IMPLEMENTATION OF AODV & DSR ROUTING PROTOCOLS IN VARIOUS MOBILITY MODELS UNDER SQUARE AREA

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IMPLEMENTATION OF AODV & DSR

ROUTING PROTOCOLS IN VARIOUS

MOBILITY MODELS UNDER SQUARE

AREA

K.LAAVANYA

Nightingale Engineering College (Women), JNTUK, Visakhapatnam, Andhra Pradesh, India

kitti.lavanya@gmail.com

V.TEJASWINI

tejaswini.teja546@gmail.com

KAKARLA CHANDRIKA

Asst. Professor , CSE Dept.,

chandu.sweet1@gmail.com

V.PADMA

padmavati.547@gmail.com

Abstract

Mobile Ad Hoc Networks are generally dynamic collections of self-organizing mobile nodes with links that are characterized by dynamic topology changes and with no fixed infrastructure. The academic communities have proposed many routing protocols for possible practical implementation of a MANET in military, commercial and governmental environments. In this paper, the Reactive routing protocols namely Ad Hoc On demand Distance Vector routing (AODV) and Dynamic Source Routing (DSR) were analyzed in various mobility models like RPGM, Manhattan and Random way point under different square dimensional areas and network density. The simulation results provides a better insight in the performance of the selected routing protocols.

Keywords: AODV, DSR, MOBILITY MODELS.

I. Introduction

There are two variations of wireless network, such as infrastructure networks and ad-hoc networks [1]. In an infrastructure network, a mobile station must find the nearest base station within its communication range before it communicates with another. In an ad hoc network where no base station exists, each mobile node acts as a router. Routing protocols [2] plays an active role in this case. The rest of the paper is organized as follows. The Protocols Description is summarized in section II, Mobility models are summarized in section III, The simulation environment is proposed in section IV, results are presented in section V and finally concluded with section VI.

II. Protocol Description

Reactive routing techniques, which are also known as on-demand routing, take different routing approaches than proactive protocols. Instead, routes are only discovered when they are actually needed. The route discovery mechanism typically consists of the network-wide flooding of a request message. Once a route is established, it is maintained by some form of route maintenance procedure until either the destination becomes inaccessible along every path or until the route is no longer desired. Reactive routing protocol includes Dynamic Source Routing (DSR) [3 4] protocol, Ad hoc On-demand Distance Vector (AODV) [5 6] protocol and Fuzzy Based Node Traversal Time AODV (FBNTTAODV) [7] etc.

A. Ad hoc On Demand Distance Vector Routing Protocol (AODV)

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consists of sequence numbers of the destination node so as to identify the current path used for transmitting data packets. AODV uses a broadcast route discovery algorithm and then the unicast route reply message for finding the route.

a. Route Discovery

Source node broadcasts a route request (RREQ) packet to its Neighbours, which then forwards the request to their neighbours and so on. Nodes generates a Route Request with Sequence number , Broadcast ID and destination address and it is sent to its neighbour nodes. Each node which receives the route request sends a route back (Forward Path) to the node .When the RREQ is received by a node that is either the destination node or an intermediate node with a fresh route to the destination, it then replies by unicasting the route reply (RREP) towards the source node. As the route reply( RREP) is routed back along the reverse path, the intermediate nodes along the reverse path set up forwards the path entries to the destination in its route table and when the route reply (RREP) reaches the source node, then a route is established from source to the destination.

b. Route Maintenance

A route established between source and destination pair is maintained as long as needed by the source. When a link break then an active route is detected, the link which is broken is invalid and a RERR message is sent to other nodes. These nodes in turn propagate the RERR message to their predecessor nodes, and so on until the source node is reached. The affected source node may either choose to stop sending data or reinitiate route discovery for that destination by sending out a new RREQ message.

