hi,
i am a M.Tech student of IIT Kharagpur and working a project on coverage area of wireless sensor network.

In this text, a simple and fast deterministic solution to the area coverage problem in wireless sensor networks has been described. The method is to is determine whether all points in a region are covered by a given set of sensors, where each sensor may have any arbitrary sensing shape. the area coverage problem is translated into the intersection points' coverage problem - simpler and more suitable for evaluating the area coverage problem.

Introduction
The quality of service (surveillance or monitoring) of a sensor network is directly related to the coverage. Generally, the sensing area is con-

sidered as a perfect disk, where each sensor has het-

erogeneous or homogeneous sensing capability.
Previous works include A solution based on geometric analysis for covering a

convex region by using the same radius of disks is pre-

sented by Wang et al, a coverage evaluation

criterion for covering any shape of monitored region

by using any covering radii circle was given by Gal-

lais.

problem and the solution.
a set of sensing areas, A = {a1 , a2 , . . . ,

an }, and a covered region R is considered. Our task is to determine

whether all points in R are covered by A, namely, any

point in R is covered at least one area in A.


A direct method can be to see all sub-regions divided by the coverage

boundaries of all given areas (e.g., a1 , a2 and a3 ), and

then check if R is covered or not by all sub-regions.
This calculation is very difficult and intensive.
Instead, we
try to look at how the intersection of any two bound-

aries of areas in A and/or the boundary of R is covered.
A set of intersection (SI) to

be collection of points inside R, which includes: (1) the

intersecting points or the two end points of intersecting

lines of any two boundaries of areas in A; or (2) the in-

tersecting points or the two end points of intersecting

lines between any boundary of area in A and the bound-

ary of R.
Sometimes it is desirable to have higher degrees of coverage.

The k-coverage problen is well defined and solved in this text:
http://sciencedirectscience?_ob=ArticleURL&_udi=B6V0F-4R53T43-1&_user=4501256&_coverDate=05%2F16%2F2008&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1203159924&_rerunOrigin=google&_acct=C000059971&_version=1&_urlVersion=0&_userid=4501256&md5=6e487279b19f38d2a6e743873b3af8db

visit this page link too:
http://www3.interscience.wileyjournal/12...1&SRETRY=0