Low-Latency Transmission and Caching of High Definition Map at a Crossroad

Abstract

High definition (HD) map attracts more and more attention of researchers and map operators in recent years and has become an indispensable part for autonomous or assistant driving. Different from existing navigation map, HD map has the features of high precision, large-volume data and real-time update. Therefore, the real-time HD map transmission to the vehicles becomes one main challenge in vehicular networks. This paper considers the scenario that a RSU at the crossroad caches and transmits HD maps to its covered vehicles in four directions. To reduce the average delay of HD map delivery, the transmission power allocation for vehicles and the cache allocation for HD maps of different road segments are optimized by leveraging the traffic density and vehicle positions. Simulation results indicate that the proposed scheme has lower latency than that of equal power allocation scheme based on real traffic data.