KR101085063B1 - Group communication method in media server system with distributed structure - Google Patents

Abstract

The present invention relates to a group communication method in a media server system having a distributed structure, wherein a plurality of distributed media servers maintain session synchronization so that large-scale geographically distributed access terminals can be serviced in real time without loss of quality on the same session. It has a distributed structure to handle distributed access terminals on a large scale, and to provide group communication with quality suitable for the corresponding group communication environment when access terminals existing in different group communication environments perform group communication. A group communication method in a media server system is provided.

To this end, the present invention provides a group communication method in a media server, in which the terminal and the group communication environment information is registered in the terminal list corresponding to the session object and notified to the access management server as the session object requested from the terminal exists. step; Checking whether the session object exists in another media server as the session object requested from the terminal does not exist; If present, accessing the other media server and performing a group communication preprocessing step to notify the access management server; Generating a session object if not present and registering the terminal and group communication environment information in a corresponding terminal list and notifying the access management server; And a group communication processing step of processing group communication between access terminals existing in different group communication environments through a corresponding session object on the same session.

Internet broadcasting, group communication environment information, dual streaming, clustering, video conferencing, distance education

Description

GROUP COMMUNICATION METHOD IN MEDIA SERVER SYSTEM WITH DISTRIBUTED STRUCTURE}

The present invention relates to a group communication method in a media server system having a distributed structure, and more particularly, a plurality of distributed media servers are provided so that a large number of locally distributed access terminals can be serviced in real time without loss of quality in the same session. In order to be able to handle largely distributed access terminals while maintaining session synchronization, and to provide group communication with a quality suitable for the corresponding group communication environment when access terminals existing in different group communication environments perform group communication, A group communication method in a media server system having a distributed structure.

In order to enable two-way group communication or two-way broadcasting in the same session, while maintaining a quality that meets each resource condition among large-scale distributed terminals having a large difference in bandwidth and performance on an Internet Protocol (IP) network, a plurality of media servers Communication for synchronizing the same session and operation of a connection management server for connecting a large media terminal to an arbitrary media server for optimal service.

In addition, in order for distributed terminals to provide intercommunication and two-way broadcasting services on a network while maintaining a quality corresponding to each resource, a special transmission scheme and a server clustering structure are required.

The conventional video conferencing method is implemented based on the performance of the MCU or the performance of the server to provide high quality communication while maintaining bidirectionality for the users who communicate on the same session. As a result, it was difficult to process large-scale video conferences.

In addition, the conventional video conferencing method has a problem that bidirectional communication is impossible on a large scale in the same session while maintaining a quality suitable for each environment in a group communication environment having a wide bandwidth and a high specification terminal and a group communication environment that is not. there was.

It is a problem of the present invention to solve the problems of the prior art as described above.

Accordingly, the present invention enables a large number of distributed media servers to handle large-scale distributed access terminals while maintaining session synchronization so that large-scale geographically distributed access terminals can be serviced in real time without loss of quality on the same session. To provide a group communication method in a media server system having a distributed structure, to provide group communication with a quality suitable for a corresponding group communication environment when access terminals existing in different group communication environments perform group communication. There is this.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a method of group communication in a terminal, the method comprising: accessing a connection management server set in a web server and receiving a media server list; Selecting and accessing an optimal media server from the provided media server list; And performing group communication with the access terminals existing in different group communication environments through the corresponding session object on the same session.

In addition, another method of the present invention for achieving the above object is, in the group communication method in the media server, the terminal and the group communication environment in the terminal list corresponding to the session object as the session object requested from the terminal exists Notifying the access management server after registering the information; Checking whether the session object exists in another media server as the session object requested from the terminal does not exist; If present, accessing the other media server and performing a group communication preprocessing step to notify the access management server; Generating a session object if not present and registering the terminal and group communication environment information in a corresponding terminal list and notifying the access management server; And a group communication processing step of processing group communication between access terminals existing in different group communication environments through a corresponding session object on the same session.

