Effect of CBR, FTP and FTP GENERIC Traffic Patterns on the Performance of Routing Protocols in MANET

In recent years mobile ad hoc networks have become very popular and lots of research is being done on different aspects of MANET. Mobile ad hoc network (MANET) is a wireless network without infrastructure. In this paper, an attempt has been made to evaluate the performance of two well known routing protocols AODV and DSR .Three traffic patterns CBR, FTP and FTP GENERIC are used to check the performance of routing protocols ( AODV,DSR) with various metrics like as Packet Delivery Ratio and throughput using GLoMoSIM (Global Mobile information systems simulation)

Neighbour coverage: a dynamic probabilistic route discovery for mobile ad hoc networks

Blind flooding is extensively use in ad hoc routing protocols for on-demand route discovery, where a mobile node blindly rebroadcasts received route request (RREQ) packets until a route to a particular destination is established. This can potentially lead to high channel contention, causing redundant retransmissions and thus excessive packet collisions in the network. Such a phenomenon induces what is known as broadcast storm problem, which has been shown to greatly increase the network communication overhead and end-to-end delay. In this paper, we show that the deleterious impact of such a problem can be reduced if measures are taken during the dissemination of RREQ packets. We propose a generic probabilistic method for route discovery, that is simple to implement and can significantly reduce the overhead associated with the dissemination of RREQs. Our analysis reveals that equipping AODV with probabilistic route discovery can result in significant reduction of routing control overhead while achieving good throughput

Mobile Codes Localization in Ad hoc Networks: a Comparative Study of Centralized and Distributed Approaches

This paper presents a new approach in the management of mobile ad hoc networks. Our alternative, based on mobile agent technology, allows the design of mobile centralized server in ad hoc network, where it is not obvious to think about a centralized management, due to the absence of any administration or fixed infrastructure in these networks. The aim of this centralized approach is to provide permanent availability of services in ad hoc networks which are characterized by a distributed management. In order to evaluate the performance of the proposed approach, we apply it to solve the problem of mobile code localization in ad hoc networks. A comparative study, based upon a simulation, of centralized and distributed localization protocols in terms of messages number exchanged and response time shows that the centralized approach in a distributed form is more interesting than a totally centralized approach.Comment: 14 Pages, IJCNC Journal 201

A performance comparison of smart probabilistic broadcasting of ad hoc distance vector (AODV).

Broadcast is a common operation used in Mobile Ad hoc Networks (MANETs) for many services, such as, routdiscovery and sending an information messages. The direct method to perform broadcast is simple flooding, which itcan dramatically affect the performance of MANET. Recently, a probabilistic approach to flooding has beenproposed as one of most important suggested solutions to solve the broadcast storm problem, which leads to thecollision, contention and duplicated messages. This paper proposed new probabilistic method to improve theperformance of existing on-demand routing protocol by reduced the RREQ overhead during rout discoveryoperation. The simulation results show that the combination of AODV and a suitable probabilistic rout discoverycan reduce the average end- to- end delay as well as overhead and still achieving low normalized routing load,comparing with AODV which used fixed probability and blind floodin

Mobile Undersea Routing Protocol

The myriad barriers to underwater communication provide a new set of challenges for network protocols. Routing protocols which operate in underwater ad hoc networks must react quickly to changing conditions without significant increase in packet overhead or congestion. Dynamic Source Routing Protocol provides a framework for accomplishing these goals. In this paper we present the Mobile Undersea Routing Protocol, which implements this framework and enhances upon it. It uses a limited propagating route request which we call a Route Recovery to quickly and inexpensively recover from routing errors. A Java based network simulator was constructed in order to test and compare the protocols. Statistics were calculated based on packets delivered, total transmissions, and time to recover from a route error as measurements of protocol effectiveness

Age Matters: Efficient Route Discovery in Mobile Ad Hoc Networks Using Encounter Ages

We propose FResher Encounter SearcH (FRESH), a simple algorithm for efficient route discovery in mobile ad hoc networks. Nodes keep a record of their most recent encounter times with all other nodes. Instead of searching for the destination, the source node searches for any intermediate node that encountered the destination {\em more recently than did the source node itself}. The intermediate node then searches for a node that encountered the destination yet more recently, and the procedure iterates until the destination is reached. Therefore, FRESH replaces the single network-wide search of current proposals with a succession of smaller searches, resulting in a cheaper route discovery. Routes obtained are loop-free. The performance of such a scheme will depend on the nodes' mobility processes. Under standard mobility processes our simulations show that route discovery cost can be decreased by an order of magnitude, a significant gain given that route discovery is a major source of routing overhead in ad hoc networks

Enhancing Performance by Salvaging Route Reply Messages in On-Demand Routing Protocols for MANETs

Researchers prefer on-demand routing protocols in mobile ad hoc networks where resources such as energy and bandwidth are constrained. In these protocols, a source discovers a route to a destination typically by flooding the entire or a part of the network with a route request (RREQ) message. The destination responds by sending a route reply (RREP) message to the source. The RREP travels hop by hop on the discovered route in the reverse direction or on another route to the source. Sometimes the RREP can not be sent to the intended next hop by an intermediate node due to node mobility or network congestion. Existing on-demand routing protocols handle the undeliverable RREP as a normal data packet - discard the packet and initiate a route error message. This is highly undesirable because a RREP message has a lot at stake – it is obtained at the cost of a large number of RREQ transmissions, which is an expensive and timeconsuming process. In this paper, we propose the idea of salvaging route reply (SRR) to improve the performance of on-demand routing protocols. We present two schemes to salvage an undeliverable RREP. Scheme one actively sends a one-hop salvage request message to find an alternative path to the source, while scheme two passively maintains a backup path to the source. Furthermore, we present the design of two SRR schemes in AODV and prove that routes are loop-free after a salvaging. We conduct extensive simulations to evaluate the performance of SRR, and the simulation results confirm the effectiveness of the SRR approach