Broadband system with topology discovery

Abstract

Hybrid fiber/coax networks employ the existing cable plant used for cable TV and transmit data signals in a frequency bandwidth above that which is used for cable TV. As this cable plant was deployed in a tree and branch topology, data transmissions may be susceptible to noise, variable transmission loss and frequency dispersion, particularly in the upstream direction. Further, due to the tree and branch topology, homes at the far end of the network experience much greater loss than do the homes that are near to the headend/ONU. The present system, which uses point-to-point data links between intelligent network elements located in the feeder/distribution network to provide reliable, secure, bi-directional broadband access. Digital signals are terminated at the intelligent network elements, switched and regenerated for transmission across additional upstream or downstream data links as needed to connect a home to a headend or router. The intelligent network elements can be co-located with or replace the standard network elements to take advantage of existing network configurations. The standard network elements can be selectively replaced by the intelligent network elements in an incremental approach. A method of discovering the network topology includes sending a message from one of the network elements on a transmission path to a topology server, the message including information identifying the one network element. At each intermediate network element in the transmission path, information identifying each intermediate network element is appended to the message. In this manner, the data links are made over relatively short runs of coax cable, which can provide greater bandwidth than the typical end-to-end feeder/distribution connection between a home and the headend or optical network unit.