4th 8th sem

Kathmandu UniversitySchool of EngineeringDepartment of Electrical & Electronics Engineering

FINAL YEARPROJECT REPORT

SimulationOf MAC Layer of IEEE 802.16 e WiMAX

A final year project report submitted in partial fulfilmentof the requirements for the degree ofBachelor of Engineering

Submitted By:Saurav Bhattarai (Regd. No.) Kastuv M. Tuladhar (Regd. No.)

1

July, 2013

CERTIFICATION

Final Year Project ReportOn

by: (Regd. No.) (Regd. No.)

Approved by: 1. Project Supervisor

___________________ ____________________________ __________ (Signature) (Name) (Date)

2. Head/In-Charge of the Department

___________________ ____________________________ __________

(Signature) (Name) (Date) vi

ABSTRACT

ACKNOWLEDGEMENT

ABBREVIATIONSAbbreviationsFull Form First Used in Page

LIST OF FIGURES

LIST OF TABLESTable 1.1: Simulation Parameters5Table 4.1: Characteristic in low traffic22Table 4.2: Characteristic in high traffic22

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TABLE OF CONTENTSABSTRACTiACKNOWLEDGEMENTiiABBREVIATIONSiiiLIST OF FIGURESivLIST OF TABLESvChapter 1: Introduction11.1Background and Objectives11.1.1 Background11.1.2 Objectives21.2System Overview21.3Methodology31.3.1 Simulation strategy31.3.2 Simulation Model41.3.3 Performance Metrics61.4Overview of Report6Chapter 2: Literature Review82.1Wireless network82.2Static and Dynamic Routing92.2.1 Dynamic Routing Categories102.2.2 Distance-vector Routing or Reactive Protocols112.2.3 Link-State Routing or Proactive Protocols122.3Network Simulator14Chapter 3: Simulation Results and Analysis153.1Network Construction153.2Analysis16Chapter 4: Discussion and Conclusion224.1Discussion and Conclusion224.2Recommendation23Bibliography24Appendix: Codes for Simulation and Analysis25Chapter 1INTRODUCTION Background and ObjectivesBackgroundA network is a collection of two or more computing devices connected by a communication medium. When a computing device wishes to send information to another device, it may do so by transmitting the information along a shared communication medium. This is why networking acts as a connecting bridge between nodes. Since majority of the networks are packet switched networks so the transmission and reception of the information is based on the method of routing which involves use of different protocols and algorithm for path selection. Wireless networking is an emerging technology that allows users to access information and services, regardless of their geographic position. Infrastructured network consists of a network with fixed and wired gateways. A mobile host communicates with a bridge in the network (called base station) within its communication radius. In ad hoc networks all nodes are mobile and can be connected dynamically in an arbitrary manner. Such networks are very useful in emergency search-and-rescue operations, meetings or conventions in which persons wish to quickly share information, and data acquisition operations in inhospitable terrain.As people become increasingly dependent on cell phones and other wireless communication links, the development of efficient and economic routing protocols has gained greater focus. The need to exchange digital information outside a typical wired office environment is growing rapidly. For example, people in a conference may wish to exchange information, a group of students may need to interact during their group discussions, or disaster recovery personal may need to provide relief information after a calamity has occurred. Each of the devices used by these people can be considered a node in an ad hoc network.There is no stationary infrastructure or base station for communication so routing in MANET has been a challenging task ever since the wireless network came into existence. The major reason for this is the constant change in network topology because of high degree of node mobility. A number of routing protocols have been developed for accomplishing such task. Among them is the dynamic routing. Dynamic routing varies from stationary routing as it can automatically update its routing table by a routing protocol running on the router.In this project, analysis of two protocols (AODV and OLSR) under different performance criteria for routing (e.g. delay, throughput) has been implemented.ObjectivesOne of the more powerful features of packet switched systems is their ability to dynamically route packets. This power also comes with a complexity that can lead to an interesting set of problems. If one could count on a network operating in a static configuration with no failures, the routing problem would be simple; static tables could suffice as the basis for all routing decisions. For each packet destined to a particular destination, the next hop would be identified in the table, and the packet would be forwarded. However, in the real world, nodes are added to networks, links fail, and topologies change. As networks get larger, administration and management problems increase. Therefore, automated route management rapidly becomes a necessity. So, simulation of the performance of two of the more significant routing mechanisms that are used in the ad hoc network, reactive Ad hoc On Demand Distance Vector (AODV) and proactive Optimized Link State Routing (OLSR) protocols was conducted. The main objectives are:Implementation of proactive (OLSR) and reactive (AODV) routing protocols.Performance analysis of OLSR and AODV based on performance metrics such as jitter throughput and average end-to-end delay.

System OverviewThis projects aims to simulate a network for evaluating performance of two different dynamic routing techniques (AODV and OLSR). The project does not consider designing a physical system. So the system will consist of a virtual network for simulation.The network will consist of hosts/nodes and links. For ad hoc network, links are wireless where each node can route packets to their respected neighboring node. Unlike infrastructured network, the ad hoc networks all nodes are mobile and can be connected dynamically in an arbitrary manner. The nodes will be considered both stationary and mobile for simulating the performance of ad hoc network designed. The different components of a network can be presented as:Address: Each node in a network has a unique identifier called the nodes address. This address is used in routing to determine where packets should be sent.Ad hoc network: A network which is formed without a priori knowledge or planning. Nodes belonging to an ad hoc network do not share any central authority or support structure.Broadcast: A packet which is broadcast is received by all nodes within transmission range of the sender.Hop: Each time a packet is transmitted, it is said to have performed one hop. Multi-hop networks require nodes in the network to enlist the aid of neighboring nodes to forward packets towards a destination node.Link: A communication channel by which a node can send packets to another node.Loop: Some protocols, when they have not converged, can set up routing loops. A loop is formed when two nodes do not agree on the shortest path to a destination. For example, suppose node. A routes a packet to node B, but B subsequently routes the packet back to A. In this example, the packet will be routed between nodes A and B, or until their routing logic is synchronized and the routing protocol converges.Mobile node: A node which is willing and able to physically move location, resulting in network topology changes.Router: A node willing to forward and route packets on behalf of other nodes. In ad hoc networks, typically every node acts as a router.Topology: The graph representing node positions and their links to other nodes. The topology is said to change when links change state (are either created or destroyed) or nodes change state.

