Vehicular Ad-Hoc Network (VANET) is an emerging technology, which provides intelligent communication between mobile vehicles. Integrating VANET with Ubiquitous Sensor Networks (USN) has a great potential to improve road safety and traffic efficiency. Most VANET applications are applied in real time and they are sensitive to delay, especially those related to safety and health. Therefore, checking the applicability of any proposed application is very important. One way to achieve that is by calculating the Round Trip Time (RTT), which is the time taken by a VANET application starting from the initiator node (source vehicle) sending a message until receiving a response from the core network. In this paper, we present a new complete analytical model to calculate the RTT of VANET applications. Moreover, we introduce a novel detailed network architecture for VANET applications using the IP Multimedia Subsystem (IMS) as a service controller in the USN environment. To the best of our knowledge, there is no previous published work that either studied the RTT of VANET applications or developed a complete architecture to implement them by integrating VANETs with USNs and IMS. The RTT is calculated by combining two analytical models. Firstly, we developed an analytical model to calculate the time needed for the communication between two nodes on a road. Secondly, we developed a queuing model using Baskett Chandy Muntz Palacios (BCMP) queuing network for the IMS servers to calculate the application's execution time in the core network. These models are general enough to be applied to any VANET application. Finally, to assess the validity and the accuracy of the proposed architecture and models, we used three different tools: C++, MATLAB, and OPNET. The analytical results were compared to the simulation results to evaluate their consistency.
['Adel Mounir Sareh Said', 'Michel Marot', 'Ashraf William Ibrahim', 'Hossam Afifi']
Modeling interactive real-time applications in VANETs with performance evaluation