An adaptive MAC for HomePlug Green PHY PLC to support realistic smart grid applications

HomePlug Green PHY (HPGP), designed to address the needs of Smart Grids, uses the carrier sense multiple access with collision avoidance (CSMA/CA) scheme to define its multiple access control (MAC). Similar to the IEEE 802.11, the MAC efficiency of HPGP protocol degrades when the number of users increases. This paper examines a comprehensive high-load simulation of the IEEE 802.11 DCF backoff mechanism, compares the performance of this mechanism with the performance of P1901/HomePlug MAC, and introduces a constant contention window MAC - a novel MAC protocol that maximizes efficiency in a heavily-loaded smart grid environment. In the proposed MAC protocol, every node generates a run-time channel traffic estimation and an adaptive contention window size adjustment. We demonstrate that, whereas the HPGP´s MAC efficiency drops down to about 15%, the proposed adaptive MAC protocol retains its efficiency at about 81% with up to 100 users.