On the other hand, the present invention provides a terminal having a processor, a function of accessing a connection management server set in a web server and receiving a list of media servers; Selecting and accessing an optimal media server from the provided media server list; And a computer-readable recording medium having recorded thereon a program for realizing a function of performing group communication with access terminals existing in different group communication environments through a corresponding session object on the same session.

The present invention also provides a function of notifying the access management server after registering the terminal and the group communication environment information in the terminal list corresponding to the session object in the media server for providing the group communication. ; Determining whether the session object exists in another media server when the session object requested from the terminal does not exist; A function of notifying the access management server after performing the group communication preprocessing process by accessing the other media server if the check result exists; Generating a session object if not present and registering the terminal and group communication environment information in a corresponding terminal list and notifying the access management server; And a computer-readable recording medium having recorded thereon a program for realizing a function of processing group communication between access terminals in different group communication environments through a corresponding session object on the same session.

In addition, the present invention provides a high-quality large-scale two-way group communication and high-quality two-way Internet broadcasting by processing a large number of users through server clustering, and reduce network traffic through network distribution and dual streaming transmission and reception.

The present invention is capable of receiving a high-definition video and a low-resolution video capable of receiving HD-quality high-definition video through a real-time video dual encoding scheme having different resolutions, frame rates per second, and bandwidth values, and dual streaming transmission. By allowing the terminal to perform bidirectional communication and broadcasting in the same session, it is possible to efficiently use the network bandwidth and the CPU of the terminal while maintaining a stable high quality video, and to increase the network traffic of various transmitting and receiving terminals locally. Group communication and broadcasting are possible in real time among a plurality of distributed terminals.

That is, in the present invention, a large number of distributed media servers process largely distributed access terminals while maintaining session synchronization, so that large-scale geographically distributed access terminals can be serviced in real time without loss of quality on the same session. The terminal with good network bandwidth and excellent CPU performance enables high-quality (HD-class) multimedia communication for its own resources, and enables seamless multimedia communication with quality that is not high-quality due to lack of resources. Let's do it.

On the other hand, large-scale group communication in the present invention, remote seminars, teleconferences, distance learning solutions, interactive multimedia broadcasting, panel video conferencing relay, large-scale real-time interactive education, home shopping, commerce (home shopping, auction), entertainment and the like.

Here, the group refers to a network connection state in which terminals belonging to the same or different networks locally can communicate with each other in real time on an IP (Internet Protocol) network.

As described above, the present invention allows a large number of distributed media servers to handle large-scale distributed access terminals while maintaining session synchronization so that large-scale locally distributed access terminals can be serviced in real time without loss of quality on the same session. In addition, when the access terminals existing in different group communication environments perform group communication, there is an effect of providing group communication with a quality suitable for the corresponding group communication environment.

In addition, the present invention implements high-quality large-scale group communication or two-way broadcasting by clustering of media servers distributed in various networks and dual streaming, so that the groups having good bandwidth and terminal performance and the groups having low bandwidth and terminal performance are mutually effective. It is possible to receive stable service while maintaining the appropriate quality for the resources of the company, and is applied to two-way distance education suitable for resource situation, entertainment requiring two-way event event relaying, two-way seminar relaying, public field for disaster response, two-way home shopping, etc. This has the effect of enabling large number of visitor processing in session.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary view of a media server system having a distributed structure to which the present invention is applied.

As shown in FIG. 1, a media server system having a distributed structure to which the present invention is applied includes a database 40 storing session information and connection management server information, session information corresponding to a session requested from a terminal, and a connection. Web server 30 for providing management server information, and manages the list of media servers, the connection management server for updating the list of media servers, the terminal list corresponding to each session object of each media server, and the media server list (Connection Management Server) 20 creates / removes a session object, updates a terminal list and a media server list corresponding to each session object, and performs group communication with terminals connected to the same session through the session object. At least one media server (Data Transferring Server) (11, 12, 13) for providing.

Here, the first media server 11 processes the group communication between the dual terminal 1 101 and the dual terminal 2 102 through session 1, and the dual terminal 6 106 and the single terminal 7 107 through session 2. Handles group communication.

Also, the second media server 12 processes group communication between the single terminal 3 103 and the single terminal 4 104 through session 1.

