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CHAPTER 1 INTRODUCTION 1.1 MOBILE AD-HOC NETWORK (MANET): A Mobile Ad-hoc Network (MANET) consists of a number of mobile battery powered energy constraint nodes communicating with each other in single or multiple hops over wireless links. They are temporary and infrastructure less without any central controller. Every node generates its own data traffic and cooperatively forwards others which are not in direct communication range of each other i.e. acts both as an end terminal and router. Due to the mobility and dynamic addition/deletion of nodes, topology changes frequently and on-demand routing protocols are required. MANETs should be capable of handling these topology changes through network reconfigurations. Routing protocols for MANET should be adaptive to the topology changes and be capable of discovering new routes when old routes becomes invalid due to such change. The number of nodes in MANET changes with time so the routing protocols should be scalable. A mobile ad hoc network is a collection of wireless mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are 1

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CHAPTER 1INTRODUCTION1.1 MOBILE AD-HOC NETWORK (MANET):A Mobile Ad-hoc Network (MANET) consists of a number of mobile battery powered energy constraint nodes communicating with each other in single or multiple hops over wireless links. They are temporary and infrastructure less without any central controller. Every node generates its own data traffic and cooperatively forwards others which are not in direct communication range of each other i.e. acts both as an end terminal and router. Due to the mobility and dynamic addition/deletion of nodes, topology changes frequently and on-demand routing protocols are required. MANETs should be capable of handling these topology changes through network reconfigurations. Routing protocols for MANET should be adaptive to the topology changes and be capable of discovering new routes when old routes becomes invalid due to such change. The number of nodes in MANET changes with time so the routing protocols should be scalable.A mobile ad hoc network is a collection of wireless mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are capable of changing on a continual basis. There are some unique characteristics of mobile ad hoc networks.1.1.1 CLASSIFICATION OF MOBILE AD HOC NETWORKCurrent researches classify mobile ad hoc networks into two categories. The first one is called a managed environment, where a common, trusted authority exists to provide certain services, such as a certificate authority. Another is called open environment, where a common authority that regulates the network does not exist. It is also referred as full self-organization environment, namely the network has the ability to work without any external management and configuration. Extensive work has been done recently in both areas.The routing protocols can be roughly divided into three categories: proactive (table driven routing protocols), reactive (on-demand routing protocols), and hybrid. The primary goal of such an ad hoc network routing protocol is to provide correct and efficient route establishment between pair of nodes so that messages may be delivered in time. Cluster Based Routing Protocol (CBRP) is a routing protocol designed for use in mobile ad hoc networks. The protocol divides the nodes into a number of overlapping or disjoint clusters in a distributed manner. A cluster head is elected for each cluster to maintain cluster membership information. Inter-cluster routes are discovered dynamically using the cluster membership information kept at each cluster head. By clustering nodes into groups, the protocol efficiently minimizes the flooding traffic during route discovery and speeds up this process as well.

1.1.2 WHAT IS MOBILE AD HOC NETWORK?Mobile Ad-hoc network is a set of wireless devices called wireless nodes, which dynamically connect and transfer information. Wireless nodes can be personal computers (desktops/laptops) with wireless LAN cards, Personal Digital Assistants (PDA), or other types of wireless or mobile communication devices. Figure 1.1 illustrates what MANET is. In general, a wireless node can be any computing equipment that employs the air as the transmission medium. As shown, the wireless node may be physically attached to a person, a vehicle, or an airplane, to enable wireless communication among them.

FIG 1.1 OVERVIEW OF MOBILE AD-HOC NETWORKIn MANET, a wireless node can be the source, the destination, or an intermediate node of data transmission. When a wireless node plays the role of intermediate node, it serves as a router that can receive and forward data packets to its neighbor closer to the destination node. Due to the nature of an ad-hoc network, wireless nodes tend to keep moving rather than stay still. Therefore the network topology changes from time to time.Wireless ad-hoc network have many advantages: Low cost of deployment: Ad hoc networks can be deployed on the fly; hence no expensive infrastructure such as copper wires or data cables is required. Fast deployment: Ad hoc networks are very convenient and easy to deploy since there are no cables involved. Deployment time is shortened. Dynamic Configuration: Ad hoc network configuration can change dynamically over time. When compared to configurability of LANs, it is very easy to change the network topology of a wireless network. MANET has various potential applications. Some typical examples include emergency search-rescue operations, meeting events, conferences, and battlefield communication between moving vehicles and/or soldiers. With the abilities to meet the new demand of mobile computation, the MANET has a very bright future.1.2 CURRENT CHALLENGESIn a mobile ad hoc network, all the nodes cooperate with each other to forward the packets in the network, and hence each node is effectively a router. Thus one of the most important issues is routing. This thesis focuses mainly on routing issues in ad hoc networks. In this section, some of the other issues in ad hoc networks are described: Distributed network: A MANET is a distributed wireless network without any fixed infrastructure. That means no centralized server is required to maintain the state of the clients. Dynamic topology: The nodes are mobile and hence the network is self-organizing. Because of this, the topology of the network keeps changing over time. Consequently, the routing protocols designed for such networks must also be adaptive to the topology changes. Addressing scheme: The network topology keeps changing dynamically and hence the addressing scheme used is quite significant. A dynamic network topology requires a ubiquitous addressing scheme, which avoids any duplicate addresses. In wireless WAN environments, Mobile IP is being used. Because the static home agents and foreign agents are needed, hence, this solution is not suitable for ad hoc network. Security: Security in an ad hoc network is extremely important in scenarios such as a battlefield. The five goals of security availability, confidentiality, integrity authenticity and non-repudiation - are difficult to achieve in MANET, mainly because every node in the network participates equally in routing packets. Security issues in MANETs are discussed in Chapter III.

1.3 OBJECTIVE:To study various cluster based routing schemes in mobile ad-hoc networks and schemes in mobile ad-hoc networks and implement distributed weighted cluster based implement distributed weighted cluster based routing algorithm.Design a routing protocol for MANET that is Efficient, scalable, distributed and simple to implement. Evaluate CBRP through simulation compare with different design alternatives compare against other MANET protocols.1.4 MOTIVATION:Major design decision use clustering approach to minimize on-demand route discovery traffic, use local repair to reduce route acquisition delay and new route discovery traffic suggest a solution to use uni-directional links A lot of research is currently going on in moiled-hoc networks. Chief occurs being to develop an efficient routing protocol which provides for efficient communication with minimum energy requirement.1.5. ROUTING PROTOCOLS BENEFITS 1.5.1 TABLE-DRIVEN (PROACTIVE) ROUTING This type of protocols maintains fresh lists of destinations and their routes by periodically distributing routing tables throughout the network. The main disadvantages of such algorithms are: Respective amount of data for maintenance. Slow reaction on restructuring and failures.

FIG 1.2: OLSR-OVERVIEWEXAMPLES OF PROACTIVE ALGORITHMS ARE: Optimized Link State Routing Protocol (OLSR) Optimized Link State Routing Protocol RFC 3626. Babel RFC 6126 Destination Sequence Distance Vector (DSDV)BENEFITES Being a proactive protocol, routes to all destinations within the network are known and maintained before use. Having the routes available within the standard routing table can be useful for some systems and network applications as there is no route discovery delay associated with finding a new route. The routing overhead generated, while generally greater than that of a reactive protocol, does not increase with the number of routes being created. Default and network routes can be injected into the system by HNA messages allowing for connection to the internet or other networks within the OLSRMANETcloud. Network routes are something reactive protocols do not currently execute well. Timeout values and validity information is contained within the messages conveying information allowing for differing timer values to be used at differing nodes.1.5.2 ON-DEMAND (REACTIVE) ROUTINGThis type of protocols finds a route on demand by flooding the network with Route Request packets. The main disadvantages of such algorithms are: High latency time in route finding. Excessive flooding can lead to network clogging.Examples of on-demand algorithms are: Ad hoc On-demand Distance Vector (AODV) (RFC 3561} Dynamic Source Routing (RFC 4728) Flow State in the Dynamic Source Routing Power-Aware DSR-basedBENEFITS The main advantage of this protocol is having routes established on demand and that destination sequence numbers are applied to find the latest route to the destination. The connection setup delay is lower. One disadvantage of this protocol is that intermediate nodes can lead to inconsistent routes if the source sequence number is very old and the intermediate nodes have a higher but not the latest destination sequence number, thereby having stale entries. Also, multiple RouteReply packets in response to a single RouteRequest packet can lead to heavy control overhead. Another disadvantage of AODV is unnecessary bandwidth consumption due to periodic beaconing.

