  The field of Wireless Sensor Networks (WSNs) is experiencing a resurgence of
interest and a continuous evolution in the scientific and industrial community.
The use of this particular type of ad hoc network is becoming increasingly
important in many contexts, regardless of geographical position and so,
according to a set of possible application. WSNs offer interesting low cost and
easily deployable solutions to perform a remote real time monitoring, target
tracking and recognition of physical phenomenon. The uses of these sensors
organized into a network continue to reveal a set of research questions
according to particularities target applications. Despite difficulties
introduced by sensor resources constraints, research contributions in this
field are growing day by day. In this paper, we present a comprehensive review
of most recent literature of WSNs and outline open research issues in this
field.
