Essay: Mobile Ad Hoc Networks- OverviewOf Routing Protocols. Mobile ad hoc network(MANET) is an advance technologyof mobileallowing communication without the help of base framingor station.The rapid development of mobility is closely related to automationofcommunication. In the current generation of technology, astaticstrategy to reduce electronic devices, tallying desirable shapeof newcomponents allowing accessibility in public market is veryessential.Over the past decades MANET has play an imperative role inautomatingcommunication. Mobile ad hoc networks are imperativelyusedincombat ground communication, rescue operation anddamagingrecovery when the wired network is inaccessible. Thereexisttwodifferent types of mobile wireless network they include infrastructureless network and infrastructure network. Infrastructure less networkismost appropriate where there is high demand of localizedtelecommunication and it is the main class of wireless network. Ontheother hand, infrastructure networks consist of communicationmobilenetworks that are connected with base station and a fixedinfrastructurenetwork. However, unlike fixed cable nets wireless mobile networksaregenerally more exposed to security threats. There is an increasedchanceof eavesdropping and attacks such as denial of services whichneedtobe considered carefully. MANET has proven its usefulness throughitflexibility hence applicable in areas such as civilian environment, remote
construction sites, commercial projects, lawenforcement andenvironmental monitoring. For Networking Assignment Help visit Myassignmenthelp.comDevelopers often find quality of service a complex task toaccomplish.,this is due to regular change of ad hoc network topology. It isquitechallenging to support certain quality of service and to reserveresourcewhen there is a constant change in the network situation. Since ad hoc networks are connected to other devicesintheneighborhood, routing continues to be a major problemtosolve. Thereis no available default route due to multi hop routing. Eachnodeforward their packet by acting as a router so as to let sharingsequenceamong mobile nodes. Generally, a wireless network is way more expose to securitythreatsthan a wired link. Security is one of the unsolved issues inadhocnetwork. It is therefore imperative to solve this issues toensureadequate performance of MANET. The routing protocol has to take into account power resourcelimitationof the wireless mobile nodes. That is to say that they shouldbeenergyaware and efficient, Sine MANET is at times interconnected with a fixed network, theroutingprotocol should consider the existence of other routing protocols. To solve this issues, different routing schemes have beendeveloped.The foremost purpose of this paper is to deliver a detailedanalysisof
mobile ad hoc network by conducting a comprehensiveanalysisonreactive and proactive routing protocols meant to resolvetheabovementioned issues. Routing refer to selection of network paths. It is normally performedbyspecial device called router. Generally, it is the act of transferringdatafrom a foundation to a destination and across inter-network. Routinghas two special types, that is dynamic sate routing meant toopenupchances of loops for routing and link state routing meant tocollectbestpaths from routing table nodes. Every node in ad hoc networkshouldbeable to accelerate data to other nodes. To effectively dothat variousrouting protocols have been developed to produceadequatepresentation of ad hoc network. MANET routing has thereforebecategorized into hybrid routing, reactive routing and proactiverouting.The below figure shows the classification Sometimes, nodes look for routing data in network. Since this protocolsare free to traffics profile, there is a possibility to fix cost andafixedupper bound. Proactive protocols are usually denoted to as tabledrivenprotocols. It main function is to minimize latency of messageproducedby route discovery, it does so by ensuring maintenance of uptodatemoving data from respectively node to another at all times. Thisisachieved through broadcast of control packets containing routingtableinformation. For the first time, these protocols enflame a largeoverheadsignal in order to make a route. Additionally, during modificationoftopology as a result of node failure or mobility, the topology informationwhich has been updated are being broadcast to each networknode.
