Patent ID: 7826491

Claim:
A method for synchronizing operation of distributed cable modem termination system components, the method comprising: operating a head end, a downstream transmitter hub, and an upstream receiver hub, each being components within the distributed cable modem termination system components, and also operating a plurality of cable modems for establishing frequency lock with a common frequency reference; transmitting a plurality of time stamps from the head end to the plurality of cable modems via a packet data network, the downstream transmitter hub, and cable modem network plant; operating each of the plurality of cable modems for performing smoothing operations on the plurality of time stamps to smooth jitter incurred within the plurality of time stamps during transmission via the packet data network and to establish phase lock with the head end; and cooperatively performing ranging operations by the downstream transmitter hub, the upstream receiver hub, and the plurality of cable modems to establish phase lock among the plurality of cable modems and to synchronize clocks respectively included within each of the downstream transmitter hub the upstream receiver hub, wherein ranging operations as performed by the plurality of cable modems involving processing first ranging bursts received from the downstream transmitter hub and ranging operations as performed by the upstream receiver hub involving processing second ranging bursts received from the plurality of cable modems.