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چكيده انگليسي :

Analysis of Geocast Routing Protocol in Vehicular Ad Hoc Networks Zeinab Rezaiefar z rezaiefar@ec iut ac ir Date of Submission 2012 03 6 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Dr F Hndessi hendessi@cc iut ac irAbstract The sharp increase of vehicles in recent years has made driving more challenging and dangerous Forsafe driving leading car manufacturers have been jointly working with national government agencies todevelop solutions to help drivers anticipate hazardous events and avoid traffic jams One of the recentoutcomes is a novel wireless architecture called wireless access for the vehicular environment WAVE thatprovides short range intervehicular communications to enable fast dissemination of emergency relatedmessages To reap the benefits of inter vehicle communication in a short time with minimal investment useof vehicular ad hoc networks VANETs is envisioned VANETs represent a particularly challenging classof MANETs that do not rely on fixed infrastructure for communication In MANETs the mobility of nodescan cause frequent topology changes which makes routing a significant challenge Most of the on demandrouting algorithms proposed for MANETs are not suitable for VANETs Their distinct characteristics suchas high node speeds constrained mobility causes to need employing relevant routing protocols that areproportional to their features A number of safety application accident and non urgent safety applications like road block and high traffic density require communications to a group of vehicles not just pair wisecommunications supported by unicast protocols Thus for these applications multicast or broadcastprotocols are more appropriate than unicast protocols In addition in some applications it may not beessential to address the message to particular nodes Instead information should be sent to all vehicles inspecial region Geocast is a kind of conventional multicast defining destination as specific region Thenodes inside this region are member of the geocast group While the major objective is to improve theoverall safety of vehicular traffic industry laboratories and academia have been exploring novel vehicularapplications such as traffic management and onboard entertainment Emerging vehicular applications oftennecessitate wide area coverage using multi hop routing protocols which is a major departure from safetyapplications that require only local coverage therefore overhead is important parameter in theseapplications In this research we analyze Geocast routing protocol in VANET networks and three newGeocast routing protocols have been proposed based on AODV to reduce overheading of networks for thatapplications They transfer data to destination region unicastly and flooding is just used inside destinationregion AODV protocol is a reactive routing protocol based on distance vector principle AODV is ondemand routing protocol i e when source node wants to send data packets to a destination finds a path andmaintains this path during its utilization In spite of flooding protocol that broadcasts data packets to findpath toward destination in AODV protocol only control packets are broadcast to find the path and then datapackets are sent on this path unicastly therefore it decreaces overhead in sending data packets We userateless coding in proposed algorithms to ensure reliability To compare with AODV based proposedalgorithms we also propose a Geocast routing protocol based on flooding with using rateless coding to sendmessages to destination region Finally we present simulations for some city scenarios to compare delay overhead and number of recived messages of the proposed approaches with each other Keywords Vehicular Ad Hoc Network MANET Geocast AODV Rateless coding

رضايي فر، زينب

بررسي پروتكل هاي مسيريابي چندپخشي ناحيه اي درشبكه هاي اقتضايي بين خودرويي

منطقه پخشي , پروتكلAOdV , كدگذاري بدون نرخ