Circuit-switched wireless sensor networks: a discrete-time communication model for performance analysis

We consider a novel discrete-time model to analyze the performance of circuit-switched sensor networks. In particular, we assume that a node, after reserving a multi-hop communication route to the desired destination, holds it for a time interval defined as reserved channel utilization interval (RCUI) and utilizes it for an effective channel utilization interval (ECUI). A realistic network communication scenario with inter-node interference (INI) and a reservation-based medium access control (MAC) protocol with finite numbers of (active) routes (FNR) in the network is first considered, and the average interference power is evaluated through a novel combinatorial analysis. Results are presented in terms of effective transport capacity and channel utilization ratio (CUR). In particular, we show that for very low values of the packet generation rate at each node, activation of the maximum possible number of routes guarantees no loss, in terms of effective transport capacity, with respect to an ideal (no INI) scenario. However, this comes at the expense of a very low utilization: in other words, once a multi-hop route has been reserved, its effective utilization time must be a few orders of magnitude lower than the duration of the reservation interval.