I J C I T A E© Serials Publications

6(1) 2012 : 17-21

*Corresponding Author’s: skshsh-eed@msubaroda.ac.in

ANALYSIS AND COMPARISON OF PROACTIVE AND REACTIVEROUTING PROTOCOLS FOR WANET IN QUALNET

SATISH K. SHAH AND DHARMISTHA D. VISHWAKARMA

Electrical Engineering Department, Faculty of Technology & Engineering, M. S. University of BarodaKalabhavan, Vadodara, Guj., India

Abstract: In case of Wireless Ad Hoc Networks (WANETs) topology changes due to freely moving mobilenodes. Conventional Routing protocols needs modifications so as to accommodate change in configuration tomaintain performance matrices.Paper presents Qualitative and Quantitative analysis of existing routing protocols through comparison oftheir properties according to different criteria. Simulation study and analysis and relative performanceevaluation according to different criteria like node mobility and node density was carried out on Qualnet.

Keywords: Wireless Ad-Hoc Network, Routing Protocols, Proactive Routing Protocol, Reactive RoutingProtocol, Qualnet

1. INTRODUCTIONWireless ad hoc networks are networks withoutinfrastructure, where every node works as arouter. In these networks, every node mustdiscover its neighbors it will communicate tonodes that are out of its transmission range(multi-hop routing). The challenge in creating arouting protocol for ad hoc networks is to designa single protocol that can adapt to the wide varietyof conditions that can be present in any ad hocnetwork environment. The routing protocol mustperform efficiently in environments in which itsuffers from high nodes mobility and manywireless transmission constraints. Since it is oftenimpossible to know in advance what environmentthe protocol will find itself in, and environmentcan change unpredictably as well, the routingprotocol must be able to adapt automatically.These networks suffer from all kinds ofuncertainty, randomness and fuzziness which isdue to; high bit error rate (BER) in the wirelesschannel, increased collisions due to the presenceof hidden terminals; signals interference andattenuation; location dependent connection;unidirectional links and frequent link breaksdue to nodes mobility. Hence there is a need

for high adaptive routing protocols withadapting capabilities to high variability networkprotocols.

2. ROUTING PROTOCOLSRouting protocol in the WANETs are responsiblefor deciding the path between the source nodeand the destination node, it must be able tochoose the best path from the available paths.Routing protocols plays very important role toimprove the performance of the Wireless Ad-HocNetwork to improve the performance and theoverall throughput of the network. Routingprotocols maintains the routing table to updatethe information about the distance betweendestination nodes, the previous and thenext node along the routes. Nodes in thenetwork exchanges the routing table to updatethe information about the network topologychanges every time due to the mobility of thenodes.

Wireless Ad Hoc Networks (WANETs) arecharacterized as having a dynamic, multihop,potentially rapid changing topology. Conventionalprotocols can be classified as reactive, proactiveand hybrid. Table 1 describes the characteristicsof routing protocols.

18 � Satish K. Shah and Dharmistha D. Vishwakarma

In the paper OLSR [3, 4] is considered as arepresentative of a proactive routing protocol forWireless ad hoc networks, while Dynamic SourceRouting (DSR) [5, 6, 7] is used as a representativefor a reactive protocol to carryout analysis andcomparison of two classes of routing protocolsusing Qualnet simulator.

3. PERFORMANCE METRICTo evaluate the performance of routing protocols,both qualitative and quantitative metrics areneeded. Routing protocols use several metrics tocalculate the best path for routing the packets toits destination. These metrics are a standardmeasurement that could be number of hops, whichis used by the routing algorithm to determine theoptimal path for the packet to its destination.Most of the routing protocols ensure thequalitative metrics. Therefore, four differentquantitative metrics are used to compare theperformance. They are,

• Packet Delivery Ratio (PDR): Theratio of the number of data packetsreceived by the receivers verses thenumber of data packets supposed to bereceived. This number presents theeffectiveness of a protocol.

• Average End-to-end delay: End-to-enddelay indicates how long it took for a

packet to travel from the source to thereceiver.

• Throughput: The throughput is definedas the total amount of data a receiveractually receives from the sender dividedby the time between receiving the fastpacket and last packet.

