Abstract-Networks which function without having any centralized fixed infrastructure or central administration are called MANETs (Mobile Ad hoc Networks). These networks are formed by small or large set of mobile nodes and communicate through the wireless links. Such Networks requires best routing protocols to establish error-free and efficient communication links. MANETs has the property of dynamically changing topology due to their mobile nodes, which move from one place to another. Overall performance of MANET routing protocols depends upon various network and protocol parameters. Mobile ad hoc networks have the characteristics of self-forming and self-healing. The routing algorithms of the routing protocols ensure selection of routes and connectivity between the mobile nodes. This paper presents analysis of three well known routing protocols of MANETs, namely; AODV (Ad hoc On Demand Distance Vector), DSDV (Destination Sequenced Distance Vector) and OLSR (Optimized Link State Routing). Analyses of these routing protocols have been carried out using NS-3 (Network Simulator-3) by varying node density and node pause time. Different performance metrics such as throughput, packet delivery ratio, end to end delay, packet loss and normalized routing load have been considered for this analysis. This analysis concludes better performance of the OLSR routing protocol.

Mobile Ad-Hoc Networks (MANETs) are self-forming, self-healing new generation infrastructure less wireless networks. Principal behind these networks is multi hop radio relaying. MANETs are very useful at locations where networking infrastructure is not available. Major applications of these networks can be accessed at military and emergency rescue operations. MANETs may contain small or large set of network nodes; each and every node requires acting as host and the router. Due to random movements of the nodes, MANETs obtain dynamic network topologies. Routing protocols in MANETs are accountable for establishing efficient and error free communication paths between network nodes. Dynamic network topologies make routing challenging. In order to meet requirement of present day applications and to overcome from routing challenges, routing protocols in mobile ad hoc networks need to perform better in terms of certain QoS (Quality of Service) parameters such as; good throughput, sustained communication links and least delay in establishing a link. In this paper, we have discussed QoS in MANETs and analyzed the OLSR (Optimized Link State Routing), a well-known routing protocol in MANETs for possible improvements in its performance. Here, we have revised attributes of core parameters of the standard OLSR routing model in order to obtain a new OLSR design. Performances of the standard and revised OLSR models have been tested and compared under different network scenarios using network simulator-3 (NS-3). Different QoS and performance evaluating metrics such as; the throughput, packet delivery ratio, end to end delay, packet loss and normalized routing load have been considered for measuring performances of either OLSR routing models. Based on the analysis, it is concluded that the revised OLSR model has shown better performances as compared to standard OLSR routing model.

MANET (Mobile Ad hoc Network) is an infrastructure less decentralized wireless network, which do not depend on centralized organization or switching points. MANET is a self-organizing and self-configuring network. In ad-hoc networks, routing protocols postulate communication between routers and prompt them to select routes between a source and a destination. Route choices are performed by the routing algorithms. In this paper, we used network simulator-3 to simulate comparative performance analysis of three MANET routing protocols. They are AODV (Ad-hoc On Demand Distance Vector Routing), DSDV (Destination Sequenced Distance Vector Routing) and OLSR (Optimized Link State Routing). We analyzed performance comparisons of these routing protocols using different performance metrics such as throughput, packet delivery ratio, end to end delay and packet loss.

In this paper we propose an efficient location management strategy called the profile-based two-level pointer forwarding cache scheme to improve the overall performance of the wireless mobile networks. It uses the two-level pointer for location update and the profile-based cache for call delivery. Location update for each Mobile Terminal (MT) is managed by the nearby Visitor Location Register (VLR) until it crosses the threshold of the number movements between Registration Areas (RAs). This reduces the frequency of accessing the remote Home Location Register (HLR) which eventually minimizes the location update cost by distributing its work. On the other hand, a profile of the MT's calling pattern is maintained in HLR and it is copied in the VLR caches from where majority of the calls are generated. These caches are searched first to find out the called MT's location in order to deliver a call. This delivery cost will be reduced if the location information is found in the caches since it does not have to access the remote HLR for searching the location information. The analytical modeling and numerical results show that the proposed method outperforms all other previous methods in terms of network signaling traffic load irrespective of the MTs' mobility and calling pattern.

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