A D2D-based Delay Optimization Method in VANET

In vehicular ad-hoc network (VANET), the standardized protocol currently is IEEE 802.11p. To reduce the end-to-end delays including store-and-catch-up (SAC) and channel access competition delays generated by IEEE 802.11p, in this paper device-to-device (D2D) communication over the cellular band is introduced, then a hybrid system combined D2D and IEEE 802.11p is proposed, finally a D2D spectrum allocation algorithm based on the hybrid system is present. Simulation results demonstrate the superiority of the proposed algorithm under different scenarios and parameter settings.