In addition, the third media server 13 processes the group communication of the dual terminal 5 105 through session 1 and the group communication of the dual terminal 8 108 and the single terminal 9 109 through session 2. .

In this case, the dual terminal is a high-end terminal located in a channel environment capable of high-speed data transmission and reception, and dual transmission of high quality image data and low quality image data. Here, the high quality video data is data for other dual terminals, the low quality video data is data for a single terminal, and since the audio data and the text are not large in capacities, the representative image data is relatively large. . As a result, it is desirable to understand the video data in terms of audio data or text.

In addition, the single terminal is a low-end terminal located in a channel environment where high-speed data transmission and reception is impossible, and transmits single-quality video data.

Hereinafter, the components will be described in more detail.

First, the web server 30 is a server to which terminals are initially connected. The web server 30 is connected to a database 40 which contains login processing for user authentication, session-specific resources (resolution, frames per second, bandwidth), user accounts, and various setting data. It is in charge of connection processing.

The connection management server 20 is a server that manages connection of all terminals connected to the session, and reacts differently according to the connection type. Here, the connection type may include a case where a general user terminal accesses, a manager terminal accesses, or a media server accesses according to a user class.

The main role of the access management server 20 provides and maintains a role corresponding to providing a list of media servers for providing data transmission services to largely distributed terminals and information corresponding to a connection type.

Each media server 11, 12, 13 transmits all data generated in the session to the terminal connected to the media server and the other media server connected to the same session.

That is, each media server 11, 12, 13 relays the high resolution image data or the low resolution image data to the corresponding terminal according to the performance of the connected terminal and the channel environment in which the terminal is located, and the other media connected to the same session. The servers relay both high resolution image data and low resolution image data.

Hereinafter, referring to FIGS. 2 and 3, the relationship between the session list 21 managed by the access management server and the media server, the media server list 22 corresponding to each object, and the information in the terminal list 23 will be described. Let's look at it.

As shown in Fig. 2, two sessions (session 1, session 2) are being serviced by three media servers (a first media server, a second media server, a third media server). The state of the terminal being directly connected to the service is shown in Table 1 below.

That is, session 1 is supported by the first media server 11, the second media server 12, and the third media server 13, and the first media server 11 includes dual terminals 1 101 and dual. Terminal 2 102 is connected, single terminal 3 103 and single terminal 4 104 are connected to the second media server 12, and dual terminal 5 105 is connected to the third media server 13. Is connected and service is in progress.

In addition, session 2 is supported by the first media server 11 and the third media server 13, and the dual terminal 6 106 and the single terminal 7 107 are connected to the first media server 11. In addition, a dual terminal 8 108 and a single terminal 9 109 are connected to the third media server 13 to provide a service.

In this state, the access management server 20 may include a session list 21 including a session 1 object and a session 2 object, a media server list 22 including a first media server, a second media server, and a third media server, And dual terminal 1 (101), dual terminal 2 (102), single terminal 3 (103), single terminal 4 (104), dual terminal 5 (105), dual terminal 6 (106), single terminal 7 (107), The terminal list 23 including the dual terminal 8 108 and the single terminal 9 109 is maintained.

At this time, the relationship between the components in the session list 21, the media server list 22, and the terminal list 23 is shown as a structure of the session object, as shown in FIG.

4 illustrates the structure of the session object in each media server in this state. That is, information of the corresponding network among the terminal list directly connected to each media server, the media server list having information on other media servers maintaining the same session object, and the terminal list directly connected to each media server (for example, Network bandwidth), and other additional session related information.

As shown in FIG. 4, the first media server 11 maintains a session 1 object 41 and a session 2 object 42, and the second media server 12 maintains a session 1 object 41. The third media server 13 holds the session 1 object 41 and the session 2 object 42.

At this time, the session 1 object 41 of the first media server 11 includes the dual terminal 1 101 and the dual terminal 2 102 in the terminal list 21, and the second media in the media server list 22. Server 12 and third media server 13.

In addition, the session 2 object 42 of the first media server 11 includes the dual terminal 6 106 and the single terminal 7 107 in the terminal list 21, and the third media in the media server list 22. Server 13.

