Optimizing energy consumption in wireless sensor
networks is of paramount importance. There is a recent trend to
deal with this problem by introducing mobile elements (sensors
or sink nodes) in the network. The majority of these approaches
assume time-driven scenarios and/or single-hop communication
between participating nodes. However, there are several real-life applications for
which an event-based and multi-hop operation
is more appropriate. In this paper we propose to adaptively
move the sink node inside the covered region, according to
the evolution of current events, so as to minimize the energy
consumption incurred by the multi-hop transmission of the eventrelated data. Both
analytical and simulation results are given
for two optimization strategies: minimizing the overall energy
consumption, and minimizing the maximum load on a specific
sensor respectively. We show that by adaptively moving the sink,significant power
saving can be achieved, prolonging the lifetime of the network.
