A system that provides additional voice lines with data over a single two-wire subscriber loop. At the subscriber premise, one or more telephone instruments and data devices are connected to a digital modem into either a voice or a data interface. Analog voice signals are PCM sampled then packetized,...http://www.google.es/patents/US6747995?utm_source=gb-gplus-sharePatente US6747995 - System for multiple voice lines with data over a single subscriber loop
System for multiple voice lines with data over a single subscriber loop
