A routing protocol is used to facilitate communication in ad hoc network. The primary goal of such a routing protocol is to provide an efficient and reliable path between a pair of nodes. Routing in Mobile Ad Hoc Networking technology (MANET) is challenging due to its route discovery feature dealing with link failures and to repair the routes in these situations. An ad hoc network is a temporarily infrastructure less network in which nodes can join and leave the network at anytime and are free to move randomly and organize themselves arbitrarily. In MANETs, each node should not only work for itself, but should be cooperative with other nodes. In this paper, we propose a scheme to evaluate effect of Time To Live (TTL) increment and threshold value to analyze route discovery process in Ad hoc on Demand Distance Vector (AODV) routing protocol for proactively less communication overheads. It is simulated using OPNET 14.5 with fixed network area and node density. Our simulation results show that performance of route discovery, link failure and repair mechanism depends on optimal choice of TTL increment and threshold.

In the mobile Ad hoc networking paradigm there is no fixed infrastructure and packets are delivered to their destinations through wireless multi hop connectivity. MANETs are in general characterized by mobile nodes with limited energy, constrained computing capability and absence of any base stations. Mobile nodes undertake role of routers engaging in some routing protocol required for deciding and maintaining the routes. MANET allows unrestricted mobility of the enlisted terminals as long as the least one terminal is within transmission range. Transmission range of wireless Adhoc network is restricted by its power consumption due to limited battery power of a wireless node. Reactive routing protocols are favoured in MANET's because they help in reducing overheads by continuously sending the data for better communication. These protocols suffer due to route discovery process. We focus on the problem of finding best search set of TTL(Time to live) values for expanding ring search to improve quality of service and evaluate performance of AODV by varying number of mobile nodes and nodes speed. Expanding ring search based on TTL in terms of early or delay in network flooding cause quality of service to fluctuate randomly. In this paper, early or delay in network flooding is employed to search for destination in a region limited by time to live (TTL). The performance of such expanding ring search schemes depends largely on TTL search sets. It is simulated using OPNET 14.5 simulator.

A MANET is a wireless network which operates by themselves without centralized administration. Each node in MANET operates as an end system and a router for all other nodes in the network. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route the traffic. Reactive routing protocols are favoured in MANET's because they generate fewer overheads in network. These protocols suffer due to network flooding in route discovery process. Expanding ring search in terms of early detection of destination cause quality of service to fluctuate randomly. Performance degradation due to quality of service is a bottleneck to fulfill stability and reliability in MANET's. In this paper, a scheme is introduced for controlling the broadcasting of RREQ information focusing on improved quality of service in AODV (Ad hoc on Demand Distance Vector) routing protocol. This is achieved by monitoring the TTL start, TTL increment and TTL threshold values of network and choosing optimum values of TTL suitable to network designed that accounts for reliability and quality of service during route discovery process. It is simulated using OPNET 14.5 with fixed node density.