 and the originating terminal 310 if necessary, and the same method can be applied to the reverse case.

In operation 416, the second terminal 360 receiving the call announcement message transmits a call announcement response message on the access channel. In this case, the call guide response message uses DOS. In step 418, the RAN / PCF 350 receiving the call announcement response message from the second terminal 360 transmits the corresponding message to the PTT server 330 via the PDSN 340. In addition, the third terminal 370 receiving the call announcement message transmits the call announcement response message on the access channel in step 420b similarly to the second terminal 360. In this case, the call guide response message may use DOS. The PTT server 330 transmits the result of processing the call announcement response message received from the second terminal 360 to the calling terminal in step 420a. If the call continues, the PTT server 330 includes the multicast IP address and the multicast port information assigned to the group in the call status message.

As described above, the calling party RAN / PCF 320 receiving the call status message from the PTT server 330 transmits the call status message using UATI1, which is a one-way address assigned to the calling terminal 310 in step 422a. . In addition, the called party RAN / PCF 350 transmits the call announcement message received from the third terminal 370 to the PTT server 330 in step 422b.

In operation 424, the second terminal 360 transmits a CR / RU message for establishing a connection to the RAN / PCF 350. Upon receiving the CR / RU message from the second terminal 360, the RAN / PCF 350 performs R-P connection establishment for the corresponding group call in step 426. In this case, the called party RAN / PCF 350 may set an R-P connection for the corresponding group call in advance, or may set it when a request of the called terminal is received. 3 illustrates setting when a request is received from the terminal. As described above, the third terminal 370 transmits a CR / RU message for establishing a connection to the RAN / PCF 350 in step 428.

In addition, the originating terminal receiving the call status message from the PTT server 330 notifies the user (User) can start a conversation (speech) to start the transmission of the conversation signal. Then, the user performs a conversation in step 430, and the caller terminal 310 that receives the voice signal is configured with media information capable of transmitting a signal requested in the conversation through a channel, and then generated by the PTT server 330 in step 432a. Transfer the media. In this way, the PTT server 330 receiving the media from the calling terminal 310 proceeds to step 434 and performs the necessary appropriate operation and then transmits the media to the called party RAN / PCF 350. The receiving side RAN / PCF 350 receiving the media from the PTT server 330 transmits the media using the MACIndex allocated to the corresponding group call in step 436.

4 is a signal flow diagram for an ad hoc group call in a cdma2000 1xEV-DO network according to another embodiment of the present invention. As described above, in the present invention, two embodiments will be described with respect to the Ed hoc group call. 4 is a signal flow for an ed hog group call according to one of the two embodiments. Next, a first embodiment of the signal flow for the ed hog group call of the present invention will be described with reference to FIG. 4. The ed hoc group call is a case where a user temporarily sets subscribers from a plurality of arbitrary groups or members not belonging to a specific group as described above.

In step 500, the user selects the called subscriber information (eg, user ID) to be included in the Ed Hoc group call using a user interface (U / I) of the terminal 310, and is provided in the terminal 310. Pressing the PTT button starts an ed hog group call. At this time, it is assumed that the called subscriber included in the Ed Hoc group call is the second terminal 360 and the third terminal 370.

In step 502, the originating terminal 310 transmits a call request message including the second terminal 360 and the third terminal 370 to the RAN / PCF 320 through the access channel. At this time, the call request message has the above-described DOS type. In this manner, the RAN / PCF 320 that receives the call request message from the calling terminal 310 uses the A10 connection assigned to the calling terminal 310 in step 504 via the PDSN (not shown in FIG. 4). The message is sent to the server 330. The PTT server 330 receiving the call request message from the calling terminal 310 analyzes the corresponding message to create a new group, and makes a call request to the second terminal 360 and the third terminal 370, which are called terminals. To judge. In operation 506, the PTT server 330 may include a multicast IP address and a multicast port number for multicast traffic transmission together with the group ID generated by the second terminal 360. The call announcement message including the multicast port number is transmitted to the called party's RAN / PCF 350 via the PDSN 340.

