A novel routing protocol for reducing packet delay with multi-beam antennas

Abstract

Ad hoc networks are infrastructureless networks consisting of static and/or mobile nodes. These networks are deployed for a wide range of applications. Having an efficient routing protocol for communication between the nodes can be critical. Our goal in this paper is to design a routing protocol that capitalizes on Multi-Beam directional Antennas (MBAs) to significantly reduce the end-to-end (E2E) delay in multi-hop ad hoc networks that service multiple traffic flows. Previously, we proposed a multi-beam directional antenna MAC protocol, and a Mixed Integer Linear Programming model that exploits MBAs’ capabilities for delay minimization. Solving this model showed that the routes that are selected for different flows need to have certain key characteristics that depart from the traditional shortest-route philosophy. Based on these characteristics, we design, in this paper, an MBA-Delay-Reducing Routing protocol (MBA-DRR) that fully harnesses the benefits of MBAs for delay reduction. The benefits of this protocol apply to all types of multi-hop MBA-based ad hoc networks, both mobile and static. The evaluation on a multi-flow static scenario shows that MBA-DRR, with a delay of just 4.4 ms, gets very close to the optimal solution with a delay of 2.5 ms. Comparatively, Reactive-Geographic hybrid Routing, a shortest-route protocol, has a delay of 48 ms. An evaluation on a representative multi-flow mobile scenario shows that, while a single-beam directional MAC reduces the E2E delay from 700 ms to 40 ms, and a multi-beam directional MAC halves this to 20 ms, our proposed routing protocol further cuts it to 9 ms.