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  • 1.Ad Hoc NetworksBYDARPAN DEKIVADIYA 09BCE008DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING AHMEDABAD-382481 April 2011

2. Ad Hoc Networks SeminarSubmitted in partial fulllment of the requirements For the degree ofBachelor of Technology In Computer EngineeringBy DARPAN DEKIVADIYA 09BCE008DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING AHMEDABAD-382481 April 2011 3. CerticateThis is to certify that the Seminar entitled Ad Hoc Networks submitted by DARPANDEKIVADIYA(09BCE008), towards the partial fulllment of the requirements for the degreeof Bachelor of Technology in Computer Engineering of Nirma University of Science andTechnology, Ahmedabad is the record of work carried out by him under my supervision andguidance. In my opinion, the submitted work has reached a level required for being acceptedfor examination. The results embodied in this Seminar, to the best of my knowledge, haventbeen submitted to any other university or institution for award of any degree or diploma. Prof.Vijay UkaniProf. D. J. Patel Assistant Professor,Professor and Head, Dept. of Computer Science & Engg.,Dept. of Computer Science & Engg., Institute of Technology,Institute of Technology, Nirma University, Ahmedabad Nirma University, AhmedabadProf. Manish ChaturvediGuide and Assistant Professor,Institute of Technology,Nirma University, Ahmedabadiii 4. Abstractiv Now a days in the many areas of the network types of the network are used.Ad hocnetwork are one of the network. It is the mobile no de network and which all are connectedwith wireless link.There are many types of the ad hoc network.The most useful ad hocnetwork is in the security purpose.Routing algorithm is same as the wired network but somevariation are made in it.There is two types table-driven and on-demand protocols for therouting in ad hoc network.iv 5. Acknowledgements vI would like to express my heartfelt gratitude to Prof. Manish Chaturvedi,Professor inDepartment of computer science and engineering for her valuable time and guidance thatmade the seminar project work a success. Thanking all my friends and all those who hadhelped me in carrying out this work. I am also indebted to the library resources centre andinterest services that enabled us to ponder over the vast subject of Ad Hoc Networks. - DARPAN DEKIVADIYA 09BCE008v 6. ContentsAbstract ivAcknowledgements v1 Introduction 11.1 Characteristics . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . 21.2 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 Major Issues and Challenges . . . . . . . . . .. . . . . . . . . . . . . . . . . 21.4 Ad Hoc versus Infrastructure based Networks. . . . . . . . . . . . . . . . . 32 Architecture of Ad Hoc Network 42.1 IEE 802.11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.1.1 History . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 42.2 Ad Hoc Mode . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 52.2.1 Medium Access Control Layer . . . . . .. . . . . . . . . . . . . . . . 52.2.2 Basic DFWMAC-DCF using CSMA/CA . . . . . . . . . . . . . . . . 62.2.3 DFWMAC-DCF with RTS/CTS . . . .. . . . . . . . . . . . . . . . 73 Routing In Ad-Hoc Networks 83.1 Requirement of the Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.2 General Issues for Ad Hoc Network Routing . . . . . . . . . . . . . . . . . .94 Routing Protocols104.1 Classication . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 104.1.1 Based on the routing information update mechanism .. . . . . . . . 104.1.2 Based on the use of Temporal information for Routing . . . . . . . . 104.1.3 Based on Routing Topology . . . . . . . . . . . . . . .. . . . . . . . 114.1.4 Based on the Utilization of specic Resources . . . . .. . . . . . . . 114.2 Proactive or table-driven routing protocols . . . . . . . . . . .. . . . . . . . 114.2.1 Destination sequenced distance-vector protocol . . . . . . . . . . . . . 114.2.2 Wireless routing protocol . . . . . . . . . . . . . . . . .. . . . . . . . 134.2.3 Cluster head Gateway Switch Routing protocol . . . . . . . . . . . . 144.3 On-Demand routing protocols . . . . . . . . . . . . . . . . . .. . . . . . . . 154.3.1 Dynamic Source Routing Protocol . . . . . . . . . . . .. . . . . . . . 154.3.2 Ad Hoc On-Demand Distance Vector Routing Protocol. . . . . . . . 174.4 Hybrid routing protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194.4.1 Zone Routing Protocol . . . . . . . . . . . . . . . . . .. . . . . . . . 