JPS63169146A - Multi-point communication call control system - Google Patents

Abstract

PURPOSE:To set a call between plural terminals without duplexing communication path by constituting the titled system so that a calling terminal gives the highest priority to its own terminal and priority order in advance to its own terminal and plural terminals requesting for connection request to all low-order terminals as a parameter with the priority. CONSTITUTION:The calling terminal gives the highest priority to its own terminal, and gives preliminarily priority order to plural terminals that request for connection, and as the parameter with this priority order, transmits a connection request. All the terminals other than the calling terminal, transmit a connection request to the terminals having lower priority orders than that of its own terminal among the plural terminals, receive responses from the opposite terminal having lower priority order than that of its own terminal, and transmit a response showing the connection status of lower-order terminal than its own terminal. The calling terminal also informs all the low-order terminals of whether or not a multi-point connection is successful or not, to set up a bidirectional communication path to each terminal. As a result, multi-point communication can be executed without duplexing a communication path between arbitrary terminals.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multipoint communication call control system for performing bidirectional communication between a plurality of terminals connected to a network.

(Prior art) Conventionally, in order for N terminals connected to a network to communicate bidirectionally with each other, each terminal communicating with the other terminals has to establish one pair of communication paths (N-1>). Set these N
Two-way communication between N points was carried out using a combination of two. This technology is described in the International Organization for Standardization (ISO) working draft addendum to ISO 7498.
Multipeer data transmission (Worki
ng Draft Addendum Lo ISO
7498 on Multi-peer Data
This can be easily inferred as a combination of the Hu setting method for performing one-to-N communication described in Transmission> (January 1906). The conventional technology will be explained below using figures. FIG. 2(a) shows four terminals connected. Now let these be A, B, C, and D, respectively.

Here, multipoint communication refers to a form in which two-way communication is performed between multiple terminals. It refers to a form of communication between terminals.

FIGS. 2(b), (c), (d), and (e) show how each terminal sets up a one-to-three communication path. For example, FIG. 2(b) shows how terminal A sets up a communication path for bidirectional communication with terminals B, C, and D. Conventionally, four 1:3 communication paths set in this manner are combined to perform bidirectional communication between four points using the communication path shown in FIG. 2(f). For example, if the calling terminal of 4-point communication is A, the second
In figure (b), when A sends a connection request to B, C, and D,
, C, and D by controlling to set 1:3 communication paths for each of them.

(Problems to be Solved by the Invention) In the conventional multipoint communication call control system described above, each of a plurality of terminals performing multipoint communication sends connection requests for all other terminals and establishes a communication path. . Therefore, as shown in FIG. 2(f), a double communication path is set up between any two terminals that perform the communication, and the communication path is set up in vain. In addition, in the conventional multipoint communication call control method, there is no notification as to whether or not the communication path for multipoint communication between all terminals has been set correctly, and when communication starts within a group performing multipoint communication. I didn't know if it was okay.

It is an object of the present invention to efficiently set up calls between multiple terminals without duplicating communication channels, and to check whether the communication channels for multipoint communication between all terminals have been set correctly. An object of the present invention is to provide a multipoint communication call control system characterized by clearly notifying all terminals of the starting point of multipoint communication.

(Means for Solving the Problem) According to the present invention, a calling terminal gives priority to its own terminal and a plurality of terminals requesting connection in advance, with its own terminal as the highest priority, and A connection request is sent to all the lower terminals indicated in the priority order as a parameter, and all terminals except the calling terminal send a first response to the connection request to the calling terminal, and the order parameter Among the terminals shown in , it sends a connection request to a lower-level terminal of its own terminal, receives a response to the connection request from the lower-level terminal, and sends a connection request to all terminals higher than its own terminal. When the calling terminal transmits a second response indicating a connection request with a lower-level terminal, and both the first and second responses received at the calling terminal indicate a successful connection, the calling terminal transmits a request to all lower-level terminals. If the received response indicates at least one unsuccessful connection, the calling terminal notifies all lower terminals of the unsuccessful multipoint connection and performs abnormal processing. and all terminals except the calling terminal start multipoint communication when receiving a notification of successful multipoint connection from the calling terminal, and perform abnormal processing when receiving a notification of unsuccessful multipoint connection. A multipoint communication call control system characterized by the following is obtained.