In addition, the session 1 object 41 of the second media server 12 includes the single terminal 3 103 and the single terminal 4 104 in the terminal list 21, and the first media in the media server list 22. Server 11 and third media server 13.

In addition, the session 1 object 41 of the third media server 13 includes the dual terminal 5 105 in the terminal list 21, and the first media server 11 and the second in the media server list 22. A media server 12.

In addition, the session 2 object 42 of the third media server 13 includes the dual terminal 8 108 and the single terminal 9 109 in the terminal list 21, and the first media in the media server list 22. Server 11.

FIG. 5 is a diagram illustrating an embodiment of a group communication method in a media server system having a distributed structure according to the present invention, wherein each dual terminal and a single terminal transmit and receive data to each other through a clustering structure of each media server. The process of doing so.

As shown in FIG. 5, the first media server 11 receives the high quality image data and the low quality image data from the dual terminal 2 102 in the session 1 object 41, and then connects to the dual media connected to the first media server 11. The terminal 1 101 transmits high quality image data, and the second media server 12 and the third media server 13 transmit both high quality (high resolution) image data and low quality (low resolution) image data.

Then, the second media server 12 transmits the low quality video data among the high quality video data and the low quality video data received from the first media server 11 to the single terminal 4 104 and the single terminal 3 103. do.

In addition, the third media server 12 transmits the high quality image data among the high quality image data and the low quality image data received from the first media server 11 to the dual terminal 5 105.

Meanwhile, the third media server 13 receives the low quality video data from the single terminal 9 109 in the session 2 object 42, and then the dual terminal 8 108 and the first media server connected thereto. Transfer to (11).

Then, the first media server 11 transmits the low quality video data received from the third media server 13 to the dual terminal 6 106 and the single terminal 7 107.

6 is a flowchart illustrating a group communication method in a media server system having a distributed structure according to the present invention.

First, a connection management server 20 for large-scale group communication, a web server 30 for providing connection information necessary for connection to the connection management server 20 to access terminals (dual terminal, single terminal) and the connection information Drive database (40) storing the prepared state.

In addition, at least one media server, which is distributed locally, for smooth media transmission between user terminal groups having different channel environments and specifications, is registered with the access management server 20 and waits for service preparation.

In addition, when the terminal logs in to the web server 30 to participate in group communication or two-way broadcasting, the web server 30 performs an authentication process.

Thereafter, the terminal accesses the access management server 20 set in the web server 30 and receives a media server list (601).

In this case, the media server list includes media server information on the shortest path, media server information having the largest free bandwidth, media server information having the smallest number of access terminals, media server information set by the user, and the like.

Thereafter, an optimal media server is selected from the provided media server list, and then accessed (602).

At this time, the optimal media server selection method is to select a media server on the shortest path, to select a media server with the largest free bandwidth, to select the media server with the smallest number of access terminals, or to set the media set by the user. Select a server.

Thereafter, the media server checks whether an object for the session requested from the terminal exists (603). In this case, the session object relays various data generated in the corresponding session in the media server.

As a result of the check 603, if the corresponding session object exists, the terminal and the group communication environment information of the terminal are registered together in the terminal list corresponding to the session object (604), and the access management server 20 is notified. Proceed to step 609 ".

At this time, the terminal receives the group communication environment information from the terminal and stores it together. Here, the group communication environment information refers to information indicating whether a dual terminal or a single terminal according to the transmission bandwidth and the performance of the terminal.

As a result of the checking (603), if the corresponding session object does not exist, the connection management server 20 checks whether the session object exists in another media server (605). That is, the other media server is inquired whether the corresponding session object exists.

As a result of the check 605, if the corresponding session object exists in the other media server, the media server accesses the other media server using the other media server information from the access management server 20 (606). In this case, the access management server 20 may instruct another media server to access the media server.

Thereafter, the media server creates a session object with the same ID as the corresponding session object in the other media server, and then registers the terminal in the terminal list in the created session object and the other media server in the media server list in the created session object. The media server list and the other media server in the corresponding session object of the server are registered (607). At this time, the terminal registers the group communication environment information indicating whether the terminal is a dual terminal or a single terminal, and notifies the access management server 20.

