Adaptive Probabilistic Broadcasting over Dense Wireless Ad Hoc Networks

We propose an idle probability-based broadcasting method, iPro, which employs an adaptive probabilistic mechanism to improve performance of data broadcasting over dense wireless ad hoc networks. In multisource one-hop broadcast scenarios, the modeling and simulation results of the proposed iPro are shown to significantly outperform the standard IEEE 802.11 under saturated condition. Moreover, the results also show that without estimating the number of competing nodes and changing the contention window size, the performance of the proposed iPro can still approach the theoretical bound. We further apply iPro to multihop broadcasting scenarios, and the experiment results show that within the same elapsed time after the broadcasting, the proposed iPro has significantly higher Packet-Delivery Ratios (PDR) than traditional methods. 1. Introduction Classical performance analyses for multihop broadcast mostly focus on single-source sporadic broadcasting over network topologies with appropriate network densities. In the paper, we examine the scenarios that two or more sources continuously broadcast over the network at the same time, and observe that the packet-delivery performance of traditional methods degrades along with the increases of the network density and the number of broadcast sources. To improve the broadcast performance, we propose an adaptive probabilistic mechanism, iPro, which operates atop standard IEEE 802.11 with constant contention window-size. The proposed method was first analyzed in one-hop saturated scenarios, where the modeling and ns2 simulation results show that the proposed iPro approaches theoretical throughput maximum. After that, the proposed iPro integrating with counter-based scheme is further applied to multihop broadcast scenarios, where the performance of the proposed method is also significantly better than existing methods. A wireless ad hoc network consists of a set of nodes where the data delivery among nodes does not depend on any infrastructure; instead, nodes self-organize and relay messages among one another. A Mobile ad hoc Network (MANET) is a kind of wireless ad hoc network with mobility. Typically, a node in MANETs does not have fixed mobility patterns, and the power of the node would be limited. A Vehicular ad hoc Network (VANET) is a special case of MANET, with less concern on power consumption, intended for vehicles to communicate with other vehicles or with the road side infrastructures. Broadcast is a common communication operation in wireless ad hoc networks. In proactive routing, a node needs to exchange