Increased Persistence of Wi-Fi Direct Networks for Smartphone-based Collision Avoidance

Inter-vehicular communication is a promising technology to improve road safety. Inter-vehicular communication over a wireless medium can be used to exchange important information such as the speed, location, and headings of a vehicle with nearby vehicles. Using this information, it is possible to calculate if a collision is imminent and warn the driver to take action. Wi-Fi can also be used to share this information, however it requires an access point hardware to facilitate communication. Wi-Fi Direct enabled devices can share information without a hardware access point. Wi-Fi Direct provides peer to peer communication by employing a software defined access point embedded within the system. Wi-Fi Direct is a technology that is present on many smart phones, eliminating the need for dedicated access point hardware. In collision avoidance application, Wi-Fi Direct maybe used to exchange safety-related information between vehicles. Collision avoidance systems developed using smartphones can also be extended to protecting pedestrians carrying a smartphone and in this role they could be a long-term solution for certain vulnerable road user collision scenarios. Smartphones with Wi-Fi Direct capability could provide a path to early, low-cost implementation of inter-vehicle communication for collision avoidance. However, there are many limitations to such a system that are addressed in this thesis. Wi-Fi Direct functions by creating groups. One of the nodes in the group is elected as the group owner that acts as an access point and manages the communication between the nodes within the group. If the group owner moves out of range, reforming the group is a lengthy process. This thesis proposes a new method for nomination of the group owner to reduce the likelihood that the group owner will move out of range. This thesis introduces the concept of nominating a Backup Group Owner that can quickly replace the group owner if the group owner shuts down or moves out of range of the group. An orderly handoff from the group owner to the Backup Group Owner can prevent loss of communication among nodes. An analytical study of the amount of time saved by adopting the proposed method of electing the BGO is presented