Performance Comparison of Distance Routing Effect Algorithm for Mobility (DREAM) and On-Demand Distance Vector (AODV) Routing Protocols

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1 MIT International Journal of Computer Science and Information Technology, Vol. 4, No. 2, August 2014, pp Performance Comparison of Distance Routing Effect Algorithm for Mobility () and On-Demand Distance Vector () Routing Protocols Shivi Rastogi Student, B.Tech Sanjay Singh Bisht Student, B.Tech. Rachit Katyal Student, B.Tech. Manoj Kumar Singh Assistant Prof. ABSTRACT Various types of routing protocols have been designed over time, keeping in view the widespread domain of networking. Wireless networking has been a trend for quite a few years. In this paper, we present a comparison of two different protocols- (Distance Routing Effect Algorithm for Mobility) and (Ad hoc On-Demand Distance Vector Routing). Both the protocols are designed for mobile networks; however the mechanism followed by each is different. is a location-aware routing protocol whereas is an on-demand routing protocol. Both the protocols are simulated in Network Simulator 2(ns2.32) and the results obtained after simulation are analysed. Analysis is based on various parameters such as delay, throughput, packet delivery ratio etc. The results obtained after analysis are summarized in the paper. Keywords: MANET,,, Location based routing protocol. 1. INTRODUCTION The need for wireless networking stemmed from the fact that computing devices had to be made portable, so that communication and computations can be performed while the user is on the move. For ex-cellular phones have replaced the traditional landline phones everywhere because of their minimal requirements in terms of energy consumed and their portability features. Due to its battery oriented operation, one can easily carry it along anywhere as there are no problems related to wiring. Earlier, wireless networking meant a number of mobile nodes connected to a fixed infrastructure without any wires. This was called a cellular network [1]. Mobile nodes communicated with each other through this fixed infrastructure (access point). But there can be times when a fixed infrastructure is not possible, or is impractical, or expensive (for ex-in military). In such a situation, a mobile ad hoc network (MANET) is used for communication by the mobile nodes. A few characteristics of a MANET are: No fixed infrastructure required. Multi-hop wireless links (packets are forwarded from one hop (or node) to another until it reaches the destination node). Self-organizing, as nodes can cooperate on their own without any central administration. Adaptation to dynamic topology changes. Every node acts as a router so as to forward data packets to other nodes. Easy to deploy. Routing plays a very crucial role in a mobile network. An optimal routing algorithm finds out the best route to forward any packet

2 MIT International Journal of Computer Science and Information Technology, Vol. 4, No. 2, August 2014, pp to its destination properly without any errors. Various routing protocols have been designed for this purpose like DSR [9], DSDV[3] etc.. Basically, routing protocols can be classified into three major categories- Reactive Proactive Hybrid Proactive or table-driven protocols are those protocols that always need to maintain information about other mobile nodes in the network. This information is maintained in a table called a routing table [2]. The tables are updated either periodically or whenever the topology changes. Example- Destination Sequenced Distance Vector protocol (DSDV) [3]. Reactive protocols (also known as source-initiated or on-demand protocols) are those which do not maintain any prior state of other nodes. However, a node initiates a route discovery process for the destination node whenever it needs to communicate with that node. Example Dynamic Source Routing protocol (DSR)[2][9]. Hybrid protocols combine the best features of both proactive and reactive protocols. Basic idea is to use table driven approach when topology changes infrequently and reactive approach is followed whenever topology changes frequently. Example Zone Routing Protocol(ZRP)[4]. Apart from these three categories, routing protocols can also be classified on basis of location, multicasting, hierarchy etc. 2. PROTOCOLS STUDIED 2.1 Distance Routing Effect Algorithm for Mobility () [5] belongs to a class of routing protocols called location-aware protocols. As the name suggests, a location aware protocol assumes that every node knows about the location or geographical position of other nodes in the network. This location information is stored in a Location Table. A Global Positioning System (GPS) can be used for this purpose. Now, this location information is utilized by the protocol for data transmission from source node to destination node. Basically works on two principles: Distance effect If distance between two nodes in greater, it appears that they are moving slowly with respect to each other. It can also be understood by considering two nodes which are moving at the same speed. It will be observed that the closer node appears to be changing its position more rapidly than the node that is farther away. If such a case is the situation, then the location table of any node will be updated frequently only for nodes that are closer to it. This is because the motion of farther away nodes will be insignificant. Hence location table entries need to be updated only for closer nodes and not for nodes that are far away. Mobility effect The mobility rate of a node is also an important factor to decide how frequently the location table entries need to be updated. If the node changes its position frequently, then its location table also needs to be updated frequently. This factor also helps a node to adapt to changing topologies of the network Maintaining Location Information in works on the fact that every node knows the geographical location of every other node in the network. This location information needs to be maintained at every node. It can be maintained using a location table. The entries of a location table at any node are nothing but co-ordinates that denote the geographical location of other nodes. Alongwith this, the time at which this location was stored is also maintained [5][6]. Whenever any node wants to communicate with any other node in the network, it will look up to its location table to find the location of that node. As soon as it finds the location, it starts flooding data packets in that direction. This directional approach of (flooding data packets in direction of the destination) assures the reliable delivery of data packets at the destination in a loop free manner Updating Location Tables in Since we are dealing with a mobile network, there is high possibility that the nodes will move. As a result of the movement of nodes, their geographical locations will also vary. Hence, location information needs to be updated in location tables of other nodes. The frequency of sending updates depends on mobility rate (mobility effect) and distance separating the nodes (distance effect). As soon as a node, say A, changes its position, it sends a location packet to other nodes in the network. This location packet contains the new coordinates of that node. Other nodes, on receiving this packet, update their location table entries for node A along with the time this location information was received Concept of directed flooding and forwarding (or expected) zone Whenever a node has to send data packets to another node, it checks its location table and finds out all the nodes which lie in the same direction as that the destination node. The location information of any node can be used to find the angular range of that node [5][10]. This angular range determines the expected zone in which the destination node is most likely to be found. So the packets are directed to nodes which lie within this particular range. This zone, therefore is also termed as forwarding zone Advantages of As far as control information is concerned, only location information is exchanged which are in form of short sized location packets. So, it saves bandwidth. Due to directed flooding, possibility of loops is minimized as packets travel in the direction of the destination. It efficiently adapts to dynamic topologies (or mobility in the network). This is because of the mobility effect.

