© 2017 Abdallah Rhattoy, Mohamed Lahmer and Idriss Chana. This open access article is distributed under a Creative Commons Attribution (CC-BY) 3.0 license. Journal of Computer Science Original Research Paper Impact of the Smart City Architecture, Speed and Traffic Density of Vehicles on the Performances of Vanets Abdallah Rhattoy, Mohamed Lahmer and Idriss Chana Department of Computer, Information and Communication Systems Engineering Research Group, Moulay Ismail University, Higher School of Technology, B.P. 3103, 50000, Toulal, Meknes, Morocco Corresponding Author: Abdallah Rhattoy Department of Computer, Information and Communication Systems Engineering Research Group, Moulay Ismail University, Higher School of Technology, B.P. 3103, 50000, Toulal, Meknes, Morocco Email: rhattoy@gmail.com Abstract: Vehicular Ad-hoc Networks (VANET) is one of the emerging and actual research fields in automotive companies and Intelligent Transportation Systems (ITS) designers. In the Smart City the presence of such networks opens the way for a wide range of applications such as safety applications, mobility and connectivity for both driver and passengers to exploit the transport systems in a smoothly efficiently and safer way. The 802.11p is a draft amendment to the IEEE 802.11 standard for vehicular communications. VANET are characterized by a dynamic topology triggered by the vehiculars mobility. In the Smart City the main problems of inter-vehicle communication are the speed, density of vehicles and the size of the buildings. For this purpose, we first examine and then display the simulation findings of the impact of different radio propagation models on the performance of vehicular ad hoc networks in terms of the characteristics of the physical layer. In our study, we have compared the performances of two routing protocols (AODV and OLSR) for three propagation model (two- Ray ground, Rice and Nakagami). We study those protocols under varying metrics such as Traffic density, Smart City Architecture (size of the scenario areas) and the mobility of vehicle. Our objective is to provide a qualitative assessment of the protocols applicability in different vehicular scenarios. These two routing protocols are simulated and compared with Network Simulator-2 under Manhattan Grid Mobility Model. To conclude, the simulation findings are to be taken as a strong reference on the three routing protocols behaviour; however, it shouldn’t be considered as an exact representation of its behaviour and real environment because of several simulation constraints such as: the dimension of movement field of vehiculars, the traffic type and the simulation timing. Keywords: Smart City, Routing Protocols, OLSR, AODV, VANET Introduction Vehicular AdHoc Networks (VANETs) are consisting of a number of vehicles traveling on urban streets, capable of communicating with each other (Delgrossi, 2014). The development of VANETs is backed by strong economical interests since Vehicle-to- Vehicle (V2V) communication allows sharing the wireless channel for mobile applications, to improve route planning, to control traffic congestion, or to improve traffic safety. Moreover, communication between vehicles depends on several parameters such as the transmission power, the propagation environment of the waves and the frequency used also play an important. The wave’s propagation obeyed strict rules, especially in the case of obstacles between the transmitter and the receiver (Rhattoy et al., 2008). Among the changes a wave may undergo, we can cite: reflection, diffraction, diffusion and absorption. One key component of VANET simulations is the movement pattern of vehicles, also called the mobility model. Mobility models determine the location of nodes in the topology at any given instant, which strongly affects network connectivity and throughput. This paper is organized as follows. To approach the architecture of the city such as roads, signal fires, buildings and other obstacles in urban areas, we give three types of radio propagation models. Next, we