The called party RAN / PCF 350 that receives the call announcement message for the second terminal 360 transmits the message on the control channel in step 508b. On the other hand, the PTT server 330 receiving the call request message from the originating terminal 310, GroupAssign message including the group information generated for the ad hoc (ad hoc group call) requested by the originating terminal in step 508a To transmit to the PCF / RNC 320 where the calling terminal 310 is located. In addition, the PTT server 330 receiving the call request message from the originating terminal 310 analyzes the message, creates a new group, and determines that the second terminal 360 and the third terminal 370 should make an incoming request. . The PTT server 330 first sends a call announcement message including a multicast IP address and a multicast port number for multicast traffic transmission together with the group ID generated by the third terminal 370 in step 510b. The PDSN 340 transmits to the called party RAN / PCF 350. Meanwhile, the originating RAN / PCF 320 that receives the GroupAssign message from the PTT server 330 transmits the corresponding message to the originating terminal 310 through the control channel in step 510a.

Then, the called party RAN / PCF 350 that receives the call announcement message for the third terminal 370 transmits the message to the third terminal 370 through the control channel in step 512.

In addition, in step 514, the originating terminal 310 transmits a CR / RU message to the RAN / PCF 320 through an access channel to establish a call.

In operation 516, the second terminal 360 receiving the call announcement message transmits the call announcement response message to the RAN / PCF 350 through the access channel. Upon receiving the call announcement response message from the second terminal 360, the RAN / PCF 350 transmits the message to the PTT server 330 via the PDSN 340 in step 518b. In this case, the originating side RAN / PCF 320 receiving the connection establishment request from the originating terminal 310 allocates resources to the originating terminal 310 in step 518a and includes the corresponding information in the traffic channel assignment message. Forward through 310 the control channel.

In addition, the third terminal 370 receiving the call announcement message transmits the call announcement response message to the RAN / PCF 350 through the access channel in step 520b. Meanwhile, the PTT server 330 that receives the call announcement response message from the second terminal 360 sends a PDSN 340 a call status message to notify the calling terminal 310 that the called party has received / answered the call request in step 520a. ) To the calling party RAN / PCF 350. Upon receiving the call announcement response message from the third terminal 370, the RAN / PCF 350 transmits the message to the PTT server 330 via the PDSN 340 in step 522b. Meanwhile, the originating side RAN / PCF 350 transmits the call state message received from the PTT server 330 to the originating terminal 310 on the control channel in step 522a.

Meanwhile, in operation 524b, the second terminal 360 sends a MATIRequest message including group information, a multicast IP address, and a multicast port number to request a multicast access terminal identifier for the corresponding group call. 350). On the other hand, the calling party receives the call status message that the called party answered in step 524a, and starts a speech after being authorized to speak. In FIG. 4, separate signaling for permission to speak is not illustrated. Depending on the type of protocol for controlling the talk right, the call status message may be delivered in an in-band format, or an out-of-band format using separate signaling. It can also be delivered.

Therefore, in step 526, the originating terminal 310 transmits a MATI request message to the RAN / PCF 350 for the MATI request for the corresponding group call. At this time, the MIT request message is transmitted on the reverse traffic if the connection setup is completed, otherwise it is transmitted on the access channel. The group information, the multicast IP address, and the multicast port number included in the MATI request message are used by the RAN / PCF 320 to map resources such as MATI and MACIndex managed by the RAN / PCF 320.

In operation 528, the third terminal 370 sends a MATI request message including group information, a multicast IP address, and a multicast port number to request an identifier of the multicast terminal for the corresponding group call. To send.

