A Comparison of Routing Protocols for MANET using NS-2 Simulator 1 Renu Singla, 2 Priyanka 1 Asst. Prof (CSE), Sri Ram College of Engg.,Palwal, India 2 M.Tech(CSE), Sri Ram College of Engg.,Palwal, India Abstract: Wireless Connections are used in Mobiles for establishing connection to various networks. A MANET is a collection of mobile users communicate over wireless links. The mobile device in MANET not only perform abilities as a host,but also as a router. The destination node can be within range of a source node or beyond the coverage of source, hence packets can be forwarded directly or via one or more intermediate nodes. In the given work, the reactive routing protocols, AODV and DSR are used and the comparison is based on the delay per packet transmitted for nodes. In this work, we have used NS-2 Visual Trace Analyzer to analyze the results using Trace file output. Simulation is performed using NS-2 Simulator and output Trace file is used to conclude final results. In MANET, nodes are autonomous and free to move randomly. Hence, the network topology is very dynamic and communication link between source and destination can vary with time. Traditional routing protocol used in wired network cannot be applied directly to wireless network. Nodes must be capable to maintain the routes so that they move to allow applications to operate without interruptions. Keywords: MANET, AODV, DSR, NS-2 Simulator, Trace File. I. INTRODUCTION An era of Mobile Computing has come up due to development of various wireless technologies such as wireless handhelds and other mobile information terminals. Vast interest and concerted work in developing and enhancing wireless and mobile network protocols are being driven by the ever increasing demand for an anytime and anywhere Internet access. Today, it is possible to create, synthesize, analyze and communicate knowledge using varieties of media forms because of access to a variety of multimedia and digital devices. Additionally, the mobile devices are getting smaller, cheaper, more convenient, and more powerful and have contributed to the explosive growth of the mobile computing equipment market. 1. Mobile Ad Hoc Network Mobile Ad Hoc Network (MANET) is a vast mobile node collection sharing wireless communication. These devices has no fixed infrastructure even when moving. Nodes can serve as both hosts and routers where communication between nodes beyond their coverage can be achieved. Figure 1: Mobile Nodes with their coverage range In the figure, Node 1 has two neighbours Node2 and Node 3. Node 4 and Node 5 are beyond the range of Node1, hence the transmission to node 4 and 5 will be done using Node 2 as intermediate node. 2. Routing Protocols in MANET There are many routing protocols have been proposed. Topology-based routing protocols route packets based on information about the network links. Topologybased protocols can be further divided into proactive routing protocols, reactive routing protocols and hybrid routing protocols. The network links are determined long before routing process in proactive protocols. ISSN: 2231-5381 http://www.ijettjournal.org Page 39
MANET s Routing Protocols Reactive Protocols Proactive Protocols Hybrid Protocols Figure 2: MANET s Topology based Routing Protocol In proactive routing protocol perform consistent and up-to-date routing information to all the nodes is maintained at each node. In Reactive (On-Demand) routing protocol, protocols find route on demand by flooding the network with Route Request packets. In the given work, we are using AODV and DSR reactive protocols for comparison. 2.1. AODV Routing Protocol AODV ABR DSDV CGSR TORA HECTOR DSR WRP ZRP Ad Hoc On Demand Distance Vector(AODV) routing protocol is a reactive routing protocol. AODV is a combination of both DSR and DSDV. It inherits the basic on-demand mechanism of route discovery and route maintenance from DSR plus the use of hop-byhop routing sequence numbers and periodic beacons from DSDV. This protocol also uses some of the characteristics of proactive routing protocol. Route Requests (RREQs), Route Replies (RREPs), and Route Errors (RERRs) are the message types defined by AODV. These message types are received via UDP, and normal IP header processing applies. In AODV when the routes are needed, they are established on demand and the established route is maintained as long as it is needed. When a network node needs a connection, it broadcasts a Request for connection. Other AODV nodes forward this message and record the node that they heard it from, creats temporary routes back to needy node. When node receives message and has a route to required node, it sends a message back through a temporary route to requesting node. The needy node then begins using the route. Unused entries are recycled in the routing table after time. 2.2. DSR Routing Protocol DSR is a simple routing protocol which is designed specifically for use in multihop wireless adhoc network of mobile node. In DSR, there is no existing network infrastructure, so it is a self organizing network. The DSR protocol allows node to dynamically discover a source route across multiple networks hops to any destination in the adhoc network. Each data packet sent then carries in its header the complete, ordered list of nodes through which the packet must pass. By including the source route in the header of each data