At&t Bell Laboratories

At+t Corp.

Bell Telephone Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

At&t Laboratories, Limited

Meyer J Zola

Thomas L Hiller

Ronald A Spanke

Alex Lawrence Wierzbicki

John J Stanaway, Jr

James J Phelan

James C Kennedy

Lawrence J Trimnell

Menachem T Ardon

Douglas S Sand

David A Pierce

Johnny Collins

James M Johnson, Jr

Christopher G McHarg

Douglas C Dowden

Thomas J Starr

Michael Hirsh Cooper

Benjamin C Widrevitz

Paul D Hunter

Ralph A Wilson, Iii

Raymond J Gill

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 being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). 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. Advantageously, large telecommunication networks can be implemented using a small number of switching units. Advantageously, an access switch comprising a cell mapping or distribution stage for assembling cells comprising PCM samples headed for a common output of the access switch are switched in a cell switch to a cell remap unit for collecting PCM samples headed for a common destination into individual cells of an ATM output stream, provides output signals that can be readily and efficiently switched by a transit network for distribution to other access switches of a large network.

Access switches for large ATM networks

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 being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). 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. Advantageously, large telecommunication networks can be implemented using a small number of switching units. For use with PCM switches, it is desirable to provide supervisory signals accompanying the PCM data. Advantageously, this arrangement permits supervisory signals to be passed within an access switch thus simplifying compatibility with existing switching systems.

Intra-switch communications in narrow band ATM networks

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 being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). 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. Advantageously, large telecommunication networks can be implemented using a small number of switching units. Advantageously, a central communications network comprising stages of cell remapping interconnected by one or more stages of cell switching provides flexibility for interconnecting large access switches; the cell remapping stage may be made part of the access switch.

ATM distribution networks for narrow band communications

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 being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). 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. Advantageously, large telecommunication networks can be implemented using a small number of switching units.

ATM networks for narrow band communications

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 being selected from the PCM data streams because they have a common destination. The cells are transmitted over ATM virtual paths, each path transmitting one cell every 125 .mu.s. The ATM signals are switched by units for switching cells (cell switching), while keeping their payload contents intact, and by units for switching the signals for individual voice connections between cells of an ATM signal (cell remapping). 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. Advantageously, large telecommunication networks can be implemented using a small number of switching units. Advantageously, such a cell remap unit provides a key element to the implementation of an efficient large ATM voice network.

Inter-cell switching unit for narrow band ATM networks

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 .mu.s. 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 the use of the principles of this invention for implementing a large switching system or a cluster of highly interconnected smaller systems.

Establishing telecommunications call paths between clustered switching

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 .mu.s. 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.

Establishing telecommunications call paths in broadband communication

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 .mu.s. 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 methods of establishing connections in accordance with the principles of the invention.

Establishing telecommunications calls in a broadband network

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 .mu.s. 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.

Apparatus for interfacing between telecommunications call signals and

A switching system including a number of switching modules each having a plurality of access ports. Incoming and outgoing packet channels are extended between each switching module and an inter-module packet switch. Each switching module includes a packet switching unit that transmits user information packets, received from the access ports, via the incoming packet channel to the inter-module packet switch, and switches user information packets, received via the outgoing packet channel from the inter-module packet switch, to the access ports for inter-module packet-switched communication. The intermodule packet switch concurrently packet switches user information packets, received on a number of the incoming packet channels, via multiple independent paths to a number of the outgoing packet channels.

Distributed packet switching sytem

An operator or agent position, for use by a telephone assistance operator or an agent of a business, communicates with the circuit and packet switching network of a telecommunication switching system using an Integrated Devices Digital Network (ISDN) B-channel and D-channel. The switching network is connected to customers, positions, data communication paths to data bases, and a data path to control processor of the system. The B-channel is connected through a circuit switching network to a customer. The D-channel is connected through a packet switching network to the control processor and to data bases. Advantageously, the positions can be located remotely from the switching network because only a single integrated facility is required to transmit the integrated voice and data signal between a position and the network. Advantageously, a variety of data bases can be rapidly and efficiently accessed by a position.

Operator communication arrangements for operator assistance systems

An arrangement comprising a host switching system and a number of remote switching modules which are directly interconnected such that voice and data traffic as well as control information can be conveyed between modules without being routed through the host system network. The arrangement allows the integrated stand-alone operation of the remote switching modules and advantageously reduces traffic through the host system network during normal operation.

Control communication in a switching system having clustered remote

An arrangement comprising a host switching system and a number of remote switching modules which are directly interconnected such that voice and data traffic as well as control information can be conveyed between modules without being routed through the host system network. The arrangement allows the integrated stand-alone operation of the remote switching modules and advantageously reduces traffic through the host system network during normal operation. For each pair of remote switching modules, one of the modules selects the channels of the direct interconnection which are used for conveying information between the modules.

Channel selection in a switching system having clustered remote

An arrangement comprising a host switching system and a number of remote switching modules which are selectively interconnected by a time-multiplexed switch such that voice and data traffic as well as control information is conveyed between modules without being routed through the host system network. The arrangement allows the integrated stand-alone operation of the remote switching modules and advantageously reduces traffic through the host system during normal operation.

Switching system having selectively interconnected remote switching

An arrangement and method for interconnecting the stages of a space division switching network which provides simple and continuous growth from a small number of lines to the system's maximum number of lines. The switching network comprises up to M input stage switches, center stage switches and up to M output stage switches. Incoming lines are connected to the input terminals of the input stage switches such that no input stage switch is connected to a number of incoming lines which exceeds the number of incoming lines connected to any other input stage switch by more than one. The number of center stage switches is established from a predetermined interconnection plan and at any given time, the number of center stage switches is a function of the number of lines connected to the input stage switch having the largest number of lines connected thereto. As each line is connected to an input stage switch, the output terminals of that switch are distributed over the available center stage switches. The output stage switches are connected to the center stage switches and to outgoing lines in analogous manner.

Growing community of inventors

Oak Park, IL, United States of America

Meyer J Zola