Count on me: lightweight ad-hoc broadcasting in heterogeneous topologies

Broadcast algorithms are a fundamental building block of a number of ad-hoc protocols and mobile applications. Broadcast primitives in ad-hoc wireless networks should ideally be lightweight and use passive data to determine whether to retransmit a message. They must also deliver messages with a high probability while tolerating adverse network conditions. This paper looks at the particular problem of heterogeneous topologies, in which some regions of an ad-hoc network are critical to the propagation of messages. Traditional broadcast protocols do not perform well in these topologies, while others require complex data structures, some form of training or convergence, or some active route discovery and maintenance. To alleviate these limitations, this paper explores three new lightweight mechanisms that use passive retransmission data to try to recognise a node's importance within a wireless network. By combining these three mechanisms, we construct a family of protocols based on the previously published PAMPA algorithm. Our preliminary evaluation shows that one of these variants is particularly promising, presenting higher delivery ratios in adverse conditions for a small communication overhead.