Model for polling in noisy multihop systems with application to PLC and AMR

The present paper presents a Markov chain model of polling in noisy multi-hop systems typical of power line communications (PLC) as well as of other systems. The model includes the transmission of a backwards error indication packet (BEIP) to the master when the transmission is blocked in one of the downstream hops as well as the possibility to reduce the global time-out value below that strictly necessary to avoid having two simultaneous polls within the system. Two case studies are presented; the OPERA PLC access broadband specification and a narrow band PLC based automatic meter reading (AMR) system. Explicit formulas for the delay in these systems and curves representing the behavior of the studied cases are given.