• Jitter: Jitter metric, which is used in thispaper, is a quantifier of the changeabilityover time of the packet latency across anetwork and can be a measurement forthe quality of a communication. A zerojitter shows a very high qualitycommunication without any latency.

4. QUALNET SIMULATORQualNet is a comprehensive suite of tools formodeling large wired and wireless networks. Ituses simulation and emulation to predict thebehavior and performance of networks to improvetheir design, operation and management [8].QualNet enables users to: Design new protocolmodels, Optimize new and existing models;Design large wired and wireless networks usingpre-configured or user-designed models andanalyze the performance of networks and performwhat-if analysis to optimize them. The kernel ofQualNet is a, SNT-proprietary, parallel discrete-event scheduler which provides the scalability andon a variety of platforms [8].

Table 1Comparison between the Proactive and Reactive Routing Protocols

Proactive Protocols Reactive ProtocolsHybrid Protocols

Characteristics

• Consistent; up-to-date routing information • On-demand operation• Table-driven; one or more tables to store routing • Route discovery by global search

information• No latency in route discovery • There are delays due to route discovery• Continuously evaluate routes • No Control packet for routing table maintenance.• No latency in route discovery • Most appropriate for environments in which nodes move

around a lot• Large number of control packets necessary to keep • Route Discovery Process

network information current • Maintenance of a Route• A lot of routing information may never be used • delays due to route discovery

Classification

Number of necessary routing-related tables Method by which route finding is performed

Examples

DSDV, CGSR, WRP, OLSR AODV, DSR, LMR, TORA, SSR

Analysis and Comparison of Proactive and Reactive Routing Protocols for WANET in Qualnet � 19

Network topology is referred to as a scenariowhich allows the user to specify all the networkcomponents and conditions under which thenetwork will operate. Procedure steps are asfollows…

• Open the Qualnet using shortcut ondesktop.

• Use file menu to open the new file orexisting file. (***.config)

• Use drag and drop to insert nodes in theworking space given for creating networktopology.

• Insert at least one wireless subnet whichwill be helpful for the wireless connection.

• Connect all the nodes to the wirelesssubnet to establish the wirelessconnection by selecting link.

• Select property of each link by right click/double click and set link parameter.

• Select the routing protocols to be followedby double click on the each node.

• Run the simulation by selection runbutton.

• On completion of simulation open theresult file to observe the results.

5. SIMULATION SETUP AND RESULTSThe simulation results were carried out Qualnetsimulator version 5 [8] to evaluate theperformance of the two routing protocol [9, 10, 11]DSR & OLSR on the Wireless Ad-Hoc networkwith the 50 nodes with the parameters selectionas follows in the simulator.

The 50 nodes were generated for each protocolwithin the terrain of 1500m X 1500m and for thenode density variation node can be enabled ordisabled according to the network topology andthe no. of nodes in the network to study theperformance of number of node variation in thenetwork. The random waypoint mobility isprovided to realization as a real time simulationwith the pause time of 30S, min speed of the 5mpsand max speed of 20 mps. We have taken thenetwork protocol as IPv4 and MAC protocol of the802.11. The packet reception model is PHY802.11b is considered here. The propagationchannel frequency is 2.4 GHz, the two ray groundpropagation model and omnidirectional antennais considered. The traffic generated between somerandom nodes is CBR type. We have carried outthe simulation for the simulation time of 300S.We have derived the simulation results based onthe above performance metric using the networkof 50 nodes and the nodes can be enabled anddisabled according to the requirement for the DSRand OLSR proactive type of protocols.