1.5.3 HYBRID (BOTH PROACTIVE AND REACTIVE) ROUTINGThis type of protocol combines the advantages of proactive and reactive routing. The routing is initially established with some proactively prospected routes and then serves the demand from additionally activated nodes through reactive flooding. The choice of one or the other method requires predetermination for typical cases. The main disadvantages of such algorithms are: Advantage depends on number of other nodes activated. Reaction to traffic demand depends on gradient of traffic volume.EXAMPLES OF HYBRID ALGORITHMS ARE: ZRP (Zone Routing Protocol) ZRP uses IARP as pro-active and IERP as reactive component.BENEFITS: What is called the Intra-zone Routing Protocol (IARP), or a proactive routing protocol, is used inside routing zones. What is called the Inter-zone Routing Protocol (IERP), or a reactive routing protocol, is used between routing zones. IARP uses a routing table. Since this table is already stored, this is considered a proactive protocol. IERP uses a reactive protocol. Any route to a destination that is within the same local zone is quickly established from the sources proactively cached routing table by IARP. Therefore, if the source and destination of a packet are in the same zone, the packet can be delivered immediately. Most existing proactive routing algorithms can be used as the IARP for ZRP. In ZRP a zone is defined around each node, called the node's k-neighborhood, which consists of all nodes within k hops of the node. Border nodes are nodes which are exactly k hops away from a source node. For routes beyond the local zone, route discovery happens reactively. The source node sends a route request to the border nodes of its zone, containing its own address, the destination address and a unique sequence number. Each border node checks its local zone for the destination. If the destination is not a member of this local zone, the border node adds its own address to the route request packet and forwards the packet to its own border nodes. If the destination is a member of the local zone, it sends a route reply on the reverse path back to the source. The source node uses the path saved in the route reply packet to send data packets to the destination1.5.4 HIERARCHICAL ROUTING PROTOCOLSWith this type of protocol the choice of proactive and of reactive routing depends on the hierarchic level in which a node resides. The routing is initially established with some proactively prospected routes and then serves the demand from additionally activated nodes through reactive flooding on the lower levels. The choice for one or the other method requires proper attributation for respective levels. The main disadvantages of such algorithms are: Advantage depends on depth of nesting and addressing scheme. Reaction to traffic demand depends on meshing parameters.EXAMPLES OF HIERARCHICAL ROUTING ALGORITHMS ARE: CBRP (Cluster Based Routing Protocol) FSR (Fisheye State Routing protocol)

1.5.4.1 APPLICATION USED ON ADHOC: To understand their application we have to see what they offer and how they establish Establishing this type of networks requires mobile devices with the right communicating chip on. While they could ideally be deployed at any where or in other words instantaneous deployment. The cooperation of the users is necessary to the operation of ad-hoc networks; therefore, game theory provides a good basis to analyze the networks. Work has been going on to introduce the fundamental concepts of game theory and its applications in telecommunications. Crisis management services applications 1.5.4.2 ADVANTAGES AND DISADVANTAGES Table 1.1: Protocol Advanages and DisadvantagesPROTOCOLADVANTAGESDISADVANTAGES

Proactive Upto date routing information Quick establishments of routes Small Delay A route to every other node in the network is always. Slow convergence Tendency of creating loops Large amount of resource are needed. Routing information in not dully used.

Reactive Reduction of routing load Saving resources Loops-free Not always up to date routes Large delay Control traffic and overhead cost

Hybrid Scalability Limited search cost Up-to date routing information within zones Arbitrary proactive schemes within zones. Inter zone routing latencies. More resource for large size zones.

The study has been done to compare the efficiency of the various categories of routing protocols: DSDV, AODV, FSR, LAR, OLSR, STAR, and ZRP. The overall goal of our simulation study is to analyze the behavior and performance of the protocols under a range of various scenarios. Simulations have been run using a mobile ad hoc networks composed of 10, 15, 25, 50 and 75 nodes moving over a rectangular 1500 m 1500 m space and operating over 30 seconds of simulation time. All nodes move according to the random way point mobility model.Table 1.2: Traditional Routing Protocols

1.5.4.3 TRADITIONAL ROUTING PROTOCOLS: Border Gateway Protocol(BGP) is the protocol backing the core routing decisions on theInternet. It maintains a table of IP networks or prefixes which designate network reach-ability amongautonomous systems(AS). It is described as apath vector protocol. BGP does not use traditionalInterior Gateway Protocol(IGP) metrics, but makes routing decisions based on path, network policies and/or rule-sets. For this reason, it is more appropriately termed a reach-ability protocol rather thanrouting protocol. Open Shortest Path First(OSPF) is anadaptiverouting protocolforInternet Protocol(IP) networks. It uses alink state routingalgorithm and falls into the group of interior routing protocols, operating within a singleautonomous system(AS).Table 1.3: Routing PropertyRouting propertyProactiveReactiveHybrid

Routing structureBoth flat and hierarchical Mostly flat, except CBRPMostly hierarchical

Route availability Always available, if the nodes reachableDetermined when neededDepends on the location of the destination

Traffic controlUsually highLowMostly lower than proactive and reactive

Mobility handling effectsusually updates occurs based on mobility at fixed intervalsABR introduced LBQ, AODV uses local route discoveryUsually more than one path may be available

Storage requirementsHighUsually lower than proactive protocolsUsually depends on the size of each cluster

Delay levelSome all routes are predeterminedHigher than proactiveFor local destination small, since inter zone may be as large as reactive protocols.

Scalability level to perform efficient routing Usually up to 100 nodesSource routing protocols up to few 100 nodes point to point may scale higherDesigned for up to 1000 or more nodes

1.6 THESIS TARGETThe mobile ad hoc network is a new model of wireless communication and has gained increasing attention from industry. As in a general networking environment, mobile ad-hoc networks have to deal with various security threats. Due to its nature of dynamic network topology, routing in mobile ad-hoc network plays a vital role for the performance of the networks. It is understandable that most security threats target routing protocols the weakest point of the mobile ad-hoc network. There are various studies and many researches in this field in an attempt to propose more secure protocols. However, there is not a complete routing protocol that can secure the operation of an entire network in every situation. Typically a secure protocol is only good at protecting the network against one specific type of attacks.Many researchers have been done to evaluate the performance of secure routing protocols in comparison with normal routing protocols. One of the objectives of this research is to examine the additional cost of adding a security feature into non-secure routing protocols in various scenarios. The additional cost includes delay in packet transmission, the low rate of data packets over the total packets sent, etc.It is well known that the real-world network does not operate in an ideal working environment, meaning that there are always threats and malicious actions affecting the performance of the network. Thus, studying the performance of secure routing protocols in malicious environments is needed in order to effectively evaluate the performance of those routing protocols. In the thesis, I have implemented two secure routing protocols: a secure version of the dynamic source routing - DSR (OLSR) and Secure Ad hoc On-demand Distance Vector routing protocol (SAODV) in the OPNET simulation environments. I will also create malicious scenarios by implementing several attacks in the simulation environments.

In ad hoc networks, nodes are not familiar with the topology of their networks. Instead, they have to discover it: typically, a new node announces its presence and listens for announcements broadcast by its neighbors. Each node learns about others nearby and how to reach them, and may announce that it too can reach them.1.7 THESIS OUTLINEThis thesis is composed of six chapters. Following the Introduction Chapter (I), Chapter II classifies the routing protocols. The working description of two reactive protocols is provided. The chapter is concluded with a summary.Chapter III discusses security issues in MANETs with a focus on secure routing in MANETs. It focuses on the attacks and exploits that are possible in an ad hoc wireless network. It explains the working mechanism of four of the state-of-the-art routing protocols including OLSR and Secure Ad hoc On-demand Distance Vector routing protocols.Chapter IV discusses the system Architecture employed to study the performance of routing protocols in MANETs. A brief description of the OPNET Modeler simulator environment is provided. The scenarios, metrics and the issues faced are explained. A summary concludes the chapter.Chapter V discusses the simulation approach employed to study the performance of routing protocols in MANETs. A brief description of the OPNET Modeler simulator environment is provided. The scenarios, metrics and the issues faced are explained. A summary concludes the chapter.Chapter VI forms the core of this thesis and discusses the experiments carried out to analyze the performance of DSR, OLSR-INRIA, AODV, ZRP and SAODV. The experimental results and their analyses follow the experiments. Chapter VII concludes this thesis along with suggestions for future work in the area of mobile ad hoc networks.CHAPTER 2LITERATURE SURVEY2.1 PERFORMANCE ANALYSIS OF ROUTING PROTOCOLS BASED ON IPV4 AND IPV6 FOR MANETAd hoc network is a collection of wireless mobile nodes where wireless radio interface connects each device in a MANET to move freely, independently and randomly. Routing protocols in mobile ad hoc network helps to communicate source node with destination node by sending and receiving packets. Many authors have compared various routing protocols such as AODV, DSR, DSDV, TORA, DYMO, OLSR etc in the past. In this paper, we have analyzed the behavior of three routing protocols AODV (Ad hoc on demand distance vector), DYMO Dynamic MANET On demand), and OLSR (Optimized link state routing) in the network protocol IPV4 & IPV6 and compared the performance of these protocols using Qualnet5.0.2 simulator. The performance metrics are Throughput, Average Jitter, Packet Delivery Ratio & Total Packets Received. To test competence and effectiveness of all three protocols under IPV4 & IPV6, Changing the speed and mobility. Finally results are scrutinized from different scenarios to provide qualitative assessment of the applicability of the protocols.A mobile ad hoc network (MANET) is a self- configuring network of mobile devices connected by wireless links. In other words, a MANET is a collection of communication nodes that wish to communicate with each other, but has no fixed infrastructure and no predetermined topology of wireless links. Each node in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Individual nodes are responsible for dynamically discovering other nodes that they can directly communicate with. Due to the limitation of signal transmission range in each node, not all nodes can directly communicate with each other. Each node must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. Therefore, nodes are required to relay packets on behalf of other nodes in order to deliver data across the network. Ad hoc networks can be built around any wireless technology, including infrared, radio frequency (RF), global positioning system (GPS), and so on. Usually, each node is equipped with a transmitter and a receiver to communicate with other nodes. Military application, Collaborative & Distributed Computing, Emergency Operation, Wireless Mesh Network and the routing protocol should be able to provide quick, secure and reliable multicast communication with support for real time traffic. The paper is distributed as follows. In section 2 we have discuss three routing protocols taken for comparison. Section 3 gives the details of simulation environment. The simulation results are shown in section 4. Sections 5 describe conclusion and future scope.SIMULATION RESULTS, WE CONCLUDE THAT FOR IPV4 AND IPV6: DYMO have better throughput than AODV and OLSR with IPV4. DYMO have better throughput than AODV and OLSR with IPV6. OLSR have low jitter and average end to end delay corresponds to high efficiency than DYMO and AODV with IPV4. OLSR have low jitter and average end to end delay corresponds to high efficiency than DYMO and AODV with IPV6. OLSR have better packet delivery ratio than DYMO and AODV with IPV4. OLSR have better packet delivery ratio than DYMO and AODV with IPV6. OLSR have better average packed received and broadcast packet received than AODV and DYMO with IPV4. OLSR have better average packed received and broadcast packet received than DYMO and AODV with IPV6. We also conclude that IPV6 performs better than IPV4.

