At+t Corp.

Lucent Technologies Inc.

Arik Kashper

Steven S Katz

Thomas S Giuffrida

Bharat Tarachand Doshi

Norman Farber

Behram H Bharucha

Kathleen S Meier-Hellstern

P Harshavardhana

Rajiv Kapoor

N Farber

Pravin Kumar Johri

Mahalakshmi Jairam

Paramasiviah Harshavardhana

Thomas S Guiffrida

Patamasiviah Harshavardhana

Notman Farber

This proposal outlines an approach for interfacing Synchronous Transfer Mode (STM) and Asynchronous Transfer Mode (ATM) networks and for transporting voice, fax and voice-band data calls by the ATM network in an efficient manner. In contrast to the well known ATM Variable Bit Rate (VBR) approach, this proposal allows one to transport 64 kb/s traffic efficiently over ATM by re-using STM network signaling and exploiting the standard AAL-1-type adaptation layer (intended for Constant Bite Rate, CBR, services). We use low bit rate encoding algorithms and achieve additional compression for speech by marking cells that do not contain talk spurts. The invention defines specific rules for STM-to-ATM interfacing, including all routing translation, and identifies necessary Terminal Adapter (TA) and ATM switch capabilities. This approach is an advancement over previous inventions that specified network architecture and terminal adapter requirements to provide a graceful transition from an STM network (for example the AT&T long distance network) to an ATM network. Prior art described how to emulate an STM network in the ATM domain, but did not permit for compression and silence elimination and, therefore, did not allow achieving efficiency gains.

Voice-over-ATM switch architecture allowing congestion-dependent transport of silence cells

Telecommunications network architecture for transporting fax, voice and data via an ATM switch including a STM to ATM terminal adapter

An Asynchronous Transfer Mode (ATM) network comprising a plurality of ATM switches may be arranged so that it receives calls from Synchronous Transfer Mode (STM) switches that employ in-band signaling by first converting in-band signals received from an STM switch to an out-of-band signaling message and then transmitting the message to the ATM switch that will route the associated call toward its destination. At an interface which interfaces the ATM switch with the out-of-band signaling network, the contents of the received message are converted to a form suitable for presentation to the ATM switch. For example, the identity of the trunk over which the call will be routed from the STM switch to the ATM switch is converted to a virtual channel identifier.

ATM network arranged to interface with STM in-band signaling

The call processing capacity of the of a telecommunications network by forming the communication switches forming the network into respective groups of communication switches. The communication switches forming a respective group of switches are fully interconnected to one another and then each of the communications switches forming a respective group is connected at least one other group of telecommunication switches as a way of interconnecting the groups with one another.

Telecommunications system architecture

The efficiency of a telecommunications network is enhanced by associating each of the communication switches forming the network with an external connection control processor and forming the switches into respective groups of communication switches. The communication switches forming a respective group of switches are fully interconnected to one another and then each of the communications switches forming a respective one of the groups is connected at least one other group of telecommunication switches as a way of interconnecting the groups with one another.

An Asynchronous Transfer(ATM) network comprising a plurality of ATM switches may be arranged so that it receives calls from Synchronous Transfer Mode (STM) switches that employ out-of-band signaling such that the ATM switches communicate telephone call signaling information between each other and the STM switches via an out-of-band signaling network associated with the ATM network and interface with out-of-band networks associated with the STM switches.

ATM network architecture employing an out-of-band signaling network

An Asynchronous Transfer Mode (ATM) network comprising a plurality of ATM switches may be arranged so that it may receive for routing telephone calls originating at Synchronous Transfer Mode (STM) switches. This may be done in the ATM network by accumulating voice signals as they are received from a STM switch and forming an ATM data-cell payload when the accumulation includes a predetermined number of the voice signals, e.g., 48 voice signals. The payload and a header, including a virtual channel identifier determined as a function of the identity of the STM trunk over which the voice signals were received, may then be supplied to an associated ATM switch for routing to an intended destination.

Terminal adapter for interfacing an ATM network with a STM network

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Holmdel, NJ, United States of America

Arik Kashper