Communication protocols in FRIEND: A cyber-physical system for traffic Flow Related Information Aggregation and Dissemination

In this paper, we explain in depth the communication protocols between different components of FRIEND: a cyber-physical system for traffic Flow-Related Information aggrEgatioN and Dissemination. Recall that FRIEND (which has been introduced in pervious work, by integrating resources and capabilities at the nexus between the cyber and physical worlds, FRIEND will contribute to aggregating traffic flow data collected by the huge fleet of vehicles on our roads into a comprehensive, near real-time synopsis of traffic flow conditions). The main goal of this paper is to discuss the communication protocols employed by various entities in FRIEND. We discuss one of the most fundamental issues in computer networking, which is how two entities can reliably communicate. We start by introducing notation and by establishing terminology that will be used. Then, we discuss how the Road Side Units (RSUs) communicate with different other entities in FRIEND. Also, how data exchange occurs between RSUs and other entities. Then, we explain the communication between Smart Cat´s Eyes (SCEs) and other FRIEND entities.