Methodology1 Simulation strategy

OTCL Script (.tcl extension file) Whole simulation study is divided into two part one is create the node (that may be cell phone, internet or any other devices) i.e. NS-2 output. Its called NAM (Network Animator) file, which shows the nodes movement and communication occurs between various nodes in various conditions or to allow the users to visually appreciate the movement as well as the interactions of the mobile nodes. And another one is graphical analysis of trace file (.tr). Trace files contain the traces of event that can be further processed to understand the performance of the network. Figure 5 depicts the overall process of how a network simulation is conducted under NS-2. Output files such as trace files have to be parsed to extract useful information. The parsing can be done using the awk command (in UNIX and LINUX, it is necessary to use gwak for the windows environment) or perl script. The results have been analyzed using Excel or Matlab. A software program which can shorten the process of parsing trace files (Xgraph and TraceGraph) has also been used in this paper. However, it doesnt work well when the trace file is too large. To generate trace file and nam file, we call tcl script in CYGWIN command shell. By varying the simulation parameter shown in table 1, we can see the graphical variation between various performance metrics like throughput, drop, delay, jitter etc. 4.2 Results Generated trace file that is (.tr) s 10.006348737 _1_ MAC --- 3 ack 118 [13a 0 1 800] ------- [1:0 0:0 32 0] [0 0] 0 0 r 10.007293041 _0_ MAC --- 3 ack 60 [13a 0 1 800] ------- [1:0 0:0 32 0] [0 0] 1 0 s 10.007303041 _0_ MAC --- 0 ACK 38 [0 1 0 0] r 10.007318041 _0_ AGT --- 3 ack 60 [13a 0 1 800] ------- [1:0 0:0 32 0] [0 0] 1 0 s 10.007318041 _0_ RTR --- 4 tcp 1560 [0 0 0 0] ------- [0:0 1:0 32 1] [1 0] 0 0 s 10.007318041 _0_ AGT --- 5 tcp 1540 [0 0 0 0] ------- [0:0 1:0 32 0] [2 0] 0 0 r 10.007318041 _0_ RTR --- 5 tcp 1540 [0 0 0 0] ------- [0:0 1:0 32 0] [2 0] 0 0 1. First field is event type; it may be r, s, f, d for received, sent, forwarded and dropped respectively. 2. The second field is the time. 3. The third field is the node number. 4. The fourth field is MAC to indicate, if the packet concerns a MAC layer; it is AGT to indicate the transport layer (e.g. tcp) packet, or RTR if it concerns the route packet. It can be IFQ for drop packets. 5. After the dashes comes the global sequence number of the packet (not tcp sequence number). 6. At the next field comes more information on the packet type (e.g. tcp, ack, or udp). 7. Next is the packet size in byte. 8. The 4 numbers in the first square brackets concern MAC layer information. The first hexadecimal number specifies the expected time in seconds to send this data packets over the wireless channel. The second number stand for the MAC-id of the sending node third is for receiving node. And fourth number, 800, specifies that the MAC type is ETHERTYPE_IP. 9. The next number in the second square brackets concern the IP source and destination addresses, then the ttl (time to live) of the packet (in our case 32). 10. The third brackets concern the tcp information: its sequence number and acknowledgement number. 4.2.1 Nam file output NAM is a Tcl/TK based animation tool for viewing network simulation traces and real world packet traces. A network animator that provides packet-level animation and protocol-specific graphs to aid the design and debugging of new network protocols have been described. 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 [7]. This trace file is usually generated by NS. Once the trace file is generated,Execute NS-2 Command (test.tcl)Output (Trace and Nam file) (.tr and .nam)Graph plotting ( awk, matlab, excel)Network AnimatorView nam file

Figure 01.1: Simulation Overview

Whole simulation study is divided into two parts, one is to create the node (that may be cell phone, internet or any other devices) i.e. NS-2 output. Its called NAM (Network Animator) file, which shows the nodes movement and communication occurs between various nodes in various conditions or to allow the users to visually appreciate the movement as well as the interactions of the mobile nodes. And another one is graphical analysis of trace file (.tr). Trace files contain the traces of event that can be further processed to understand the performance of the network [1]. Figure 1.1 depicts the overall process of how a network simulation is conducted under NS-2. Output files such as trace files have to be parsed to extract useful information. The parsing can be done using the awk command in Ubuntu. The results have been analyzed using Excel or Matlab. To generate trace file and nam file, that is called as tcl script in Ubuntu terminal. By varying the simulation parameter, the graphical variation can be seen between various performance metrics like throughput, delay and jitter. The required bash file to run simulation for multiple samples was also written.After gaining knowledge about NS-2 basics, wireless network was simulated. First wrote aodv.tcl and olsr.tcl with 16 nodes network and simulation was done.Trace and nam files were created.Network animator was used to visualize the network.Awk script was used to extract useful information from trace file generated, to calculate average end-to-end delay, jitter, throughput and maximum delay.Bash file was written to conduct simulation for multiple time using power the network as random parameter varying from 0 to 2 watts.The parameters were plotted using excel.

