Efficient flooding scheme based on 2-hop backward information in ad hoc networks

Flooding is a basic operation to propagate control messages in most ad hoc routing protocols. Recently, many flooding schemes have been studied to avoid the problems of severe redundancies, contentions, and collisions in traditional implementations. One of the recent efficient approaches is 1HI by Liu et al., which uses only 1-hop neighbor information. The advantage of this scheme is that it achieves local optimality in term of the number of retransmitting nodes with the time complexity O(nlogn), although considerable redundant transmissions still remain. In this paper, we present a novel flooding algorithm to efficiently reduce the number of retransmitting nodes and to solve the broadcast storm problem in ad hoc networks by using our proposed concept of "2-hop backward information." The most important feature of the proposed algorithm is that it does not require any extra communication overhead other than the exchanging of 1-hop HELLO message, while maintaining the high deliverability. Comprehensive simulations are performed to show that the proposed scheme significantly reduces the redundant transmissions in 1HI and pure flooding; accordingly it alleviates the contentions and collisions in networks.