Performance Analysis of Single- and Multi-Channel Contention Resolution Algorithm for the DOCSIS MAC Protocol

Data-over-cable service interface specification (DOCSIS) MAC protocol is the de facto standard for hybrid fiber coax (HFC) network, and has also given leverage to IEEE 802.16 MAC protocol. The primary medium access control (MAC) function is contention resolution algorithm (CRA), called frame-based truncated binary exponential back-off (F-TBEB), for bandwidth requests from cable modems. The DOCSIS MAC is on the upgrade by introducing channel bonding concept in that the multiple channels can be combined together to get greater aggregate bandwidth. This paper provides a simple analytical model to compute the F-TBEB delay and throughput in single DOCSIS channel. Furthermore, we give two solutions to the problem of CRA on multiple channels and use the analytical model to determine which solution is superior.