Transmission device control system equipped with high-efficiency coding scheme in communication network

• US 6,385,314 B1
• Filed: 05/14/1998
• Issued: 05/07/2002
• Est. Priority Date: 05/21/1997
• Status: Expired due to Fees

• Current Assignee: KDDI Corporation
• Original Assignee: Kokusai Densin Denwa Kabushiki Kaisha
• Inventors: Furuya, Nobuo
• Primary Examiner(s): SMITH, CREIGHTON H
• Application Number:
  US09/078,822
• Time in Patent Office: 1,454 Days
• Field of Search: 379/221, 379/229, 379/230, 379/346, 379/347
• US Class Current: 379/219
• CPC Class Codes: H04Q 11/0442 Exchange access circuits
• CPC Class Codes: H04Q 2213/13034 A/D conversion, code compression/expansion
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/1322 PBX
• CPC Class Codes: H04Q 2213/13297 Coupling different rates in TDM systems, data rate adaptation

Abstract

A control system for transmission devices equipped with a high-efficiency coding scheme in a communication network which avoids degradation of the quality of an acoustic signal for transmission and permits an efficient transfer of the acoustic signal. The control system has a structure in which: information on a high-efficiency coding scheme used in the preceding transmission device is sent to the current exchange from the preceding one through the use of an out-band signaling system for transmitting and receiving a call control signal via a channel different from a speech channel; and based on the information sent to the current exchange, second-placed transmission devices connected to the current and following exchanges avoid effectively decoding/coding of the acoustic signal transferred thereto, or the use of these transmission devices is avoided.

Claims

1. A control system for transmission devices each equipped with a high-efficiency coding scheme in a communication network in which a first transmission line through each of said transmission devices provided with a coding/decoding circuit for high-efficiency coding/deoding of an acoustic signal and a second transmission line not through said each transmission device are connected to one of a predetermined number of exchanges, CHARACTERIZED IN:

that, in the case of starting the terminating of a transfer operation of a high-efficiency-coded acoustic signal from one of said predetermined number of exchanges, a type of high-efficiency coding scheme to be used and an identifier, which indicates that said acoustic signal has been coded or decoded by said high-efficiency coding scheme, are sent as processing information on said coded acoustic signal which is transferred from said one of said exchanges to a following exchange in said communication network, said processing information being contained in a call control signal indicative of a start of a call; and

that each of said exchanges in said communication network, through which said coded acoustic signal passes in said transfer operation, uses said processing information transferred thereto to select said first transmission line or said second transmission line as an outgoing line so as to avoid degradation of the quality of said acoustic signal due to multi-stage coding and decoding for said high-efficiency coding scheme and to efficiently transfer said acoustic signal.

2. A transmission device control system in a communication network according to claim 1, characterized in that said one of said exchanges is provided with a call controller for effecting a call control operation by a processing function of an out-band signaling system and a switching circuit for circuit switching, said call controller of said one of said exchanges being connected to said transmission device via a transmission switching signal link.

3. A transmission device control system in a communication system according to claim 1, characterized in that said transmission device is provided with a coding/decoding controller, which, based on said processing information, controls whether to enable a high-efficiency coding/decoding scheme of said acoustic signal or to disable the high-efficiency coding/decoding in said transmission device, and a coding rate converter for converting a coding rate of said coded acoustic signal, said coding/decoding controller of said transmission device being connected to a call controller of said one of said exchanges via a transmission switching signal link.

4. A transmission device control system in a communication network according to claim 3, characterized in that:

said processing information is analyzed in said call controller of said one of said exchanges; and

when the transfer of an acoustic signal coded with the same high-efficiency coding scheme as the high-efficiency coding scheme of said first transmission line immediately preceding said one of said exchanges is possible over said first transmission line immediately following said one of said exchanges, said one of said exchanges selects as an outgoing line said first transmission line through said transmission device and provides an instruction via said transmission switching signal link to said coding/decoding controller of each of said transmission devices preceding and following said one of said exchanges connected thereto so that said one of said exchanges permits the passage therethrough of said coded acoustic signal intact without coding or decoding the same, and provides onto said immediately a coding rate of said coded acoustic signal in said coding rate converter.

5. A transmission device control system in a communication network according to claim 3, characterized in that:

said processing information is analyzed in said call controller of said one of said exchanges; and

when the transfer of an acoustic signal coded with the same high-efficiency coding scheme as the high-efficiency coding scheme of said first transmission line immediately preceding said one of said exchanges is impossible over said first transmission line immediately following said one of said exchanges, said one of said exchanges selects as an outgoing line said second transmission line not through said transmission device and provides an instruction via said transmission switching signal link to said coding/decoding controller of said transmission device preceding said one of said exchanges so that said transmission device decodes said coded acoustic signal, and provides onto said immediately following second transmission line said signal decoded to an acoustic signal of non-high-efficiency coding scheme.

6. A transmission device control system in a communication network according to claim 3, characterized in that:

said processing information is analyzed in said call controller of said one of said exchanges;

when it is judged that the transfer of an acoustic signal coded with a second high-efficiency coding scheme different from said high-efficiency coding scheme is possible over said first transmission line immediately following said one of said exchanges, and that degradation of the quality of said coded acoustic signal will be avoided in a coding step by said second high-efficiency coding scheme, said one of said exchanges;

selects as an outgoing line said first transmission line through said transmission device;

provides an instruction via said transmission switching signal link to said coding/decoding controller of said transmission device preceding said one of said exchanges so that said transmission device decodes said coded acoustic signal;

provides an instruction via said transmission switching signal link to said decoding/coding controller of said transmission device following said one of said exchanges so that said transmission device encodes said acoustic signal by said second high-efficiency coding scheme; and

transfer to said immediately following first transmission line a signal obtained by said second high-efficiency coding scheme.