Available-bandwidth-based routing in IEEE 802.15.4-based Ad-Hoc networks: Proactive vs. opportunistic technique

In this paper, we present an available-bandwidth-based proactive routing protocol for IEEE 802.15.4-based single-sink and multi-sink ad-hoc networks. The available-bandwidth-based proactive routing protocol maintains the best forwarding path in terms of the end-to-end available bandwidth towards each sink node present in a network. Moreover, a node can maintain more than one data forwarding path towards the same sink node. We performed extensive simulations, and compared our proactive routing protocol with a state-of-the-art opportunistic routing protocol. The simulation results demonstrate that the opportunistic routing protocol can distribute data load unevenly (in case of multiple sink nodes), hence results in high end-to-end delay and low Packet Delivery Ratio (PDR). In case of our proactive routing protocol, selecting forwarding paths by only considering the end-to-end available bandwidth invariably results in lengthy data forwarding paths. Lengthy data forwarding paths results in higher intra-flow contention, hence PDR and end-to-end delay are impacted. One of the simulation scenarios, using multiple sink nodes, demonstrates that in case of our proactive routing protocol, carefully selecting the data forwarding path(s) that are not too long compared to the shortest available data forwarding path(s), but have better end-to-end available bandwidth significantly improves the performance of the proactive routing protocol. Therefore, our results hint that, in general, trading off end-to-end available bandwidth and the length of a data forwarding path may improve end-to-end PDR and delay