Performance-lifetime tradeoff for source extraction in multihop sensor networks

This paper intends to reveal the performance-lifetime tradeoff for source extraction in a multihop sensor network. The randomly deployed sensor network consists of multiple independent branches. The leaf node in each branch takes an observation from the sensing field. The observation is assumed to be a noisy instantaneous linear mixture of the sources. To account for the bandwidth constraint, each leaf node quantizes its observation and sends the quantized data to the sink in a multihop fashion. The observed mixtures are reconstructed at the sink and are utilized to extract the sources. The accumulated bit error probability in each branch depends on the number of hops and the bit error probability of each channel in that branch. The communication errors affect the accuracy of reconstructing mixtures, and hence affect the performance of source extraction. Network lifetime is defined and analyzed under both per-sensor energy constraint and network energy constraint. The tradeoff between performance and network lifetime is described by optimization problems and the conditions for optimization are identified. As a by-product, the conditions for maximizing the network lifetime are also identified. Simulation results demonstrate that the tradeoff exists under certain situations.