In addition, the other media server adds the media server to the media server list in the session object and informs the access management server 20.

Thereafter, the process proceeds to "609".

As a result of the check 605, if the session object does not exist in the other media server, the media server creates the session object, registers the terminal and the group communication environment information in the corresponding terminal list, and then access management server 20 (608).

Through this process, the connection process is completed.

Thereafter, the media server processes group communication between access terminals existing in different group communication environments through the corresponding session object (609).

In more detail, when a dual terminal transmits video / audio / data in the same session, a video signal inputted to an external input according to dual encoding conditions (Resolution, Frame Rate, Bandwidth) set in a web server or set in its registry is displayed. Encode each one and send it to the media server. That is, dual transmission of high quality video data and low quality video data is performed.

In addition, when a single terminal transmits video / audio / data in the same session, it encodes a video signal input from an external input according to encoding conditions (Resolution, Frame Rate, Bandwidth) set in a web server or in a registry of its own terminal. Send to media server. In other words, single-quality video data is transmitted.

Therefore, when the media server receives both the high quality video data and the low quality video data, the media server transmits the high quality data to the dual terminals in its terminal list, the low quality data to the single terminal, and the other media server in the media server list. The furnace transmits both high quality image data and low quality image data.

In addition, when the media server receives only the low quality image data, the media server transmits all the terminals in its terminal list and other media servers in the media server list.

In this case, when the other media server receives both high quality video data and low quality video data, the other media server transmits the high quality video data to the dual terminals in its terminal list and the low quality video data to the single terminal.

In addition, when the other media server receives only low quality image data, it transmits to all terminals without distinguishing between dual and single in the terminal list.

At this time, the other server does not transmit any image data to the media server in its media server list. This is to prevent infinite circulation and repetitive transmission of image data.

Subsequently, when all terminals registered in the terminal list corresponding to the session object and other media servers registered in the media server list corresponding to the session object are disconnected, the corresponding session object is removed, and the connection management server ( 20) (610). Then, the connection management server 20 reflects this information and updates it.

In the present invention, the reason why the connection management server maintains all the information that the media servers have is because of the role of providing comprehensive information when monitoring the progress and some of the media servers serving the service unintentionally. When the service is stopped, the access management server 20 serves to maintain information necessary to allow the terminals receiving the service to continue to receive the service from another appropriate media server without interrupting the service.

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention can be used in high-quality large-scale group communication system Internet broadcasting system, distance education, video conferencing system and the like.

1 is an exemplary view of a media server system having a distributed structure to which the present invention is applied;

2 and 3 are exemplary views illustrating the structural relationship between the session list managed by the access management server and the media server, the media server list corresponding to each object, and the information in the terminal list according to the present invention;

4 is an exemplary view illustrating a structure of a session object in each media server according to the present invention;

5 is a diagram illustrating an embodiment of a group communication method in a media server system having a distributed structure according to the present invention;

6 is a flowchart illustrating a group communication method in a media server system having a distributed structure according to the present invention.

* Explanation of symbols for the main parts of the drawings

11: first media server 12: second media server

13: third media server 20: access management server

30: Web Server 40: Database

Claims (16)

