PERFORMANCE ANALYSIS OF AODV, DSR AND DSDV IN MANET USING NS-2 Subhrananda Goswami 1 * and Chandan Bikash Das 2 1 Assistant Professor, Department of IT, Global Group of Institutions, Haldia, Purba Midnapore, West Bengal, India. 2 Assistant Professor, Department of Mathematics, Tamralipta Mahavidyalaya, Tamluk, Purba Midnapore- 721636,West Bengal, India. * Corresponding author. Tel.: +919734635890; email: subhrananda_usca@yahoo.co.in Abstract: A mobile ad hoc network (MANET) consists of mobile wireless nodes. MANET is a self organized and self configurable network where the mobile nodes move arbitrarily. In this paper, we analyzed AODV,DSR and DSDV routing protocol using different parameter of QoS metrics such as packet delivery ratio(pdr), control overhead, throughput and delay. In this work, an attempt has been made to understand the characteristics of Ad hoc On Demand Distance Vector (AODV),DSR and Destination Sequence Distance Vector (DSDV) routing protocols when operating in more challenging environment such as frequent change in network topology and node density. Our simulation tool is NS-2. The comparison analysis will be carrying out about these protocols and in the last the conclusion will be presented, that which routing protocol is the best one for mobile ad hoc networks. Keywords: AODV, DSR, DSDV, MANET, Throughput, Packet Delivery Ratio, Delay and Control Overhead, NS2. 1. Introduction Tenenbaum [7] defines computer networks as a system for communication between computers. These networks may be fixed (cabled, permanent) or temporary. MANET is a collection of wireless mobile nodes that communicate with each other using multi-hop wireless links without any existing network infrastructure or centralized administration. Since the nodes are highly mobile in nature, the changes in network topology are very frequent and the nodes are dynamically connected in an arbitrary manner. The topology of Ad hoc network is dynamic in nature, design of suitable routing protocol is essential to adapt the dynamic behavior of the network. Various dedicated routing protocols have been proposed to the Internet Engineering Task Force (IETF) MANET Working Group [8]. Some of these protocols have been studied and their performances have been analysed in detail. J. Broch et al [9] evaluated four protocols using mobility and traffic scenarios similar to those we used. They focused on packet loss, routing message overhead and route length. In [10], P. Johansson et al, compare three routing protocols, over extensive scenarios, varying node mobility and traffic load. They focus on packet loss, routing overhead, throughput and delay, and introduce mobility measures in terms of node relative speed. Finally, in [11] S. R. Das et al, compare the performance of two protocols, focussing on packet loss, packet end to end delay and routing load. They obtained simulation results consistent with previous works and conclude with some recommendations for improving protocols. In this work, we measure and compare three performance parameter behavior of two routing protocols; respectively Ad-hoc On Demand Distance Vector (AODV) [12] and Destination-Sequenced Distance Vector (DSDV). 2. Ad-hoc On Demand Distance Vector (AODV) In AODV [1], the only nodes that participate in the entire routing process are those sitting in the direct path between the source and destination node. Hence those nodes that do not lie on active paths neither maintain any routing information nor participate in any periodic routing table exchanges. Thus AODV seeks to minimize the number of control messages sent between the nodes. AODV experiences unacceptably long waits frequently before transmitting urgent information because of its on demand fashion of route discovery [icce9]. In AODV, each host maintains a traditional routing table, one entry per destination. Each entry records the next hop to that destination and a sequence number generated by the destination, which indicates the freshness of this information. The routing tables of the nodes within the neighborhood are organized to optimize response time to local movements and provide quick response time for requests for the establishment of new routes. The algorithm s primary objectives as stated in [1] are: 1. To broadcast discovery packets only when necessary. 2. To distinguish between local connectivity management (neighborhood detection) and general topology maintenance. 75
