Adtran Gmbh

Lonnie S McMillian

Michael Scott Sansom

W Stuart Venters

Wade S Schofield

Barry S Smith

Robert James Toth

Gary M Willoughby

Roger W Cain

Robert E Bowlin

A multi-circuit emulating line card is installable in a single line card slot of the backplane of digital switch, and is configured to emulate the functionality of each of a plurality of digital switch line cards, respectively associated with plural digital subscriber circuits served by the switch. In the course of emulating these plural line cards, the multi-circuit line card provides connectivity between each digital subscriber circuit and a digital carrier communication link to plural digital subscriber loop circuits, such as BRITE cards of a remote terminal site. The line card of the invention also includes network and subscriber circuit-associated metallic link impedance simulation circuits for terminating a metallic test bus.

Digital switch-resident multi-circuit line card providing direct connection to remote terminal

Digital switch-resistant multi-circuit line card providing direct connection to remote terminal

A composite circuit card architecture conforms with a prescribed form factor for installation in a card slot and connection to a backplane of a multiple circuit card-supporting housing. Only a portion of the card is comprised of printed wiring board material, while the remainder, where no printed circuit components are installed, is a support substrate formed of a material other than that of said printed wiring board. Also, a front panel portion is formed of the material other than that of the printed wiring board, such as plastic integrally molded with the support substrate, thereby significantly reducing the cost associated with the conventional approach of making the entire card from printed circuit board material. At one communication link, such as a ribbon cable, may be coupled between the printed wiring board and at least one input/output port at the front panel.

Form factor-configured channel bank card containing form factor non-conformal printed circuit board

Form factor-configured channel bank card containing form factor

To extend the transmission distance for basic rate integrated services digital network (ISDN) communications between a first site and a second site, the basic rate ISDN channel is demultiplexed onto a pair of half-rate digital subscriber loop channels, which employ an out of band maintenance channel to convey differential delay compensation information, but without modifying the framing structure of the transported channels, or requiring additional bandwidth for a separate framing channel. Halving the data rate, to increase the distance over which the basic rate ISDN channel may be transported, operates as a trade-off against loop loss, while still complying with ANSI standards.

Four-wire, half-rate architecture with embedded differential delay

An office channel unit data port is modified to incorporate a test tone detector and modified control software, to provide an analog service channel port that is capable of responding to analog test tones sourced from an analog tone-based test service facility, in order to test local and remote communication channels and analog/digital interface equipment. In addition, operation control codes have prescribed function-representative values that do not introduce disturbing `glitches` onto the analog line; instead when converted into analog format they produce respective voltages that effectively correspond to voltage levels expected to be seen by an analog channel, while conforming with the accepted practice of permitting a zero to be used in the LSB position for control code purposes.

Analog service channel port for digital interface

Growing community of inventors

Madison, AL, United States of America

Lonnie S McMillian