JPS63202153A - Communication equipment - Google Patents

Abstract

PURPOSE:To prevent a useless operation by using a notice means so as to inform the release of a specified address or the address to be released to the network side, thereby informing the release of the specified address surely to a network side. CONSTITUTION:When a terminal equipment side discriminates the assignment of a duplicated subaddress TEI, that is, the possibility of the same TEI assigned to two terminal equipment, a TEI release control section 5 is used to allow the terminal side to inform the occurrence of an event to release the TEI to the network side. An LAPD control section 6 of the network equipment 2, in receiving a UI frame set with the ID release display message, informs the released TEI to the TEI release control section 5 of the network equipment 2 based on the message of the received UI frame to release the TEI. The LAPD control section 6 of the terminal equipment 1 releases the TEI of its own equipment side in receiving the UI frame set with the ID release request message.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a communication device used in a communication system in which at least one line is used by a plurality of communication terminals;
[Prior art] Conventionally, as this type of communication system, for example, rsDN (
Integrated 5 services Digi
tal Network) system is known. In this I5DN system, one line has two data channels (B channel) and one control channel (D channel).
It has three communication channels consisting of
Up to eight communication terminals can be connected to one line. This l
In the 5DN system, two terminals can communicate at the same time (three terminals can communicate using the D channel), and when communicating with the other party, the address assigned to that line is sent to the line. By calling all terminals connected to the line and communicating with any of the called terminals, add a subaddress to the above address to specify the terminal to communicate with and send it to only the specified terminal. It is also possible to call.

[Problems to be solved by the invention] In this I5DN system, each communication terminal connected to the line is given a subaddress, but this subaddress (TEI) is arbitrarily assigned to each terminal by the user. If there is a possibility that the same TEI has been assigned to two terminals by mistake, it is necessary to cancel this TEI.

At that time, when canceling the TEI from the terminal side, if you do so without notifying the network side that the TEI will be canceled, the TEI that the network side recognizes as being assigned may actually be assigned to the terminal. A situation occurs where the TE is not
The disadvantage is that the network cannot detect the status until the I check routine checks whether the TEI has been assigned.

[Means and effects for solving the problem] According to the present invention, the notification means notifies the network side that the unique address is or should be canceled, so that the network side is surely aware of the cancellation of the unique address. It is possible to prevent unnecessary movements.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In the following embodiments, an I5DN system will be described as an example.

This example will be described in detail below.

FIG. 1 is a block diagram of the terminal side and the network side showing one embodiment of the present invention, and FIG. 2 is a frame sequence diagram between the terminal and the network showing one embodiment of the present invention.

In FIG. 1, l is a terminal device, 2 is a network device, and 3 is a TE.
4 is a TEI release detection unit that detects that TEI should be released; 5 is a TEI release control unit that performs TEI release and control; 6 is LAPD control that manages the data link protocol. Section 7 is a demultiplexing section that transmits and receives frames.

In the above configuration, if the terminal side determines that there is a possibility of double TEI allocation, that is, the same TEI is allocated to two terminals, the TEI should be canceled by the TEI cancellation detection unit 4 in the terminal device l. is detected,
The TEI release control unit 5 notifies the network side that a situation has occurred in which the terminal side should release the TEI. At this time, ID
An Ul frame with a new message type called release indication (an Ul frame is a frame that indicates that a response from the other party is not required) is provided, and the above terminal uses this ID.
By transmitting an Ul frame with a message type of cancellation indication to the network side through the demultiplexer 7, the intention to cancel the TEI is notified to the network side. The TEI release control unit 5 in the network device 2 that received the above Ul frame,
In order to release the TEIs of all terminals, a UI frame having a message type of ID release request is transmitted to the terminal side through the demultiplexer 7, and the release of the TEIs with the possibility of double TEI allocation is completed.

Here, if an ID cancellation request in response to an ID cancellation display is not received from the network side within a certain period of time, the terminal
It is necessary to perform processing such as retransmitting the Ul frame with the message type of D cancellation indication or canceling the TEI.

FIG. 4 is a flowchart showing the control operation of the terminal device 1 of this embodiment.

First, when the TEI release detection unit 4 detects that a TEI has been allocated twice, the TEI release control unit 5 outputs a release signal to the LAPD control unit 6 indicating that the TEI is to be released. When the LAPD control unit 6 receives the release signal, it sets a message indicating ID release in the Ul frame and transmits it to the network device 2. Next, the LAPD control unit 6 of the network device 2
When receiving the UI frame in which the ID release indication message is set, the TEI release controller 5 of the network device 2 notifies the TEI to be released based on the message of the received UL frame, and causes the TEI release control unit 5 to release the TEI. When the TEI is released, the LAPD control unit 6 of the network device 2 sets the L of the UI frame terminal device l that has set the ID release request message.
It is transmitted to the APD control unit 6. In step S2 of FIG.
When the LAPD control unit 6 of the terminal device 1 receives the UI1 frame in which the ID release request message is set, the process proceeds to step S3, and the LAPD control unit 6 of the terminal device 1 releases the TEI on its own side.

In the above embodiment, when the terminal side transmits an Ul frame with a message type of ID release indication to the network side, and the terminal side receives an Ul frame with a message type of ID release request from the network side as a response, the TEI UI that has a message type of ID cancellation display on the terminal side without waiting for the ID cancellation request as a response.
It can also be configured by canceling the TEI at the time the frame is transmitted. In this case, when the network side receives a UI frame with a message type of ID release indication, appropriate processing such as TEI release or activation of a TEI check routine is performed instead of sending an IU frame with a message type of ID release request. It becomes necessary.

The frame sequence of the above embodiment is shown in FIG.

〔Effect of the invention〕

As explained above, by providing a means for notifying the network side that the terminal side should or will cancel the unique address, the network side can receive TEI from the terminal side.
Detects allocation and provides error-free TEI between terminals and networks
This has the effect of allowing cancellation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram between a terminal and a network implementing the present invention; FIG. 2 is a frame sequence diagram in one embodiment of the present invention; FIG. 3 is a frame sequence diagram in another embodiment of the present invention; The figure is a flowchart showing the control operation on the terminal side in this embodiment. 1 is a terminal device, 2 is a network device, 3 is a TEI management unit, 4 is a T
EI release detection unit, 5 is TEI release control unit, 6 is LAPD
The control section 7 is a demultiplexing section. Figure 4

Claims (1)

[Scope of Claims] A communication device used in a communication system in which at least one line is used by a plurality of communication terminals, comprising means for calling all or any of the plurality of communication terminals; A setting means for setting a unique address for each of the plurality of communication terminals in order to make it possible to call any communication terminal, and canceling or should cancel the unique address setting of the communication terminal by the setting means. 1. A communication device comprising means for notifying a network that controls a line.