Optimal Transmission Range and Node Degree for Multi-hop Routing in Wireless Sensor Networks

The energy consumed by radio transceivers is a significant factor limiting the lifetime of wireless sensor networks (WSNs). Maximizing WSN lifetime is the overall aim of this work, which proposes that optimal routing be defined with a network design that minimizes the energy consumed by transceivers. This definition of optimal routing is greatly influenced by transmission range, which is adjustable and therefore a candidate predictor or independent variable that affects the criterion, which is the need to minimize energy consumption and thereby maximize lifetime. The effects of transmission range depend on the physical dimensions and node density of the WSN being observed. This dependency binds the result to a particular design and therefore, to be more general, it is noted that transmission range directly controls neighborhood size also known as node degree which forms a more generic predictor of optimal routing as defined in the empirical experiments of this work. Increasing node degree saves energy by reducing hop-count. This benefit, however, is vitiated in a complicated tradeoff that is understood through a broad view of the routing behavior observed at multiple network layers. A final investigation into the primary causes of wasted energy identifies future work that will enable WSNs to reap the energy savings made possible by the improved transmission ranges available with new transceivers.