Extending lifetime of sensor surveillance systems in data fusion model

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I. INTRODUCTION
In sensor surveillance system, it consists of a set of wireless
sensor nodes and a set of targets. Each target needs to be
monitored by sensors all the time. The sensors which are
powered by batteries have limited energy constraint and it
is not easy to recharge them. Hence, energy efficiency is an
important issue. The lifetime of the sensor surveillance system
needs to be extended as long as possible.

II. RELATED WORK
There are some research works about how to prolong the
lifetime of sensor networks. The basic idea of these papers is
to save the energy of sensor nodes by activating them in turn.
In [1], Liu et al. determined the workload matrix by using
linear programming and achieved the maximal lifetime by
decomposing the matrix into a series of scheduling ones. They
assumed that every sensor node can monitor at most one target
at each time. This work was extended in [2] by considering the
communication cost. In [4], Tian and Georganas turned off the
sensor node when its neighbors can help it to watch the area
by proposing a localized scheduling scheme.


III. BACKGROUND AND PROBLEM STATEMENT
In this section, we introduce the background of this paper,
which includes the sensing model and the data fusion model.
Then, we present the problem statement.

IV. OUR SOLUTION
In this section, we introduce our solution. The basic idea
is to find cover sets one by one. We find and activate only
one cover set at a time and let sensors in it work until one of
them depletes its energy. Then we find another cover set and
activate it. This process is repeated until one or more targets
can not be monitored by sensors which have remaining energy.
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