I. J. Computer Network and Information Security, 2016, 3, 41-51 Published Online March 2016 in MECS (http://www.mecs-press.org/) DOI: 10.5815/ijcnis.2016.03.06 Copyright © 2016 MECS I.J. Computer Network and Information Security, 2016, 3, 41-51 A Stable Backbone-Based on Demand Multipath Routing Protocol for Wireless Mobile Ad Hoc Networks Sujata V. Mallapur Godutai Engineering College for Women, Kalburgari, Karnataka, India E-mail: sujatavmallapur@gmail.com Siddarama R. Patil and Jayashree V. Agarkhed Poojya Doddappa Appa College of Engineering, Gulbarga, Karnataka, India E-mail: {pdapatil, Jayashreeptl}@yahoo.com Abstract—In mobile ad hoc networks (MANETs), high node mobility leads to frequent link breaks and creates complexities in route discovery, this effect on the quality of service (QoS) and degrades the systems performance. So, providing a high quality communication using stable links among mobile nodes is a challenging issue in MANETs. Existing stability based routing algorithms initiate estimation of route stability metrics during the routing process, results in increased delay and overhead. In order to overcome these issues, in this paper, we construct a stable backbone-based multipath routing protocol (SBMRP). Initially, the nodes with high residual bandwidth, residual power, link quality and low mobility are designated as candidate nodes. Then multiple paths are established between source and destination through these candidate nodes, thus forming a routing backbone. If any candidate node in the path tend to fail due to lack of bandwidth, energy or link quality, alternate path through other candidate node is established before path breaks. Proposed routing scheme has been compared with other three existing protocols: AODV, AOMDV and RSQR. The protocol performance has been evaluated in terms of packet delivery ratio, normalized routing load, delay and packet drop ratio. Index Terms—MANETs, Candidate nodes, Residual bandwidth, Residual energy, Link quality. I. INTRODUCTION The mobility of nodes in mobile ad hoc networks (MANETs) causes the change in network topology; frequent path breaks and increases the packet drops [1] [2]. Other than node mobility, link failure may also depend on other factors, such as energy of node, bandwidth available for node and link quality etc. If link failure takes place in the network, frequent route discovery attempts could congest the network and also knock out the battery power at critical nodes. Multi- media applications requires the packets to be delivered in-order with negligible variance in the inter-packet delay, frequent changes in the routes traversed by the packets could result in out-of-order packet delivery with high jitter [3]. When any link of a path breaks, this path needs to be either repaired by finding another link if any or replaced with a newly found path. The rerouting operation cost, the scarce radio resource and battery power rerouting delay may also affect QoS and degrade the network performance. Most of the routing algorithms proposed for ad hoc networks are based on on-demand routing [4 - 8]. In these routing algorithms, when a route is broken, route recovery and maintenance procedures are initiated. These procedures consumes substantial amount of resources (in terms of wireless bandwidth, power, processing capacity at nodes) and introduce extra delay in the network. The existing protocols try to improve routing efficiency either by using mobility prediction technique and energy consumption or link quality or residual bandwidth of a node. None of them address the combination of mobility, residual energy, residual bandwidth and link quality parameters to select the reliable nodes. In most of the existing stability based routing protocol link quality and residual energy of each node is estimated during the routing process which results in increased delay and overhead. The proposed work is motivated by observing the limitations of the existing stability based routing protocols. The main aim of this work is to propose a reliable routing protocol for MANET. The proposed method attempts to maximize the link stability for the transmission of packets. By considering these issues, proposed to construct a stable backbone-based multipath routing protocol (SBMRP) for MANETs. Initially, the nodes with high residual bandwidth, residual power, link quality and low mobility nodes are designated as candidate nodes. Then multiple paths are established between source and destination through these candidate nodes, thus forming a routing backbone. If any candidate node in the path tend to fail due to lack of bandwidth, residual energy or link quality, alternate path through another candidate node is established. By simulation results, we show that proposed technique minimizes the