JPH05110582A - Non-disconnection communication method for voice call - Google Patents

Abstract

PURPOSE:To obtain a non-disconnection communication service by providing a function for detecting disconnection of one piece of existing path, and continuing immediately a communication by using another ATM logical communication path as an existing path, in a voice cell-conversion trunk circuit. CONSTITUTION:Between voice cell-conversion trunk circuits 10, 11 in two terminal stations, at least two pieces of logical communication paths whose physical paths are different are set. Also, this system is provided with a cell- conversion/reverse cell-conversion control circuit 110 for always transmitting simultaneously a voice data cell onto plural ATM logical communication paths, and also, selecting one piece in plural ATM logical communication paths as an existing path, receiving the voice data cell and executing its reverse cell- conversion, in the voice cell-conversion trunk circuits 10, 11. Moreover, this system is provided with a path disconnection detecting circuit 140, and an existing path switching control circuit 130 for giving an instruction to the cell- conversion/reverse cell-conversion control circuit 110 so that when disconnection of the existing path is detected, a stand-by ATM logical communication path is used immediately as a new existing path. In such a way, a conversation between users is not suspended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of disconnecting a voice call, and more particularly, in an ATM voice communication network.
The present invention relates to a communication method for disconnecting a voice call when a trunk line fails.

[0002]

2. Description of the Related Art A conventional example of a disconnection communication system for a voice call when a trunk line fails in an ATM voice communication network will be described with reference to FIG. Conventionally, one ATM logical communication path 250 is provided between the voice cell trunk circuits 220.221 of the terminal stations 200 and 201 accommodating the telephone terminals 230 and 231.
Which has been set up to realize this ATM logical communication path
When a failure occurs in the M relay lines 240 and 241 and the relay station 210, the ATM relay lines 242 and 242 are newly provided between the voice cell trunk circuits 220 and 221 of the terminal stations 200 and 201.
In this system, the ATM logical communication path 251 is set on another route via the relay station 243 and the relay station 211 to continue the voice call connection between the telephone terminals 230 and 231. With this method, even if a trunk line failure or the like occurs, mutual communication between the telephone terminals 230 and 231 can be continued without executing the call connection request procedure again.

[0003]

However, in the above-mentioned conventional disconnection communication system for voice calls, the ATM logical communication path is re-established by another route when a failure such as a trunk line occurs. Since it takes at least several seconds until communication using the new ATM logical communication path becomes possible again after detection of communication interruption due to occurrence of a trunk line failure, there is a problem that normal conversation between users cannot be performed.

The present invention has been made in view of the above-described problems, and after the communication interruption due to the occurrence of the trunk line failure is detected, the communication can be resumed within a processing time of about 10 ms, and therefore, the present invention is practically used. An object of the present invention is to provide a communication method for disconnecting a voice call without relaying a conversation between persons.

[0005]

In order to achieve the above object, a communication method for disconnecting a voice call according to the present invention is used in an ATM voice communication network in which digital coded voice data is set in a fixed length cell for communication. , At least two physical communication paths having different physical paths are set up between the voice cellized trunk circuits in the two terminal stations respectively accommodating two telephone terminals to be communicated, and the voice cellized trunk circuit is provided. Multiple voice data cells within ATM
Simultaneous transmission on the logical communication path and multiple ATs
Celling / decelling control circuit for selecting one of the M logical communication paths as a working path and receiving voice data cells for decellization, and path disconnection detection for detecting disconnection of the active ATM logical communication path A circuit and a working path switching control circuit for instructing the cell assembling / decelling control circuit to immediately use the spare ATM logical communication path as a new working path upon detection of disconnection of the working path are provided. ..

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of a voice cell forming trunk circuit or the like in a terminal station for carrying out the method of the present invention, and FIG. 2 is a block diagram showing an ATM voice communication network including this terminal station.

In FIG. 1, the terminal station is a TD switch 20,
ATM switch 3 for executing ATM cell switching switch
0, the voice cell conversion trunk circuit 10 directly connected to these two switches, the ATM relay trunks 40 and 41 connected to the ATM switch 30, and the line circuit 50 connected to the TD switch 20. It is configured. The line circuit 50 controls the telephone terminal 60 via the subscriber line. The ATM relay trunks 40 and 41 accommodate the ATM relay lines 70 and 71, respectively.

The inside of the voice cell conversion trunk circuit 10 includes a cell conversion / decellization control circuit 110, a TD switch interface circuit 120, and a working path switching control circuit 130.
And a path disconnection detection circuit 140.

The cellization / decellization control circuit 110 is an AT
ATM relay lines 70, 71 directly connected to the M switch 30
A plurality of ATM logical communication paths on the ATM relay trunk 4
0, 41 and the ATM switch 30 are used to store the data. At the time of transmission, the cellization / decellization control circuit 110 receives digitally encoded voice data from one telephone terminal via the TD switch interface circuit 120, sets it to a fixed length cell, and sets it to a plurality of cells. Simultaneously on the ATM logical communication path. Further, upon reception, the cellization / decellization control circuit 110 selects one of the plurality of ATM logical communication paths as a working path, receives a voice data cell, and decellizes it. It has a function of transmitting only digitally encoded voice data to the telephone terminal through the TD switch interface circuit 120.