“Proactive routing protocols include; OLSR-optimized link stateroutingprotocol, DSDV- destination sequence distance vector, DSR- demandsignal repository STAR- Source tree adaptive routing protocol andFSRfisheye state routing.” Destination sequence distance vector DSDVandOLSR are the selected protocol to be evaluated in this study. It belongs to proactive family and is an improved type of dispersedBellman ford algorithm. In DSDV there is continuous maintenanceandupdating of correct route leading to any node in the network. Theimprovement made from the previous version include loops freedominrouting table through the use of sequence number. In DSDVprotocolseach performing nodes are assumed to be routers in wirelesssensornetwork. All nodes usually keep a routing table that containall thepotential destination. The destination address identifiers arefoundinevery in entry of the routing table. It also consists of the shortest metricdistance to the destination and is measured in hop count. Theinitial hopon the shorter path to the destination is the destinationaddressidentifier. A routing table is maintained by all mobile nodesinthesystem, all hop numbers and potential destination are recorded. Inthemeantime, every host propagated route is being periodically updatedsoas to achieve the most accurate and the latest routing table. Eachpathor route is marked with a structured quantity for which destinationnodeallocated. The route with the highest structured number is normallyused and the number helps in identification of stale routes inthenewones therefore avoiding loops formation. There are two major typesofpackets in the system that helps in minimization of traffic. Oneiscalled
full dump and it plays an essential role in carrying all thenecessaryinformation concerning change. However, incremental packetisnormally used when the regular movements in the networkoccurs.Incremental packet carries only the changes therefore increasingthesystem’s overall efficiency. DSDV needs an occasional routingtableupdates, which requires a lot of battery-operated power andabandwidth in lesser quantity despite the network topologyisnotchanging. A new sequence of number is always needed beforethere-converges of network whenever there is a change in thetopologyofnetwork. This is to say that, DSDV is not measurable intheadhocnetwork which is highly dynamic in terms of topology networkandhassmall amount of bandwidth. Availability of routes in all destinationsmeans that less and lesser interruption in the process of routesetupisinvolved. The inavailibity of a scalable standard makes someparametersof the protocol to lack clear definition. OLSR refers to pure state algorithm optimization, multi point relaystheory is used to forward control traffic, proposed intotheentirenetwork distribution. The multi point relays is selected insuchawaythat all nodes situated two hops apart are all covered. It is anessentialtype of proactive protocol as it is measurable and scalable. It playsamajor role in optimizing pure state algorithmand in forwardingtrafficcontrol, hence reducing traffic in the system. OLSR works closelywithperiodic messages replace such as topology control and hellomessagesand it is only through its multi point relays. The parameters thatarebeing used by OLSR tin controlling the protocol overheads aretopology
control intervals parameters, Hello intervals parameters, topologycontrol intervals parameter and multi point reporting parameters. The key idea in the OLSR protocol is the multipoint relaywhichisimperative in reducing exchange of information overhead, multi pointrelay function by reducing the host number propagating informationinthe network instead of pure flooding.to allow efficiency intheprotocol,multi point relay set a host which is usually kept small throughouttheprocess. To allow topological information exchange, multi pointrelaynodes are required to send topology control message. Thesemessagesare propagated throughout the network and multi point relayistheonlyone allowed to send topology control messages. For it assignment help visit Myassignmenthelp.comThe above discussion can be summarized as shown in the belowtableTable driven / proactive routing protocol Protocol Class of Routing Protocol Structur e of routing Multiple Routes Method of Route Metric Maintena nce of route Advantage/ Disadvantage
(OLSR) Proactiv e Routing Protocol Regular Not Sporadi c Multipoint Relay used to reduce overhead control Reducedcontrol overheadandcontention/2-hopneighborknowledgerequiredDestinati on- sequence d distance vector (DSDV) Proactiv e Routing Protocol regular Not Sporadi c and as needed free loop High overheadorfree loopThese type of routing protocol is usually referred to as “ondemand”routing protocol, this is because, the routes between the nodesareonlybeing built as per the requirement of the source nodes. Theroutingprotocol explains the perfect ad hoc network nature. The networkedisdescribed to be much more dynamic as compared toinfrastructurenetworks. When a routing requirement is presented, routinginformation in the reactive routing protocol is updatedfromtimetotime. These reduces the control overhead, majorly inhighmobility
networks with the help of periodical update guiding towards significantuseless overhead. Reactive routing protocols was developed to reduce theoverheadsproduces by proactive routing protocol through maintenanceofinformation only on active routes. Once the route has beendetermined,the route maintenance procedure tries to maintain it until therouteisno longer needed or until there is inaccessibility of thedestination.Reactive routing protocols are more appropriate indynamicenvironments although it leads to a higher latency and its pathsneedsto be established using control packet in a source initiatedflooding.Hayat et al., (2019) stated that “Ad hoc on demand distancevector(AODDV), dynamic state routing protocol (DSR), locationaidedroutingprotocol (LAR), Associativity base routing (ABR), and Ad hoc ondemandmultipath distance vector are examples of reactive routing protocols.”According to Alslaim, Alaqel, and Zaghloul ,(2014) “AODVis areactiverouting protocol developed for wireless ad hoc networks andisabletoboth unicast and multicast routing. Since it is an on demandalgorithm,nodes between the routes are built only as required by the sourcenodes.Once the route has been determined, the route maintenanceproceduretries to maintain it until the route is no longer needed or until thereisinaccessibility of the destination.” Reactive routing protocols aremoreappropriate in dynamic environments although it leads toahigherlatency and its paths needs to be established using control packetinasource initiated flooding. When a routing requirement is presented,routing information in the reactive routing protocol is updatedfrom
time to time. “These reduces the control overhead, majorlyinhighmobility networks with the help of periodical update guidingtowardssignificant useless overhead.” (Hayat et al, 2019) AODV is an improved version of DSDV as it allows minimizationofsequence number of the needed broadcast through creationof routesonly on demand basis. It uses a demand mechanismto carry out aroutediscovery procedure. During discovery of routes process, theprotocolfunction by the use route request (RREQ) and routereply(RREP)message This type of reactive protocol is associated with fixed link stateprotocol.The way of distributing sequences in DSR has been enhancedunlikeinliked state algorithm. It does so restricting messages updateinonlyinthe intermediate nodes. In this type of protocol everynodeismaintained depending on the information updates receivedfromtheneighboring nodes, and it exchanges its kink state data fromtimetotime with only the neighboring. As a results the number of transmittedmessage has much reduce in the network the size of messages updatedis however large and they become even much higher as thesizeofnetwork grows. Routing is a procedure of making decisions inwhichtherouter (which is a hardware device used in networking toreceiveandsend data in the form of packets on a network) selects thebest pathtomake data transfer from source to destination. A router existsinthenetwork layer in the OSI as well as TCP/IP model. Some functionsofarouter are:
Building an ideal way on an organization to arrive at its objective(wherein static and dynamic steering happen). Taking directing choices. Adjusting load. Sorts of Routing: ● Static directing ● Default directing ● Dynamic directing Static and Default directing has a few downsides, becauseof whichDynamic Routing was presented. It is a difficult undertaking to summarize or add-oneachcoursephysically to the directing guide in an enormous organization. Dealing with its requesting is tedious. It can't reroute traffic in the event that some connection falls flat. Downsides of Default directing was: In the event that the organization is intricate, it is more hardtoset up. To defeat the inadequacies of static and default directing, Backduringthe 1980s, the very first Dynamic steering was utilized inaPCandtheconvention which was utilized in it was the RIP(routing data convention).