Simulation Model Scenario: For the simulation scenario, 400*400 m2 square was considered taking into account of reference paper [3]. 16 nodes were considered for simulation as we initialized that it optimizes the result considering the area chosen. Two-ray-ground model was taken for radio propagation, as it considers both indoor and outdoor propagation. Each wireless node is considered to have omni directional antenna. The remaining parameter of the network is tabulated in Table 1 [4].

Table 1.1: Simulation ParametersParameterValue

SimulatorNS-2 (Version 2.34 )

Channel typeWireless channel

Radio-propagation modelTwo ray ground wave

Network interface typeWireless

MAC TypeMac /802.11

Interface queue TypeQueue/DropTail/PriQueue

Link Layer TypeLogical Link

AntennaOmni Antenna

Maximum packet in buffer50

Area ( m2)400 * 400

Number of mobile node16 / 50

Source TypeUDP

Simulation Time1000 sec

Mobility modal Movement patternspeed (m/s) Random5

CBRPacket sizeIntervalRate 1000 bytes0.02 sec256kbps

Routing Protocols AODV, OLSR

Capture Threshold 10 dB

Carrier Sense Threshold2.78831e-9 watt

Transmitted Power0 to 2 watt

Receiver Threshold Power1.11532e-8 watt

Operating Frequency2.4 GHz for 802.11g

System Loss0 dB

Coverage Radius0 - 260 m

Channel Bandwidth1Mbps

Transmitter Antenna Gain 0 dB

Receiver Antenna Gain0 dB

Antenna TX-RX height1.5m

1 2 3 39.1 39.2 Performance MetricsThe following different performance metrics are evaluated to understand the behavior of OLSR and AODV routing protocols Throughput Throughput is the number of packet that is passing through the channel in a particular unit of time. This performance metric shows the total number of packets that have been successfully delivered from source node to destination node. Equation (i) shows the mathematical expression for throughput. -------------------------------------------- (i)Average Endto-End delay A specific packet is transmitted from source to destination node and calculation of the difference between send time and received time gives end-to-end delay. Delays due to route discovery, queuing, propagation and transfer time are included in the delay metric. Equation (ii) shows the mathematical expression for average end to end delay.----------------- (ii)Jitter The term jitter is often used as a measure of the variability over time of the packet latency across a network. A network with constant latency has no variation (or jitter). Packet jitter is expressed as an average of the deviation from the network mean latency. In other word jitter is the variation of the packet arrival time. In jitter calculation the variation in the packet arrival time is expected to be minimum. The delays between the different packets need to be low if we want better performance in Mobile Ad-hoc Networks. Equation (iii) shows expression for jitter calculation. ----------------------------------------------------- (iii) Overview of ReportThis project is divided into four different chapters, each one illustrating the description of the project in detail. The report highlights the system overview and the technology and literature review conducted for the completion of the project.Chapter 1 discusses the introduction part regarding the project. The background of the project and its objective initiate the report. The system overview defines the components of a network. As simulation is conducted for analysis, the system overview explains the basic components of network. The simulation strategy and different parameters considered for simulation are classified under methodology heading. Chapter 2 deals with the Literature Survey where we have tried to put all necessary details that helps to understand technical terminologies of the project. The research and survey done during the project time are also included in the survey which could be referred to understand the project.Simulation Results and Analysis are dealt in the chapter 3. The subsystems, in the two different sections considering low and high density traffic are explained with the results after the simulation.Chapter 4 emphasizes on the conclusion of the project. The outcome of the project under different parameter is highlighted under this section. The chapter includes recommendation for the further research and analysis that can be conducted in this field of MANET.

Chapter 2LITERATURE REVIEW2 1 Wireless networkWireless networking allows users to access information, without any dedicated line connected within them. Wireless networks can be classified in two types:Infrastructured networksInfrastructured network consists of a network with fixed and wired gateways as shown in Figure 2.1. A mobile host communicates with a bridge in the network (called base station) within its communication radius. The mobile unit can move geographically while it is communicating. When it goes out of range of one base station, it connects with new base station (handoff) and starts communicating through it. In this approach the base stations are fixed.

Figure 01.1: Infrastructured network

Infrastructureless networksIn ad hoc networks all nodes are mobile and can be connected dynamically in an arbitrary manner. All nodes of these networks behave as routers and take part in discovery and maintenance of routes to other nodes in the network as shown in Figure 2.2 and Figure 2.3. Ad hoc networks are very useful in emergency search-and-rescue operations, meetings or conventions in which persons wish to quickly share information, and data acquisition operations in hostile landscape.

