Impact of Mobility on the Performance of Multicast Routing Protocols in MANET

10.5121/ijwmn.2010.2208 110
 

      


  R. Manoharan and E. Ilavarasan Department of Computer Science and Engineering Pondicherry Engineering College, Puducherry INDIA.

ABSTRACT The advent of ubiquitous computing and the proliferation of portable computing devices have raised the importance of mobile ad-hoc network. A major challenge lies in adapting multicast communication into such environments where mobility and link failures are inevitable. The purpose of this paper is to study impact of mobility models in performance of multicast routing protocols in MANET. In this work, three widely used mobility models such as Random Way Point, Reference Point Group and Manhattan mobility models and three popular multicast routing protocols such as On-Demand Multicast Routing Protocol, Multicast Ad hoc On-demand Distance Vector Routing protocol and Adaptive Demand driven Multicast Routing protocol have been chosen and implemented in NS2. Several experiments have been carried out to study the relative strengths, weakness and applicability of multicast protocols to these mobility models.

KEYWORDS Mobile Ad hoc Network, multicast routing, mobility models, ODMRP, MAODV, ADMR.

1. INTRODUCTION Mobile ad hoc networks (MANETs) are self-organizing networks that do not require a fixed infrastructure. Two nodes communicate directly if they are in the transmission range of each other. Otherwise, they reach via a multi-hop route. Each MANET node must therefore be able to func- tion as a router to forward data packets on behalf of other nodes [1]. Because of their unique benefits and versatilities, MANETs have a wide range of applications such as collaborative, distributed mobile computing (e.g., sensors, conferences), disaster relief (e.g., flood, earthquake), war front activities and communication between automobiles on highways. Most of these applications demand multicast or group communication.
   Each of these applications can potentially involve in different scenarios with different mobility patterns, traffic rates dependent on the environment and the nature of the interactions among the participants. In order to thoroughly study the protocols for these applications, it is imperative to use the mobility models that accurately represent the mobile nodes which utilize the protocols. In this paper, it is proposed to analyze the performances of widely used multicast routing protocols namely Multicast Ad hoc On-demand Distance Vector (MAODV) routing protocol [2, 3], On-Demand Multicast Routing Protocol (ODMRP) [4, 5] and Adaptive Demand driven Multicast Routing protocol (ADMR) [6] against three different mobility model that characterize the realistic behaviours such as Random Waypoint, Reference Point Group and Manhattan mobility models.
   Rest of the paper is organized as follows: Section 2 reviews the related work. Section 3 summarizes the Mobility Models that are considered in this paper. Section 4 explains the multicast protocols while Section 5 explains the experimental scenarios and methodology. Section 6 deals with experimental results. Finally, concluding remarks are given in section 7.

          
     

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2. RELATED WORK An extensive literature survey has been done to analyze the performance of routing protocols for various mobility models. Few researchers have carried out experiments to study the performance of unicast routing protocols such as DSR, DSDV, AODV and TORA in mobile environments [7]. Most of the initial research was using Random Waypoint as the underlying mobility model and CBR traffic consisting of randomly chosen source destination pairs. The protocols were mainly evaluated for packet delivery ratio and routing overhead. It was inferred that, the on-demand protocols such as DSR and AODV performed better than table driven ones such as DSDV at high mobility rates [7], while DSDV performed quite well at low mobility rates.
   A comparison study of the two on-demand routing protocols namely DSR and AODV [2] was prepared with the packet delivery ratio and end to end delay metrics. It is inferred that DSR outperforms AODV in less demanding situations, while AODV outperforms DSR at heavy traffic load and high mobility. Another work proposed a framework to analyze the impact of mobility pattern on unicast routing performance of mobile ad hoc network [3], considering the Freeway mobility, Manhattan and RPGM mobility model.
   The impacts of different mobility models on the performance of mobile IP multicast protocols are evaluated for two mobility metrics such as number of link changes and multicast agent density [8]. In [9], the auth

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