Energy optimization in multihop wireless embedded and sensor networks

The paper provides an analytical model for the study of energy consumption in multihop wireless embedded and sensor networks. The nodes in this type of network are battery-powered and therefore must be extremely frugal with their energy budget. The networks usually have a large number of nodes whose deployment and topology is application dependent. Low-power optimization techniques developed for conventional ad hoc networks are not sufficient as they do not properly address particular features of embedded and sensor networks. As well as reducing overall energy consumption, it is also important to maximize the network lifetime, that is, maintain full network connectivity for as long as possible. The paper considers different multihop scenarios to compute the energy per bit, efficiency, and the energy consumed by individual nodes and by the whole network. The analysis uses a detailed model for the energy consumed by the radio at each node. Multihop topologies with equidistant and optimal node spacing are studied. Numerical computations illustrate the effects of packet routing. These results show that using a simple multihop message relay strategy is not always a good procedure to extend a network´s lifetime. Depending on the radio hardware characteristics and on the topology, direct relay to a sink or a routing mechanism that bypasses intermediate nodes can sometimes be the recommended procedure.