Figure 2.2: Infrastructureless network

Figure 2.3: Ad hoc network with three nodes4 5 59.3 Static and Dynamic Routing There are two basic methods of building a routing table:Static RoutingDynamic RoutingA static routing table is created, maintained, and updated by a network administrator, manually. A static route to every network must be configured on every router for full connectivity. This provides a rough level of control over routing, but quickly becomes impractical on large networks. Routers will not share static routes with each other, thus reducing CPU/RAM overhead and saving bandwidth. However, static routing is not fault-tolerant, as any change to the routing infrastructure (such as a link going down, or a new network added) requires manual intervention. Routers operating in a purely static environment cannot seamlessly choose a better route if a link becomes unavailable.A dynamic routing table is created, maintained, and updated by a routing protocol running on the router. Examples of routing protocols include AODV (Ad hoc on demand distance vector), EIGRP (Enhanced Interior Gateway Routing Protocol) and OLSR (Optimized Link State Routing Protocol). Routers do share dynamic routing information with each other, which increases CPU, RAM, and bandwidth usage. However, routing protocols are capable of dynamically choosing a different (or better) path when there is a change to the routing infrastructure.Most of the protocols available in the network are categorized as: RIP- Routing Information Protocol AODV-Ad-hoc On-demand distance vector OLSR-Optimized Link State Routing Protocol OSPF-Open Shortest Path FirstThe following briefly outlines the advantages and disadvantages of static routing:Advantages of Static Routing: Minimal CPU/Memory overhead No bandwidth overhead (updates are not shared between routers) Granular control on how traffic is routedDisadvantages of Static Routing: Infrastructure changes must be manually adjusted No dynamic fault tolerance if a link goes down Impractical on large network

The following briefly outlines the advantages and disadvantages of dynamic routing:Advantages of Dynamic Routing: Simpler to configure on larger networks Will dynamically choose a different (or better) route if a link goes down Ability to load balance between multiple linksDisadvantages of Dynamic Routing: Updates are shared between routers, thus consuming bandwidth Routing protocols put additional load on router CPU/RAM The choice of the best route is in the hands of the routing protocol, and not the network administrator

Dynamic Routing CategoriesDistance-vector protocolsLink-state protocolsHybrid protocols

ProactiveReactiveHybridRouting ProtocolsOLSRAODVZRP

Figure 2.4: Ad-hoc Routing ProtocolsFigure 2.4 shows the different types of routing protocol adapted in MANETs. It presents main groups of protocol under which OLSR and AODV are included. So, OLSR is proactive and AODV is reactive routing protocol.Distance-vector Routing or Reactive ProtocolsAll distance-vector routing protocols share several key characteristics: Periodic updates of the full routing table are sent to routing neighbors. Distance-vector protocols suffer from slow convergence, and are highly susceptible to loops. Some form of distance is used to calculate a routes metric. The Bellman-Ford algorithm is used to determine the shortest path.A distance-vector routing protocol begins by advertising directly-connected networks to its neighbors. These updates are sent regularly (RIP every 30 seconds; IGRP every 90 seconds). Neighbors will add the routes from these updates to their own routing tables. Each neighbor trusts this information completely, and will forward their full routing table (connected and learned routes) to every other neighbor. Thus, routers fully (and blindly) rely on neighbors for route information, a concept known as routing by rumor. There are several disadvantages to this behavior. Because routing information is propagated from neighbor to neighbor via periodic updates, distance-vector protocols suffer from slow convergence. This, in addition to blind faith of neighbor updates, results in distance-vector protocols being highly susceptible to routing loops. Distance-vector protocols utilize some form of distance to calculate a routes metric. RIP uses hop count as its distance metric, and IGRP uses a composite of bandwidth and delay.Ad-hoc On-demand distance vector (AODV)Reactive protocols discover routes only as needed [4]. When a node wishes to communicate with another node, it checks with its existing information for a valid route to the destination. If one exists, the node uses that route for communication with the destination node. If not, the source node initiates a route request procedure, to which either the destination node or one of the intermediate nodes sends a reply back to the source node with a valid route. A soft state is maintained for each of these routes, if the routes are not used for some period of time, the routes are considered to be no longer needed and are removed from the routing table. Example of this type algorithm is DSR and AODV. AODV is a reactive protocol, even though it still uses characteristics of a proactive protocol. AODV takes the interesting parts of DSR and DSDV in the sense that it uses the concept of route discovery and route maintenance of DSR and the concept of sequence numbers and sending of periodic hello messages from DSDV. AODV uses a destination sequence number for each route entry. The destination sequence number is created by the destination for any route information it sends to requesting nodes [7]. Using destination sequence numbers ensures loop freedom and allows knowing which of the available routes is fresher and requesting node always selects the one with greatest sequence number. When a node wants to find a route, it broadcasts a RREQ to all network till either destination is reached or another node is found with a fresh enough route to the destination. Then a RREP is sent back to the source and the discovered route is made available. Fresh Enough route is a valid route entry for the destination whose associated sequence number is at least as great as that contained in RREQ. Nodes that are part of an active route may offer connectivity information by broadcasting periodically local hello messages (special RREP messages) to its immediate neighbors. If hello messages stop arriving from a neighbor beyond some given time threshold, the connection is assumed to be lost. When a node detects that a route to a neighbor node is not valid it removes the routing entry and sends a RERR message to neighbors that are active and use the route; this is possible by maintaining active neighbor lists. This procedure is repeated at nodes that receive RERR messages. A source that receives an RERR can reinitiate a RREQ message.

Advantages: Routes are established on demand and destination sequence numbers are used to find the latest route to the destination. Lowered delay for connection setup.