3 MIT International Journal of Computer Science and Information Technology, Vol. 4, No. 2, August 2014, pp Ad hoc On Demand Distance Vector Routing Protocol () [7][8] is a reactive or on-demand protocol, developed as an improvement over DSDV [9], which was a table driven protocol. On-demand implies that a route to a particular node, say X is found only when some other node wishes to communicate with X. Distance Vector implies that it uses distance vector algorithms to find routes. Such algorithms return shortest route to any destination node Route Discovery Phase When a node wants to communicate with another node, it checks its routing table to see if it has a route to that node. This is because routes once discovered are cached in the routing table for a period of time. If a route exists, it forwards the data packets to the next hop along the route, this hop follows the same process until destination node is reached. If no route exists, the sender node initiates a route discovery process to find a route to the destination node. It broadcasts a Route Request packet (RREQ) to its neighbours. This packet holds the following information Source address and source sequence number. Destination address and destination sequence number. Broadcast id (incremented on every broadcast by the source). Hop count (incremented whenever a node forwards the packet to another node). RREQs are uniquely identified by <source address, broadcast id>. In case of multiple RREQs, this pair is checked for discarding the packet. Sequence numbers are used to indicate the freshness of routes. If a node that receives a RREQ packet, it checks its routing table if it has a sequence no. at least as great as the one in RREQ packet. If no, it forwards the RREQ, otherwise a route reply packet (RREP) is unicasted back to the source. Every node that receives a RREQ, maintains the following information in order to facilitate sending RREP back to the originating source: Source and destination addresses. Destination sequence number. Hop count Lifetime (expiration time for backward pointers) Forward pointers, Backward Pointers and Link Breakages Every node that receives a RREQ packet caches the route to the originating source temporarily. Moreover, it maintains backward pointers to the nodes that used it as a next-hop towards destination. These backward pointers can also be termed as precursor lists. These pointers are maintained as long as a RREP is produced. When the destination is reached finally, RREP propagates back to the source using these backward pointers. Along with this, forward pointers are also set up so that the source node can communicate with the destination node using the active route found. Routes are maintained only till they are active. If a link breaks on the active route, other nodes on that route are notified with a route error message (RERR).No notifications are sent if the link breaks anywhere else apart from the active route. This notification mechanism uses backward pointers Routing tables in Routing tables are maintained in for active paths only. A routing table entry consists of the followingà: Destination address and its sequence number. Number of hops needed to reach destination. Next hop. Backward pointers List. Lifetime (denotes the time after which the route will expire and hence will be deleted). In case of multiple routes, the route with greater sequence number is chosen. If sequence number s are same, route with smaller number of hops lying on it is considered Advantages of Use of sequence number s ensure loop freedom. Supports both unicasting and multicasting routing mechanism. Most recent or latest route is used. 3. SIMULATION AND RESULTS Extensive simulations have been carried out to evaluate the performance of and routing protocols in MANETs by using the network simulator ns-2 [10][11] in its version ns We simulated the protocols, and, for varying number of nodes in each simulation trial. The parameters shown in Table 1 were kept constant. The mobility of the nodes depends on the model of mobility being preferred. Here random waypoint model for mobility is used. In this model, a pause time is specified for nodes after which nodes start their movement. The nodes move independently, irrespective of motion of other nodes. 3.1 Performance Parameters There are certain parameters for evaluating whether a routing protocol is optimal or not. The parameters we have chosen to compare the performance of and are: a. End-to-end delay: The time taken between the sending of a packet by a source and its reception at the destination is termed as end to end delay. Lower value implies better performance. b. Packet Delivery Ratio (or Fraction): It indicates the number of packets received over a number. of packets sent. Greater this ratio, better the performance of the protocol. c. Drop packet Ratio: the total number of packets dropped during the simulation.

