On the number of transmissions vs. redundancy tradeoff for flooded fountain codes

Abstract

We consider a multihop ad hoc network where a source node must reliably deliver a set of data packets to a given destination node. To do so, the source applies a fountain code and floods the encoded packets through the network, until they reach their destination or are lost in the process. We model the probability that the destination can recover the original transmissions from the received coded packets as a function of the network topology and of the number of redundant packets generated by the source, and show that our analytical results predict the outcome of simulations very well. These results are finally employed to discuss how the number of cooperating relays and the redundancy of the code should be set in order to achieve a good working point on the tradeoff between the reliability of end-to-end communications and the number of packet transmissions that take place in the network

Controlled Flooding of Fountain Codes

“…In this paper, we extend the work in [11] in several respects. First, while we maintain the analysis simple and tractable, we employ a more realistic physical layer model including path loss and fading in our simulation results.…”

“…In our recent work [11], we analyzed the interplay between fountain codes and flooding, by considering both a full flooding and a restricted flooding policy. Given the amount of redundancy generated at the source, the number of hops, and the number of relays that interact at each hop, we derive the average number of transmissions required to achieve a prescribed probability of success at the destination.…”