Disadvantages: AODV does not allow handling unidirectional links. Multiple Route Reply packets in response to a single Route Request packet can lead to heavy control overhead. Periodic beaconing leads to unnecessary bandwidth consumption

Link-State Routing or Proactive ProtocolsLink-state routing protocols were developed to lessen the convergence and loop issues of distance-vector protocols. Link-state protocols maintain three separate tables:Neighbor table It contains a list of all neighbors, and the interface each neighbor is connected off of. Neighbors are formed by sending Hello packets.Topology tableThe otherwise known as the link-state table, contains a map of all links within an area, including each links status.Shortest-Path tableIt contains the best routes to each particular destination (otherwise known as the routing table). Link-state protocols do not route by rumor. Instead, routers send updates advertising the state of their links (a link is a directly-connected network). All routers know the state of all existing links within their area, and store this information in a topology table. All routers within an area have identical topology tables. The best route to each link (network) is stored in the routing (or shortest path) table. If the state of a link changes, such as a router interface failing, an advertisement containing only this link-state change will be sent to all routers within that area. Each router will adjust its topology table accordingly, and will calculate a new best route if required. By maintaining a consistent topology table among all routers within an area, link-state protocols can converge very quickly and are immune to routing loops. Additionally, because updates are sent only during a link-state change, and contain only the change (and not the full table), link-state protocols are less bandwidth intensive than distance-vector protocols. However, the three link-state tables utilize more RAM and CPU on the router itself. Link-state protocols utilize some form of cost, usually based on bandwidth, to calculate a routes metric. The Dijkstra formula is used to determine the shortest path.

Optimized Link State Routing Protocol (OLSR)Optimized Link State Protocol (OLSR) is a proactive routing protocol, so the routes are always immediately available when needed. OLSR is an optimization version of a pure link state protocol. So the topological changes cause the flooding of the topological information to all available hosts in the network. To reduce the possible overhead in the network protocol uses Multipoint Relays (MPR) [5]. The idea of MPR is to reduce flooding of broadcasts by reducing the same broadcast in some regions in the network, more details about MPR can be found later in this chapter. Another reduce is to provide the shortest path. The reducing the time interval for the control messages transmission can bring more reactivity to the topological changes.OLSR uses two kinds of the control messages: Hello and Topology Control (TC) [7]. Hello messages are used for finding the information about the link status and the hosts neighbors. With the Hello message the Multipoint Relay (MPR) Selector set is constructed which describes which neighbors has chosen this host to act as MPR and from this information the host can calculate its own set of the MPRs. The Hello messages are sent only one hop away but the TC messages are broadcasted throughout the entire network. TC messages are used for broadcasting information about own advertised neighbors which includes at least the MPR Selector list. The TC messages are broadcasted periodically and only the MPR hosts can forward the TC messages. There is also Multiple Interface Declaration (MID) messages which are used for informing other host that the announcing host can have multiple OLSR interface addresses. The MID message is broadcasted throughout the entire network only by MPRs. There is also a Host and Network Association (HNA) message which provides the external routing information by giving the possibility for routing to the external addresses. The HNA message provides information about the network- and the net mask addresses, so that OLSR host can consider that the announcing host can act as a gateway to the announcing set of addresses. The HNA is considered as a generalized version of the TC message with only difference that the TC message can inform about route cancelling while HNA message information is removed only after expiration time.

Advantages:Reduce the number of duplicate retransmissions while forwarding a broadcast packet.Restrict the set of nodes retransmitting a packet from all nodes (regular flooding) to a subset of all nodes. The size of this subset depends on the topology of the network.

Network SimulatorFor the simulation of the developed system, version 2.34 of NS-2 has been used in this project. Ns-2 is a discrete event simulator targeted at networking research. It began as a part of the REAL network simulator and is evolving through an ongoing collaboration between the University of California at Berkeley and the VINT project. It is an Object oriented program written C++/OTCL. It works in Linux, Mac and Windows. It can simulate existing network protocols: TCP, routing, and multicast protocols over both wired and wireless networks. It also provides possibility to implement and test new protocols and applications [2].

Chapter 3SIMULATION RESULTS AND ANALYSIS3 2 Network TopologySimulation of a wireless network was done using NS-2 simulator, NAM (network animator) and awk scripting as described in methodology section. AODV and OLSR, these routing protocols are also related Distance Vector and Link State respectively as RIP and OSPF are.The further tcl script written for the wireless network according to Simulation Model is presented in Appendix.

Figure 3.1: NAM 16 nodes wireless network Figure 3.1 presents the snapshot of virtual network constructed in NS-2. Network Animator (NAM) is used to visualize the nodes in the network considered. The network shown consists of 16 nodes connected wirelessly. Each of the node moves randomly to the destination point at a constant velocity of 5 m/s as defined in .tcl script. Here node 0 is the source node whereas node 15 is the sink or destination node. The circular ring shows the coverage area of respective nodes transmitting packets.

Results and Analysis6 7 8 9 99.4 99.5 For single node transmission

Figure 3.2: Throughput for low trafficFigure 3.2 shows throughput of the network increases with increase in transmission power.In case of low traffic with low node density beyond 1 watt transmission power, AODV protocol delivers almost all originated data packets (around 90-100%). OLSR performs less efficiently then AODV when number of source nodes are low (1 source node) with low node density (16 nodes). With increase in power level the coverage area of each node increases hence decreasing the number of nodes the packets have to travel for transmission from source to destination. AODV uses only one route that is shortest path for delivery of data from source node to destination node due to throughput increases effectively for AODV than OLSR for low node density.The performance of AODV is significantly better below power level of 1 watt.

Figure 3.3: Average End-to-End Delay for low trafficWith increase in power level the coverage area of each node increases hence decreasing the number of nodes the packets have to travel for transmission from source to destination. AODV uses only one route that is shortest path for delivery data from source node to destination node due to this reason maximum delay for AODV is low as compare to OLSR as shown in Figure 3.3. OLSR use more than one route to transfer data packet from source node to destination node which causes more delay as it is not always using shortest path for delivering all data packet from source node to destination node.The performance of AODV is significantly better below power level of 1 watt.