19 vi 7. Chapter 1IntroductionIn computer networking, an Ad Hoc Network refers to a network connection establishedfor a single session and does not require a router or a wireless base station.Mobile nodes that are within each others radio range communicate directly via wirelesslinks that. Here mobile nodes are cause the dierent topology in the networks.In the above diagram nodes A and D have direct connection between them. In the rstradio station shows that in same radio stations both A and D are directly connected. Butas the show in the second radio station, when nodes d are goes away from the these stationthe connection link was broken between them. But still A and D are connected via nodesA-B-C-D. So this type of networks connections is held in ad hoc networks. So it is widelyused in the military application and other temporary networks. For example, military units(e.g., soldiers, tanks, or planes), equipped with wireless communication devices, could forman ad hoc network when they roam in a battleeld. Ad hoc networks can also be used foremergency, law enforcement, and rescue missions. 1 8. 1.1Characteristics Operating without a central coordinator Multi-hop radio relaying Frequent link breakage due to mobile nodes Constraint resources (bandwidth, computing power, battery lifetime) Instant deployment1.2Applications Military applications Collaborative computing Emergency rescue Mesh networks Wireless sensor networks Multi-hop cellular networks Wireless Community Network1.3Major Issues and Challenges Hidden terminal problem Exposed terminal problem Channel eciency Access delay and fairness Dierential service Realistic mobility modeling power-aware routing Constructing virtual backbone Distinguish contention, packet drop, and noise errors Security Ecient multicasting 2 9. 1.4 Ad Hoc versus Infrastructure based NetworksIn infrastructure based Networks , communication typically takes place only between thewireless nodes and the access point , but not directly between the wireless nodes.Infrastructure Networks contain special nodes called access points(APs), which are con-nected via existing networks. APs are special in the sense that they can interact with wirelessnodes as well as with the existing wired network. The other wireless nodes , also known asmobile stations , communicate via APs. The APs also act as bridges with other networks.Ad hoc LANs do not need any xed infrastructure. These networks can be set up on they at any place. Nodes communicate directly with each other or forward messages throughother nodes that are directly accessible. The design of infrastructure based networks issimpler because most of the network functionality lies within the access point ,whereas theclient can remain quite simple.In Ad hoc networks, the complexity of each node is higher because every node has toimplement medium access mechanisms to provide certain quality of service. Infrastructurebased networks lose some of the exibility which wireless networks can oer. They cannotbe used for disaster relief in cases where no infrastructure is left, where ad hoc networks canbe used.3 10. Chapter 2Architecture of Ad Hoc Network The architecture of ad hoc network can be explained by IEEE 802.11 standards.2.1 IEE 802.11 IEEE 802.11 is a set of IEEE standards that govern wireless networking transmissionmethods.2.1.1History802.11 technology has its origins in a 1985 ruling by the U.S. Federal CommunicationsCommission that released the ISM band for unlicensed use. In 1991 NCR Corporation (nowAlcatel-Lucent and LSI Corporation) invented the precursor to 802.11 in Nieuwegein, TheNetherlands. The inventors initially intended to use the technology for cashier systems; therst wireless products were brought on the market under the name WaveLAN with raw datarates of 1 Mbit/s and 2 Mbit/s.Vic Hayes, who held the chair of IEEE 802.11 for 10 years and has been called thefather of Wi-Fi was involved in designing the initial 802.11b and 802.11a standards withinthe IEEE.In 1992, the Commonwealth Scientic and Industrial Research Organisation (CSIRO)obtained a patent in Australia for a method of wireless data transfer technology based onthe use of Fourier transforms to unsmear the signal. In 1996, CSIRO obtained a patentfor the same technology in the US. In April 2009, 14 tech companies selling Wi-Fi devices,including Dell, HP, Microsoft, Intel, Nintendo, and Toshiba, agreed to pay CSIRO 250 dollorsmillion for infringements on the CSIRO patents Mobile terminals can operate in two modes under IEEE 802.11 : Infrastructure Mode Ad Hoc Mode 4 11. 2.2 Ad Hoc Mode IEEE 802.11 only covers PHY layer and MAC layer PHY layer is subdivided into Physical Layer Convergence Protocol (PLCP) Physical Medium Dependent sub layer (PMD) PHY management include channel tuning and responsible for higher layer functions (e.g.control of bridging). MAC management controls authentication mechanism and power man-agement to save battery power.2.2.1Medium Access Control LayerThe basic servies provided by the MAC layer are the mandatory Asynchronous dataservice and an optional Time bounded service. while 802.11 only oers the Asynchronousdata service in ad-hoc mode,both service types can be oered using an Infrastructure basednetwork.The following three mechanisms for IEEE 802.11 : The mandatory basic method basedon a version of CSMA/CA, an optional method avoiding the hidden

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