In the group communication method in the terminal, Accessing a connection management server set in a web server and receiving a list of media servers; Selecting and accessing an optimal media server from the provided media server list; And A group communication step of performing group communication with access terminals existing in different group communication environments through a corresponding session object on the same session. Group communication method using a media server of a distributed structure in a terminal including a. The method of claim 1, Access terminals present in the different group communication environment, High-quality terminals located in a channel environment capable of high-speed data transmission and reception, Dual terminals for dual transmission of high-quality video data and low-quality video data, and Low-end terminals located in a channel environment where high-speed data transmission and reception are not possible. Group communication method using a media server of a distributed structure in a terminal comprising a single terminal for transmitting a single data. The method of claim 2, The group communication step, In the case where the access terminal is a dual terminal, the high quality video data and low quality video data are dual-transmitted to the media server, and the high quality video data or the low quality video data is transmitted from the media server. Group communication method using a distributed media server. The method of claim 2, The group communication step, When the access terminal is a single terminal, the group communication method using a distributed media server in a terminal, characterized in that single transmission of low-quality video data to the media server, and receives the low-quality video data from the media server . The method according to any one of claims 1 to 4, The optimal media server selection process, Group communication method using a media server of a distributed structure in the terminal characterized in that the media server on the shortest path is selected. The method according to any one of claims 1 to 4, The optimal media server selection process, A group communication method using a media server of a distributed structure in a terminal, characterized by selecting a media server having the largest margin bandwidth. The method according to any one of claims 1 to 4, The optimal media server selection process, A group communication method using a media server of a distributed structure in a terminal, wherein the media server having the smallest number of access terminals is selected. In the group communication method in the media server, Registering the terminal and the group communication environment information in a terminal list corresponding to the session object when the session object requested from the terminal exists and notifying the access management server; Checking whether the session object exists in another media server as the session object requested from the terminal does not exist; If present, accessing the other media server and performing a group communication preprocessing step to notify the access management server; Generating a session object if not present and registering the terminal and group communication environment information in a corresponding terminal list and notifying the access management server; And A group communication processing step of processing group communication between access terminals existing in different group communication environments through a corresponding session object on the same session; Group communication method using a media server of a distributed structure in a media server comprising a. The method of claim 8, When the terminals registered in the terminal list corresponding to the corresponding session object and the other media servers registered in the media server list corresponding to the corresponding session object are disconnected, the corresponding session object is removed, and the access management server Informing you Group communication method using a media server of a distributed structure in a media server further comprising. 10. The method according to claim 8 or 9, The group communication preprocessing step, After generating a session object with the same ID as the corresponding session object in the other media server, the terminal is registered in the terminal list in the generated session object, and the corresponding media server list is included in the generated media server list in the generated session object. A group communication method using a media server having a distributed structure in a media server, wherein the media server list and another media server are registered in the session object. 11. The method of claim 10, The terminal, High-quality terminals located in a channel environment capable of high-speed data transmission and reception, Dual terminals for dual transmission of high-quality video data and low-quality video data, and Low-end terminals located in a channel environment where high-speed data transmission and reception are not possible. Group communication method using a media server of a distributed structure in a media server comprising a single terminal for transmitting a single data. The method of claim 11, The group communication processing step, As the high quality image data and the low quality image data are transmitted from the dual terminal, the high quality image data is transmitted to the dual terminal connected to the terminal, and the high quality image data and the low quality are transmitted to other media servers on the media list. Transmitting all image data; Transmitting, by the other media server, the low quality video data among the high quality video data and the low quality video data received from the media server to a single terminal connected to the other media server; And Transmitting, by the other media server, the high quality image data among the high quality image data and the low quality image data transmitted from the media server to the dual terminal connected to the other media server. Group communication method using a media server of a distributed structure in a media server comprising a. 13. The method of claim 12, When the other media server receives only the low quality image data from the media server, transmitting the low quality image data to the dual terminal and the single terminal connected to the media server. Group communication method using a media server of a distributed structure in a media server further comprising. 13. The method of claim 12, The other media server, Group communication method using a media server of a distributed structure in a media server, characterized in that the video data received from the media server does not transmit to another media server on its media list. In a terminal equipped with a processor, Accessing a connection management server set in a web server and receiving a list of media servers; Selecting and accessing an optimal media server from the provided media server list; And Ability to perform group communication with access terminals in different group communication environment through corresponding session object on the same session A computer-readable recording medium having recorded thereon a program for realizing this. In the media server to provide group communication, A function of notifying a connection management server after registering the terminal and group communication environment information in a terminal list corresponding to the session object as a session object requested from the terminal exists; Determining whether the session object exists in another media server when the session object requested from the terminal does not exist; A function of notifying the access management server after performing the group communication preprocessing process by accessing the other media server if the check result exists; Generating a session object if not present and registering the terminal and group communication environment information in a corresponding terminal list and notifying the access management server; And Ability to process group communication between access terminals in different group communication environment through corresponding session object on same session A computer-readable recording medium having recorded thereon a program for realizing this.

Images