(Function) According to the multipoint call setup method of the present invention, the calling terminal gives priority to itself and a plurality of terminals requesting connection in advance, with its own terminal as the highest priority, and connects using the priority as a parameter. Submit a request. All terminals except the calling terminal send a connection request to a terminal with a lower priority than the own terminal among the multiple partner terminals indicated in the parameter, and the other terminal with a lower priority than the own terminal sends a connection request. Upon receiving response 1, it transmits response 2 indicating the connection status with lower-level terminals to all higher-level terminals than the own terminal, and the calling terminal informs all lower-level terminals whether the multipoint connection is successful or not. In order to set up a communication path for bidirectional communication with each terminal, a communication path for multi-point communication is set up without duplicating the communication path between any terminals. This also notifies whether or not a communication path for performing multipoint communication between all terminals has been correctly set, and clearly informs all terminals of the starting point of multipoint communication.

(Embodiment) FIG. 1 is a flowchart showing a control algorithm at each terminal in the multipoint call control system of the present invention. The flowchart shown in the figure is composed of 19 control blocks numbered 100 to 118. FIG. 1(a) shows the algorithm at the calling terminal, and FIG. 1(b) shows the algorithm at the other terminals.

In control block 100, the calling terminal creates parameters by prioritizing the calling terminal and a plurality of terminals requesting connection, with the calling terminal as the highest priority. In the control block toi, the calling terminal uses the order of the plurality of terminals requesting connection as a parameter and sends a connection request to all the lower terminals indicated by the order parameter. In control block 102, the calling terminal receives the first
receive a response. In the control block 103, second responses indicating the connection status of the terminal with the lower terminals are received from all the lower terminals. Here, the first response refers to a response to a connection request to a lower-level terminal in a calling terminal and a terminal other than the calling terminal, and the second response refers to a response to a connection request to a lower-level terminal at a calling terminal and a terminal other than the calling terminal, and a second response refers to a response to a connection request to a lower-level terminal received from all lower-level terminals. Refers to the response to the upper terminal that is generated from the response. For example, when all the first responses received by a terminal indicate that connection is possible, the second response indicates to the higher-level terminal that the terminal has successfully connected with all its lower-level terminals; When at least one of the first responses indicates connection failure, the second response indicates connection failure for the E terminal. control block 1
In step 04, it is determined whether or not both the first and second responses indicate successful connection, and if so, in control block 105, all lower terminals are notified of successful multipoint connection.

If not indicated, the control block 106 notifies the multipoint connection failure and controls the control block 106.
In step 7, abnormality processing is performed. Here, multipoint connection refers to setting up a communication path for communication between all terminals that perform multipoint communication. In FIG. 1(b),
In control block 108, all terminals except the calling terminal receive the connection request. In control block 109, all terminals except the calling terminal send a first message to the calling terminal.
send a response. Then control block 110.111
．． 112, 113, 114. are executed, but control blocks 110.111. indicates a connection request transmission process, and control blocks 112, 113, and 114 indicate a connection request reception process. In control block 110, all terminals except the calling terminal send connection requests to all terminals lower than their own terminal. In control block 111, all the terminals except the calling terminal receive the first response from the terminal lower than the terminal, and end the connection request transmission process.

In addition, in the control program 112, all terminals except the calling terminal receive connection requests from terminals higher than their own terminals. In control block 113, all terminals except the calling terminal send first responses to the terminals that have sent connection requests. In the control block 114, all terminals except the calling terminal determine whether or not they have received connection requests from all higher-level terminals, and if they have not received connection requests from all higher-level terminals, the control block 112 When the connection request is received, the connection request reception process is terminated. The transmission processing and reception processing of these connection requests are executed independently in each terminal, and when the transmission processing and reception processing are completed, the control block 115 instructs all terminals higher than the own terminal to communicate with terminals lower than the own terminal. Send a second response indicating the connection status. The control block 116 receives the multipoint connection status from the calling terminal, and the control block 117 receives the status of the multipoint connection from the calling terminal.
It is determined whether the multipoint connection is successful or not, and if it is unsuccessful, abnormality processing is performed in control block 118.

The present invention will be explained below with reference to the drawings. Figure 2(a)
This figure shows how the multipoint communication call control algorithm shown in FIG. 1 is implemented using the four terminals shown in FIG. 1 as an example.