packe, other nodes forwarding or overhearing any of these packets may also easily cache this routing information for future use. DSR is composed of two mechanism which work together to allow discovery and maintenance of source routes in ad hoc network. Route Discovery is a mechanism in which a source node wishing to send a packet to destination node obtains a source node towards destination. Route Maintenance is mechanism by which source node is able to detect, while using a source route to Destination node. If the network topology has changed such that it can no longer use its route to Destination because a link along the route no longer works. When Route Maintenance indicates a source route is broken, Source node can attempt to use any other route it happens to know to Destination, or can invoke Route Discovery again to find a new route. Route Maintenance is used only when Source is actually sending packets to Destination. II. EXISTING WORK Lot of work is already done by different researchers in the field of MANET and mobile computing. Some of the efforts of earlier researchers are discussed in this section. Broch et al [1] gave a detailed packet level simulation comparing four multihop ad hoc network routing protocols DSDV, TORA, DSR and AODV. They also contributed in terms of describing modifications to ns network simulator to provide an accurate simulation of the mac and physical layer behaviour of the IEEE 802.11 wireless LAN standard. Each of the protocol in ad hoc network of 50 mobile nodes, experiments were done for a range of node mobility rates and movement speeds. It was observed that DSDV delivered virtually all data packets when node mobility rate and movement speeds were low but failed to converge as node mobility increases. TORA although was the worst performer but delivered over 90% of the packets ISSN: 2231-5381 http://www.ijettjournal.org Page 40
with 10 or 20 sources. DSR performed well at all algorithms optimize the network performance by mobility rates and movement speeds, but its source utilizing trustworthy nodes in effective way and routing increases the number of routing overhead penalizing non-cooperative nodes. The paper presents bytes. Finally, AODV performs as well as DSR and a survey on trust based routing protocols for MANET. also eliminates source routing overhead. But at high D.A. Maltz[5] proposed the effects of on-demand rates of node mobility is actually more expensive than behavior in routing protocols for multihop wireless ad DSR. hoc networks. A number of on demand routing Kuppusamy et al[2], proposed a study and comparison protocols proposed for use in multihop wireless ad hoc of OLSR, AODV and TORA routing protocols in ad networks In this paper, he analyzed the use of ondemand hoc networks. He studied that in MANET, there is a behavior in such protocols, focusing on its collection of mobile nodes in which the wireless links effect on the routing protocol's forwarding latency, are frequently broken down due to mobility and overhead cost, and route caching correctness, drawing dynamic infrastructure. In ad hoc networks, routing is examples from detailed simulation of the dynamic a significant issue and challenge. Many routing source routing (DSR) protocol. He studied the protocols have been proposed like OLSR, AODV, protocol's behavior and the changes introduced by DSR, ZRP, and TORA so far to improve the routing variations on some of the mechanisms that make up performance and reliability. He presented a work the protocol, examining which mechanisms have the which describes the characteristics of ad hoc routing greatest impact and exploring the tradeoffs that exist protocols OLSR, AODV and TORA based on the between them performance metrics like packet delivery ratio, end-toend K.N. Durai[6] proposed a work on Energy efficient delay, routing overload by increasing number of random cast DSR protocol with mediation device in nodes in the network. This comparative study proves MANET. MANET basically have dynamic topology, that AODV, TORA performs well in dense networks as the routing system's list of neighboring nodes and than OLSR in terms of packet delivery ratio. routers changes its location from time to time. Another work was done by Ismail, Z[3]. He presented MANET's medium is shared with other nodes, so often Effects of Packet Size on AODV Routing Protocol it consumes lot of bandwidth. The drawback is mainly Implementation in Homogeneous and Heterogeneous because of limitations of the technology and routing MANET. Three scenarios have been defined from this protocols available. MANET's are vulnerable to attack architecture: scenario I (communication entirely as they share a wireless medium with infrastructure within MANET, homogeneous MANET), scenario II less backbone. The system proposes a Routing (communication between MANET and wireless LAN, protocol in MANET which enables efficient usage of heterogeneous MANET) and scenario III power and bandwidth in Mobile Ad-hoc networks (communication between MANET with wireless LAN (MANET). Randomized Overhearing techniques is and wired LAN, heterogeneous MANET). The aim of proposed to reduce power consumption and enhance this research is to assess the effects of different packet effective Routing in MANET. Minimum hop path is size with the implementation of AODV routing introduced to reduce excess bandwidth consumption. protocols