Implementation and analysis of traffic safety protocols based on ETSI Standard

The European Telecommunications Standards Institute (ETSI) standard has defined the Basic Set of Applications (BSA) which is composed of three main application classes road/traffic safety, traffic efficiency, and other value-added applications. Traffic safety applications strongly rely on the exchange of two types of safety messages that have been standardized by ETSI namely Cooperative Awareness Messages (CAMs) and Decentralized Environmental Notification Messages (DENMs). The ETSI's comprehensive and well documented standards present the structures and implementations guidelines of these safety messages yet there is lack of extensive work on the implementation and validation. Therefore, this paper presents a comprehensive architecture and implementation that has been developed to validate the potentials of CAM and DENM messaging capabilities. This paper evaluates the performance of CAM and DENM facilities through a custom IEEE 802.11p (ITS-G5) based prototype (IT2S) deployed in a field trial. The tests validates the CAM performance by tracking vehicles and various performance indicators such the packet error rate (PER), Received Signal strength (RSSI), connection distance between the OBUs and RSU, number of messages transmitted, GPS coordinates and successful packets received. Similarly, DENMs are validated by events such as traffic information, hazardous location and accidents. These tests motivate towards the unified solution for the implementation of a complete ITS.