Method and apparatus for the generation of analog telephone signals in digital subscriber line access systems

摘要

A method and apparatus for providing analog telephony services over a digital subscriber loop access system is presented. Digital subscriber loop technologies including Asymmetric Digital Subscriber Loop (ADSL) leave existing POTs services undisturbed by utilizing spectrum above the POTs band for data services. An Asynchronous Transfer Mode (ATM) cell mapping is utilized on an ADSL linecard which permits flexible mapping of compressed or uncompressed voice signals into ATM cells along with overhead and signaling channels. Echo cancellation is used to enhance the voice quality in compressed voice signals. The ATM cells can be transmitted to a subscriber residence or a business and one to four additional analog telephony lines supported a receiving units, in addition to data services. This allows the first telephone line to be operated in the traditional manner as an analog connection over the twisted wire pair, data services provided in the ADSL connection, and additional phone lines to be supported without the installation of more twisted wire pair connections to the residence or business.