In addition, in step 534, the RAN / PCF 320 receiving the MATI request message from the calling terminal 310 allocates MATI and transmits a MATI assignment message including the corresponding information to the first terminal 310. At this time, the MATI assignment message is transmitted on the forward traffic channel if the connection is established, otherwise on the control channel. In addition, it is assumed that the calling terminal 310 has been assigned the first MATI (MATI1). However, the first MATI allocated by the calling party RAN / PCF 320 to the calling terminal 310 may be the same as or different from the MATI allocated by the called party. If the calling party RAN / PCF 320 and the called party RAN / PCF 350 are the same, they have the same MATI ID and the same value. Otherwise, the calling party RAN / PCF 320 may have different MATI IDs or even different IDs. Through the above-described process, the RAN / PCF 350 that receives the MATI request message from the second terminal 360 allocates the MATI and transmits the MATI allocation message including the corresponding information to the second terminal 360 in step 532. To send. At this time, if the connection is established when the MATI assignment message is transmitted, it is transmitted on the forward traffic channel, otherwise it is transmitted on the control channel.

In addition, the calling party RAN / PCF 320 determines that the calling terminal 310 participates in the group call in step 534, allocates a new MACIndex to the corresponding terminal for use in the group call, and includes a common TCA message (SharedTCA). message). In this case, the RAN / PCF 320 may release the MACIndex previously assigned to the calling terminal 310. In case of not releasing, for example, the calling terminal 310 may be performing a separate unicast call together with the group call.

On the other hand, the RAN / PCF 350 that receives the MATI request message from the third terminal 360 allocates the MATI in step 536 and transmits the MATI allocation message including the corresponding information to the third terminal 370. At this time, the MATI assignment message is transmitted on the Forward Traffic Channel if the connection is established, otherwise on the Control Channel. The originating terminal 310 transmits the media from the user to the PTT server 330 via the PDSN in step 538. In this case, if the calling party 310 is the only subscriber that participated in the corresponding group call in the calling party RAN / PCF 320, the media is delivered to the calling terminal 310 using the previously assigned A10 connection, and then another subscriber who participated in the group. Can also set up a new A10 connection for use in group calls when it moves into the RAN / PCF area. Alternatively, the originating side RAN / PCF 320 may establish a new A10 connection for the group call even if the originating terminal 310 is the only participant in the corresponding area, and may use it for media transmission. In FIG. 4, it is assumed that the RAN / PCF 320 transmits media using an A10 connection previously established for the calling terminal 310. Therefore, the procedure for setting up an A10 connection to use for a separate group call is not shown.

Meanwhile, the second terminal 360 transmits a CR / RU message for establishing a connection to the RAN / PCF 350 using the MATI2 allocated in step 540. In this case, the CR / RU message may be transmitted prior to transmitting the MATI request message as performed by the originating terminal 310 to allocate the one-way resource first and then the resource for the group call. Unlike at the called party, the originating party performs connection setup first in order to give a user a faster speaking opportunity.

The RAN / PCF 350, which is requested to establish a connection for the group call from the second terminal 360, performs the A10 connection for the group call with the PDSN 340. Then or simultaneously with the second terminal 360, the third terminal 370 transmits a CR / RU message for connection establishment to the RAN / PCF 350 using the assigned MATI2. In this case, the CR / RU message may be transmitted prior to transmitting the MATI request message as performed by the originating terminal 310 to allocate one-way resources first and then allocate resources for use in the group call. Unlike on the called side, the originating side first establishes a connection to give the user a faster speaking opportunity as described above. In FIG. 4, for convenience of description, although the CR / RU message is transmitted first by the second terminal 360 and the third terminal 370 is transmitted later, it may be simultaneously performed.

The PTT server 330 receiving the media from the calling terminal 310 transmits the media to the called party RAN / PCF 350 using the multicast IP address and the multicast port number assigned to the corresponding group call. In this case, the PTT server 330 does not need to perform a media copy operation for the same RAN / PCF area.

In step 548, the RAN / PCF 350, which is requested to establish a connection from the second terminal 360 and the third terminal 370, allocates a shared resource for the corresponding group call and includes a shared TCA message (SharedTCA). message) is transmitted to the second terminal 360 and the third terminal 370 using the MATI address. In this case, it is assumed that the second terminal 360 and the third terminal 370 are assigned MACIndex2. After receiving the media from the PTT server 330, the called party RAN / PCF 350 delivers the media to the second terminal 360 and the third terminal 370 at the same time using the shared resources.

