A typical wireless sensor network performs only one
action: sensing the environment. The need for smart interaction
with the environment has led to the emergence of Wireless Sensor
and Actor Networks (WSANs), where a group of sensors, actors
and the sink linked by wireless medium perform distributed
sensing and acting tasks.
In WSANs, it is important that the actors act only to the
appropriate level when the event occurs in order to perform the
desired action on the evironment. In this context, we identify the
problem of mutual exclusion, which is the need to act only once
for any particular location and command. We define three flavors
for mutual exclusion and show the undesirable consequences of not
providing mutual exclusion. In this context, we discuss the design of
centralized and distributed approaches required to address this
problem efficiently. Through a preliminary set of simulations we study the
performance of the proposed solution and two basic strategies.