36 Int. J. Sensor Networks, Vol. 10, Nos. 1/2, 2011 Copyright © 2011 Inderscience Enterprises Ltd. Enhancing AODV routing protocol over mobile ad hoc sensor networks Hamdy Soliman and Mohammad Al-Otaibi* Department of Computer Science and Engineering, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA Email: hss@nmt.edu Email: motaibi@nmt.edu *Corresponding author Abstract: In this paper, we efficiently adapt the prominent Ad hoc On-demand Distance Vector (AODV) routing protocol with a reactive Local Link Repair (AODV-LR) for effective deployment in Mobile Ad hoc Sensor Networks (MASNETs) with restricted power and bandwidth. We introduce two replacement mechanisms to the local repair phase of the AODV. Our new approaches are self-repairing AODV algorithms called Reactive Self-repairing AODV (AODV-RSR) and Pre-emptive Self-repairing AODV (AODV-PSR). These two algorithms are able to find an alternative route to a failing link without depending only on broadcasting Route Request (RREQ) packets. Experimental results show that the new algorithms achieve better performance than the AODV-LR and Self-repair Algorithm (SRAODV) by obtaining lower packet delay, higher packet delivery ratio and lower control message overhead. Keywords: routing algorithms; computer network performance; AODV; AODV-RSR; AODV- PSR; SRAODV. Reference to this paper should be made as follows: Soliman, H. and Al-Otaibi, M. (2011) ‘Enhancing AODV routing protocol over mobile ad hoc sensor networks’, Int. J. Sensor Networks, Vol. 10, Nos. 1/2, pp.36–41. Biographical notes: Hamdy Soliman is currently a Full Professor in the Department of Computer Science and Engineering at New Mexico Tech (NMT). He received his BS in 1978 from Alexandria University (Egypt), MS in 1983 from Florida Institute of Technology and PhD in 1989 from New Mexico State University (USA); all degrees are in Computer Science. His research interests include neural networks applications in data/image compression, all-fibre networks admission control, computer networks security, wireless sensor networks routing and security protocols. Mohammad Al-Otaibi is currently an Assistant Professor in the Department of Computer Science at Imam Mohammad Ibn Saudi University (Riyadh, Saudi Arabia). He received his PhD from the Department of Computer Science and Engineering at New Mexico Tech (USA), MS in Electrical and Computer Engineering from Colorado State University (USA), and BS in Computer Engineering from King Fahd University of Petroleum and Minerals (Saudi Arabia). His research interests are in the fields of computer networks, heterogeneous computing and mobile ad hoc sensor networks. 1 Introduction In Mobile Ad hoc Sensor Networks (MASNETs), nodes communicate in the absence of a fixed infrastructure. The nodes in MASNETs have limited processing capabilities, energy resources and communication bandwidth. They also move about randomly, changing the topology of the network. These constraints and properties make it very difficult to find routing mechanisms that ensure high network throughput. In recent years, researchers have proposed many protocols to enable nodes to find single or multi-hop communication routes (Perkins and Bhagwat, 1995; Hass, 1997; Johnson and Maltz, 1999; Lee and Gerla, 2000; Marina and Das, 2001; Perkins et al., 2003). Ad hoc On-demand Distance Vector (AODV) routing is one of the promising protocols for deployment in a MASNET, due to its ability to cope with network dynamic changes and its ability to repair broken links in routes. AODV is a ‘reactive’ routing protocol where the search for a particular route is performed only when needed. Nodes do not need to maintain routes unless they are being used. AODV with Local Link Repair (AODV-LR) is an optimised version of AODV (Perkins et al., 2003). It has an enhanced route maintenance mechanism which allows intermediate nodes to perform a local repair to a link breakage. Otherwise, a total new route can be re-established. It has been shown experimentally that route reconstruction and maintenance in AODV-LR introduce packet loss, high delay in packet delivery and extra