QoS aware distributed dynamic channel allocation for V2V communication in TVWS spectrum

Abstract

Vehicles use Dedicated Short Range Communication (DSRC) standard for communicating among themselves. But, with the increased number of on-road vehicles, DSRC channels get congested. So, an alternative to DSRC needs to be introduced, to meet the diverse demand for various vehicular applications. Federal Communication Commission released TV White Space (TVWS) for dynamic spectrum access. These TVWS channels has the potential to be used for Vehicle-to-Vehicle (V2V) communication. However, the vehicles are highly mobile and communicate in an adhoc manner. Thus, employing TVWS in V2V communication requires efficient optimized channel allocation technique. In this work, a distributed joint channel and power allocation technique is devised, that considers both spatio-temporal change of TVWS availability and vehicular mobility. The channels are allocated based on user's transmission requirement with an adjusted power level such that significant interference is not caused to neighbouring primary users and other secondary users, transmitting in the same channel. Multiple vehicles are assigned a single channel using the proposed optimization technique to increase the system throughput. Vehicles are enabled with cognitive facility that allows them to sense the spectrum availability instead of relying on the geo-location TVWS database. The optimized channel and power allocation problem is a Mixed Integer Non-Linear Programming model which is solved using Lagrange's dual method. Simulation analysis shows that proposed optimization technique achieves high throughput while maintaining the network's QoS.