Lucent Technologies Inc.

Randy Lee Hafer

Dewayne Alan Spires

John C Gammel

Robert H Vaiden

Ronald Joseph Rees

Christine Mary Gervesh

Automatic testing a group of line circuits on a smart line card served by a central switch over a PCM bus is localized by using the microprocessor/DSP that provides codec functions for the group of line circuits. Tests such as DC overhead that are not performable by the central switch over the PCM bus are performed by the microprocessor/DSP when informed by the central switch that at least one of the channels is not processing voice signals. The microprocessor/DSP controls test switches on the line card to set-up various test terminations for the idle circuit as well as to selectively control the gain of the idle channel's amplifiers. The microprocessor/DSP synthesizes test tones and executes test tone detection processes within the time slot intervals accorded by the central switch to the idle channel. Among the tests performed are Forward Loop Gain with different resistance terminations, cable and fuse tests, DC overhead, and idle channel noise utilizing a limited number of test routines such as tone generation, DC generation, discrete Fourier transform, peak detection and variance from acceptable limits. The pass/fail condition of the idle channel under test is reported to the central switch.

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Kutztown, PA, United States of America

Randy Lee Hafer