3. To disseminate information about changes in local connectivity to those neighboring mobile nodes that are likely to need the information. AODV borrows the concept of DSDV with the aim of reducing the need for system wide broadcasts as much as possible and AODV improves it by using a monotonically increasing number for the destination sequence number to replace old and stale routes, the result of which is a loop-free, highly situational responsive and bandwidth-efficient routing protocol. AODV is capable of both unicast and multicast routing. 3. Dynamic Source Routing (DSR) Dynamic Source Routing (DSR) is a reactive routing algorithm based on link state routing and it was first proposed by [6].It is based on the concept of source routing. Routes caches are kept at the mobile nodes so as to enhance the discovery process. These caches are also continuously updated throughout the process. DSR allows for packets to travel over a different route from source to destination than from destination to source. Given this flexibility in DSR, each sender can choose its optimal path to reach its destination, thereby achieving some sort of load balancing and making the data transfer process more robust. Two major phases take place in DSR: route discovery and route maintenance. In route discovery, the sender floods the network with RREQ messages (including source IP address, destination IP address and an unique request ID) and nodes receiving the flood message will forward the RREQs after appending their names onto the RREQs. In route maintenance, the maintenance is achieved through means of two types of control packets, i.e., route error and acknowledgements. Once there is a data-link failure, a route error message is generated. Upon receipt of the route error packet, the hop in error is removed from the route cache and all routes using this hop will be truncated. A rediscovery process is necessary to establish alternate paths. 4. Destination Sequenced Distance Vector (DSDV) The C. Perkins and P. Bhagwat developed this routing protocol in 1994. Destination sequenced distance vector(dsdv) is a proactive hop-by-hop distance vector routing protocol, requiring each node to broadcast routing updates periodically. It is based on modified bellman ford routing algorithm with some enhancement to calculate path [2]. It overcomes some of weaknesses of bellman ford algorithm like poor looping properties in case of broken links. Each node maintains total related information about the local network topology. This information is stored through periodic exchange of partial routing stored at each node. Since each node knows complete topology information very well. Each node maintain routing information which stores address of next hop, cost matrix towards each destination, sequence number which is created by the destination node. The cost matrix is used for hop count, by which we can determine how many number of hops it takes for the packet to reach the destination. The "full dump" and "incremental update" is two ways in DSDV for sending information of routing table updates. As like name "full dump" the complete routing table is send in update message while incremental update contains only the entries with metric that have been changed since last update was sent. DSDV protocol guarantees loop free paths and Count to infinity problem is reduced in DSDV [3].On the contrary in DSDV there is wastage of bandwidth due to unnecessary advertising of routing information even if there is no change in the network topology [4] also DSDV doesn t support Multi path Routing. It is difficult to determine a time delay for the advertisement of routes [5]. 5. Simulation Model The simulation software used in this paper is the network simulator, NS-2. The software version used is the latest release at the time of the commencement of simulation, namely, ns- 2.34, which can be downloaded from NS2.In addition, many existing ad hoc routing protocols modules have already been implemented in NS2. Three such protocols are AODV, DSR and DSDV. NS2 is a discrete-event driven simulation software targeted for network simulation. This software is currently maintained by the Information Science Institute of University of Southern California. 5.1. Random Waypoint Model Generation NS2 can generate random waypoint mobility using a function that comes with the installation software-setdest. Setdest is located in the sub folder../ns 2.34/indeputils/cmu scen gen/setdest/direct ory 5.2. Simulation Experiment In order to analyze and compare the performance of the three routing protocols AODV, DSR and DSDV, simulation experiments were performed. The purpose of the simulations was to compare the efficiency of the routing 76
