Mathematical Modeling of Channel Load in Vehicle Safety Communications

Vehicle safety communications research is rapidly advancing in Europe and the U.S. from proof of concept to large scale field testing. Congestion control is a key challenge facing the current efforts to develop a deployable system able to function properly once the penetration rate reaches a high level. This paper focuses on how channel load forms in the context of vehicle safety communications. How a transmitting vehicle contributes to channel load is described mathematically. It is then shown that load contributions from all transmitting vehicles can be aggregated to give a complete picture of channel load at all positions on the road. This paper provides a very efficient method to quantitatively analyze channel load given an input of RF model, vehicle distribution and each vehicle's transmission behavior.