Patent ID: 6937617

Claim:
An remote transceiver for use in a system having a plurality of remote transceivers that transmit synchronous time division multiplexed frames of upstream data to a central transceiver on a shared medium on the same frequency, comprising: a time division multiplexed receiver having clock and carrier recovery circuits, for recovering a master clock and master carrier transmitted downstream and generating local clock and carrier signals that are synchronized with the recovered master clock and master carrier, and having conventional demodulator, demultiplexer and detector circuits to recover downstream payload data; a time division multiplexed transmitter coupled to receive upstream payload data and said local clock and local carrier signals and including a circuit to organize said payload data into timeslots with preamble data known to said central transceiver inserted into at least some of said timeslots so as to cause said preamble data to be received by said central transceiver preceding reception of any payload data when data in said timeslots is transmitted, and said transmitter including circuitry to transmit said payload data and preamble data in said time slots, but said transmitter having an improvement comprising a ranging circuit that carries out a ranging protocol with a central transceiver to determine a transmit frame timing delay which, when imposed by said time division multiplexed transmitter prior to transmission of each upstream frame, will cause frame synchronization to exist such that each upstream frame transmitted by said remote transceiver arrives at said central transceiver timed so as to have its timeslot boundaries exactly lined up in time with the timeslot boundaries of upstream frames transmitted by other remote transceivers that have already achieved frame synchronization.