5 is a signal flow diagram for an ad hoc group call in a cdma2000 1xEV-DO network according to another embodiment of the present invention. As described above, in the present invention, two embodiments of the Ed Hoc group call will be described, and FIG. 5 is a signal flow for the Ed Hoc group call according to the second method. Next, with reference to FIG. 5, a second embodiment of the signal flow for the Ed Hoc group call of the present invention will be described.

The user of the calling terminal 310 selects the called subscriber information (e.g., user ID) to be included in the ed hog group call and presses the PTT button provided in the calling terminal 310 to start the group call request. This group call request is illustrated in step 600 in FIG. At this time, it is assumed that the called subscriber included in the Ed Hoc group call is the second terminal 360 and the third terminal 370. In this way, the originating terminal 310 transmits a call request message including the second terminal 360 and the third terminal to the RAN / PCF 320 through the access channel. At this time, the call request message has a DOS type. Upon receiving the call request message from the first terminal 310, the RAN / PCF 320 uses the A10 connection assigned to the calling terminal 310 in step 604 via a PDSN (not shown in FIG. 5) via a PSN server. The message is sent to 330.

The PTT server 330 receiving the call request from the originating terminal 310 analyzes the corresponding message to create a new group, and determines that the second terminal 360 and the third terminal 370 should make an incoming request. Based on this determination, the PTT server 330 transmits the multicast traffic together with the group ID generated by the second terminal 360 in step 606b, including the multicast IP address and the multicast port number. The call announcement message is transmitted to the PDSN 340. Meanwhile, when this process is performed, the originating terminal 310 transmits a CR / RU message on the access channel to establish a connection in step 606a.

After receiving the call announcement message including the group information from the PTT server 330, the PDSN 340 analyzes the message in step 608, extracts information such as a multicast IP address, a multicast port number, and then refers to the group A10 to be set later. The message received from the PTT server 330 is transmitted to the RAN / PCF 350 using an A11-CallAnnounce message. Upon receiving the A11 call announcement message from the PDSN 340, the called party RAN / PCF 350 analyzes the corresponding message in step 610c, allocates a MATI to be used for the group, and sends the call announcement message including the call announcement message to the second terminal 360. send. In this case, the transmission order to the second terminal 360 or the third terminal 370 may be determined by the RAN / PCF 350.

Meanwhile, the PTT server 330 transmits a group assignment message including the group information generated for the calling terminal 310 to the PDSN 340. In addition, the originating RAN / PCF 320 allocates resources in response to the connection establishment request from the originating terminal 310 in step 610a, and transmits a TCA message including information on the control channel. In this case, it is assumed that the RAN / PCF 320 allocates MACIndex4 to the calling terminal 310. In addition, although the RAN / PCF 320 generates a MATI for the group, the corresponding MATI information is not yet shared with the second terminal 360 and the third terminal 370. 360) and third terminal 370 must be delivered separately using respective addresses.

Upon receiving the A11 call announcement message from the PDSN 340, the called party RAN / PCF 350 analyzes the message in step 612b, allocates a MATI to be used for the group, and sends the call announcement message including the call announcement message to the third terminal 370. send. In this case, the transmission order to the second terminal 360 or the third terminal 370 may be determined by the RAN / PCF 350. On the other hand, PDSN (340) receiving the group creation information for the originating terminal 310 from the PTT server 330 analyzes the information in step 612a to extract the multicast IP address, multicast port number and refer to the group connection to be set later This information is transmitted to the RAN / PCF 320 using an A11 group assignment message.

Upon receiving the A11 group assignment message, the RAN / PCF 320 analyzes the information in step 614, allocates a MATI for the corresponding group, and transmits a group assignment message including the information. The group assignment message is then sent on the forward traffic channel if a connection is established, otherwise it is sent on the control channel. In FIG. 5, since the connection setup is made, the transmission on the forward traffic channel is illustrated.