Dynamic steering is known as a strategy of tracking downthebestwayfor the information to go over an organization in this interactionaswitch can send information through different various coursesandarrive at its objective based on conditions aroundthenofcorrespondence circuits. Summary of reactive routing protocols can be described as inthetablebelow. Protocol Class of RoutingPr otocol RoutinStr ucture MultipRo utes RouteMetric Method RouteMaint enance Advantage/DisadvantageAd hoc OnDem and distance vector (AODV) Reactive Routing Protocol Level Not Freshest and shortes path Route able Adaptabletohighly dynamicTopologiesScal ability problems,hellomessageslargedelays,
Dynami cs routing (DSR) Reactive Routing Protocol level Affirmati ve Shorts path, or nextavail able in route cache RouteCache Multipleroutes, PromiscuousOverhearing/Scalabilityproblemsdueto sourceroutingandflooding, largedelaysBased on the above mention literature on proactive andreactiveprotocols, the two approaches have been critically asses todeterminetheir difference and similarities in its performance. the parametersusedin the analysis include, storage requirement, mobility support, routingscheme, storage capacity, routing overheads and routing information.The table below shows the comprehensive analysis of proactiveandreactive routing protocols. Parameters Proactive Reactive
Storage Requirement Higher Dependent onnumberof Routesmaintainedorneeded Routing Schema Ondemand Tabledriven Mobility support RouteMaintenance Periodicalupdates RoutingOverhead Low High Routing information Keepstored in table Do not store StorageCapacity Generally low High ,as a result ofrouting tables In order to support the above assessment quantitative evaluationwascarried out by selectig one sample protocol fromeachstrategyandevaluating their performance under varying operating conditions. To conduct an effective performance comparison, the studyselectedAODV and OLSR protocols from MANET topology. A networkstimulatorof ns-2 was used for this analysis.
The simulation parameters used in the study are as listedinthebelowtable Simulation Parameters Value Networ Area 700mx700mNodesnumber 30 60 ,90 , 120 Type of traffic CBR/UDP Number of Flows 5 Size of packet 1500Bytes MACProtocol IEEE802.11b DateRate 11Mbps Frequency 2.5GHz
Propagation Model Two-RayGround Transmission Power 281mWAntenna Omni-Directional Simulation Time 200s AODV and OLSR performance comparison was done by varyingtraffic,network size, and mobility. Their comparison is given basedontheselected evaluation metrics. A 95% confidence interval was usedtoprove observation of the sample variation among the twoprotocolscalculated. The below formula was used It can be concluded that there is a decrease in performanceforbothprotocols as load increase. That is why the packet delivery ratedecreaseas the packet loss rate increase for both protocals Based on the result it can be said that, OLSR overhead areminimal forminimal topologies, nevertheless performance of OLSRoverheadaresuggestively reduced by larger topologies. This result increationsnooping within network hence leading to packets loss. Onthecontrary,AODV generates minimal overhead significantly causing littlecollisiondespite the topologies being large therefore attaining better PDR.
Conclusion To conclude, MANET has play an imperative role inautomatingcommunication. MANET are imperatively used in combat groundcommunication, rescue operation and damaging recoverywhenthewired network is inaccessible. To effectively do that variousroutingprotocols have been developed to produce adequate performanceofadhoc network. Mobile ad hoc network routing has thereforebecategorized into hybrid routing, reactive routing and proactiverouting.The below figure shows the classification. The major functionofproactive protocol is to minimize latency of message producedbyroutediscovery, it does so by ensuring maintenance of up to dateroutingdatafrom respectively node to another at all times. This is achievedthroughbroadcast of control packets containing routing table information. Onthe other hand, reactive protocol is an upgrade of proactiveanditisintended to allow minimization of sequence number of theneededbroadcast through creation of routes only on demand basis. It usesademand mechanism to carry out a route discovery procedure. Original Source: https://myassignmenthelp.com/free- samples/comp7055-mobile-and-wireless-networks/proactive-and- reactive-routing-file-A1E62A9.html