Page 2 Lecture Notes in Computer Science 2865 Edited by G. Goos ...

SAFAR: An Adaptive Bandwidth-EfficientRouting Protocol for Mobile Ad Hoc NetworksJigar Doshi and Prahlad KilambiSri Venkateswara College of EngineeringUniversity of MadrasPennalur, Sriperumbudur 602 105jigar@doshi.com, prahlad@acm.orgAbstract. A mobile ad hoc network suffers from the same cost constraintsas most wireless networks. In particular bandwidth constraintsof wireless links are severe. We present a scalable adaptive fitness-basedrouting protocol, SAFAR, for mobile ad hoc networks in which we tryto optimize the usage of this bandwidth at every stage. The protocol ishybrid, i.e. it makes use of both proactive and reactive procedures forrouting in an attempt to reduce route acquisition latency. Using a fitnessfunction, a node decides how many other nodes can be proactivelymaintained by it. Each node tries to know the best(most fit) nodes inits neighborhood. Hence, high bandwidth nodes are well known. Mostof the traffic is routed through these nodes and hence performance isoptimized. We present simulation results to substantiate the protocolsperformance. We also extend this protocol to show how it can be usedfor power aware routing.Keywords: MANETs, Hybrid, Adaptive, Fitness.1 IntroductionMobile Ad hoc Networks (MANETs) are multi-hop wireless infrastructure lessnetworks. All nodes are capable of movement and can be connected dynamicallyin an arbitrary manner. Nodes in these networks function as routers that discoverand maintain routes to other nodes in the network. Applications of ad-hocnetworks have been widely studied and they find extensive use in emergencyservices. Mobile ad hoc networking can support robust and efficient operationin mobile wireless networks by incorporating routing functionality into mobilenodes. The topology in such networks is dynamic and sometimes rapidly changing.Therefore a protocol for such a network has to be robust as well as efficient.Mobile networks have many interesting characteristics, which differ from traditionalwired networks as described in detail in [1]. In particular Wireless linkswill have significantly lower capacity than their hardwired counterparts. Thethroughput of wireless communications has to take into account the effects ofmultiple access, fading, noise, and interference conditions, etc. Therefore, transmissionrate is bound to suffer [1]. One effect of the relatively low to moderatelink capacities is that congestion is typically the norm rather than the exception.S. Pierre, M. Barbeau, and E. Kranakis (Eds.): ADHOC-NOW 2003, LNCS 2865, pp. 12–24, 2003.c○ Springer-Verlag Berlin Heidelberg 2003