2.2. PERFORMANCE COMPARISON OF OLSR, GRP AND TORA USING OPNETA MANET is an autonomous collection of mobile users that communicate over relatively bandwidth constrained wireless links. Since the nodes are mobile, the network topology may change rapidly and unpredictably over time. The network is decentralized, where all network activity including discovering the topology and delivering messages must be executed by the nodes themselves, i.e., routing functionality will be incorporated into mobile nodes.. In this paper routing protocols OLSR, GRP and TORA for mobile ad hoc network are compared on the basis of delay, load, media access delay and throughput.MANET is a dynamic distributed network [1], in which mobile devices with limited energy can move arbitrary. MANET is a self-configurable network without infrastructure in which nodes are free to move randomly, so topology may change and this event is unpredictable [6]. Because of these characteristics, routing is a critical issue and an efficient routing protocol needs to be chosen to make the MANET reliable [2]. The most popular routing protocols [3] in MANET are OLSR (proactive) and TORA(reactive) and GRP(hybrid) .Proactive protocols are table driven protocols and find routes before they need it. Reactive protocols find the routes when they are needed And finally hybrid routing protocols offer an efficient framework that can simultaneously draw on the strengths of proactive and reactive routing protocols. In this paper, three MANET routing protocols ,OLSR, TORA and GRP are evaluated on the basis of four parameters : delay, load, throughput and routing overhead.

ROUTING PROTOCOL:The performance investigation of reactive and proactive MANET routing protocols, namely AODV, DSR, TORA and OLSR is done by Ashish Shrestha and Firat Tekiner. They have concluded that with regards to overall performance, AODV and OLSR performed pretty well. However, AODV showed better efficiency to deal with high congestion and it scaled better by successfully delivering packets over heavily trafficked network compared to OLSR and TORA. Comparison of OLSR and TORA has been done by Pankaj Palta and Sonia Goyal in.They have concluded that OLSR is better in those scenario where bandwidth is large as OLSR always updated their nodes so large bandwidth is used than TORA on same conditions. Simulation and analysis of GRP routing protocol has been done by kuldeep vats, Mandeep Dalal , Deepak Rohila and Vikas Laura.Simulation results show that GRP protocol has better performance in terms of delay , total traffic sent and received routing traffic sent and received in packet and bit form ,packet copy, packet created and packet destroyed. Manijeh Keshtgary and Vahide Babaiyan, used OPNET 14.5 for simulation. The simulation study for MANET network under routing protocols AODV, DSR, OLSR, and GRP were deployed using FTP traffic analyzing. These protocols were tested with QOS parameters. From their analysis, the OLSR outperforms others in overall performance and GRP has least media access delay and delay. This result is verified by Kuldeep Vats, Monica Sachdeva and Dr .Krishan Saluja in. They also concluded that OLSR is best in overall performance followed by GRP. In this paper, performance of three routing protocols namely OLSR, GRP and TORA was analyzed .OLSR performs best in terms of load and throughput.GRP performs best in terms of delay and routing overhead.

2.3. PERFORMANCE ANALYSIS OF MULTICAST ROUTING PROTOCOL FOR WIRELESS AD HOC NETWORK BASED ON TRAFFIC PATTERN WITH VARYING NODE MOBILITYData and information transmission in a wireless mobile ad-hoc networks (MANET) mainly relies on the performance of the traffic pattern (application traffic agent and data traffic) used in a network. The reliability and capability of routing protocols can be determined using different traffic scenarios, which insist its performance analysis using traffic patterns TCP/FTP and UDP/CBR with routing protocol generally implemented in a mobile ad-hoc environment. This paper describes the performance analysis and comparison of CBR and TCP traffic over conventional AODV and multicast AODV. The performance metrics, such as throughput, packet delivery ratio and average end to end delay is used for comprehensive performance analysis. The average end to end delay of CBR/UDP for MAODV and AODV is lesser than TCP/FTP. The Average End2End Delay of MAODV is lesser than that of AODV for both traffics. The results follow these trends over a wide range of simulations based on node mobility.The mobile ad-hoc network is a self-configuring infrastructure less network without the need of any central administration. Therefore, they are well suited for the environments as earthquake prone areas, military battlefield operation, virtual classrooms, and many other emergency services. AODV is a protocol which is capable of unicast and multicast transmission. Multicasting in a wireless network is a diverse technique through which the message can be transferred to multiple nodes simultaneously using fewer links. The information is delivered to each of the links only once, and copies are created when the link to the destination splits, thus creating an optimal distribution path. In general, for multicast transmissions there are two types of nodes, source node and multicast member node. The source node primarily spreads out a multicast data to multiple multicast member nodes that want to receive that data and join the multicast group. A big challenge in the design of ad hoc networks is the development of dynamic routing protocols that can find routes, transfer information and data efficiently between two nodes. Each node in the network also acts as a router, forwarding data packets for other nodes. The study of performance of two protocols, unicast AODV and multicast MAODV has been analysed over different scenarios. The analysis has been carried out with two traffic types, TCP/FTP and CBR/UDP. From the analysis it is concluded that MAODV performs slightly better than AODV in terms of Packet Delivery Ratio, End2End delay with varying node speed over two traffics, TCP and CBR. From experimental analysis it is concluded that in low density and in low speed the Packet Delivery Ratio (PDR) is high for both TCP and CBR. In the same scenario the End2End Delay for CBR traffic is lower than TCP traffic for both protocols. With mobility model it is also concluded that MAODV performs better than AODV for both TCP and CBR traffic patterns. In future the analysis may be extended to analyze the performance with node density, packet generation rate, varying pause time etc. By evaluating the performance of these two protocols over different scenarios, it will help in designing a new protocol or improvement in the existing protocol.

2.4. AD HOC WIRELESS NETWORKS: ANALYSIS, PROTOCOLS, ARCHITECTURE AND TOWARDS CONVERGENCETraditional routing protocols were developed to support user communication in networks with a fixed infrastructure with reliable, high-capacity links. On the other hand Mobile Ad-hoc Network is a collection of wireless mobile nodes which dynamically forms a temporary network without the use of any existing network infrastructure or centralized administration. These networks need efficient routing protocols; various ad hoc routing protocols have been proposed and compared based on some metrics. We present the analytical simulation results of routing protocols DSR, AODV, OLSR and GRP for two applications namely ftp and email, using the network simulator OPNET 14.0.Traditional routing protocols were developed to support user communication in networks with a fixed infrastructure with reliable, high-capacity links. However, in the mobile ad hoc network, the network infrastructure is dynamically changing, and the links are wireless with less capacity and more prone to errors. These nodes generally have a limited transmission range and, so, each node seeks the assistance of its neighboring nodes in forwarding packets and hence the nodes in an ad-hoc network can act as both routers and hosts, thus a node may forward packets between other nodes as well as run user applications. Some examples of the possible uses of ad hoc networking include students using laptop computers to participate in an interactive lecture, business associates sharing information during a meeting, soldiers relaying information for situational awareness on the battlefield and emergency disaster relief personnel coordinating efforts after a hurricane or earthquake.It is evident from Table 6 that the performance of DSR for all parameters is worst as compared to the other protocols. On the other hand OLSR is performing well for all parameters. The performance of GRP is also very close to OLSR but not better than it. As far as the present results are concerned in the given scenario the protocols are ordered in the increasing order of their performance as DSR, AODV, GRP and OLSR.GEOGRAPHIC ROUTING PROTOCOL (GRP)GRP is a kind of position-based protocol which belongs to Proactive Routing Protocol. Each position of the node will be marked by GPS and flooding will be optimized by quadrants. Flooding position updates on distance the node moved and neighborhood crossings. A hello protocol will be exchanged between nodes to identify their neighbors and their positions. At the same time, by means of route locking a node can return its packet to the last node when it cant keep on sending the packet to the next node.AD-HOC ON DEMAND DISTANCE VECTOR (AODV)AODV discovers routes on an as needed basis via a similar route discovery process. However, AODV adopts a very different mechanism to maintain routing information. It uses traditional routing tables, one entry per destination. Without source routing, AODV relies on routing table entries to propagate an RREP back to the source and, subsequently, to route data packets to the destination. AODV uses sequence numbers maintained at each destination to determine freshness of routing information and to prevent routing loops. All routing packets carry these sequence numbers. An important feature of AODV is the maintenance of timer-based states in each node, regarding utilization of individual routing table entries. A routing table entry is expired if not used recently.

