Efficient flooding in ad hoc networks: a comparative performance study

Many ad hoc network protocols (e.g., routing, service discovery, etc.) use flooding as the basic mechanism to propagate control messages. In flooding, a node transmits a message to all of its neighbors. The neighbors in turn transmit to their neighbors and so on until the message has been propagated to the entire network. Typically, only a subset of the neighbors is required to forward the message in order to guarantee complete flooding to the entire network. If the node geographic density (i.e., the number of neighbors within a node’s radio reach) is too high, one can easily see that flooding can become very inefficient because of redundant, “superfluous” forwarding. In fact, superfluous flooding increases link overhead and wireless medium congestion. In a large network, with heavy load, this extra overhead can have severe impact on performance and should be eliminated. Many efficient flooding schemes have been recently proposed in ad hoc networks. In this paper, we compare the performance of a set of representative schemes via simulation using as criteria the flooding efficiency and the delivery ratio.