الفهرس 
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Abstract
Vehicular Adhoc networks VANETs are going to be an important communication infraarchitecture in our life, as it has tremendous potential to enhance vehicle and road safety, traffic
facility, and convenience as well as comfort to the drivers and passengers. They are considered as a subclass of mobile Adhoc networks (MANET). In these networks, the nodes are vehicles
themselves by which the network is formed and deformed. VANETs turn each participating car into a wireless router or node, enabling cars around 100 to 300 meters of each other to
connect and, in turn, establish a network with a wide range. As cars fall out of the signal range
and DROP out of the network, additional cars can join in, so an Adhoc vehicular network is constructed. Because nodes move with high velocity in VANETs, and the channel condition of
each link is highly error-prone due to the reflection of tall buildings and obstacles along the road and interference from additional sources (e.g. Wi-Fi hotspots), the network topology of VANETs could be highly continually changing, which means frequent link disconnection may
happen. This makes it difficult to group up a robust pathway between the source and the target in VANETs.
To solve resulted problems of termination and link disconnection between out of range mediums, various routing techniques are employed for continuous communication manageability purposes. The main objective of this thesis is to propose a new routing technique to overcome the
problems of high-density VANET networks. To achieve this objective, a comparative study for the recently used routing techniques is carried out for network density (50 – 450 nodes). The
four selected routing techniques are Destination-Sequenced Distance Vector (DSDV) - Ad-hoc On-demand Multipath way Distance-vector (AOMDV) - Dynamic Source Routing (DSR) - Ad-hoc On-demand Distance-vector - (AODV).
The performance of these protocols is measured using the Average throughput, Packet delivery ratio, and Packet Loss evaluation metrics. The analysis of the comparison results proves that AODV has the best throughput for the specified network density (50-450 nodes).
Also, the DSDV protocol fails to respond when the number of nodes exceeds 250. This thesis proposes a new routing technique combining both AODV & AOMDV to manage
communications in high-density VANETs. Then, the performance of the proposed routing technique is measured using the same evaluation parameters. The analysis of the results of applying the proposed routing technique proves that average throughput and packet delivery ratio are improved when using the proposed technique than that gained using AODV or AOMDV individually.