2.5. SIMULATION AND PERFORMANCE ANALYSIS OF AODV, TORA & OLSR ROUTING PROTOCOLSAn ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any pre-existing network infrastructure. A number of ad hoc routing protocols have been developed during the time, but none of these is able to produce efficient routing of packets in large number of nodes due to their own limitations. Therefore, scalability is an open issue in all routing protocols. In this paper, we presented our observations regarding the scalability comparison of the three MANET routing protocols, Ad hoc On Demand Distance Vector (AODV), Temporally Ordered Routing Protocols (TORA) and Optimized Link State Routing (OLSR) by varying the number of nodes. In last three decades, wireless network has grown enormously. Although, wireless network has eased the information sharing and communication but we have to setup static links before we can start the communication between two systems. This form of network is known as infrastructure network. These networks can only work in the environment where a fixed infrastructure exists. This motivates the need of infrastructure less networks which are known as ad hoc networks. Ad-hoc means for one specific purpose only. Hence, these networks are formed when needed. All available nodes are aware of all other nodes within range. The entire collection of nodes is interconnected in many different ways. The topology of such networks changes very rapidly because the nodes in ad hoc network are mobile and independent of each other. This makes the routing very difficult.In this research study, we have performed simulations of three MANET routing protocols AODV, TORA and OLSR to evaluate their scalability and then compared them. Simulation is done using the OPNET Modeler 14.5. In the research work, Average end to end delay and throughput are considered as the performance evaluation parameters. HTTP heavy browsing is used for traffic generation. The simulation results conclude that on increasing the number of nodes there is performance degradation in all protocols, but it varies from protocol to protocol. As the number of nodes increased the network average end to end delay also increased for all three routing protocols. However, OLSR protocol outperformed the AODV and TORA protocols and has least network latency. TORA performed worst even it uses the localization.In case of network throughput too, it is observed that on varying the number of nodes performance of TORA protocol was very poor. Whereas, the performance of the OLSR protocol was far better than the AODV and TORA in terms of throughput. AODV performance was average during the simulation however; it reduces the routing overhead to great extent and reacts quickly during its operation. Hence, this paper concludes that the OLSR protocol in highly scalable with reference to varying network size, however the AODV protocol is almost equally scalable but less than OLSR. This comparative analysis is done to identify the suitable protocols according to the network size, so that the routing could be more efficient and cost effective.

TABLE 2.1: ANALYZING METHODAuthor Name ReferencesProtocols UsedSimulatorPerformance Metrics Variable Parameters

Guntupalli et al.DSDV, DSR, AODVNS2Average End to End Delay, Normalized Routing Load, Packet Delivery RatioNumber of nodes, Speed, pause time, Transmission Power.

Yogesh et al.AODV, DSRGLOMOSIMPacket Delivery Ratio, End to End Delay, Normalized routing overhead.Number of nodes, Speed, pause time

Chenna et al,DSDV, AODV, DSR, TORANS2Throughput, Routing Overhead, Path Optimality, Packet Loss, Average DeLayTraffic Loads, Movement Patterns.

G. Jayakumar et al,AODV, DSRNS2Packet Delivery Ratio, Routing Overhead, MAC load and average End to End DelaySpeed

Birdar et al, AODV, DSRPacket Delivery Ratio, Routing Overhead, Normalized Routing Overhead and Average End to End DelayPause Time

Vijayalaskhmi et al,DSDV, AODVNS2Packet Delivery Ratio, Average End to End Delay and Throughput.Number of Nodes, Speed, Time

Shaily et al,AODV, ZRPQual NetPacket Delivery Traction, Average End to End Delay and Throughput.Pause Time

Li Layuan st al,DSDV, AODV, DSR, TORANS2Average Delay, Jitter, Routing Load, Loss Ratio, Throughput and ConnectivityNetwork Size.

CHAPTER 3SYSTEM ANALYSISIn MANET the wireless links between adjacent nodes are subject to interference from external sources, intra and inter transmission in the network, ambient noise in the system and jamming signals from malicious nodes. The cumulative effect of all these factors results in low link capacity and reliability. In literature Kumar et al modifies the MANET routing protocols to reduce network congestion without taking into account the reliability of wireless links. It resulted in an only traffic load aware routing to reduce congestion. On the other hand Vijayavani et al modifies and compares various routing protocols in MANET based on network size, density and node mobility. Here also the wireless link status is not considered. Ghosh et al considered the status of wireless links in DSR and achieved good results. In our work we have modified the route discovery process of OLSR-INRIA, DSR and ZRP to select the most reliable path amongst multiple available paths based on its SNR value. The reliability of a path is the minimum SNR value of the wireless links constituting the path as it defines the weakest portion of the path. The structure of the RREQ packet is modified to include an additional field known as ROUTE_MIN_SNR, to store the minimum SNR value among all the path links. It gives us a measure of the path reliability. During the initial stages of the route discovery process the source node broadcasts RREQ packets to its immediate neighborhood. The ROUTE_MIN_SNR field of the RREQ packets received by the neighborhood nodes is updated with the SNR value of the link from the physical layer. After this updating the RREQ packets are further broadcasted in the immediate neighborhood. This process continues until the RREQ packets reaches destination node. When the destination node receives the RREQ packets, it compares the SNR value of each path to the source which is above a certain threshold (10dB in our method). Among the possible paths one with the maximum SNR value is selected as it gives the maximum throughput, reliability with minimum delay. How to analyze (Mobile Ad HOC) NETWORKS?

FIG 3.1: ADHOC NODE3.1 CHALLENGE: Qualify and quantify the effects of Node misbehavior on the overall performance of the routing system. We would like to see how the system behaves. What about choice of evaluation technique? Real world observations are not possible because there is no large scale manet, and it would be expensive to set up a new one. Emulation / Tested experiments are possible but in a small scale. Simulation studies are being conducted. Security, QoS,TABLE 3.1: SUMMARY RESULT FOR TEST AODV, ERS, 250 NODES

It is for sure that there are many issues need to be handled if an optimized ad hoc network needs to be implemented which does not seem possible with today's technology.3.2 ROUTING DEPENDABILITY IN AD HOC NETWORKS The effects of node misbehavior. Modeling adhoc networks.There might be cases that the protocols that we have discussed cannot help out. For instance what if there are some nodes that do not want to cooperate? Or some other problems related proximity to each other. Some might behave as malicious and etc.Recall that in ad hoc networks, there is mobility, dynamic situations. In this part, our concern is Routing system.

FIG 3.2: ROUTING SYSTEM3.2.1 NODE MISBEHAVIORA node in the middle may keep the message and not forward to package. It can affect the overall performance of the system. There are three different nodes.1. Well-behaving nodes: that works, forwards the packet.2. Malicious nodes: the ones that inject false information into messages or remove them completely from the network (black holes).It has been proven that if the number of selfish nodes increases the packet loss in the network increases linearly as well.

Besides that, in case of AODV, if there are many selfish nodes in the network we need to incerase the number of control messages ( to keep the track of what is going on in the network , and reestablish route if a node does not forward the packet ) . It results in increase of routing overhead. Selfish nodes: the ones that receives the packet but do not forward it.

3.2.2 ROUTING DEPENDABILITY PROBLEMS Most ad hoc routing algorithms assume only well-behaving nodes to support multi-hop operation of the network. However if something goes wrong in between, everything can be affected in a negative way. UNDERLYING PROBLEMS Induced by mobility : High topology dynamics Induced by wireless communication Induced by node misbehavior ( we might want to add some extra mechanisms to overcome this)3.2.3 SYSTEMATIC PERFORMANCE EVALUATION Performance analysis = analysis + computer systems System = any collection of hardware + software Metrics = the criteria used to evaluate the system performance Workloads = the requests made by the users of the systemYou need to know what you want to characterize in your system. You need to have a proper goal first. There is no such thing as general model.Goals -> correct metrics, workloads, methodology. Your performance evaluation should represent the actual usage of the system.

