(under subclass 1) Subject matter including transmitting a known signal from a testing location over a communication path to a second remote location which retransmits the known signal back to the testing location for use in evaluating the transmission path or a device are the remote location.
SEE OR SEARCH CLASS
370, Multiplex Communications,
249, for loopback testing in a multiplex system.
714, Error Detection/Correction and Fault Detection/Recovery,
716, for loopback testing of a communications circuit of general utility by a digital test signal.