B. Dynamic source routing (DSR)

The Dynamic Source Routing Protocol (DSR) is a reactive routing protocol . By the means of this protocol each node can discover dynamically a source route to any destination in the network over multiple hops. In ad hoc wireless networks, bandwidth is drained by control packets. Hence, regular table update messages used in the table driven routing protocols are removed, thereby controlling the bandwidth consumption. The two main mechanisms of DSR are Route Discovery and Route Maintenance, which together work to discover and maintain source routes to arbitrary destinations in the network.

a. Route Discovery

If a node S wants to send to a destination node D, it needs a source route. S searches its Route Cache for a valid route to D. If the Route Cache contains a valid route, node S directly fills this route into the header of the packet and sends the data packet following this sequence of hops to the destination D. No Route Discovery is carried out in this case. If no route is found in the Route Cache.

b. Route Maintenance

The node which originates or forwards a packet using a source route which is responsible for confirming the receipt of the packet by the next node. A packet is retransmitted continuously until a receipt is received or the number of retransmission is exceeded. This confirmation is cost less for DSR by using link-level acknowledgement frame defined by IEEE 802.11 or passive acknowledgement (the forwarding of the packet to next but one from the next node is looked as a confirmation by the node). If no confirmation is received, the node transmits a ROUTE ERROR message to the original sender indicating a broken link. The sender will remove this link from its cache and look for another source route to the destination in its cache. If the route cache contains another source route, using this route the node sends the packet. Otherwise, it will initialize a new Route Request.

III. Mobility models

The protocol performance evaluation for an ad-hoc network is necessary to be tested under realistic conditions, especially including the movement of the mobile nodes which includes different mobility models [8] [9] like Random Waypoint Model, Manhattan Grid Mobility Model and Reference Point Group Mobility (RPGM) Model.

1. Random Waypoint Mobility Model

The Random Waypoint model has been used extensively, to evaluate the ad-hoc routing protocols. Each host is initially placed at a random position within the simulation area at a random position . As the simulation proceeds, each host pauses at its current location for a determinable period called the pause time. Pause time is used to overcome abrupt stopping and starting in the random walk model. Upon expiry of this pause time, the node will arbitrary select a new location to move towards it at a randomly selected velocity between a minimum and maximum value, which are stated at the start of the generation. Every host will continue this type of behavior throughout the entire duration of the simulation.

2. Manhattan Grid Mobility Model

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an environment. The Manhattan model can be described by the following parameters: mean speed, minimum speed (with a defined standard deviation for speed - normal distribution), a probability to change speed at position update, and a probability to turn at cross junctions. . In the simulation of the Manhattan Grid model, such a setup was chosen. Initially, nodes are positioned randomly surrounding a target reference. Over time, each node will move in a grid-like fashion but gravitate towards the same common objective. The nodes will zoom into the target of interest. In this case, the centre of the simulation area was chosen as the target of interest. When nodes move towards the target, they are still governed by the parameters previously described.

3. Reference Point Group Mobility (RPGM) Model Generation

In the RPGM model nodes cluster together to form groups. Together they move towards a specific target in unison as a group. Group nodes are bounded within a certain distance between each other. The logical centre (i.e., the reference point) of this group defines its movement. Within a group, each node has its own movement vector, which is still confining the node within the vicinity defined by the radius _{of the logical centre. Group}

motions are often generated as a series of random movements forming a path. Such a path is given by defining a sequence of check points along the path corresponding to given time intervals. Nodes movements within a group can also be random within the group. Each time the group reaches its destination, they pause for some time before moving on.

IV. Simulation Environment

The software used for implementing this project is the network simulator_{, NS2, ns-2.34[10]. The overall goal of}

this simulation study is to evaluate the performance of existing wireless routing protocol AODV in various nodes placement models like RPGM, Manhattan and Random way point.

A. Simulation model for AODV and DSR

In this the performance of AODV & DSR routing protocols are evaluated by keeping the network speed, pause time constant and varying the network size (number of mobile nodes).

SIMULATION ENVIRONMENT

AREA 1000X1000 SIMULATION TIME 360 sec

NODES 20,30,40,50,60,70

PAUSE TIME 0

MOBILITY MODELS RANDOMWAY POINT, RPGM, MANHATTAN GRID

MAXIMUM SPEED 5mps

TRAFFIC CBR PACKET SIZE 512 bytes

MAC LAYER 802.11

ROUTING PROTOCOLS AODV,DSR B. Simulation model for AODV and DSR

In this the performance of AODV & DSR routing protocols are evaluated by keeping the network speed ,pause time constant and varying the square area.

SIMULATION ENVIRONMENT

AREA 900X900, 1000X1000,

1100X1100, 1200X1200, 1300X1300, 1400X1400,

1500X1500 SIMULATION TIME 360 sec

NODES 30

PAUSE TIME 0

MOBILITY MODELS RANDOMWAY POINT, RPGM, MANHATTAN GRID

MAXIMUM SPEED 5mps

TRAFFIC CBR PACKET SIZE 512 bytes

MAC LAYER 802.11

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V. Results

The following metrics are involved in evaluating the performance of the routing protocol.