TABLE 3.2: SYSTEMATIC PERFORMANCE EVALUATION

3.3 Ad hoc Wireless Routing Protocols3.3.1 CLASSIFICATION OF BASIC ROUTING PROTOCOLSRouting protocols in ad hoc mobile wireless network can generally be divided into three groups (Figure 3.2):

FIG 3.3 HIERARCHY OF AD-HOC ROUTING PROTOCOLS

Table driven: Every node in the network maintains complete routing information about the network by periodically updating the routing table. Thus, when a node needs to send data packets, there is no delay for discovering the route throughout the network. This kind of routing protocols roughly works the same way as that of routing protocols for wired networks. Source initiated (or demand driven): In this type of routing, a node simply maintains routes to active destination that it needs to send data. The routes to active destinations will expire after some time of inactivity, during which the network is not being used. Hybrid: This type of routing protocols combines features of the above two categories. Nodes belonging to a particular geographical region or within a certain distance from a concerned node are said to be in the routing zone and use table driven routing protocol. Communication between nodes in different zones will rely on the on-demand or source-initiated protocols. In the rest of this chapter, I will give an overview of two of the most common routing protocols used in mobile ad hoc network: Dynamic Source Routing protocol (DSR) and Ad hoc On-demand Distance Vector routing protocol (AODV)

3.4 DYNAMIC SOURCE ROUTING PROTOCOL (DSR)The Dynamic Source Routing Protocol is one of the on-demand routing protocols, and is based on the concept of source routing. In source routing, a sender node has in the packet header the complete list of the path that the packet must travel to the destination node. That is, every node in the path just forwards the packet to its next hop specified in the header without having to check its routing table as in table-driven routing protocols. Besides, the nodes dont have to periodically broadcast their routing tables to the neighboring nodes. This saves a lot of network bandwidth. The two phases of the DSR operation are described below:

3.4.1 ROUTE DISCOVERY PHASE In this phase, the source node searches a route by broadcasting route request (RREQ) packets to its neighbors. Each of the neighbor nodes that has received the RREQ broadcast then checks the packet to determine which of the following conditions apply: (a) Was this RREQ received before ? (b) Is the TTL (Time To Live) counter greater than zero? (c) Is it itself the destination of the RREQ? (d) Should it broadcast the RREQ to its neighbors? The request ids are used to determine if a particular route request has been previously received by the node. Each node maintains a table of RREQs recently received. Each entry in the table is a pair. If two RREQs with the same are received by a node, it broadcasts only the one received first and discards the other. This mechanism also prevents formation of routing loops within the network. When the RREQ packet reaches the destination node, the destination node sends a reply packet (RREP) on the reverse path back to the sender. This RREP contains the recorded route to that destination. Figure 3.2 shows an example of the route discovery phase. When node A wants to communicate with node G, it initiates a route discovery mechanism and broadcasts a request packet (RREQ) to its neighboring nodes B, C and D as shown in the figure. However, node C also receives the same broadcast packets from nodes B and D. It then drops both of them and broadcasts the previously received RREQ packet to its neighbors. The other nodes follow the same procedure. When the packet reaches node G, it inserts its own address and reverses the route in the record and unicasts it back on the reversed path to the destination which is the originator of the RREQ.The destination node unicasts the best route (the one received first) and caches the other routes for future use. A route cache is maintained at every node so that, whenever a node receives a route request and finds a route for the destination node in its own cache, it sends a RREP packet itself instead of broadcasting it further.

FIG 3.4: ROUTE DISCOVERY IN DSR3.4.2 ROUTE MAINTENANCEThe route maintenance phase is carried out whenever there is a broken link between two nodes. A broken link can be detected by a node by either passively monitoring in promiscuous mode or actively monitoring the link. As shown in Figure 3.3, when a link break (F-G) happens, a route error packet (RERR) is sent by the intermediate node back to the originating node. The source node re-initiates the route discovery procedure to find a new route to the destination. It also removes any route entries it may have in its cache to that destination node. DSR benefits from source routing since the intermediate nodes do not need to maintain up-to-date routing information in order to route the packets that they receive. There is also no need for any periodic routing advertisement messages.

FIG 3.5: ROUTE MAINTENANCE IN DSR3.5 AD-HOC ON-DEMAND DISTANCE VECTOR (AODV) ROUTING PROTOCOL To find routes, the AODV routing protocol uses a reactive approach and to identify the most recent path it uses a proactive approach. That is, it uses the route discovery process similar to DSR to find routes and to compute fresh routes it uses destination sequence numbers. The two phases of the AODV routing protocol are described below.3.5.1 ROUTE DISCOVERYIn this phase, RREQ packets are transmitted by the source node in a way similar to DSR. The components of the RREQ packet include fields such as the source identifier (SId), the destination identifier (DId), the source sequence number (SSeq), the destination sequence number (DSeq), the broadcast identifier (BId), and TTL. When a RREQ packet is received by an intermediate node, it could either forward the RREQ packet or prepare a Route Reply (RREP) packet if there is an available valid route to the destination in its cache. To verify if a particular RREQ has already been received to avoid duplicates, the (SId, BId) pair is used. While transmitting a RREQ packet, every intermediate node enters the previous nodes address and its BId. A timer associated with every entry is also maintained by the node in an attempt to delete a RREQ packet in case the reply has not been received before it expires. When a node receives a RREP packet, the information of the previous node is also stored in it in order to forward the packet to it as the next hop of the destination. This plays a role of a forward pointer to the destination node. By doing it, each node contains only the next hop information; whereas in the source routing, all the intermediate nodes on the route towards the destination are stored. Figure 3.5 depicts an example of route discovery mechanism in AODV. Suppose that node A wishes to forward a data packet to node G but it has not an available route in its cache. It then initiates a route discovery process by broadcasting a RREQ packet to all its neighboring nodes (B, C and D).

FIG 3.6: ROUTE DISCOVERY IN AODV

All the SId, DId, SSeq, DSeq, BId, and TTL fields are inserted in the RREQ packet. When RREQ packet reaches to nodes B, C and D, these nodes immediately search their respective route caches for an existing route. In the case where no route is available, they forward the RREQ to their neighbors; otherwise a comparison is made between the destination sequence number (DSeq) in the RREQ packet and the DSeq in its corresponding entry in the route cache. It replies to the source node with a RREP packet consisting of the route to the destination in the case the DSeq in the RREQ packet is greater. In Figure 2.4, node C gets a route to G in its cache and its DSeq is greater when compared with that in the RREQ packet. 3.6 OLSR-INRIAThe Optimized Link State Routing (OLSR) protocol was designed by the French National Institute for Research in Computer Science and Control (INRIA) for mobile ad-hoc networks. It is a proactive routing protocol that employs an efficient link state packet forwarding mechanism called multipoint relaying on its way to optimize pure link state routing protocol. There is a two way optimization. One by reducing the size of the control packets and other by reducing the number of links that are used for forwarding link state packets. The reduction in the size of the link state packets is made by declaring only a subset of the links in the link state updates which are assigned the responsibility of packet forwarding known as Multipoint Relays. Periodic link state updates are facilitated by the optimization done by multipoint relaying facilities. No control packet is generated on the event of a link break or addition of a new link by the link state update mechanism which achieves higher efficiency when operating in a highly dense network.

FIG 3.7: ROUTE OLSR.3.7HYBRIDS - ZRP

FIG 3.8: ZONES A PRO-ACTIVE ROUTING PROTOCOL IS USED WHILE A RE-ACTIVE PROTOCOL IS USED BETWEEN ZONES.

Hybrid protocols seek to combine the proactive and reactive approaches. An example of such a protocol is theZone Routing Protocol (ZRP). ZRP divides the topology into zones and seek to utilize different routing protocols within and between the zones based on the weaknesses and strengths of these protocols. ZRP is totally modular, meaning that any routing protocol can be used within and between zones. The size of the zones is defined by a parameterrdescribing the radius in hops. Figure3.6illustrates a ZRP scenario with r set to 1. Intra-zone routing is done by a proactive protocol since these protocols keep an up to date view of the zone topology, which results in no initial delay when communicating with nodes within the zone. Inter-zone routing is done by a reactive protocol. This eliminates the need for nodes to keep a proactive fresh state of the entire network.ZRP defines a technique called theBorder cast Resolution Protocol(BRP) to control traffic between zones. If a node has no route to a destination provided by the proactive inter-zone routing, BRP is used to spread the reactive route request. Figure3.7illustrates the different components of ZRP.

FIG 3.9:THE DIFFERENT COMPONENTS OF THE ZONE ROUTING PROTOCOL.

