Patent ID: 6415133
Filing Date: 2002-07-02
Classification: G06F,H03M,H04B,H04H,H04J,H04K,H04L,H04M,H04N,H04W,Y02D

Abstract:
In a bidirectional multipoint-to-point multichannel communications system having a single central head end and a plurality of remote units located remotely from the head end and from each other, a method performed by both said one remote unit and said central head end for acquiring one of said remote units into said system, said method comprising:initializing said one remote unit to communicate with said central head end sending a sync tone from said head end to all of said remote units; sending from said head end an identifier specifying said one remote unit; recognizing said identifier at said one remote unit; at said remote unit, adjusting the frequency of a tuner in response to the frequency of said sync tone; sending an upstream frequency-band designation from said head end unit to said one remote unit; at said remote unit, tuning to said designated frequency band; transmitting a ranging tone at a predetermined power level from said remote unit to said head end; at said head end, comparing a power level of said ranging tone to a desired power level, and sending a power-adjust message to said remote unit; at said remote unit, adjusting a transmission power level in response to said power-adjust message; at said head end, comparing the phase of said ranging tone to the phase of said sync tone, and sending a phase-adjust message to said remote unit; at said remote unit, adjusting the phase of said ranging tone toward a desired phase in response to said phase-adjust message; at said remote unit, sending a locked-in message to said head end when said remote unit has properly adjusted its frequency, phase, and power level.