PCUP - PIPELINED CYCLIC UPSTREAM PROTOCOL OVER HYBRID FIBER COAX

In order to bring NII (National Information Infrastructure) into the h ome, the community cable TV networks have to be reengineered to suppor t two-way interactive services. In this work, the authors propose PCUP (Pipelined Cyclic Upstream Protocol) as the upstream MAC (medium acce ss control) protocol for HFC (hybrid fiber coax) community access netw ork. PCUP is designed with the intention of pipelining the upstream ch annel. This is achieved by proper station positioning, which measures the station propagation offset from the headend, and transmission sche duling, which assigns each station a transmission starting time and du ration in a cycle. By taking into account the propagation offsets and transmission times, transmitted cells can appear back-to-back (i.e., p ipelined) at the headend. Since only the active stations are scheduled to transmit in a cycle, a membership control mechanism, which runs a contention-based tree walk algorithm, is executed periodically to allo w the stations to join or leave. The authors also compare PCUP with va rious schemes proposed to IEEE 802.14 committee.