Figure 3.4: Jitter for low trafficAs power increases the number of hubs packets has to travel through decreases so the jitter decreases. As presented in Figure 3.4, average jitter is always high for OLSR protocol because OLSR uses more than one route to transfer data packets from source node to destination node. These different routes cause variation in delay to delivering the data packet from source node to destination node due to this average jitter increase significantly in case of OLSR. In case of AODV it uses only one route to deliver data packet until this route fails in that situation it starts new route discovery process for destination node. So jitter performance of AODV is better.The performance of AODV is significantly better below power level of 1 watt.

For six sources transmission and 50 nodes

Figure 3.5: Throughput for high trafficFor the multiple source transmission to the same source, (here we have considered six sources transmitting to node 15) throughput increases. As the multiple sources are transmitting packets at same observation time, throughput increases than in single source transmission.Throughput of the network increases with increase in transmission power up to 1.5 watt. As OLSR uses more than one route to transfer packets, in higher traffic density the throughput for OLSR is more than that of AODV. AODV uses only one route to transfer packets to destination and does not update its routing table unless the existing route fails. So throughput is lower for AODV than OLSR in high traffic density. Figure 3.5 shows the throughput of OLSR and AODV within power range of 0-2 watts.Beyond 1.5 watt transmission power, the throughput decreases due to CSMA technique used. As power increases, coverage increases and nearer nodes interfere with each other. Since multiple nodes are transmitting at the same time, each node has to wait until it finds the free link using CSMA.

Figure 3.6: Average End-to-End Delay for high trafficFor higher node density, the average end-to-end delay increases than in single source transmission as nodes have to queue the packets before transmission and low link access due to CSMA used.With increase in power level the coverage area of each node increases hence decreasing the number of nodes the packets have to travel for transmission from source to destination. AODV uses only one route that is shortest path for delivery of data from source node to destination node due to this reason maximum delay for AODV is low as compare to OLSR as presented in Figure 3.6. OLSR use more than one route to transfer data packet from source node to destination node which causes more delay as it is not always using shortest path for delivering all data packet from source node to destination node.

Figure 3.7: Jitter for high traffic

Figure 3.8: N.Jitter for high trafficFor higher node density, the average jitter increases than in single source transmission as nodes have to queue the packets before transmission and low link access due to CSMA used. As power increases the number of hubs packets has to travel through decreases so the jitter decreases.Average jitter is always high for OLSR protocol because OLSR uses more than one route to transfer data packets from source node to destination node. These different routes cause variation in delay to delivering the data packet from source node to destination node due to this average jitter increase significantly in case of OLSR. In case of AODV it uses only one route to deliver data packet until this route fails in that situation it starts new route discovery process for destination node. So jitter performance of AODV is better. Figure 3.7 shows the jitter performance of these routing protocols AODV and OLSR in different transmitted power.

Chapter 4DISCUSSION AND CONCLUSION3 Discussion and ConclusionAODV and OLSR are the two different routing techniques adapted in dynamic routing protocol. So, this project helps to analyze their characteristic behavior in ad hoc network. The nodes in ad hoc network can be mobile so it is necessary for packets from one node to properly route to destination node. The delay, jitter and throughput are the basic characteristic of routing protocol in a network. This project helps to find suitable routing protocol in given condition of the network.This report discusses about the introduction to network and the types of dynamic routing. The AODV and OLSR are the two techniques adapted in Distant-vector Routing Protocol (DVRP) and Link-state Routing Protocol (LSRP) respectively. Their analysis gives the function of these protocols; DVRP and LSRP. The characteristic of this network is simulated on NS-2 simulator. OLSR and AODV have minimum throughput of 0 kbps at power below receiver sensitivity for both high and low traffic density. The rounded minimum and maximum of the matrices values are tabulated in Table 4.1 and Table 4.2.Table 4.1: Characteristic in low trafficThroughput (kbps)Average End-to-End Delay (ms)Jitter (ms)

MINMAXMINMAXMINMAX

OLSR0254101400265

AODV02561510025

Table 4.2: Characteristic in high trafficThroughput (kbps)Average End-to-End Delay (ms)Jitter (ms)

MINMAXMINMAXMINMAX

OLSR0612404253024201

AODV052040385192143

We can conclude that for low node density and low traffic, AODV performs better in context of jitter, delay, and throughput and power utilization than OLSR. For high node density and high traffic, OLSR performs better than AODV in context of throughput but average end-to-end delay is still lower for AODV.

RecommendationThe simulation analyzes the performance of the respective protocols considering low network density (16 nodes and single source) and high network density (50 nodes and six sources) in a predefined area. The simulation also takes into account power analysis from 0-2 watts.The simulation can be further carried out for different parameters (area, node density, etc.) other than considered in this project. MANETs have dynamic range. So, there is always a unique scenario even if a single parameter of node (transmitted power, carrier threshold, receiver sensitivity, etc.) is changed. The simulation carried out does not perfectly represent a practical scenario. So, this simulation can also be carried out for or by setting up a practical existing network. Performance of other dynamic routing protocols like DSR, DSDV, RIP and OSPF can also be analyzed.

