Vehicular Ad Hoc network is a versatile mobile wireless Ad-Hoc network targeted to support traffic monitoring, vehicular safety and many more applications. For the robust and reliable services in the VANET there is need to investigate the performance under frequent handovers in Mobile IP to prevent packet loss. Mobile IP is an interface that helps to track the mobile nodes and deliver messages even if vehicles are out of the coverage area of home node. In order to find the achievable performance bounds in terms of throughput, packet drop, collision rate and packet broadcast rate, extensive simulations have been done. A realistic city scenario has been proposed here by using the Rayleigh channel simulator, mobile IP enabled IEEE 802.11p OBUs and RSUs. The transmission powers of RSUs and threshold power levels have been varied to obtain the optimum performance through realistic conditions. Simulations are performed using NCTUns6.0 (National Chiao Tung University Network Simulator) in mobile IP interface.

VANET deployment in real world has become a living reality by the successful allotment of 5.9GHz to Dedicated Short Range Communication (DSRC) by WLAN technologies. Dynamically changing topology and establishment of reliable path between nodes with minimum bandwidth consumption and lesser routing overheads are the main aims of ad- hoc network routing. To exploit effective and reliable communication among vehicles routing is a major factor which needs to be investigated. This paper intends to evaluate the performance of AODV and GOD routing protocols in city scenario under different application types and different fading environment using IEEE 802.11b MAC standard. Simulations are performed using NCTUns 6.0 (National Chung Tung University Network Simulator) and found that AODV performance is better in fading channel even if we increase rician factor. Also the performance of GOD is better in ideal fading (AWGN) channel, although the performance of routing protocols vary from one scenario to other and application traffic.