Broadcast in a MANET based on the beneficial area

Broadcasting is a common operation in mobile ad hoc networks (MANET). A straightforward approach to perform broadcast in such a mobile environment is by flooding, which will result in the socalled broadcast storm problem with serious redundant rebroadcasts, contentions and collisions. Many methods have been proposed to solve this problem, whose theoretical foundation is to prohibit the rebroadcast when the non-redundant transmission area, namely beneficial area, is too small. It's an open problem to compute the beneficial area for a receiving host when the number of the sending hosts reaches 3 or more. In this paper, we identify this problem by showing how rapidly the complexity of computing the beneficial area rises with respect to the number of sending hosts when a broadcast task is being performed. We propose an efficient approximation method to compute the beneficial area by recursively filling a grid matrix, which can approach the actual one at an arbitrary accuracy. Moreover, we statistically estimate the exponential relationship between the beneficial area and the number of sending hosts, from which we can assert with high possibility that the beneficial area would decrease to zero when the number of the sending hosts reaches six or more.