3.8 Security aware routing protocolsMANETs have certain unique characteristics that make them vulnerable to several types of attacks. Since they are deployed in an open environment where all nodes co-operate in forwarding the packets in the network, malicious nodes are difficult to detect. Hence, it is relatively difficult to design a secure protocol for MANET, when compared to wired or infrastructure-based wireless networks. This section discusses the security goals for an ad hoc network. Sample attacks and threats against existing MANET routing protocols are then discussed. I then discuss the working of two secure routing protocols to address these threats, OLSR and SAODV. 3.8.1 SECURITY GOALSTo secure the routing protocols in MANETs, researchers have considered the following security services: availability, confidentiality, integrity, authentication and non-repudiation Availability guarantees the survivability of the network services despite attacks. A Denial-of-Service (DoS) is a potential threat at any layer of an ad hoc network. On the media access control layer, an adversary could jam the physical communication channels. On the network layer disruption of the routing operation may result in a partition of the network, rendering certain nodes inaccessible. On higher levels, an attacker could bring down high-level services like key management service. Confidentiality ensures that certain information be never disclosed to unauthorized entities. It is of paramount importance to strategic or tactical military communications. Routing information must also remain confidential in some cases, because the information might be valuable for enemies to locate their targets in a battlefield. Integrity ensures that a message that is on the way to the destination is never corrupted. A message could be corrupted because of channel noise or because of malicious attacks on the network. Authentication enables a node to ensure the identity of the peer node. Without authentication, an attacker could masquerade as a normal node, thus gaining access to sensitive information. Non-repudiation ensures that the originator of a message cannot deny that it is the real originator. Non-repudiation is important for detection and isolation of compromised nodes. The networking environment in wireless schemes makes the routing protocols vulnerable to attacks ranging from passive eavesdropping to active attacks such as impersonation, message replay, message littering, network partitioning, etc. Eavesdropping is a threat to confidentiality and active attacks are threats to availability, integrity, authentication and non-repudiation. Nodes roaming in an ad hoc environment with poor physical protection are quite vulnerable and they may be compromised. Once the nodes are compromised, they can be used as starting points to launch attacks against the routing protocols. 3.8.1.1 ATTACKS AND EXPLOITS ON THE EXISTING PROTOCOLSIn general, the attacks on routing protocols can generally be classified as routing disruption attacks and resource consumption attacks. In routing disruption attacks, the attacker tries to disrupt the routing mechanism by routing packets in wrong paths; in resource consumption attacks, some non-cooperative or selfish nodes may try to inject false packets in order to consume network bandwidth. Both of these attacks are examples of Denial of Service (DoS) attacks. Figure 3.1 depicts a broader classification of the possible attacks in MANETs.

FIG 3.10: CLASSIFICATION OF ATTACKS ON MANET ROUTING PROTOCOLS

CHAPTER 4SYSTEM ARCHITECTURE4.1 TECHNICAL APPROACH: Uses the Open Access Research Test bed for Next-Generation Wireless Networks (ORBIT), which consists of open API wireless terminals, forwarding nodes, access points, switches and routers, to evaluate different approaches both in terms of protocol functionality and software performance. Compatible upgrades to WLAN protocols for service features such as flow QoS and multicasting; interworking (global roaming, handoff, etc.) of multiple radio link technologies such as Bluetooth, 802.11, GPRS and 3G/WCDMA. Self-organizing ad-hoc network protocols for discovery and routing, with particular focus on a hierarchical 802.11b architecture consisting of mobile nodes (MN), radio forwarding nodes (FN) and access points (AP). Theoretical analysis of the capacity and scaling properties of the three-tier hierarchical hybrid wireless network, and system evaluation for an 802.11-based hierarchical network. Cross-layer approaches to MAC, routing and transport in ad-hoc network scenarios. Global Control Plane (GCP) approach to help disseminate control information among ad-hoc nodes and facilitate cross-layer algorithms such as the integrated routing/MAC scheduling algorithm and cross-layer transport protocol. Content delivery techniques for mobile users, including those based on proactive Infostations caching and novel semantic routing techniques. [This project involves collaboration with Semandex Networks, Princeton, NJ

FIG 4.1: INTERNET SYSTEM ARCHITECTURE4.2 TECHNICAL RATIONALE:

Mobile networks have traditionally been designed via extensions of existing fixed network protocols to support key mobility functions such as location management, authentication and handoff. Typically, these protocols were used in the context of homogeneous vertical architectures in which a single service such as GSM or 3G is provided to large numbers of mobile users. With the emergence of various new short-range and medium-range wireless data networks (such as Bluetooth and WLAN), there is a need for a more horizontal network architecture that accommodates heterogeneous radio links and permits evolution of mobile network services to include basic mobility features as well as newer requirements such as self-organization, ad-hoc routing, QoS, multicasting, content caching, etc. Such 4G wireless networks can be realized with an IP-based core network for global routing along with more customized local-area radio access networks that support features such as dynamic handoff and ad-hoc routing.4G is all about an integrated global network based on an open-systems approach. Integrating different types of wireless networks with wireline backbone networks seamlessly and the convergence of voice, multimedia, and data traffic over a single IP-based core network will be the main focus of 4G. With the availability of ultrahigh bandwidth of up to 100 Mbps, multimedia services can be supported efficiently. Ubiquitous computing is enabled with enhanced system mobility and portability support, and location-based services and support of ad hoc networking are expected. The illustration below shows the networks and components within the 4G network architecture.

FIG 4.2: 4G NETWORK ARCHITECTURE4.3 STRUCTURE CHART

AD-Hoc Mobile routing protocols

On demand driven reactiveHybridTable Driven proactive

DSRABRZRPWRPDSDV

RDMBRCBRPSTARCGSR

AODVTORA

FIG 4.3: MANET ROUTING PROTOCOLSSurvey of applications of MANET : We shall now get an overview of different types of MANET and their uses.4.3.1 PURE GENERAL PURPOSE MANETThe mostly discussed application scenario for pure general-purpose MANET is Battlefield or disaster-recovery networks. However, these kinds of networks have not yet achieved the envisaged impact in terms of real world implementation and industrial deployment.

4.3.2 MESH NETWORKSMesh networks are built upon a mix of fixed and mobile nodes interconnected via wireless links to form a multihop ad hoc network. Unlike pure MANETs, a mesh network introduces a hierarchyin the network architecture by adding dedicated nodes (called mesh routers) that communicate wirelessly to construct a wireless backbone. An example is MIT Roofnet providing the city of Boston, with broadband access with an 802.11b-based wireless network backbone infrastructure.Opportunistic Networking (Delay Tolerant Networking)(I)POCKET SWITCHED NETWORKS IN THE HAGGLE PROJECTIt targets solutions for communication in autonomic/opportunistic networks. In this framework, researchers are studying the properties of Pocket Switched Networks (PSNs), i.e., opportunistic networks that can exploit any possible encountered device (e.g., cell phones and PDAs that users carry in their pockets) to forward messages.(II)WILDLIFE MONITORINGWildlife monitoring is an interesting application field for opportunistic networks. It focuses on tracking wild species to deeply investigate their behavior and understand the interactions and influences on each other, as well as their reaction to the ecosystem changes caused by human activities.(III)VEHICULAR AD HOC NETWORKSVANETs use ad hoc communications for performing efficient driver assistance and car safety. The communications include data from the roadside and from other cars. VANET research aims to supply drivers with information regarding obstacles on the road and emergency events, mainly due to line-of-sight limitations and large processing delays. VANET can be used to communicate premonitions, notification of emergencies, and warnings about traffic conditions.(IV) WIRELESS SENSOR NETWORKS (WSN) Benefit from the advances in computing technology, which led to the production of small, wireless, battery powered, smart sensor nodes. These nodes are active devices with computing and communication capabilities that not only sample real world phenomena but also can filter, share, combine, and operate on the data they sense.

The general process of creating a simulation can be divided into several steps:- Topology definition:- To ease the creation of basic facilities and define their interrelationships, ns-3 has a system of containers and helpers that facilitates this process. Model usage:- Models are added to simulation (for example, UDP, IPv4, point-to-point devices and links, applications); most of the time this is done using helpers. Node and link configuration:- Models set their default values (for example, the size of packets sent by an application or MTU of a point-to-point link); most of the time this is done using the attribute system. Execution:- Simulation facilities generate events, data requested by the user is logged. Performance analysis:- After the simulation is finished and data is available as a time-stamped event trace. This data can then be statistically analysed with tools likeRto draw conclusions. Graphical Visualization:-Raw or processed data collected in a simulation can be graphed using tools likeGnuplot,matplotliborXgraph. Xgraph is the plotting tool bundled with many of the installation packages.

Start4.4 FRONT END DESIGN

Broadcast Packets (BP)

Authentication

Neighbor discovery and exchange of ID

Cluster maintenance by detecting events

Received NBR Info ?

