Digital signal processor-based telephone test set

摘要

A digital signal processor-based test set programmed to enable a craftsperson to monitor, and process signals of a variety of formats that are present on a line under test, including user feature analog modem type signals. Such signals may include caller-identification signals, visual message waiting indicator signals, and analog display services interface signals. Through embedded mirrored echo cancellation routines, the test set's supervisory DSP is able to provide what is effectively 'hands-free', full-duplex, dual direction acoustic speakerphone functionality, that allows the field technician to talk, while simultaneously listening to an acoustic output being generated by the test set's receiver.