in homogeneous and heterogeneous MD(Mediation Device)protocol is proposed to extend MANET through the simulation method. The three the battery life of nodes in the MANET scenario. scenarios above have been developed in the Y.Lacharite[7] presented a Simplified Approach to OMNeT++ network simulator. The results achieved Multicast Forwarding Gateways in MANET. from the test have been evaluated using the metrics Simplified multicast forwarding (SMF) provides an assigned, throughput and packet delivery ratio (PDR). optimized flooding mechanism in MANET The tests show that the increase of throughput and environments to efficiently propagate multicast PDR performance was parallel with the increase of packets. The main difference between the SMF and packet size. From the test also, we can conclude that traditional multicast routing is that no multicast tree is the performance due to the packet size effect in built and maintained, and no group membership homogeneous MANET is better than in heterogeneous management is needed. He presented the results of a MANET. tested single-gateway MANET implementation, and S.A. Thorat[4] proposed a work on Design issues in also introduced a proposal for the multiple-gateway trust based routing for MANET. MANET works well scenario. In the IETF MANET working group, the if the participating nodes cooperate with each other. SMF design group also presents proposals for For individual nodes it may be benefcial to be noncooperative handling multiple gateways;. However this approach and selfsh. However non-cooperation, implies that equal multicast packets disseminated into selfshness and malicious behavior of the participating the MANET by different gateways have different nodes may result into collapse of a MANET. Trust taggerld, and hence these packets cannot be detected based routing algorithms aim to identify misbehaving as duplicates. This article demonstrates a successful and non-cooperating nodes in the MANET. These implementation of the gateway functionality and ISSN: 2231-5381 http://www.ijettjournal.org Page 41
extends its analysis by proposing a solution for the III. SIMULATION multiple-gateway configuration. Q. Razouqi [8] presented extensive Simulation For Simulation Purpose, NS-2.34 used in Linux Performance Analysis for DSDV, DSR and AODV Environment(Ubuntu). The whole scenario is MANET Routing Protocols. In this work, Destination simulated in the network simulator. Delay per packet Sequenced Distance vector (DSDV), Dynamic Source is noted down for the comparison of AODV and DSR. Routing(DSR) and Ad hoc On demand Distance The nodes generation, nodes movement and transfer of Vector(AODV) routing protocols that are widely data between nodes is displayed as output in Network simulated in this paper using different scenarios in Animator(NAM). The NAM scenario of 20 nodes of terms of different Traffic types, constant bit AODV and DSR is shown in figure below rate(cbr), variable bit rate(vbr) then combining both classes in one scenario to scrutinize the impact of this combination. Performance metrics used for comparison are Average energy consumption, Average throughput, Normalized routing load (NRL), packet delivery fraction(pdf) and total dropped packets(tdp). Combined traffic results pronounce that DSR and AODV exhibit better behaviors overall the performance metrics examined. V.K. Taksande[9] presented a a Simulation Comparison Among AODV, DSDV, DSR Protocol with IEEE 802.11 MAC for Grid Topology in MANET.He performed comprehensive analysis among AODV, DSDV, DSR routing protocols of adhoc network with IEEE 802.11 Mac protocol in grid topology using Network Simulator-2(NS-2). Performance metrics of MANET such as Received Packet Vs. no. of nodes, Packet delivery ratio Vs. no. of nodes, Total dropped packets Vs. no. of nodes, Average end to end delay Vs. no. of nodes are investigated to confirm the best routing protocol in the simulation environment. B.S. Gouda[10] presented A comprehensive performance analysis of energy efficient routing protocols in different traffic based mobile ad-hoc networks. In this paper word is done to enhance the network performance of different routing protocols,. The performance analysis and simulation are carried out to evaluate network performance using Network Simulator (NS-2), based on the different load, node mobility, delay, packet sending rate and energy consumption. It has been verified through various simulations, Results conclude that energy AODV deliver the better performance as that of the modern protocols DSDV, TORA, DSDV, DSR and AODV in terms of energy efficiency but it is observed that DSR needs significantly smaller energy overheads than other protocols. M.N. Alslaim[11] presented a comparative study of MANET routing protocols. In this paper, the MANET characteristics and challenges are highlighted. Additionally, the previously mentioned categories of routing protocols, proactive and reactive, are explored. and a comparison is conducted between DSDV, DSR and AODV in terms of both properties and performance. Finally, a critical analysis is performed on some papers that discussed routing in MANET. Figure 3: NAM Scenario for AODV 20 nodes Figure 4: NAM Scenario for DSR 20 nodes Some parameters taken into account for the simulation are 1. Network Simulator : NS-2.34 2. Protocols studied : AODV,DSR 3. Node mov. Model : Random waypoint 4. Traffic type : CBR 5. Data payload : Bytes/packet 6. No. of Nodes : 20, 40, 80 7. Packet Size : 1024 bytes 8. Metric for Comparison : Delay/Packet 9. Flow considered for Comparison : tcp In this work, NS2 Trace file analyzer(ns-2 Visual Trace Anlyzer-2.72) is used to compare the results using trace file output. Packets generated and packet loss during transfer of data is noted down for the comparison and graphs are generated according to the tcp flow (Delay per packet) for both AODV and DSR. ISSN: 2231-5381 http://www.ijettjournal.org Page 42