Data aggregation at CH & Uploadat BP

Create neighbor table

Wait for Time T (stop)

Wait for Time T (boostrap)

Receive CH &join Selected CH by CH Transmit CH

Counter ExpiredCompute counter weight values

StopFIG 4.4: FLOW CHART OF ROUTING PROTOCOLThe Secure Ad hoc On-Demand Distance Vector (SAODV) protocol was proposed to answer the challenge of securing a MANET network. SAODV is an extension of the AODV routing protocol, and it can be used to protect the route discovery mechanism by providing security features like integrity, authentication and non-repudiation.SAODV assumes that each ad hoc node has a signature key pair from a suitable asymmetric cryptosystem. Further, each node is capable of securely verifying the association between the address of other node and the public key of that node. A key management scheme is needed for SAODV. Two mechanisms are used to secure the AODV messages: Digital signatures to authenticate the non-mutable fields of the messages, and Hash chains to secure the mutable hop count field of the message. For the non-mutable fields, authentication can be performed in a point-to-point manner, but the techniques cannot be applied to the mutable information. Route error messages are protected in a different manner because of a big amount of mutable information. According to the author, it is not important which node started the route error and which nodes are just forwarding it. The important information is that a neighbor node is informing other nodes that it is not able to route messages to certain destinations anymore. Therefore, every node (generating or forwarding a route error message) uses digital signatures to sign the whole RERR message and that any neighbor that receives RERR verifies the signature. The RREQ and RREP have the following extension fields

TABLE 4.1: HASH FUNCTIONValueHash function

0Reserved

1MD5HMAC96

2SHA1HMAC96

3 127Reserved

128 255Implementation dependent

4.5 ROUTE DISCOVERY TESLA handles the authentication of RERR messages in a way similar to how the RREQ messages are handled. In order to avoid the injection of invalid route errors (RERR) into the network by any node other than the node that sees a broken link, each node on the return path to the source node just forwards the RERR. On the other hand TESLA authentication is delayed, so all the nodes on the return path buffer the error but do not process it until it is authenticated. Later, the node that saw the broken link discloses the key and sends it over the return path, which enables nodes on that path to authenticate the buffered error message. The RERR contains six fields

FIG 4.5: ROUTE REQUEST AND ROUTE REPLY4.5.1 CHARACTERISTIC OF MANET

TABLE 4.2: SURVEYING DIFFERENT TECHNIQUES WE DEFINE THE ADVANTAGES AND DISADVANTAGES OF TECHNIQUESTechniquesAdvantages/ MeritsDisadvantages /Future Improvement Direction

MANET, AODV, Trusted Networks; Trust ModelThe proposed approach is the extension of existing AODV routing protocol for creating secure route for communication. Proposed modifications are in acceptable limit. With this minimum overhead, we can easily eliminate the malicious node as well as they can establish a best trusted route between source and destination.Using simulation results, the performance of this protocol is not sufficient justified. In the future, it will be incorporate with other MANET routing protocols.

DAAODV, Secure Routing ProtocolThey presented a secure ad hoc routing protocol which can prevent most attacks including worm-hole attacks, vertex cut attacks, and traffic analysis attacks, and adopt a new efficient signing and verifying scheme preventing DoS attacks.This protocol doesn't use TTP, and doesn't add much overhead in ns-2 simulation. In future work is to make a fine-grained construction of the routing software, as the design of DAAODV on software level is a little coarsegrained.

Multipath Routing, Ad-hoc Networks, AODVsecThe results show that AODVsec outperforms traditional multipath routing on ensuring security. As a common case, attacker cannot intercept all the paths, AODVsec avoids maliciously accessing a entire data packet, so it improves system's security with negligible routing overhead.The AODVsec still has some imperfect points. As a future work, it will need to focus on designing the synchronization control mechanism to solve this problem .

WirelessSsecurity1,; MANE, IEEE 802.11b4The efficient security algorithm ES-AODV enhances the security in ad hoc wireless networks. According to the analysis of the results obtained from extensive simulation, it concludes that the secure routing solution scales well to both mobility and network size.The routing protocol performs Does not better than the existing secure AODV routing protocol with increased mobility in the network. It should be improve in future extension .

MANET, Routing, SecurityIn the implementation of such routing protocols, the need is to eliminate the shortcoming of these protocols by evaluating performance of them on a simulation platform. To minimize the associated overhead like delay, routing overhead demands an intensive optimization in both the protocols.In future it will require more specifically SAODV to decrease the processing requirements to tackle hash chains and digital signatures to implement the security.

MANET, SecureAODVThis paper, presents the protocol being proposed which utilizes the dual cooperative mobile agents and stationary agents for routing in dynamic networks as MANET. Every mobile agent computes the transmission capacity of all the nodes so that Routing Agent System (RAS) can take the efficient reliable decision which routing path is more efficient and reliable.The transmission capacity factor into the networking as MANET of the protocol will need to improve in future.

TABLE 4.3: COMPARISON BETWEEN MANET-PROTOCOL

FIG 4.6: SOFTWARE ARCHITECTURE OF THE AODV

The component called AODV defines the main flow of control inside the AODV routing daemon. The control flow is based on an event-driven design. The set of possible events include reception of routing control packets, expiration of various timers, and reception of route requests on the ASL socket. Possible actions include sending out packets, setting new timers and updating various data structures. The daemon program is essentially a big select() loop which monitors various file descriptors for the events and takes the appropriate actions. This component also initializes ASL by calling the functions int route_add() and open\_route\_request(). The RREQ, RREP and RERR components take care of both generating as well as processing incoming route requests, route replies and route error packets respectively. The Routing Table component (routeTable) handles updates to the aodv routing table as well as to the kernel routing table. It also maintains a route cache using the aodv-helper module through the corresponding API function query_route_idle_time_aodv(), as explained in the next subsection. The Pending Route Request component (rreqPendingList) implements the expanding ring search and RREQ retransmission features of the AODV routing protocol. The Forward Route Request component ensures that a node does not process a particular RREQ packet multiple times, by storing a list of recently seen RREQ packets. The Local Repair component attempts to repair links locally and the Blacklist component takes care of routing in the presence of uni-directional links. Finally, the TimerQueue component maintains various AODV timers including reboot timer, periodic refresh timer, hello timer and rreq retransmission timer. 4.5.2 A SPLIT DESIGN As we have explained earlier, due to the inseparable forwarding and routing functions, there are usually two ways to implement such protocols: a complete in-kernel approach, and a complete user-space approach. Both approaches have pros and cons. A complete user-space approach will be inefficient for the forwarding function, but an in-kernel approach is different to maintain, different to modify, and different to port to other operating systems. In our implementation, we attempt a split-system approach. The idea is to segregate the forwarding and routing functions to some extent, even though they are intermixed in the protocol design. We believe that the core of the source-routing based forwarding activities, i.e., to send a data packet to the next-hop based on its DSR header, should be as efficient as possible and reside inside the kernel. We call this the source forwarding function. The majority of other source routing activities, which are induced by source forwarding, need to be flexible and can reside in user-space.

FIG 4.7: SPLIT DESIGN

Chapter 5Experimental Setup

5.1 SIMULATION TOOLOne common method to conduct research in the networking and security fields is to simulate and evaluate the protocol(s) in various scenarios. Fortunately, there are various computer simulation applications that are available for doing those tasks, such as NS-2, OPNET, GLOMOSIM, etc. My thesis is heavily based on the implementation and experiments in the OPNET simulation environment. OPNET Modeled was chosen as a simulation environment because it is one of the leading environments for network modeling and simulation. It supports large number of built-in industry standard network protocols, devices, and applications. In addition, its programming library helps researchers to easily modify the network elements and measure their performance in the simulation environment. OPNET also provides rich data analysis features.5.2 OPNET ARCHITECTUREOPNET provides a comprehensive environment to model and do performance evaluation of networks and distributed systems. The OPNET package includes numbers of tools. Those tools fall into three categories corresponding to the three phases of modeling and simulation projects: Specification, Simulation and Data Collection, and Analysis. These phases should necessarily be in sequence and form a simulation cycle as in Figure 4.1.OPNET uses the concept of modeling domains to represent its modeling environments, and graphical editors for editing the Network, Node and Process models. Specifically, there are several editors in OPNET: project editor, node editor, process editor, external system editor, link model editor, packet format editor, Interface Control Information editor, and probability density function editor.

FIG 5.1: SIMULATION CYCLE IN OPNET

Network Domain is used to define the network topology of a communication network. The communicating entities are called nodes. Network domain is created by using the Project editor tool of the OPNET modeler. Node Domain describes nodes internal architecture in terms of functional elements in the node and data flow between them.Process defines the behavior of processes, including protocols, algorithms and application, specified using infinite state machines and an extended high-level language.External System specifies the interfaces to the models provided by other simulators running concurrently with an OPNET simulation (a co-simulation).

5.3 NETWORK SIMULATORNetwork simulator 2 is the result of an on-going effort of research and development that is administrated by researchers at Berkeley. It is a discrete event simulator targeted at networking research. It provides substantial support for simulation of TCP. Routing, and multicast protocols.The simulator is written in C++ and a script language called OTcl2. Ns uses an Otcl interpreter towards the user. This means that the user writes an OTcl script that defines the network (number of nodes, links), the traffic in the network (sources, destinations, type of traffic) and which protocols it will use. This script is then used by ns during the simulations. The result of the simulations is an output trace file that can be used to do data processing (calculate delay, throughput etc) and to visualize the simulation with a program called Network Animator (NAM). See Appendix C for a screenshot of NAM. NAM is a very good visualization tool that visualizes the packets as they propagate through the network. An overview of how a simulation is done in NsThe current version of the Network simulator does not support mobile wireless environments. The Network simulator alone is only intended for stationary networks with wired links. This caused us some problems in the beginning of this master thesis. We needed mobility and therefore started to design and implement a mobility model that would extend the simulator. We also started to implement the AODV protocol. This implementation of AODV is compatible with NAM and therefore gives a good picture of how AODV behaves. It is very easy to follow for instance the route discovery procedure. About two months later, in August 1998. two separate mobility extensions were released. These extensions had everything that we wanted from an extension, so we decided to use one of them. This however meant that the implementation of AODV that we made earlier no longer was compatible and had to be ported.