4 MIT International Journal of Computer Science and Information Technology, Vol. 4, No. 2, August 2014, pp d. Routing Overhead: It denotes the number of routing or control packets sent over the no. of data packets received. Following are the constants for simulation environment: Table 1: Simulation Constants PARAMETER VALUE No. of mobile nodes 10,20,30,40,50 Average pause time Maximum speed Dimensions of topology Simulation time Movement model Traffic type 10 sec 5 m/sec 300m 600m 1000 ms Random Waypoint model CBR (Constant Bit Rate) Number. of nodes vs PDF The simulation result shows that and produces almost same PDF for lower no. of nodes, but as number of nodes increases PDF decreases rapidly in. PDF of decreases with the increase in number of nodes but it is still better than. Table 3, Fig. 2. Table 3: Number of nodes vs PDF No. of PDF nodes Packet size Packet rate 64 bytes packet/s 3.2 Results and Discussion Results of simulation can be understood with the help of following tables and graphs No. of nodes vs Delay The simulation result shows that and produces almost same delay for lower no. of nodes, but as number of nodes increases produces more delay. Table 2, Fig. 1. Table 2: Number of nodes vs Delay No. of Nodes Delay(ms) Fig. 2: Number of nodes Vs Packet Delivery Fraction Number. of nodes vs DPR The simulation result shows that and produces almost same Packet Drops for lower number of nodes, but as number of nodes increases packet drop increases. Here also performs better than for larger no. of nodes. Table 4, Fig. 3. Table 4: Number of nodes vs DPR Fig. 1: Number of nodes Vs Delay (milliseconds) DPR No. of nodes

5 MIT International Journal of Computer Science and Information Technology, Vol. 4, No. 2, August 2014, pp CONCLUSION In this paper, we presented the simulation results after simulating and. is a reactive protocol whereas is a location aware protocol. After simulating these protocols in the same simulation environment, and analysing the results, it can be concluded that for lower no. of nodes and both gives approximately similar performance but as the no. of mobile nodes increases, performs relatively better than. REFERENCES Fig. 3: Number of nodes Vs Drop Packet Ratio (DPR) No. of nodes vs Routing Overhead Simulation results shows that routing overhead in is more than. Table 5, Fig. 4. Table 5: Number of nodes vs Overhead Overhead (%) No. of Nodes Fig. 4: Number of nodes Vs Routing Overhead 1. John R. Vacca, Computer and Information Security Handbook, Second Edition, Morgan Kaufmann Publications, pp. 286, Azzedine Boukerche, Begumhan Turgut, Nevin Aydin, Mohammad Z. Ahmad, Ladislau Bölöni, Damla Turgut, Routing protocols in ad hoc networks: A survey. 3. Charles E. Perkins, Highly Dynamic Destination Sequenced Distance Vector Routing for Mobile Computers. 4. P. Samar, M. Pearlman and S. Haas, Independent zone routing: an adaptive hybrid routing framework for ad hoc wireless networks,ieee/acm Transactions on Networking Vol. 12, No. 4, August 2004, pp Stefano Basagni, Imrich Chlamtac, Violet R. Syrotiuk, and Barry A. Woodward. A Distance Routing Effect Algorithm for Mobility (),In Proceedings of the 4th Annual ACM/ IEEE International Conference on Mobile Computing and Networking (MobiCom 98), 1998,pages M. Bakhouya, J. Gaber and M. Wack, Performance Evaluation of Protocol for Inter-vehicle Communication, mbakhouya.free.fr/site/pdf/v2v-crv-v4.pdf. 7. Charles E. Perkins, Elizabeth M. Royer., Ad hoc On Demand Distance Vector Routing, wmcsa99.pdf. 8. C. Perkins,E. Belding-Royer, Ad hoc On-Demand Distance Vector () Routing, Request for Comments: D. B. Johnson, D. A., Maltz, Y. C. Hu, and J. G. Jetcheva,.The dynamic source routing protocol for mobile ad hoc networks (DSR) Draft-ietf-manet-dsr-07.txt Marc Greis tutorial on ns Matthias Transier Ns2 tutorial running simulations.