A New Hierarchical and Adaptive Protocol for Minimum-Delay V2V Communication

The majority of vehicle-to-vehicle (V2V) protocols presented in the literature utilize a combination of controlled access techniques (e.g., TDMA, FDMA, CDMA) to provide prioritized access to the communication medium. While these protocols split the capacity of the communication link to support a maximum number of users with different priority levels, our work utilizes a combination of CDMA and TDMA techniques to increase the number of concurrent users sharing the bandwidth. The proposed protocol provides an adaptive scheme that classifies the vehicle\´s messages as "urgent" or "non-urgent" based on its statistical parameters (e.g., speed, acceleration, directional stability) and the state of its neighboring vehicles (e.g., normal or urgent) . Furthermore, the proposed protocol achieves intelligent scheduling and allocation of messages and the underlying bandwidth to minimize the end-to-end communication delay and the costs associated with the deployment of vehicle infrastructure integration (VII) without the need for road-side equipment.