International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 08 | Aug-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 1271 Energy Efficient Multipath OLSR in Mobile Adhoc Networks Shilpa M. Chauhan 1 , Dr. Amit M. Lathigara 2 1,2 School of Engineering, RK University, Rajkot-Bhavnagar Highway, Rajkot-360020, Gujarat, India. ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Mobile Adhoc Networks is a wireless network, which is self- configuring of mobile nodes communicated by wireless link. Now a days MANETs is a wider area for the research in which energy efficiency is the key feature to research where minimum power consumption is required in the network. Optimized Link state Routing (OLSR) protocol is a table driven, proactive protocol, which provides an immediate route between nodes when needed. In this paper, OLSR protocol has modified with the technique of energy efficiency. In this technique, the routing table is modified by saving multiple shortest path for immediately next shortest link available in case of first link goes down without running route discovery algorithm. So there is less overhead and less energy consumption in the network. At last implementation detailed is given by comparing original OLSR protocol and modified OLSR protocol with the graphs of Throughput, Packet Delivery ratio, energy efficiency, Normalized routing load, and End-to-End Delay Parameters of the network. Key Words: OLSR, Multipoint relaying, Routing protocol, energy efficiency, Multipath routing. 1.INTRODUCTION 1.1 MANETs Mobile Adhoc Networks (1) are the types of wireless networks which are infrastructure less. It is a decentralized wireless network. In MANETs every node are itself router. In MANETs nodes are in mobile nature, because of that the network topology is changed frequently .MANETs have following characteristics: Infrastructure less(No any mediator network device is required for communications), Multi-hop routing(there is no default router available, nodes are themselves router, so shares information via many hosts), Dynamic topologies(In mobile Adhoc networks, because nodes can move arbitrarily, the network topology changes frequently, which is responsible to link failure, partitioning.). MANETs have following Characteristics : (1) Military battlefield, (2) Collaborative work, (3) Local level , (4) Commercial sector,( 5) Personal area network and Bluetooth. 1.2 Optimized Link State Routing Protocol (OLSR) Optimized Link State Routing protocol (OLSR) (3) is the link state protocol, so it provides the link immediately when required because of its proactive nature. OLSR floods link or control messages to keep updated of the every node in the network and maintains table up-to-date. Instead of transmitting the control messages to each node, OLSR will transmit it to particular selected nodes who are Known as multipoint relays. The multipoint relays task is to disseminate the messages in the network. 1.2.1 Multipoint Relays (MPRs) The main perception of the MPRs is to decrease the flood of the broadcast packets in the network. It reduces replica of retransmission, in same region. Multipoint relays are a subset of nodes, which are selected by its neighbors. Each MPR node in the network retransmits its packets to the two hop neighbor. The multipoint relays (MPRs) of the node are following in figure 1. Multipoint Relays(MPR) Wireless Nodes Fig -1: Multipoint relays (3) 1.2.2 Protocol Functioning The OLSR protocol contain various functions those are responsible to perform the task of routing. these functions of the protocol are discussed follow : 1) Containing Neighbor node Information (neighbor discovery) (4) : In this function, the HELLO messages is broadcasts by Each node periodically with containing its neighbours’ information and its link position. These