protocols based on different simulation parameters. The focus was concentrated on four performance metrics: 1. Packet delivery ratio. 2. End-to-End delay. 3. Throughput. 4. Control Overhead. figure 1, which is visualized the traces of communication or packets movements between mobile nodes [14]. 5.3. NS2 Environment We have used Linux for NS2.The hardware specification of the Linux that we have used is an follows. Processor: Intel(R)Core(TM)i3CPUM 370@2.40 Linux Kernel Version: Linux 2.6.18-53.el5 i686 Total Memory: 515524 KB The Simulation environment hat we have used for our simulation are: Table1:Simulation Environment Parameter Values Simulator NS2(Version 2.34) Channel/Wireless Channel Channel Type Radio-propagation model Propagation/Two Ray Ground Network Interface Type Phy/WirelessPhy MAC Type Mac/802.11 Interface Queue Type Queue/DropTail/PriQueue Link Layer Type LL Antenna Model Antenna/OmniAntenna Maximum packet in ifq 50 Area(M*M) 800 Source Type CBR Routing Protocol DSR, DSDV, AODV 5.4. Result Generated trace file that is (.tr) s -t 2.000000000 -Hs 1 -Hd -2 -Ni 1 -Nx 282.78 -Ny 298.25 -Nz 0.00 -Ne 10.000000 -Nl AGT -Nw - -Ma 0 -Md 0 -Ms 0 -Mt 0 -Is 1.0 -Id 3.0 -It cbr -Il 210 -If 0 -Ii 0 -Iv 32 -Pn cbr -Pi 0 -Pf 0 -Po 1 1: A simple Nam output. 6. Simulation Results & Observation 6.1. Packet Delivery Ratio The ratio of the number of data packets successfully delivered to the destinations to those generated by CBR sources. The higher the delivery ratio, better is the performance of the routing protocol. PDR is determined as: Packet delivery Ratio = (Received packets/sent packets)*100 2: Packet Delivery Ratio (PDR) at 10m/s 5.5. Nam file output NAM is a Tcl/TK based animation tool for viewing network simulation traces and real world packet traces. Taking data from network simulators (such as ns) or live networks, NAM was one of the first tools to provide general purpose, packet-level, and network animation, before starting to use NAM, a trace file needs to create [13]. This trace file is usually generated by NS. Once the trace file is generated, NAM can be used to animate it. A snapshot of the simulation topology in NAM for 15 mobile nodes is shown in 3: Packet Delivery Ratio (PDR) at 25m/s 77
4: Packet Delivery Ratio (PDR) at 50m/s 6: Throughput at 25m/s The 2, 3 and 4 clearly indicates that the AODV routing protocol outcomes is better with the CBR traffic. However in the low node scenario i.e. 7 node scenario it perform better with the TCP traffic but with all other network scenarios the protocol outcomes better with the CBR traffic. AODV protocol performs better in comparison of other two selected routing protocols in such network environment. The performance of AODV is better from DSR and DSDV in low traffic but not significant or can say lesser from the outcome of AODV routing protocol performance with both CBR and TCP traffic. So we can that AODV is better in most of the cases PDR. 6.2. Throughput Throughput is defined as; the ratio of the total data reaches a receiver from the sender. The time it takes by the receiver to receive the last message is called as throughput. Throughput is expressed as bytes or bits per sec (byte/sec or bit/sec). Some factors affect the throughput as; if there are many topology changes in the network, unreliable communication between nodes, limited bandwidth available and limited energy.a high throughput is absolute choice in every network. 7: Throughput at 50m/s Based on the result of simulation as indicated in 5, 6 and 7 shows that performance of AODV is better than DSR and DSDV. Another characteristic that has come to the notice is that pause time does not have significant bearing on the throughput whereas the performance is dictated only by the density of the network. After analyze the simulation work we say that AODV gives the better as compared to DSR and DSDV in case of throughput. 6.3. Control Overhead Control Overhead is the number of packet generated by routing protocol during the simulation. The generation of an important overhead will decrease the protocol performance. 5: Throughput at 10m/s 78
