%0 Journal Article
%T Robust On-Demand Multipath Routing with Dynamic Path Upgrade for Delay-Sensitive Data over Ad Hoc Networks
%A Sunil Kumar
%A Siddharth Khimsara
%A Kashyap Kambhatla
%A Kalyani Girivanesh
%A John D. Matyjas
%A Michael Medley
%J Journal of Computer Networks and Communications
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/791097
%X Node mobility in mobile ad hoc networks (MANETs) causes frequent route breakages and intermittent link stability. In this paper, we introduce a robust routing scheme, known as ad hoc on-demand multipath distance vector with dynamic path update (AOMDV-DPU), for delay-sensitive data transmission over MANET. The proposed scheme improves the AOMDV scheme by incorporating the following features: (i) a routing metric based on the combination of minimum hops and received signal strength indicator (RSSI) for discovery of reliable routes; (ii) a local path update mechanism which strengthens the route, reduces the route breakage frequency, and increases the route longevity; (iii) a keep alive mechanism for secondary route maintenance which enables smooth switching between routes and reduces the route discovery frequency; (iv) a packet salvaging scheme to improve packet delivery in the event of a route breakage; and (v) low HELLO packet overhead. The simulations are carried out in ns-2 for varying node speeds, number of sources, and traffic load conditions. Our AOMDV-DPU scheme achieves significantly higher throughput, lower delay, routing overhead, and route discovery frequency and latency compared to AOMDV. For H.264 compressed video traffic, AOMDV-DPU scheme achieves 3£¿dB or higher PSNR gain over AOMDV at both low and high node speeds. 1. Introduction Wireless mobile ad-hoc networks (MANETs) are usually bandwidth limited and characterized by time-varying error-prone channels due to node mobility, resulting in the link loss, route breakage, and short route lifetime. These characteristics pose a serious challenge in designing efficient routing schemes, especially for supporting the delay-sensitive traffic such as video streaming. The proactive routing protocols (e.g., destination sequenced distance vector (DSDV) [1] and optimized link state routing (OLSR) [2]) generate too much overhead in MANET because they find paths in advance for all source and destination pairs and periodically exchange topology information to maintain them, even when no data is being transmitted [3, 4]. In contrast, the reactive routing protocols (e.g., ad-hoc on-demand distance vector (AODV) [5] and dynamic source routing (DSR) [6]) have lower overhead as they find a route from the source to destination as and when required [3, 4]. Many on-demand routing protocols proposed for MANET in the past do not sufficiently address the issue of frequent route breakage due to high node mobility. Two approaches employed to overcome this problem are (i) frequent link updates along the route to notify
%U http://www.hindawi.com/journals/jcnc/2013/791097/