Bibliography[1] Gupta, S. K., & Kumar, R.K. Performance Metric Comparison of AODV and DSDV Routing Protocols in MANET Using NS-2. Retrieved from http:// www.csjournals.com/IJITKM/PDF%203-1/74.pdf

[2] Network simulator NS-2. Retrieved December 10, 2011, from http://www.isi.edu/nsnam/ns/index.html

[3] Gowrishankar, S., Basavaraju, T.G., Singh, M., & Sarkar, S.K. Scenario based Performance Analysis of AODV and OSLR in Mobile Ad hoc Network. Retrieved December 9, 2011, from http://www.ijcim.th.org/SpecialEditions/v15nSP4/P08SEARCC_ScenariobasedPerformanceAnalysis.pdf

[4] Fakhri, Y., Amnai, M., & Abouchabaka, J. Traffic Multiservice Based performance Analysis of OLSR and AODV Protocols for Mobile Ad hoc Networks. Retrieved January 10, 2012, from http://www.aicit.org/ijact/ppl/36_IJACT9-8.pdf

[5] Singh, S., Sran, S.S., & Chand, T.(2008, March 29). Performance Comparison of AODV, OLSR and OFLSR in Wireless Mesh Networks. Retrieved January 10, 2012, from http://www.rimtengg.com/coit2008/proceedings/NW3.pdf

[6] Liu, K. (2006). Network Simulator 2: Introduction. Retrieved January 12, 2012, from http://cs.binghamton.edu/~kliu/ta/cs527/ns2pre.pdf

[7] Holter, K. (2005, April 23). Comparing AODV and OLSR. Retrieved January 27, 2012, from http://folk.uio.no/kenneho/studies/essay.pdf

AppendixCODES FOR SIMULATION AND ANALYSISTcl file for aodv protocol, aodv.tcl:# ====================================================================# Define options# ======================================================================set val(chan)Channel/WirelessChannelset val(prop)Propagation/TwoRayGroundset val(netif)Phy/WirelessPhyset val(mac)Mac/802_11set val(ifq)Queue/DropTail/PriQueueset val(ll)LLset val(ant) Antenna/OmniAntennaset val(x)400 ;# X dimension of the topographyset val(y)400 ;# Y dimension of the topographyset val(ifqlen)50 ;# max packet in ifqset val(rp) AODVset val(nn) 16 ;# how many nodes are simulated

### Setting The Simulator Objects set ns_ [new Simulator]#create the nam and trace file: set tracefd [open aodv.tr w] $ns_ trace-all $tracefd $ns_ use-newtrace

# set namtrace [open aodv.nam w] #$ns_ namtrace-all-wireless $namtrace $val(x) $val(y)

set topo [new Topography] $topo load_flatgrid $val(x) $val(y) create-god $val(nn) set chan_1_ [new $val(chan)] # Defining Node Configuration $ns_ node-config -adhocRouting $val(rp) \ -llType $val(ll) \ -macType $val(mac) \ -ifqType $val(ifq) \ -ifqLen $val(ifqlen) \ -antType $val(ant) \ -propType $val(prop) \ -phyType $val(netif) \ -topoInstance $topo \ -agentTrace ON \ -routerTrace ON \ -macTrace ON \ -movementTrace ON \ -channel $chan_1_

#set random transmitter powerset power [expr (rand()*2)]

#Open the file for writing power random valueset out [open "aodv_power.xls" a+]puts $out "$power"close $out

Phy/WirelessPhy set CPThresh_ 10.0Phy/WirelessPhy set CSThresh_ 2.78831e-9 Phy/WirelessPhy set RXThresh_ 1.11532e-8 Phy/WirelessPhy set bandwidth_ 1Mb#Phy/WirelessPhy set Pt_ 0.281838Phy/WirelessPhy set Pt_ $powerputs "power=$power"Phy/WirelessPhy set freq_ 2.4e+12Phy/WirelessPhy set L_ 1.0Antenna/OmniAntenna set X_ 0Antenna/OmniAntenna set Y_ 0Antenna/OmniAntenna set Z_ 1.5Antenna/OmniAntenna set Gt_ 1Antenna/OmniAntenna set Gr_ 1

### Creating The WIRELESS NODES for {set i 0} {$i < $val(nn) } {incr i} { set node_($i) [$ns_ node] $node_($i) random-motion 1 ;# enable random motion }

### Setting The Initial Positions of Nodes # Here node0 is the source.

$node_(0) set X_ 50.0 $node_(0) set Y_ 50.0 $node_(0) set Z_ 0.0 $node_(1) set X_ 144.0 $node_(1) set Y_ 274.0 $node_(1) set Z_ 0.0 $node_(2) set X_ 90.0 $node_(2) set Y_ 90.0 $node_(2) set Z_ 0.0

