Energy efficiency of large-scale wireless networks: proactive versus reactive networking

An analytical approach to the characterization of energy consumption of large-scale wireless networks is presented. The radio model includes energy consumption of nodes at various operating states. We analyze the total energy consumption of the proactive and the reactive networking strategies, taking into account transmitting, listening, and sleeping energy. Scaling laws with respect to the increase of node density and geographical size are derived. Energy efficiency and overhead at the physical and the network layers are evaluated against message duty cycle, channel fading rate, and node mobility. The crossover point in message duty cycle below which reactive network has assured advantages is obtained. The analysis is then applied to large-scale sensor networks for applications involving data-centric and location-centric queries. The ad hoc sensor network architecture is compared with sensor networks with mobile access points.