A digital radiotelephone exchange having self diagnostic individual subchannel loopback is disclosed. An individual subchannel of an outbound PCM data stream is substituted for an individual subchannel of an inbound PCM data stream. The removed individual subchannel of the inbound PCM data stream is...http://www.google.fr/patents/US4860281?utm_source=gb-gplus-shareBrevet US4860281 - Individual subchannel loopback in the PCM interfaces of a digital telephone exchange with control of the outbound path
Individual subchannel loopback in the PCM interfaces of a digital telephone ...
