Testing of Vehicular Traffic Monitoring Technique by Using WIFI Packet Measurement in Software-defined Wireless Mesh Network

The popularity of wireless mesh network (WMN) systems grows rapidly with its main usefulness to expand the coverage of wireless communication without wired-based infrastructures. Together with software-defined networking, WMN can be programmed and adapted to dynamic wireless environments. Software-defined wireless mesh network (SDWMN) gets therefore increasing attentions in networking research as well as network-centric application communities. In this paper, SDWMN has been designed as the main underlying platform that allows sensor nodes installed on the road to relay their sensed data. Particularly, this research is concerned with the development of vehicular traffic monitoring technique that can sense the presence of vehicles passing by the SDWMN sensor nodes. Since the penetration of vehicles equipped with WIFI devices is significantly increased, a WIFI packet measurement application has been developed for each SDWMN node to detect the service set identifier (SSID) of the wireless communication for monitoring the vehicle traffic. Each traveling vehicle that provides SSID can be sensed by each SDWMN node along with the corresponding time stamp. A functionality has then been developed to map the raw sensor data to obtain the travel time of vehicles. This technique has been developed on a real SDWMN system testbed and its functionality is tested on Phayathai road in Bangkok, Thailand. The obtained experimental results suggest the practicality of this vehicular traffic monitoring technique with up to 5,000 data records obtainable per sensor node per day. With continuously growing number of WIFI-equipped vehicles, it is believed that the proposed technique can be used cost-effectively to provide real-time vehicular traffic conditions in the future without cost burdens from other conventional vehicular traffic sensors requiring highly costed communication infrastructures.