8: Control Overhead at 10m/s d end end = End to end delay d trans = Transmission delay d prop = Propagating delay d proc = Processing delay 9: Control Overhead at 25m/s 11: Delay at 10 m/s 10: Control Overhead at 50m/s Based on the result of simulation as indicated in 8, 9 and 10 shows that performance of DSR is better than AODV and DSDV. At all the considered mobility DSR is the best protocol as compared to other protocols. 6.4. Delay A specific packet is transmitting from source to destination node and calculates the difference between send times and received times. Delays due to route discovery, queuing, propagation and transfer time are included in the delay metric. There are different kinds of activities because of which network delay is increased. Packet end-to-end delay is a measure of how sound a routing protocol adapts to the various constraints in the network to give reliability in the routing protocol. We have several kinds of delays which are processing delay (PD), queuing delay (QD), transmission delay (TD) and propagation delay (PD). The queuing delay (QD) is not included, as the network delay has no concern with it. Mathematically it can be shown as equation 1 d end end= N [d d d ] (1) trans prop proc Where 12: Delay at 25 m/s 13: Delay at 50m/s Based on the result of simulation as indicated in 11 and 13 shows that performance of AODV shows the minimum delay than DSR and DSDV. 12 shows that DSDV has minimum delay. So we say that AODV shows the minimum delay. 7. Conclusion 79
A The MANETs works under different environment which have different requirement. In some environment the factors are PDR, Throughput, delay etc. For this work we have used a simulator which provides the virtual environment for the testing different parameters. This paper is mainly focused on the comparative analysis of different parameters of the simulation under different environment of the three routing protocols namely AODV, DSR AND DSDV. Using NS 2 simulator we created the scenarios under which using tcl script, it is run. After analyzing the X-graphs we can conclude that in long run the performance of the AODV was found better than DSR, where is turn DSR is found to be better than DSDV. The analysis is done on the basis of four parameters namely PDR, throughput, control overhead and delay. After the analyzing we concluded that AODV indicating its highest efficiency and performance under high mobility than DSR and DSDV, and the performance of TCP and UDP packets with respect to the average end to end delay, throughput, control overhead and PDR, and the performance of AODV is better than DSR and DSDV routing protocol for real time applications from the simulation results. References [1] Perkins,C.E.and Royer, E. (1999) Ad-Hoc On- Demand Distance Vector Routing, Proceeding of 2nd IEEE Workshop on Mobile Computing & Systems and Applications. [2] Maan, F. and Mazhar, N. (2011) MANET Routing Protocols Vs Mobility Models: A Performance Evaluation, IEEE proceedings. Networks, Ad Hoc Networking, edited by Charles E. Perkins,Addison-Wesley, pp. 139-172. [7] Tanenbaum, S.A. (2002) Computer Networks PRENTICE HALL. [8] Internet Engineering Task Force MANET Working Group Charter., http://www.ietf,org/html.charters/manetcharter.html. [9] Broch, J., Maltz, A.D., Johnson, D.B., Hu, Y.C. and Jetcheva,J. (1998) A Performance Comparison of Multi-hop Wireless Ad Hoc Networks, In Proceedings of the 4th Int. Conjkrence on Mobile Computing and Networking (ACM MOBICOM 98), pp. 85-97. [10] Broch, J., Maltz, A.D. and Johnson, D.B. (1999) The Dynamic Source Routing Protocol for Mobile Ad Hoc Networks, lntemet Draft, MANET Working Group. [11] Perkins,C.E., Belding-Royer, E.M. and Das, S.R. (2002) Ad hoc On-Demand Distance Vector Routing, IEFT MANET Draft, Charles E. Perkins, Ad Hoc Networking, ISBN 0-201-3097. [12] Perkins,C.E.and Royer, E. (2000) Ad Hoc On- Demand Distance Vector (AODV) Routing, lntemet Draft, MANET Working Group. [13] Network simulator-ns-2, www.isi.edu/nsnam. [14] NS Manual/Documentation-The VINT Project Collaboration between researcher, UC Berkeley, LBL. [3] Lu, Y., Wang, W., Zhong, Y. and Bhargava, B. (2003) Study of Distance Vector Routing Protocols for Mobile Ad Hoc Networks, Proceedings of the First IEEE International Conference on Pervasive Computing and Communications (PerCom 03),pp 187-194. [4] Baumung, P., Zitterbart, M. and Kutzner, K. (2005) Improving Delivery Ratios for Application Layer Multicast in Mobile Ad-hoc Network journal of computer communication,vol.28,issue 14,pp.1669-1679. [5] Bein, D.,Datta,K.A., Jagganagari, R.C. and Villain, V. (2005) A Self-stabilizing Link- Cluster Algorithm in Mobile Ad Hoc Networks, Proceedings of The International Symposium on Parallel Architectures, Algorithms, and Networks (I-SPAN), vol.4,no.2,pp. 436-441. [6] Johnson, B.D.,Maltz,A.D., and Broch, J. (2001) A Self-stabilizing Link- Cluster Algorithm in Mobile Ad Hoc 80