Influenced by Wi-Fi signal interference, Shenzhen subway is forced to stop frequently, which has caused enormous safety hazard. This paper proposes a method to test the interference transferred from Wi-Fi signals to the Communication Based Train Control (CBTC) systems, then the testing data are collected and analysed. The test is aim to two signal transmission modes: free wave and leaky cable. The test result shows that the signal transmission mode of leaky cable is more reliable, while the transmission mode of free wave has the worse anti-interference capability to Wi-Fi signals. Particularly, it is an effective way to apply for specific frequency bands, which will make a contribution to reducing the interference effect on the CBTC systems caused by Wi-Fi signals.

By analyzing the demand of traffic simulation of I-VICS (Intelligent Vehicle Infrastructure Cooperative System) and the information communicating of vehicle-to-vehicle and vehicle-to-road, a traffic simulation platform is designed based on I-VICS. Firstly, a traffic simulation platform design method is proposed based on the HLA simulation platform. Then, a road matching method is used to gather the exact position of the vehicle to improve the efficiency of the cases. Thirdly, according to the hierarchical decomposition and location constraints, this paper gives the simulation scene optimization method, and gives the number of vehicles which are not executing cases based on different simulation step. At last, two different scenes are simulated on the platform to compare the average travel time and average delay which indicate feasibility and practicality respectively.

Vehicular Ad-hoc network (VANET) is a promising technology in enabling highway active safety applications such as collision warning and information broadcasting. Nowadays, VANET is extended to offer more services like vehicle tracking, WI-FI access, and Global Positioning System (GPS) services. However, there`s still serious challenges in enabling information disseminated while avoiding broadcast storm. In this paper, we develop an HLA Federation with two federates to evaluate the VANET performance with or without Road-side Unit (RSU) in the same scenarios. We use OPNET Modeler to evaluate the performance of VANET and use Paramics to set the trajectory of vehicle node in OPNET Modeler and find out the improvement of communication quality brought by RSU.