In Figure 2 (a), the source terminal is A, and from terminal A to terminal B.
, C, and D for setting up a communication path for multipoint communication. Terminal A sets its own terminal as the highest priority,
For example, priorities are given to other terminals in the order of B, C, and D (control block 100). Next, terminal A sends connection requests to terminals B-C and D using this priority order as a parameter (control block 101). An example of the transmission frame at this time is shown in FIG. In the figure, 300 is a frame header, 301 is a control field, and a flag indicating that it is a connection request is set. 302 is a parameter field; in the example, parameters (A, B, C
,D) are written. This parameter indicates that the terminal written on the left has the highest priority, and the figure shows that the priority is highest in the order of terminals A, B, C, and D, as described above. When terminals B, C, and D receive the connection request from calling terminal A (control block 108), they then transmit a response to terminal A (control block 109). On the other hand, calling terminal A receives the first response (hereinafter referred to as response 1) from terminals B=C and D (control block 102), and sets up a bidirectional communication path with the connectable terminals. This situation is shown in Figure 4 (1), +21, (3), 4), (51, (6)
). In the figure, (1), (21, and (3)) indicate connection requests, and (4), (5), and (6) indicate response 1.

Terminal B knows from the parameters (A, B, C1D) that it has the highest priority next to terminal A, and sends connection requests to terminals C and D, which have lower priority than the own terminal (control block 110). Terminals C and D similarly know the priority order from the parameters, and when they receive a connection request from terminal B, which has a higher priority than their own terminals (control block 1
12), returns correspondence 1 to terminal B (control block 113)
. When terminal B receives response 1 from terminals C and D, the second
A response (hereinafter referred to as response 2) is generated and transmitted to terminal A (control block 115). For example, when response 1 from terminals C and D both indicate that connection is possible, terminal B sets up a communication path with terminals C and D, and terminal B's response 2 to terminal A
notifies that terminal B has successfully connected to terminals C and D. Furthermore, if there is at least one response 1 from terminals C and D indicating that connection is not possible, terminal B will not establish a communication path between the two terminals, and response 2 to terminal A will indicate that terminal B is unable to connect. Notify that the connection with terminals C and D was unsuccessful. The situation is shown in Figure 4 m, 咄, (9), (10), (1
1) 4.1:.

show. In the figure, (71, (to) indicates a connection request, (9),
(10) indicates response 1, and (11) indicates response 2.

On the other hand, in terminal C, parameters (A, B,
C and D), it learns that its own terminal has the next highest priority after terminal B, and sends a connection request to the terminal with a lower priority than its own terminal (control block 11O). Similarly, the terminal learns the priority order from the parameters, and when it receives a connection request from terminal C with a higher priority than its own terminal (control block 112), it returns a response 1 to terminal C (control block 11).
3). Here, the terminal has the lowest priority as indicated by the parameters, and will not receive a response 1 from a terminal lower than itself. Therefore, it is assumed that response 2 generated from response 1 from the lower-level terminal is generated when the lowest-level terminal is connected to terminal C, which is one level higher, and response 1 also serves as response 2. Furthermore, the terminal transmits response 2 to terminals A and B (control block 115). This situation is shown in Figure 4 (12).
Shown in (13), (16), and (17). In the figure, (12) indicates a connection request, and (13) indicates response 1, which also serves as response 2.
, and (16) and (17> indicate response 2. 5゜Also, since there is no terminal with a lower priority than the terminal, the terminal C does not transmit the connection request. Terminal C does not send a connection request. When response 2 is received, terminal A and terminal B, which are higher-level terminals,
(control block 115). For example, when response 1 from the terminal indicates that connection is possible, terminal C sets up a communication path with the terminal, and response 2 from terminal C to terminal B indicates that terminal C has successfully connected to the terminal. Notify. In addition, when response 1 from the terminal indicates that connection is impossible, terminal C does not set up a communication path with the terminal, and response 2 for terminals A and B, which are higher-level terminals, indicates that terminal C is connected to the terminal. to notify that the connection was unsuccessful. This situation is shown in FIG. 4 (14) and (15). In the figure (14〉, (
15) shows response 2.

In this way, each terminal can know the connection status between itself and the lower terminals by receiving the response l from each of the lower terminals, and by receiving the response 2, it can know the connection status between the lower terminals of the own terminal. It is possible to know the connection status between the terminal and its lower-level terminals. For example, terminal A can know the connection status with terminals B, C, and D by receiving responses 1 shown in FIG. 4 (4), (5), and (6), and (
By receiving the responses 2 shown in 11), (15), and (17), it is possible to know the connection status between terminal B and terminals C and D, and between terminal C and terminals. After receiving these responses 1 and 2, terminal A notifies terminals B, C, and D of successful multipoint connection using connection status notifications to start multipoint communication when they all indicate successful connection.

In addition, at least one of the received responses 1 and 2
If there are two connection failure indications, terminals B and C
, D is notified of the failure of the multipoint connection using a connection status notification, and handles the abnormality. Here, the abnormality processing refers to canceling all previously set communication channels, starting communication between connected terminals using the set communication channels, etc., but is not particularly stipulated here.

