Bosunia et al. / IJCCNet Vol. 2, Issue 2 / Page No: 26 –39. Journal homepage: www.setscholars.org/index.php/ijccnet 26 IJCCNet Vol. 02. Issue 02. Article No. 03 www.setscholars.org/index.php/ijccnet International Journal of Computing Communication and Networking Research A Robust and Reliable Routing Protocol for Energy-Constrained Mobile Ad Hoc Networks Md. Mahfuzur Rahman Bosunia 1* , Md. Abdur Razzaque 2* , Md. Manowarul Islam 3* 1,2 University of Dahaka, Bangladesh 3 Mawlana Bhashani Science and Technology University, Bangladesh * e-mail: mahfuz_babu10@yahoo.com, razzaque@cse.univdhaha.edu, manowar_cse_du@yahoo.com Article History ABSTRACT Received: 09-05-2013 Accepted: 09-06-2013 Available online: 11-07-2013 Keywords: Mobile Ad Hoc Network; Link Lifetime; Routing Stability; Local Route Recovery; Reliability. The mobility of the nodes and time-varying wireless channel quality causes routes to fail frequently in a mobile ad hoc network (MANET), decreasing data delivery performance of the network. In this paper, we first propose a robust and reliable energy-aware routing metric, known as RRE, that combines three sub-metrics: link lifetime, link reliability and residual energy of nodes. Then, we develop a robust and reliable routing protocol, R 2 -Routing, and a local route recovery mechanism based on the proposed RRE metric. Thus, our routing protocol not only discovers an efficient route between a source and a destination, but also takes routing decisions adaptively to accommodate in such a dynamic network environment. The simulation results, carried out in NS-2, show that our proposed R 2 -Routing protocol outperforms the state-of-the-art protocols in terms of throughput, reliability, energy- efficiency, etc. Citation: Bosunia et al., A Robust and Reliable Routing Protocol for Energy-Constrained Mobile Ad Hoc Networks, IJCCNet 2(2): p. 26 – 39. Copyright: @ 2013 Bosunia et al. This is an open access article distributed under the terms of the Creative Common Attribution 3.0 License. 1.0 Introduction A mobile ad hoc network (MANET) is a collection of self-organizing mobile nodes that communicate each other using unreliable wireless communication channels. The nodes are energy-constrained having small transmission ranges and thus they use multihop transmission routes for long distance data transfer. Due to dynamic network topology, time-varying wireless channels and shortage of power in mobile nodes, the MANET routes are often unstable, causing routes to break frequently. Therefore, providing reliable and timely data delivery for a number of MANET applications in an energy-efficient way is challenging. Ad-hoc-On Demand Distance Vector (AODV) [1][2] is the highly used routing protocol for MANETs that works on-demand basis, i.e., a route is discovered when it is needed and it lasts till the required data transfer is completed. When a source node S requires a route to any destination D, it broadcasts route request (RREQ) packet in the network, as shown in Fig. 1. When the RREQ packet reaches at destination D, it sends back a route reply (RREP) message towards the source node S and thus the route is IJCCNet ISSN: 1839-7212