In operation 616, the second terminal 360 receiving the call announcement message generates a call announcement response message and transmits the call announcement response message on the access channel. In this case, the second terminal 360 may use UATI or may use a newly allocated MATI. As such, the RAN / PCF 320 receiving the call announcement response message from the second terminal 360 transmits the message to the PTT server 330 via the PDSN 340 in step 618b. On the other hand, the RAN / PCF 320, which has been requested to establish a connection to the calling terminal 310, determines that the terminal has participated in the group call in step 618a, allocates shared resources and sends a shared TCA message including the same to the calling terminal 310. send.

Upon receiving the call announcement message, the third terminal 360 transmits the call announcement response message on the access channel in response to the call announcement message in step 620b. In this case, the third terminal 360 may use UATI or may use a newly allocated MATI. Meanwhile, the PTT server 330 receiving the call announcement response message from the second terminal 360 sends the call status message via the PDSN to the RAN / PCF 320 to notify that the called party has received / answered the call request in step 620a. To send.

The second terminal 360 transmits a CR / RU message to the RAN / PCF 350 on the access channel in step 622b to establish a connection. In this case, the second terminal 360 makes a request using the MATI, and the RAN / PCF 350 that receives the request may start the shared resource allocation procedure by determining the resource request for the group call. Meanwhile, the RAN / PCF 320 that receives the call status message from the PTT server 330 to the calling terminal 310 transmits the message to the calling terminal 310 in step 622a. At this time, if the connection is established, the call status message is transmitted on the forward channel, and the call status message is transmitted on the control channel. In FIG. 5, since the connection is established, an example of transmission on the forward traffic channel is illustrated.

In step 624, the RAN / PCF 350 that receives the connection establishment request from the second terminal 360 performs the group call A10 connection establishment with the PDSN 340. In operation 626, the third terminal 370 transmits a CR / RU message to the RAN / PCF 350 through an access channel to establish a connection. In this case, the third terminal 370 makes a request using the MATI, and the RAN / PCF 350 that receives the request may start the shared resource allocation procedure by determining the resource request for the group call. Upon receiving the call announcement response message from the third terminal 370, the RAN / PCF 350 transmits the message to the PTT server 330 via the PDSN 340 in step 628. In step 630, the RAN / PCF 350 that receives the connection establishment request from the second terminal 360 and the third terminal 370 allocates a shared resource and sends a shared TCA message including information on the group to which the corresponding UE belongs. It transmits to the second terminal 360 and the third terminal 370 using the MATI assigned to.

After this process, the user of the calling terminal 310 starts a speech. The user may start speaking after being authorized to speak. Signaling for permission to speak to the calling terminal is not shown in FIG. 5. The permission to speak may be supported in an in-band or out-of-band format according to a protocol used for the control of the voice. FIG. 5 illustrates an in-band signaling format in which a talk right is allowed simultaneously with a call state.

The originating terminal 9310 transmits the media from the user to the PTT server 330 in step 634. In this case, the media may be delivered using an A10 connection previously assigned to the calling terminal 310 or may be delivered using a newly assigned group A10 connection for the corresponding group. In FIG. 5, it is assumed that the resource is previously transmitted using A10. In addition, the RAN / PCF / PDSN may establish a new A10 connection at the time when the subscriber joining the group enters the service area, or may set up from the beginning. In FIG. 5, since only the originating terminal 310 is initially located in the service area, common resources are assumed to be allocated later when necessary.

In step 363, the PTT server 330 receiving the media from the calling terminal 310 transmits the media to the called party's RAN / PCF 350 using the multicast IP address and the multicast port number assigned to the corresponding group. In this case, the PTT server 330 does not need to perform a media copy operation on the same RAN / PCF area. The RAN / PCF 350 receiving the media from the PTT server 330 simultaneously transmits the media to the second terminal 360 and the third terminal 370 using the shared resources allocated to the group.