As another example, as shown in FIG.
It is also possible to omit the response 2 from the terminal shown in G) and (17). This is because there is no terminal lower than the terminal, so the response 2 sent by the terminal has no particular meaning. Also, at this time, the response shown in FIG. 5 (13) is recognized by terminal C as response 1, and does not serve as both response 1 and response 2 as in FIG. 4 (13). At this time, terminal A generates a connection state notification from responses 1 from terminals B, C, and D and responses 2 from terminals B and C.

As another example, as shown in FIG. 6, response 2 is actually used only when terminal A generates a connection status notification, so each terminal responds to There may also be an example in which the message is not sent.

Furthermore, as shown in FIG. 7, an embodiment in which FIGS. 5 and 6 are combined is also conceivable.

(Effect of the invention) As mentioned above, in the conventional multipoint communication call control system, each terminal independently set up a 1:N bidirectional communication path, so the bidirectional communication path between each terminal is doubled. The communication path was set up in vain. It is an object of the present invention to efficiently set up calls between multiple terminals without duplicating communication channels, and to check whether the communication channels for multipoint communication between all terminals have been set correctly. An object of the present invention is to provide a multipoint communication call control system characterized by clearly notifying all terminals of the starting point of multipoint communication. According to the multipoint call control method according to the present invention, a calling terminal gives priority to its own terminal and a plurality of terminals requesting connection in advance, with its own terminal as the highest priority, and sends a connection request using the priority as a parameter. However, each other terminal sends a connection request to a terminal with a lower priority than its own terminal among the plurality of partner terminals indicated in the parameter, and receives a response from the partner terminal with a lower priority than its own terminal. is received and sent to all terminals higher than the own terminal.
By transmitting response 2 indicating the connection status with lower-level terminals than the calling terminal, and notifying all lower-level terminals whether the multipoint connection is successful or not, the calling terminal can establish two-way communication with each terminal. To set up a communication path for communication, set up a communication path to perform multipoint communication without duplicating the communication path between arbitrary terminals, and to perform multipoint communication between all terminals. It is possible to notify whether the route has been correctly set up or not, and to clearly inform all terminals of the multipoint communication start point.

[Brief explanation of the drawing]

FIG. 1<a) is a flowchart showing the control algorithm at the calling terminal of the multipoint call control system of the present invention, and FIG. 1(b) is a flowchart showing the algorithm at other terminals. 2 is a diagram showing the algorithm of the conventional multipoint communication call control system, FIG. 3 is a diagram showing an example of a connection request frame in the multipoint communication call control system of the present invention, and FIG. 4 is a diagram showing the algorithm of the conventional multipoint communication call control system. FIG. 5 is a diagram showing an embodiment using the multipoint communication call control method of the present invention. FIG. 6 is a diagram showing an embodiment using the multipoint communication call control method of the present invention. FIG. 7 is a diagram showing an embodiment of the multipoint communication call control system of the present invention. In the figure, 100 to 118 are control blocks, 300 is a header, 301 is a control field, and 302 is the first priority parameter.
Figure 1 Figure 2 Terminal B0 (a) Terminal AO Terminal C0 Figure 2 B (e) B (f) B Figure 3 300301 3U'l Figure 4 Terminal A Terminal B Terminal C Terminal C0 Figure 5 Terminal A Terminal B Terminal C Terminal D Figure 6 Terminal A Terminal B Terminal C Figure 7

Claims (1)

[Claims] The calling terminal sets its own terminal as the highest priority, assigns priorities in advance to its own terminal and multiple terminals requesting connection, and uses the priority as a parameter to send connection requests for all lower-level terminals indicated in the priority. Then, all terminals except the calling terminal transmit the first response to the connection request to the calling terminal, and connect to the lower terminal of the own terminal among the terminals indicated in the order parameter. Sending a request, receiving a response to the connection request from the lower terminal, and transmitting a second response indicating the connection state between the own terminal and the lower terminal of the own terminal to all terminals higher than the own terminal, In the calling terminal, when all of the received first and second responses indicate a successful connection, the calling terminal notifies all lower-level terminals of the successful multipoint connection, and adds at least one response to the received response. When there are two connection failure indications,
The calling terminal notifies all lower terminals of multipoint connection failure and performs abnormal processing, and all terminals except the calling terminal receive notification of multipoint connection success from the calling terminal. A multipoint communication call control method characterized by starting multipoint communication and performing abnormality processing upon receiving a notification of multipoint connection failure.