1) Packet Delivery Ratio: The fraction of packets sent by the application that are received by the receivers. The variation of Packet Delivery Ratio with varying the number of mobile nodes and area dimensions are shown in Figure 1 and Figure 2 respectively.

2) Throughput: The total amount of data a receiver R actually receives from the sender divided by the time it takes for R to get the last packet. The variation of throughput with varying the number of mobile nodes and area dimensions are shown in Figure 3 and Figure 4 respectively.

Figure 1: Packet Delivery Ratio Vs Nodes Figure 2: Packet Delivery Ratio Vs Square Area

Figure 3: Throughput Vs Nodes Figure 4: Throughput Vs Square Area

VI. Conclusion and Future Scope

In this paper two reactive routing protocols AODV and DSR are analyzed under various mobility models such as random waypoint mobility model (RWP), Manhattan grid mobility model and Reference point group mobility model (RPGM) in different square dimensional areas. From the results it is observed that the throughput of DSR is better than AODV in case of Manhattan Grid mobility model for varying network size, In case of varying the area dimensions it is evident that DSR is better than AODV in Random way point (RWP). From the results it is also found that the Packet Delivery Ratio for DSR is better than AODV while varying the network size in RPGM mobility model .And in case of varying the area dimensions it is observed that DSR is better than AODV in RPGM mobility model. These protocols can be implemented in various propagation models. 0 20 40 60 80 100 120

20 30 40 50 60 70 P a c k e t D e l i v e r y R a t i o

Number of nodes Packet delivery ratio vs nodes

aodv man aodv rpgm aodv rwp dsr man dsr rpgm dsr rwp 0 20 40 60 80 100 120 P a c k e t D e l i v e r y R a t i o AREA

Packet delivery ratio vs Square Area

AODV MAN AODV RPGM AODV RWP DSR MAN DSR RPGM DSR RWP 0 1 2 3 4 5

20 30 40 50 60 70 T h r o u g h p u t ( k b p s )

NUMBER OF NODES

Throughput vs Nodes

AODV MAN AODV RPGM AODV RWP DSR MAN DSR RPGM DSR RWP 0 5 10 15 20 25 30 35 900X900 1000X100 0 1100X110 0 1200X120 0 1300X130 0 1400X140 0 1500X150 0 T h r o u g h p u t ( k b p s ) AREA

Throughput vs Square Area

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References [1] Perkins C., Ad Hoc Networking, Addison Wesley, 2001.

[2] E. M. Royer and C.-K. Toh, “A review of current routing protocols for ad-hoc mobile wireless networks,” IEEE Personal Commun. Mag., vol. 6, no. 2, Apr. 1999.

[3] D.Johnson and D. Maltz . Dynamic Source Routing in ad-hoc Wireless Networks in Computer Communication Review – Proceedings of SIGCOMM 96 Aug-1996.

[4] D.Johnson, D.Maltz, and J .Broch. Dsr the dynamic source routing protocol for multihop wireless ad-hoc network ,2001. [5] Perkins C., “Ad Hoc on Demand Distance Vector(AODV)Routing,”availablet:http://draft-ietf-manet-aodv-00.txt,November 1997. [6] Perkins C. and Royer E.M., “Ad-Hoc on-Demand Distance Vector Routing,” in proceedings of the 2nd IEEE Workshop on Mobile

Computing Systems and Applications, New Orleans, LA,pp.90-100,February 1999.

[7] S.P.Setty, “Design and Analysis of Fuzzy based Node Traversal Time AODV for Improving the QoS in Mobile Ad Hoc Networks”, International Journal of Computer Applications (0975 – 8887), November 2012

[8] "Perfect Simulation and Stationarity of a Class of Mobility Models", J.-Y. Le Boudec and M. Vojnovic, Best Paper Award Infocom 2005.

[9] X.Hong, M. Gerla, G. Pei and C.C. Chiang. “A Group Mobility Model for Ad Hoc Wireless Networks,” Proceeding of the 2nd ACM/IEEE Int. Workshop on Modeling and Simulation of Wireless and Mobile Systems (MSWiM'99), 1999, pp. 53-60.