Figure 1: Simulation Scenario in Qualnet

Figure 2: Average Packet Delivery Ratio V/S Mobility

Figure 3: Average Packet Delivery Ratio V/S node Density

20 � Satish K. Shah and Dharmistha D. Vishwakarma

Figure 4: Average End to end Delay V/S Mobility

Figure 5: Average End to end Delay V/S node Density

Figure 6: Average Throughput V/S Mobility

Figure 7: Average Throughput V/S Node Density

Figure 8: Average Jitter V/S Mobility

Figure 9: Average Jitter V/S node Density

Analysis and Comparison of Proactive and Reactive Routing Protocols for WANET in Qualnet � 21

Performance results of packet delivery ratioare shown in Figure 2 and 3. Figure 2 showspacket delivery ratio of routing protocolsaccording to the increase of node’s maximumspeed. As the nodes maximum speed increase, apacket delivery rate of proactive and reactiveprotocols decreases. Figure 3 depicts effect ofvariation in node density on packet delivery ratio.The packet delivery ratio in both the cases(proactive and reactive protocols) proportionatelyvaries with variation in node density. Howeverreactive routing protocol shows betterperformance.

Figure 4 and 5 shows simulation results onthe aspect of average end-to-end delayperformance for reactive and proactive routingprotocols by varying the node’s maximummovement speed and the node density (numberof nodes). The average end-to-end delay of packetdecrease as node’s maximum speed increases incase of reactive but it is less in proactive routingprotocols. This is due to size of the overheadpackets are large in reactive routing protocolsthan the proactive routing protocols.

It is observed that the Throughput forproactive and reactive routing protocol in Figure6 and 7 is very similar in low mobility and reactiveprotocols has higher throughput compared toproactive in high mobility of the nodes.

Figure 8 and 9 shows the simulation resultsfor the jitter produced whenever we vary thenode’s maximum movement speed and nodedensity in the network. The increase in themovement speed and node density proactiveprotocols has the less jitter compared to thereactive protocols.

6. CONCLUSIONDSR may be preferred in the situations whereEnd-to-End delays are very critical. Proactiveprotocols perform well in low/ medium nodedensity where as Reactive performs well for highdensity environment. The proactive routing

protocols performs better when the density of thenetwork is less, as the density and mobility ofnodes increases the performance of the reactiveprotocols are better than the proactive protocols.

In our simulation results, on-demand routingprotocols DSR perform well in high maximumspeed and high density then the table-driven(Proactive) routing protocol, OLSR shows theworst performance because its periodic routeupdate and hello messages become the severeoverhead in highly mobile and dense network.

References[1] T. Vadar, “Scalable Routing Mechanism in Ad Hoc

Networks,” Master Thesis, March 2006.

[2] A. Iwata, C. Chiang, G. Pei, M. Gerla and T. W. Chen,“Scalable Routing Strategies for Ad Hoc WirelessNetworks,” IEEE Journal on Selected Areas inCommunications, Special Issue on Wireless Ad HocNetworks, 17(8), 1369-1379, 1999.

[3] P. Jacquet, P. Muhlethaler, T. Clausen, A. Laouiti, A.Qayyum, L. Viennot, Optimized Link State RoutingProtocol fo Ad-Hoc Networks. Hipercom Project , INRIARocquencourt. 4 Lars Christensen, Gitte Hansen, TheOptimized Link State Protocol Performance Analysisthrough Scenario Based Simulations., Master’s thesis,Spring 2001. 5 Pekka Savola, “DSR: Dynamic SourceRouting”, CSC/FUNET, Helsinki University ofTechnology.

[6] D. Johnson, D. Maltz, J. Jetcheva, The Dynamic SourceRouting Protocol for Mobile Ad hoc Networks, InternetDraft, draft-ietf-manet-dsr-07.txt, work in progress,2002.

[7] Pekka Savola, “DSR: Dynamic Source Routing”, CSC/FUNET, Helsinki University of Technology.

[8] Scalable Solutions Inc., http://www.scalble-solutions.com.QualNet

[9] Camp, T., J. Boleng, B. Williams, L. Wilcox and W.Navidi, “Performance Comparison of two Locationbased Routing Protocols for Ad hoc Networks”,Proceedings of IEEE Infocom 2002, New York.

[10] Jiang, H. and J.J. Garcia-Luna-Aceves, “PerformanceComparison of three Routing Protocols for Ad hocNetworks”, Proceedings of IEEE ICCCN 2001, 547-554.

[11] S. R. Das, R. Castaneda and J. Yan, “Simulation BasedPerformance Evaluation of Mobile, Ad Hoc NetworkRouting Protocols,” ACM/MONET Journal, 179-189,July 2000.