5.3.1 AODVWe have implemented the AODV protocol The implementation is done accord to the AODV draft released in August 1993. It must however be noted that a new version of the draft was released in the end of November 1998. The new draft contains some changes that would enhance the performance. These changes that affect the unicast routing part is primarily: Reduced or complete elimination of hello messages. Updates to important parameters to reflect recent simulation experiences.To be able to test how the hello messages and link layer support affects the behavior of the protocol we have implemented three versions: AODV with only IP-based hello messages AODV with only Link Layer notification of broken links AODV with both IP-based hello messages and Link layer notification of broken links

The implementation of the different versions lias some major differences that will affect the performance. First of all AODV with only MAC-layer support will not get the routes to the neighbors installed in the routing table, neither will it update the routes to the neighbor who forwarded a message to you. Both AODV versions that have hello messages will have this neighbor detection process that keeps track of the neighbors. This means that the protocols with this feature will have more information in the routing tables. Without this support buffering of the packets may be necessary while a request is sent out in search for a node that could be a neighbor. It must however be noted that the removal of hello messages somewhat changes the behavior of the AODV protocol. The hello messages add overhead to the protocol, but also give us some prior knowledge of link breakages. Removing the hello messages makes the protocol completely on-demand, broken links can only be detected when actually sending something on the broken link.The DSR implementation that was included in the mobility extension used a sendbuffer that buffered all packets that the application sent while the routing protocol searched for a route. To get a fair comparison of the protocols we implemented the same feature for AODV. This buffer can hold 64 packets and packets are allowed to stay in the buffer for 8 seconds.The parameters that can be adjusted for AODV and the values we have used is . Some of these parameters are very important and affects the performance of the protocol in drastic ways. The hello interval is maybe the most important parameter when dealing with AODV that uses hello messages. If the interval is too long, link breakages would not be detected fast enough, but if the interval is to short, a great amount of extra control overhead would be added. Most of the parameters in Table 3 are obvious. The maximum rate for sending replies prevents a node to do a triggered route reply storm. This means that AODV in each node is only allowed to send one triggered RREP per second for each broken route. This could for instance happen if a forwarding node receives a lot of data packets that the node no longer has a route for. In this case the node should only send a triggered RREP. as a response to the first data packet and if the node keeps receiving data packets after that, a triggered RREP is only allowed to be sent once per second.TABLE 5.1: CONSTANTS USED IN THE AODV IMPLEMENTATION.ParameterValue

Hello interval1,5 s

Active route timeout300 s

Route reply lifetime300 s

Allowed hello loss2

Request retries

Time between retransmitted requests3 s

Time to hold packets awaiting routes8 s

5.3.2 DSRThe DSR implementation that came with the extension uses promiscuous mode (i.e. eavesdropping), which means that the protocol learns information from packets that it overhears. The question is how realistic this is in a real environment. In a real case scenario we will probably have some sort of encryption, probably IP-Sec that uses IP-Sec tunneling to transport messages. We have made some small change to DSR that makes it possible to turn the eavesdropping feature on and off. The parameters that are configurable for DSR are shown in These values are the values specified in the DSR draft and have not been changed. The no propagating timeout is the time a node waits for a reply for a no propagating search. A no propagating search is a request that first goes to the neighbors. If the neighbors do not answer in this specified amount of a tune, a new request that will be forwarded by the neighbors will be sent. The send buffer in the DSR can hold 64 packets and the packets are allowed to stay in the buffer for 30 seconds

FIG 5.2: CONSTANTS USED IN THE DSR

ParameterValue

Time between retransmitted requests500 ms

Size of source route header carrying n addresses4n + 4 bytes

Timeout for no propagating search30 ms

Time to hold packets awaiting routes30 s

5.3.2.1 FLOODINGWe have implemented a simple flooding protocol that simply floods all user data packets to all nodes m the network. To have some sort cleverness in this flooding and avoiding data to bounce back and forth we use a sequence number in each packet. This sequence number is incremented for each new packet. Each node keeps track of (source IP, sequence number) for all destinations and does not process a packet if the packet has a sequence number smaller than the stored sequence number. The idea was to do the simulations on the flooding protocol and compare the results with the results for the routing protocols. After some initial simulations on flooding this plan was abandoned. The simulations took too long to complete. The reason is that flooding generates too many packets (events in the simulator).

5.4 OPNET MODELER WIRELESS SUPPORTThe Wireless module in OPNET provides a flexible and scalable wireless network modeling environment, including a broad range of powerful technologies. The Wireless module integrates OPNETs full protocol stack modeling capability, including MAC, routing, higher layer protocols, and applications, with the ability to model all aspects of wireless transmissions, including: Radio Frequency propagation (path loss with terrain diffraction, fading, and atmospheric and foliage attenuation) Interference Transmitter/receiver characteristics Node mobility, including handoverThe wireless module has rich protocol model suites to optimize the R&D processes, and more effectively design technologies such as MANET, 802.11, 3G/4G, Ultra Wide Band, 802.16, Bluetooth, and Transformational Communications systems. Wireless network planners, architects, and operations professionals can analyze end-to-end behavior, tune network performance, and evaluate growth scenarios for revenue-generating network services.

5.4.1 IMPLEMENTING THE PROTOCOLS IN THE OPNET MODELERIn this thesis, I have implemented two secure routing protocols, SAODV and OLSR, in the OPNET Modeler simulation environment, using the Application Programming Interface functions of the OPNET development kit and the embedded C language. The malicious feature of a wireless node is integrated into the routing protocol model, so that each wireless node can be easily switched back and forth between the normal mode and the malicious mode. We can use the C/C++ language to implement/modify the behavior of a module. For easy development, OPNET provides quite a large library with over 400 predefined functions and procedures . Figure 5.2 shows steps to add new secure routing protocols OLSR and SAODV into the OPNET Modeler. OLSR and SAODV are respectively based on the DSR and AODV protocols, which are supported in OPNET, so I did not have to re-implement the whole protocols. Instead, I duplicate the original protocols (DSR and AODV) and then add security features to turn them into the secure versions (that is, OLSR and SAODV).

FIG 5.2: STEPS TO ADD NEW SECURE ROUTING PROTOCOLS INTO OPNET

Step 2 in Figure 5.2 (Add security features into new protocols) is further concretized in Figure 5.3. At the origin nodes that generate the routing packets, the security fields are added into the routing packets at the packet creation phase of the routing process. These security fields will be verified against the secure conditions at the intermediate nodes and at the destination node. If the security conditions are not met, the nodes will discard the routing packets; otherwise they accept the packets and proceed to next appropriate processing phase. These conditions are defined by each specific protocol and added at the processing phase of the routing process.

FIG 5.3: SECURE CONDITIONS AT THE INTERMEDIATE NODES

TABLE 5.3: HASH CHAIN FUNCTION

Function NamePurpose

initialize_hash ()Convert a string into an array of bytes

generate_hash_chain ())Hash an array for a given number of times

generate_signature ())Generate a digital signature based on the private/public key pair of a wireless node

publickey_extraction ())Get the public key of a wireless node (to be sent to other nodes)

verify_signature ())Verify the signature of a routing packet

verify_hop_count ())Verify the hop count field contained in a routing packet

initialize_mac ())Generate a hash value based on the MD5 algorithm

OLSR_generate_hash ())Generate a hash value for the OLSR protocol

OLSR_verify_hash ())Verify the hash values in an OLSR routing packet

5.4.2 IMPLEMENTING THE ATTACK MODELS IN THE OPNET MODELERIn the simulation, the attack models are implemented as part of the routing process. Figure 4.4 illustrates how attack models are integrated into the routing processes. Each wireless node, during the routing process, will check if it itself is a malicious node. If it is, it will turn on the appropriate attacking process; otherwise, it will process the routing packets as a normal node. FIGURE 5.4: PROCEDURE TO INTEGRATE ATTACK MODELS IN THE ROUTING PROCESS

5.4.3 RUNNING SIMULATIONS IN THE OPNET MODELER AND COLLECTING EXPERIMENT RESULTS Figure 5.5 shows the steps to run experimental scenarios in OPNET. There are two ways to collect the experimental data from OPNET. The first approach is to use the OPNET Statistic Analysis tool. Values such as average number of routing packets, number of data sent or received over various points during the simulation time, etc., are collected by this tool. Other values like average number of end-to-end delay of data packets are dumped into a scalar file. This scalar file needs to be converted into a text file to be readable by other tools.

FIG 5.5: THE FLOW CHART ILLUSTRATING THE PROCESS OF RUNNING SIMULATION EXPERIMENTS AND COLLECTING EXPERIMENTAL DATA

TABLE 5.4: IMPLEMENTATION MATRIX OF ROUTING ATTACK MODELS.PROTOCOLATTACK-1ATTACK-2ATTACK-3

DSRRoute DropRoute modification Route Fabrication

OLSRRoute DropRoute modificationRoute Fabrication

AODVRoute DropRoute modificationImpersonation

SAODVRoute DropRoute modificationImpersonation

5.5 SCENARIO SETUPIn this thesis, I set up a network with 25 wireless nodes moving at random, each with various speed between 1 and 10 meters per second, which is the average speed of a walking person or a running vehicle. This is a medium group that represents some of the typical scenarios, such as a rescue team working in a disastrous area, a group of moving vehicles in the city, a squad of soldiers or armored vehicles in an army operation, or a place of an event. The pause time values represent the movement of the objects. Each of the obje