$node_(3) set X_ 143.0 $node_(3) set Y_ 266.0 $node_(3) set Z_ 0.0








# Node_(21) is the data collection point


## Giving Mobility to Nodes $ns_ at 0.01 "$node_(0) setdest 50.0 50.0 5.0"$ns_ at 5.0 "$node_(0) setdest 350.0 350.0 5.0"$ns_ at 6.0 "$node_(0) setdest 45.0 350.0 5.0"$ns_ at 7.0 "$node_(0) setdest 50.0 50.0 5.0"$ns_ at 0.01 "$node_(1) setdest 10.0 1.0 5.0"$ns_ at 2.01 "$node_(2) setdest 10.0 100.0 5.0"$ns_ at 3.01 "$node_(3) setdest 10.0 200.0 5.0"$ns_ at 2.01 "$node_(4) setdest 10.0 300.0 5.0"$ns_ at 4.01 "$node_(5) setdest 10.0 350.0 5.0"$ns_ at 4.01 "$node_(6) setdest 100.0 1.0 5.0"$ns_ at 5.01 "$node_(7) setdest 100.0 100.0 5.0"$ns_ at 12.01 "$node_(8) setdest 100.0 200.0 5.0"$ns_ at 3.01 "$node_(9) setdest 100.0 300.0 5.0"$ns_ at 6.01 "$node_(10) setdest 100.0 350.0 5.0"$ns_ at 0.01 "$node_(11) setdest 200.0 1.0 5.0"$ns_ at 0.01 "$node_(12) setdest 200.0 100.0 5.0"$ns_ at 2.01 "$node_(13) setdest 50.0 50.0 5.0"$ns_ at 7.01 "$node_(14) setdest 200.0 300.0 5.0"$ns_ at 3.01 "$node_(15) setdest 170.0 10.0 5.0"$ns_ at 9.0 "$node_(0) setdest 1.0 200.0 5.0"$ns_ at 4.01 "$node_(1) setdest 100.0 1.0 5.0"$ns_ at 2.01 "$node_(2) setdest 100.0 100.0 5.0"$ns_ at 3.01 "$node_(3) setdest 100.0 200.0 5.0"$ns_ at 2.01 "$node_(4) setdest 100.0 300.0 5.0"$ns_ at 4.01 "$node_(5) setdest 100.0 350.0 5.0"$ns_ at 4.01 "$node_(6) setdest 50.0 1.0 5.0"$ns_ at 5.01 "$node_(7) setdest 20.0 100.0 5.0"$ns_ at 10.01 "$node_(8) setdest 20.0 200.0 5.0"$ns_ at 14.01 "$node_(9) setdest 20.0 300.0 5.0"$ns_ at 14.01 "$node_(10) setdest 20.0 350.0 5.0"$ns_ at 11.01 "$node_(11) setdest 20.0 1.0 5.0"$ns_ at 11.01 "$node_(12) setdest 10.0 100.0 5.0"$ns_ at 11.01 "$node_(13) setdest 100.0 160.0 5.0"$ns_ at 11.01 "$node_(14) setdest 50.0 240.0 5.0"

## Setting The Node Size $ns_ initial_node_pos $node_(0) 60 $ns_ initial_node_pos $node_(1) 40 $ns_ initial_node_pos $node_(2) 40 $ns_ initial_node_pos $node_(3) 40 $ns_ initial_node_pos $node_(4) 40 $ns_ initial_node_pos $node_(5) 40 $ns_ initial_node_pos $node_(6) 40 $ns_ initial_node_pos $node_(7) 40 $ns_ initial_node_pos $node_(8) 40 $ns_ initial_node_pos $node_(9) 40 $ns_ initial_node_pos $node_(10) 40 $ns_ initial_node_pos $node_(11) 40 $ns_ initial_node_pos $node_(12) 40 $ns_ initial_node_pos $node_(13) 40 $ns_ initial_node_pos $node_(14) 40 $ns_ initial_node_pos $node_(15) 60 ## SETTING ANIMATION RATE$ns_ at 0.0 "$ns_ set-animation-rate 30.0ms"

#### Establishing Communication

#Set Udp, cbr agent and attach those with nodes

set udp1 [new Agent/UDP]$ns_ attach-agent $node_(0) $udp1$udp1 set class_ 0

set cbr1 [new Application/Traffic/CBR]$cbr1 attach-agent $udp1$cbr1 set packetSize_ 1000$cbr1 set interval_ 0.02$cbr1 set rate_ 256kb

# Attach null agent for sinkset null1 [new Agent/Null]$ns_ attach-agent $node_(15) $null1$ns_ connect $udp1 $null1

# Start the traffic generator$ns_ at 0.0 "$cbr1 start"

# Setting the time to stop the simulation$ns_ at 1000.0 "stop"$ns_ at 1000.01 "puts \"NS EXITING...\" ; $ns_ halt" ### PROCEDURE TO STOP

proc stop {} { global ns_ tracefd $ns_ flush-trace close $tracefd exec nam aodv.nam exit 0

}

puts "Starting Simulation........" $ns_ run

For olsr protocol following parameters has been changed:set val(rp) OLSR#OLSR behaviour Agent/OLSR set use_mac_ trueAgent/OLSR set debug_ falseAgent/OLSR set willingness 3Agent/OLSR set hello_ival_ 2Agent/OLSR set tc_ival_ 5

Awk script for analyzing system matrics from trace file:# ===================================================================

# AWK Script for calculating:

# ===================================================================

BEGIN {recvdSize = 0startTime = 500stopTime = 0flow = 0pkt = 1000}{# Trace line format: newif ($2 == "-t") {event = $1time = $3node_id = $5flow_id = $39pkt_id = $41pkt_size = $37flow_t = $45level = $19}# Store packets send timeif (level == "AGT" && flow_id == flow && node_id == src && sendTime[pkt_id] == 0 && (event == "+" || event == "s") && pkt_size >= pkt) {if (time < startTime) {startTime = time}sendTime[pkt_id] = timethis_flow = flow_t}# Update total received packets' size and store packets arrival timeif (level == "AGT" && flow_id == flow && node_id == dst && event == "r" && pkt_size >= pkt) {if (time > stopTime) {stopTime = time}# Rip off the headerhdr_size = pkt_size % pktpkt_size -= hdr_size# Store received packet's sizerecvdSize += pkt_size# Store packet's reception timerecvTime[pkt_id] = time}}END {# Compute average delaydelay = avg_delay = recvdNum = tot_delay = 0for (i in recvTime) {delay = delay + (recvTime[i] - sendTime[i]);if((recvTime[i] - sendTime[i])>max_delay){max_delay=recvTime[i] - sendTime[i];}recvdNum ++}if (recvdNum != 0) {avg_delay = delay / recvdNumtot_delay = delay} else {avg_delay = 0}# Compute average jittersjitter1 = 0prev_time = delay = prev_delay = processed = deviation = 0prev_delay = -1for (i=0; processed> aodv_status.xls(( count++ ))done

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