IV. RESULTS The number of nodes was varied as 20, 40,80 with different traffic sources. Also the type of traffic sources was TCP. The packet size was taken to be the same 1024 bytes. Each of the mobile nodes selects a random destination at the specified time and moves towards it. Firstly, number of packets, number of bytes generated, and lost number of packets and bytes are noted down for each scenario which is shown below. Figure 7.b: DSR 20 nodes Figure 7: Delay Per Packet For AODV and DSR 20 nodes The above graphs shows that when 20 nodes are considered, the delay per packet using AODV protocol is very high comparatively using DSR protocol. Figure 5: Generated and Lost Packets for 80 nodes using AODV Routing Figure 6: Generated and Lost Packets for 80 nodes using DSR Routing Figure 8.a: AODV 40 nodes According to the number of packets lost considered, DSR routing protocol has less number of lost packets as compare to AODV protocol. As we increased the number of nodes in both protocols, the lost number of packets decreased gradually. The term DELAY implies the delay a packet suffers between leaving the sender application and arriving at the receiver application The graphs are generated for Delay per packet and results are observed for final conclusion of comparison between AODV and DSR routing protocol. Figure 8.b: DSR 40 nodes Figure 8: Delay Per Packet For AODV and DSR 40 nodes The above graphs shows that when 40 nodes are considered,i.e the number of nodes increases then the delay per packet using AODV protocol decreases as compared to 20 nodes using AODV but using DSR delay per packet increases as compared for 20 nodes using DSR routing. Figure 7.a: AODV 20 nodes Figure 9.a: AODV 80 nodes ISSN: 2231-5381 http://www.ijettjournal.org Page 43
[7] Lacharite, Y., A Simplified Approach to Multicast Forwarding Gateways in MANET, Wireless Communication Systems, 2007. ISWCS 2007, pp 426-430, 2007 [8] Razouqi, Q., Extensive Simulation Performance Analysis for DSDV, DSR and AODV MANET Routing Protocols, Advanced Information Networking and Applications Workshops (WAINA), 2013, pp 335-342, 2013 [9] Taksande, V.K., A Simulation Comparison Among AODV, DSDV, DSR Protocol with IEEE 802.11 MAC for Grid Figure 9.a: DSR 80 nodes Topology in MANET, (CICN), 2011, pp 63-67, 2011 [10] Gouda, B.S., A comprehensive performance analysis of energy efficient routing protocols in different traffic based mobile adhoc networks, Automation, Computing, Communication, Figure 9: Delay Per Packet For AODV and DSR 80 nodes Control and Compressed Sensing (imac4s), 2013, pp 306-312, 2013 [11] Alslaim, M.N., A comparative study of MANET routing The graphs shows that when the number of nodes protocols, e-technologies and Networks for Development increases as 80 then the delay per packet using AODV (ICeND), 2014, pp 178-182, 2014 protocol decreases and becomes very less as compared to 20 and 40 nodes using AODV but using DSR for increasing number of nodes, delay per packet increases. V. CONCLUSION On the basis of result, it was concluded that as the packet size is increased the end-to-end delay of AODV is lesser than that of DSR for larger number of nodes. DSR (Dynamic source routing) protocol is not a winner when it comes to the large size of the network. The end-to-end delay is increased when the packet size is increased. The degraded performance might be because of the aggressive use of caching. The basic problem is that in highly dynamic environment, the cache becomes stale and could lead to significant downfall in performance. There is a lot of scope related to the use of caching in DSR.So, AODV gave the best performance overall, making it suitable for medium as well as larger networks. References [1] Broch et al "Performance comparison of multihop wireless ad hoc network routing protocols " http://www.monarch.cs.cmu.edu/ [2] Kuppusamy, P, A study and comparison of OLSR, AODV and TORA routing protocols in ad hoc networks, Electronics Computer Technology (ICECT), 2011, DOI: 10.1109/ICECTECH.2011.5941974 (pp 143-147) [3] Ismail,Z, Hassan, R., Effects of Packet Size on AODV Routing Protocol Implementation in Homogeneous and Heterogeneous MANET, Computational Intelligence, Modelling and Simulation (CIMSiM), 2011, pp 351-356, 2011 [4] Thorat, S.A., Design issues in trust based routing for MANET, Computing, Communication and Networking Technologies (ICCCNT), 2014, pp 1-7, 2014 [5] Maltz, D.A., The effects of on-demand behavior in routing protocols for multihop wireless ad hoc networks, Selected Areas in Communications, IEEE Journal on (Volume:17, Issue: 8 ), pp 1439-1453, August 1999 [6] Durai, K.N., Energy efficient random cast DSR protocol with mediation device in MANET, Advanced Computing and Communication Systems (ICACCS), 2013,pp 1-5, 2013 ISSN: 2231-5381 http://www.ijettjournal.org Page 44