The path disconnection detection circuit 140 monitors the voice data output after being decellized by the cellization / decellization control circuit 110, and when the voice data is not output for a certain period of time (for example, 1 second). Judges that the active ATM logical communication path has been disconnected and notifies the active path switching control circuit 130 of the occurrence of the path disconnection.

When the working path switching control circuit 130 receives the working path disconnection notification, it performs cellization / decellization control so that another ATM logical communication path is used as the working path to perform the processing for de-cellizing the voice data cells. Instruct the circuit 110.

FIG. 2 shows an ATM voice communication network including terminal stations for carrying out the method of the present invention. As shown in FIG. 2, the ATM voice communication network includes terminal stations 100 and 101 for implementing the above-described method of the present invention, relay stations 210 and 211, and ATM trunk lines 240, 241, and 2.
42 and 243. Terminal stations 200, 20
1 accommodates telephone terminals 60 and 61, respectively, and comprises voice cellized trunk circuits 10 and 11 for implementing the method of the present invention. Telephone terminal 60 and telephone terminal 6
In the voice communication between the two, the ATM trunk line 240 or 242, the relay station 210 or 211 and the ATM trunk line 241 or between the voice cell trunk circuit 10 of the terminal station 100 and the voice cell trunk circuit 11 of the terminal station 101 are used. It is realized by setting either one of the ATM logical communication path 250 or 251 via the H.243.

Next, the control flow of the communication method for disconnecting voice calls according to the present invention will be described. When the voice call between the telephone terminal 60 and the telephone terminal 61 is for very important communication, a single A is placed between the voice cell trunk circuits 10 and 11.
Not only the TM logical communication path 250 but also the ATM relay line 24
2, another relay station 211 and another ATM logical communication path 251 passing through the ATM relay line 243 are set, and the former is the working path and the latter is the backup path.
0 and 11 are instructed to control communication without disconnection.

Thus, for example, the ATM trunk line 240
Even if the communication by the ATM logical communication path 250 is disabled due to the disconnection of the ATM, the communication using the other ATM logical communication path 251 is continued in the processing time of about 10 ms by the control of the voice cell assembling trunk circuits 10 and 11. Therefore, without substantially interrupting the communication between the telephone terminals 60 and 61,
Undisconnected communication of voice calls is realized.

When the voice call between the telephone terminals 60 and 61 is for less important communication,
Similar to the conventional disconnection communication system for voice calls, one ATM logical communication path may be set, and when a failure occurs, another route ATM logical communication path may be set again. That is, the method of the present invention and the conventional method may be used in combination.

The method of the present invention is not limited to the above-mentioned embodiment, and can be carried out by appropriately modifying it. For example, three or more logical communication paths having different physical paths may be provided.

[0017]

As described above, according to the present invention, at least two different ATM logical communication paths of physical paths are set between the voice cell trunk circuits of two terminal stations, and one of them is used. Detects disconnection of one working path and another ATM
Since the voice cell cell trunk circuit has a function to continue communication immediately with the logical communication path as the working path, communication can be re-established within a processing time of about 10 ms after detection of communication interruption due to occurrence of a trunk line failure or the like. Therefore, a completely undisconnected communication service can be provided to the user.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit in a terminal station for implementing the method of the present invention.

FIG. 2 is a block diagram showing an ATM voice communication network including the terminal station of FIG.

FIG. 3 is a block diagram showing a conventional ATM voice communication network.

[Explanation of symbols]

 10, 11 ... Voice cell conversion trunk circuit 20 ... TD switch 30 ... ATM switch 40, 41 ... ATM relay trunk 50 ... Line circuit 60, 61 ... Telephone terminal 70, 71 ... ATM trunk line 100, 101 ... Terminal station 110 ... Cell Deserialization control circuit 120 ... TD switch interface circuit 130 ... Working path switching control circuit 140 ... Path disconnection detection circuit 210, 211 ... Relay station 240, 241, 242, 243 ... ATM relay line 250, 251, ... ATM logical communication path

Claims (1)

[Claims] 1. An ATM voice communication network for setting digitally coded voice data in fixed length cells for communication, and a voice cell trunk circuit in two terminal stations respectively accommodating two telephone terminals to be communicated. , At least two different logical communication paths of physical paths are set up, and voice data cells are always transmitted simultaneously on a plurality of ATM logical communication paths in the voice cell forming trunk circuit, and Celling / decelling control circuit that selects one of the ATM logical communication paths as the working path to receive voice data cells and decellize them, and path disconnection detection that detects disconnection of the active ATM logical communication path Instructs the cell and de-cellization control circuit to immediately use the spare ATM logical communication path as a new working path when the working path disconnection is detected. Working path switching control circuit and a non-cutting method of communication voice call, characterized in that a that.