Utility-based fair bandwidth sharing in vehicular networks

The time-constraint data traffic is very common in vehicle-toinfrastructure (V2I) and vehicle-to-vehicle (V2V) communications. Time-constraint flows are those who have fixed start and stop times and try to maximize the transferred data volume during the limited connection time. From the view of users, the total data transmitted by each flow should be proportional to each one's holding time if the network resources are allocated fairly. However, we find that the traditional fairness concept solely based on flow rates is not suitable for this scenario. Therefore, we redefine the fairness concept regarding the application utility for time-constraint flows. According to this utility-based fairness definition, we propose a new practical bandwidth sharing scheme using TCP parameter tuning for transferring data with fast-moving wireless nodes such as vehicles. Simulations through ns-2 show that the proposed algorithm can achieve better utility fairness than the standard TCP and it is also friendly to TCP in the long term.