Abstract: Connected and Autonomous Vehicles (CAVs) is becoming more and more popular for automobile academic and industry community. Communication mechanisms play an important role in CAVs applications and services. However, lack of detailed comparison of different communication mechanisms is the main obstacle for the deployment of CAVs applications and services. In this paper, we set up an end-to-end prototype which supports WiFi, LTE, and DSRC based communications and evaluate the performance in latency, power dissipation, and system utilization. Three observations are summarized for the real deployment of VEC applications.