Coverage restricted to an angle

Given a set S of n antennas and point q on the plane, q is @a-covered by S if @?s"i,s"j@?S such that the angle @?(s"i,q,s"j)>=@a. It is shown how to minimise the transmission range of S to @a-cover a point in O(n) time and space, and how to construct the @p2-covered region in O(nlogn) time and O(n) space. Finally, this paper introduces the Coverage Voronoi diagram and an algorithm to construct it in O(n^4logn) time.