PCUP: pipelined cyclic upstream protocol over hybrid fiber coax

In order to span the NII (National Information Infrastructure) into the homes, the community cable TV networks have to be re-engineered to support two-way interactive services. We propose the PCUP (pipelined cyclic upstream protocol) as the upstream MAC (medium access control) protocol for HFC (hybrid fiber coax) community access network. The PCUP is designed with the intention of pipelining the upstream channel. This is achieved by proper station positioning, which measures the station propagation offset from the headend, and transmission scheduling, which assigns each station the transmission starting time and duration in a cycle. By taking into account the propagation offsets and the transmission times, the transmitted cells can appear back-to-back, ie. pipelined, 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 allow the stations to join or leave. We also compare the PCUP with various schemes proposed to IEEE 802.14 committee.