As described above, the PTT group call support scheme proposed in the present invention provides a large benefit to the operator by providing a limited benefit to the predefined group and the ad hoc group and provides a faster PTT service to the subscriber. There is an advantage to this.

Claims (7)

In the method for providing a PTT service to a terminal of a preset group in a mobile communication system, Transmitting, by the PTT server, a call guide message to a called party PCF / RAN where the remaining terminals of the group are located when a call request message for requesting communication with the terminals in the group is received from the predetermined terminal of the preset group; Each called party PCF / RAN receiving the call announcement message transmits a call announcement message indicating a group to terminals in the preset group located in its area and delivers it to the PTT server when a response is received. and, When the PTT server receives the response message from the called PCF / RAN, generating a call status message for each of the terminals in the preset group, and transmitting the call status message to the calling PCF / RAN where the calling terminal is located; The calling PCF / RAN provides a PTT service by transmitting a call setup completion to the calling terminal by using a shared traffic channel assignment message; The called PCF / RANs may assign a shared channel by allocating a shared traffic channel assignment message to terminals located in the called PCF / RAN when receiving a call request / route update message with the terminals. Said method. The method of claim 1, And the calling party PCF / RAN transmits a voice acquiring in the call status message. The method of claim 1, The calling PCF / RAN further comprises the step of informing the calling terminal of the acquisition of the voice through a predetermined predetermined signaling. A method for providing a PTT service to a calling terminal requesting communication with a group of terminals not preset in a mobile communication system, When the PTT server receives a call request message requesting communication with predetermined terminals of the group requested by the originating terminal, the PTT server transmits a call announcement message to the called party PCF / RAN where the terminals of the requested group are located; Each called party PCF / RAN receiving the call announcement message transmits a call announcement message indicating a group to the terminals designated by the calling terminal among the terminals located within its own area, and upon receiving the response, the PTT server. The process of The PTT server generates a call status message for each terminal when receiving a response message from the destination PCF / RAN and delivers to the calling PCF / RAN where the calling terminal is located; The calling PCF / RAN is configured to deliver a call setup completion to the calling terminal by using a shared traffic channel assignment message and to notify call status of other terminals; The destination PCF / RANs allocate and notify the multiple access terminal identifiers to the corresponding terminals when receiving the multiple access terminal identifier (MATI) request message from the terminals; The called PCF / RANs include a process of assigning a shared channel by allocating a shared traffic channel assignment message to terminals located in the called PCF / RAN when a call request / route update message is received from called terminals. Said method. The method of claim 4, wherein And the calling party PCF / RAN transmits a voice acquiring in the call status message. The method of claim 4, wherein The calling PCF / RAN further comprises the step of informing the calling terminal of the acquisition of the voice through a predetermined predetermined signaling. A method for providing a PTT service to a calling terminal requesting communication with a group of terminals not preset in a mobile communication system, When a PTT server receives a call request message requesting communication with predetermined terminals of a group requested by the originating terminal, the PTT server sends a call announcement message to the called PDSN using multiple IP addresses of the PDSN where the terminals of the requested group are located. Conveying process, The called PDSN transmits a call announcement message to the called PCF / RAN; Each called party PCF / RAN receiving the call announcement message transmits a call announcement message indicating a group to the terminals designated by the calling terminal among the terminals located within its own area, and upon receiving the response, the PTT server. The process of The called PDSN generates and delivers a group assignment message to the calling PCF / RAN; The PTT server generates a call status message for each terminal when receiving a response message from the destination PCF / RAN and delivers to the calling PCF / RAN where the calling terminal is located; The calling PCF / RAN is configured to deliver a call setup completion to the calling terminal by using a shared traffic channel assignment message and to notify call status of other terminals; The destination PCF / RANs allocate and notify the multiple access terminal identifiers to the corresponding terminals when receiving the multiple access terminal identifier (MATI) request message from the terminals; The called PCF / RANs include a process of assigning a shared channel by allocating a shared traffic channel assignment message to terminals located in the called PCF / RAN when a call request / route update message is received from called terminals. Said method.

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