This paper proposes a suitable scalability principle for each major vehicular communication scenario: periodic safety broadcasts, event-driven safety broadcasts, and unicast message forwarding. Each scenario section investigates an appropriate design of individual congestion control tools for the implementation of related scalability principle.

Estimating channel utilization at beaconing edge is important, so that power control feedback can be based on comparing this utilization rate to a target level. The beaconing edge channel utilization estimate presented in the ‘Resource Sharing Principles for Vehicular Communications’ paper is revised with the following aspects; taking an estimate of link asymmetry into account, interpolating on link attenuation metric instead of distance metric.

This paper proposes a timing algorithm for assignment of beacon transmissions. The proposed geographically derived beacon timer solves the problem of ‘hidden-terminal’ packet collisions for periodic broadcasts and certain unicast messages, regardless of particular road network topology details.