Method and apparatus for coordinating multi-point to point communications in a multi-tone data transmission system

摘要

A variety of bidirectional data transmission systems that facilitate communications between a plurality of remote units ( 15 ) and a central unit ( 10 ) using a frame based discrete multi-carrier transmission scheme are disclosed. In each of the systems, frames transmitted from the plurality of remote units ( 15 ) are synchronized at the central unit ( 10 ). A variety of novel modem arrangements and methods for coordinating communications between a plurality of remote units ( 15 ) and a central unit ( 10 ) to facilitate multi-point-to-point transmission are disclosed. The invention has application in a wide variety of data transmission schemes including Asymmetric Digital Subscriber Line systems that includes the transmission of signals over twisted pair, fiber and/or hybrid telephone lines, cable systems that includes the transmission of signals over a coaxial cable, and digital cellular television systems that include the transmission of radio signals.