Patent ID: 7738478

Claim:
An apparatus for determining a downstream topology in a hybrid-fiber-coaxial network, comprising: a signal branching unit for branching a signal received from a cable modem termination system into a plurality of branched signals; a plurality of signal selecting units for selectively receiving a frequency band signal corresponding to a specific downstream channel among the plurality of branched signals; a downstream topology determining unit for analyzing a downstream ambiguity resolution frequency list contained in a channel information message of a downstream primary channel received from the cable modem termination system, collecting in parallel channel information messages with respect to a plurality of downstream channels, and determining a downstream topology at a high speed using the collected channel information messages; and a plurality of packet generating units for setting downstream channel frequency bands of the signal selecting units under control of the downstream topology determining unit, and sending the channel information messages of the collected downstream channels to the downstream topology determining unit; wherein the downstream topology determining unit analyzes the channel information message received through a downstream primary channel to create a visible downstream channel ID list having a downstream channel ID of a current downstream channel as a first entry, determines if a downstream channel ID list of a downstream service group containing the created visible downstream channel ID list exists uniquely, records a downstream service group ID of the unique downstream service group list to determine the downstream service group of the apparatus when the downstream channel ID list exists uniquely; collects the channel information messages from a plurality of downstream channels according to an order recorded in the downstream ambiguity resolution frequency list when the downstream channel ID list does not exist uniquely; and wherein the process of determining the downstream topology determines number (N) of current receivable channels and number (M) of downstream ambiguity resolution frequency lists, sets a frequency selectable from the downstream ambiguity resolution frequency list as a downstream frequency by decreasing the values of M and N by one while sequentially selecting frequencies according to the order recorded in the downstream ambiguity resolution frequency list, collects the channel information messages from the downstream channels in parallel when the value M or N is zero, and repeats the process of determining the downstream topology.