الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Vehicular Ad hoc Network (VANET) aims to support safety, traffic monitoring and comfort related services. Though functioning of the network closely resembles with that of MANET, its high speed mobility and unpredictable movement characteristics are the key contrasting feature from that of MANET. This similarity nature suggests that the prevailing routing protocol of MANET is very much applicable to VANET. However, on the same line, the dissimilarity characteristic resulted in frequent loss of connectivity. This necessitates upgrade of the existing routing protocol to adapt itself into VANET scenario. The key parameter that needs to be fed into these protocols is a realistic mobility model which contains criterion linked to speed, road intersections, traffic light effect, etc. this thesis investigates different ad hoc routing protocols for VANET. The thesis aims to adapt Ad hoc On-demand Multipath Distance Vector (AOMDV) routing protocol for highly mobile environment of VANET.
The thesis proposes SD-AOMDV as VANET routing protocol. SD-AOMDV is an adaptive version of AOMDV to suit VANET characteristics. It adds the mobility parameters: speed and direction to hop count as new AOMDV routing metric to select next hop during the rout discovery phase. Extensive simulation study shows that SD-AOMDV has a better ability to handle high mobility of vehicles by finding much more stable paths than AOMDV. It gives good average delay and packet delivery fraction in highway and city scenarios. However it has high normalized routing load due to considering speed and direction in its routing decision.
As a solution to this problem, the thesis proposes SW-AOMDV routing protocol that dynamically switches between AOMDV and SD-AOMDV based on roads traffic condition. In some mobility patterns where vehicles are moving with the same speed and direction, we don‟t have to consider speed and direction in routing decision. SW-AOMDV proposes that AOMDV has better performance than SD-AOMDV when most of neighbor‟s nodes move in the same direction with minimum speed differences (relative static to each other). Simulation results show that SW-AOMDV reduces the overall network routing overhead and achieves good results with average delay and packet delivery fraction.
Finally the thesis also proposes SSD-AOMDV as VANET routing protocol. It adds the mobility parameters: stop times, speed and direction to hop count as new AOMDV
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routing metric to select next hop during the rout discovery phase. Stop_times metric is added to simulate buses mobility pattern and traffic lights at intersections.
Simulation results show that SSD-AOMDV has outperformed AOMDV in different traffic scenarios with different percentages of periodically stopped nodes that simulate buses mobility pattern.