JPH0693698B2 - Terminal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] A communication method between multimedia terminals connected to a digital subscriber line, in which subaddresses are exchanged with each other in making and receiving a first call, and one communication channel is used. When the second communication channel is secured and another communication channel is required, the sub-address of the partner terminal is designated to make the second call and the second communication channel is secured. By using the existing communication procedure, two communication channels can be secured between the multimedia terminals.

TECHNICAL FIELD The present invention relates to a communication system between multimedia terminals connected to a digital subscriber line.

With the recent development of digital technology, the digitization of transmission lines and the digitization of exchanges are progressing.
The concept of ISDN (Integrated Digital Service Network), which provides various non-telephone services, was born.

According to CCITT's recommendation regarding digital subscriber line signaling, there are two communication channels (64 kbps, 64 kbps, used for telephone call or data communication) between the home terminal device and the exchange.
Hereinafter, it is connected by a subscriber line composed of a B channel) and a control signal channel (16 kbps, hereinafter referred to as D channel) for passing a control signal. Therefore,
Sometimes expressed as + D.

In a normal telephone, one B channel may be used for each call, but a so-called multimedia terminal, for example, a writing communication terminal for communicating using voice and a screen at the same time as shown in FIG. Thus, even one call may use two B channels for communication.

The present invention relates to a communication procedure in such a case.

[Prior Art] In communication between multimedia terminals as described above,
Either two B channels are secured when a call is made, or one B channel is initially used for communication (telephone), and another B channel is secured in the middle.
A communication procedure different from that for general calls must be prepared.

[Problems to be Solved by the Invention] As described above, preparing a new communication procedure corresponding to a new terminal is not a good idea considering the amount of control program development.

The present invention seeks to provide a new scheme for connecting two B channels using existing procedures as much as possible.

[Means for Solving Problems] FIG. 1 shows an example of a communication procedure according to the multimedia communication system of the present invention.

The communication procedure between the terminal device, the exchange and the terminal device will be described below along with the control sequence.

Call from terminal A to terminal B. At this time, its own sub-address a is added as additional information for transmission.

The exchange returns the call acceptance to the terminal A and sends the incoming signal to the terminal B. In this signal, the sub-adrea
Is added.

When the terminal B receives this incoming signal, it stores the sub-address a of the terminal A and returns the incoming call acceptance. The incoming call reception reaches the terminal A through the exchange.

The terminal B subsequently adds its own subaddress b and sends a response signal. The response signal goes through the exchange to the terminal A.
Reach The terminal stores the sub-address b of the terminal B.

As described above, one B is provided between the terminal A and the terminal B.
The channel is reserved.

Then, when another B channel is required, the terminal A specifies the sub-address b of the terminal B, and
Make a call.

The exchange returns the call acceptance to the terminal A and sends the incoming signal to the terminal B by designating the subaddress b.

A response signal is sent from the terminal B of the sub address b, and this is delivered to the terminal A via the exchange.

The second call for securing another B channel may be originated from the terminal B side. As described above, two B channels are secured between the terminal A and the terminal B.

[Operation] In the present communication system, a call is initially made using one B channel like a general terminal, and then a new terminal is newly designated to make a call like a general telephone. Therefore, another B channel is to be secured.

That is, although two B channels are used for one call in this way, a new terminal can be handled relatively easily by treating it as if there were two normal calls in processing.

[Embodiment] The gist of the present invention will be specifically described with reference to the communication procedure diagram shown in FIG. 1 and the embodiment shown in FIG.

FIG. 2 is connected to a subscriber line 1 having three terminals A, B, and C with subaddresses a, b, and c via a switch DX.
It is a figure which shows the example of a communication procedure with the subscriber line 2 which has three terminals D, E, and F which are subaddresses d, e, and f.

Each terminal connected to both subscriber lines is the third
It is assumed that the writing communication terminal is as shown in the figure.

FIG. 2 (a) shows that the terminal A of the subscriber line 1 adds its own sub-address a and originates the first (first) call to communicate with any terminal on the subscriber line 2. It is shown that one communication channel (for voice) is secured during the communication.

In the subscriber line 2, it happens that one terminal E responds to this incoming call by adding its own subaddress e.

If only voice communication is needed, one communication channel (for voice) may be used to continue this.

When it becomes necessary to use the writing communication, another communication channel is acquired as follows.

FIG. 2 (b) shows the subaddress e of the terminal E from the terminal A.
Is designated to make a second call to secure a second communication channel (for screen).

Since the subaddress e is specified in the incoming signal to the subscriber line 2, the terminals D and F ignore it and only the terminal E having the subaddress e responds.

[Effects of the Invention] As described above, according to the present invention, it is possible to connect two B channels between terminal devices by utilizing existing communication procedures as much as possible, and easily cope with a new terminal device. It is possible, and the practical effect is extremely large.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a communication procedure of the present invention, FIG. 2 is a diagram for showing an embodiment of the present invention, and FIG. 3 is a diagram for explaining stroke communication.

Claims (1)

[Claims] 1. A plurality of terminal devices are connected to an exchange through a digital subscriber line capable of simultaneously using a control channel and a plurality of communication channels, and a telephone number of the subscriber line and a peculiar to each terminal device. In a digital network to which an address is assigned, at the time of call setup using the control channel, the telephone number and the address unique to the other party terminal device are received from the other party terminal device, and in addition to the communication channel currently in use, A terminal device characterized in that, when a new communication channel is needed, a new address is set by designating an address unique to the partner terminal device.