Apparatus for interfacing between telecommunications call signals and broadband signals

Patent 5327421 Issued on July 5, 1994. Estimated Expiration Date:

November 6, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

System for cross-connecting high speed digital SONET signals
Patent #: 4967405
Issued on: 10/30/1990
Inventor: Upp, et al.

Resource-decoupled architecture for a telecommunications switching system
Patent #: 4970721
Issued on: 11/13/1990
Inventor: Aczel, et al.

Service clock recovery for variable bit rate services Patent #: 5204882
Issued on: 04/20/1993
Inventor: Chao, et al.

Inventors

Assignee

AT&T Bell Laboratories

Application

No. 972786 filed on 11/06/1992

US Classes:

370/395.61, Adapting constant bit rate (CBR) data (e.g., voice, or narrow band ISDN over ATM, or using AAL1)370/369, Having time and space switches370/474Assembly or disassembly of messages having address headers

Examiners

Primary: Chin, Wellington
Assistant: Ton, Dang

Attorney, Agent or Firm

Ulrich; Werner

Foreign Patent References

0225714 EP. 06/13/1987

International Class

H04L 012/56

Abstract

In accordance with the principles of this invention, Pulse Code Modulation (PCM) signal streams are converted into Asynchronous Transfer Mode (ATM) cells for switching and transmission across a telecommunications network. Each cell carries one PCM sample of up to 48 different voice connections, the voice connections selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual circuits, each circuit transmitting one cell every 125 μs. Advantageously, ATM transmission systems interface with PCM systems without adding appreciable delay and without requiring additional buffering. Advantageously, new voice paths can be established most of the time by using available slots in the cells of existing virtual paths. This application relates to arrangements for converting the PCM signal streams into ATM cells.

Other References

R. Hazell, editor, "Broadband Technology", Electrical Communication, vol. 65, No. 1, (Telecom 91), Oct. 1991, pp. 12-18--Broadband Technology, pp. 19-21--Evolution of Alcatel Exchanges
K. Y. Eng et al., "A Framework For A National Broadband (ATM/B-ISDN) Network", International Conference on Communication ICC'90, vol. 2, Apr. 1990, Atlanta, pp. 515-52