# Wireless Communication Technologies for Safe Cooperative Cyber Physical Systems
## 2 Technical Background
### SafeCOP Use Cases
#### Vehicular Applications
In addition, a wireless network of in-vehicle sensors and actuators is exchanging data with the on-board unit to inform about the status of different automotive systems. * Vehicles and Roadside Unit (RSU) interaction This use case has been built upon the data exchange between the roadside road weather station and a passing vehicle. Road weather stations (RWS) are typically installed to fixed  
Figure 3: Vehicle control loss warning. locations beside the road, collecting different measurement parameters related to weather and traffic, and delivering this data to a single data collection point, typically being the road administrator. Within its operative RWS and vehicular measurement entity, FMI demonstrates this operational environment [49]. During the RWS pass, the vehicle receives up-to-date local road weather information. As an exchange, vehicle can also deliver its own observational information back to RWS, to be used as local supporting data in meteorological services. In this vehicle-roadside unit interaction, we must ensure that the delivered data is not altered or violated by a third party or some communication malfunctioning. The primary scenario in this use case is data exchange between vehicle and RWS, when and where the vehicle is passing the RWS. The basic scenario is introduced in [50]. This scenario is extended to cover also data exchange between two vehicles (scenario 2). In this case, both vehicles share the data received from the latest RWS, and as a result both vehicles will obtain up-to-date road weather data from the area ahead. The communication in this scenario is naturally local area communication. In the final extension (scenario 3), we employ an IoT cloud as communication entity, and instead of direct data exchanges between vehicles and RWSs, the IoT cloud shares the location-based relevant data with vehicles and RWSs. The architecture of these resulting three scenarios are presented in Figure 4. A vehicle and a roadside unit are participating in the first scenario (vehicle-to-infrastructure), two vehicles in the second scenario (vehicle-to-vehicle) and, finally, a service provider, a vehicle and a roadside unit to the final (third) IoT-cloud scenario. * V2I Cooperation for Traffic Management This use case aims at providing an innovative platform that integrates into the V2I network both traffic management (TM) and Video Content Analysis (VCA) functionalities, as shown in Figure 5. VCA consists in the acquisition from video cameras (referred to as RSU-C in Figure 5) and subsequent elaboration through appropriate algorithms. Active road safety  
Figure 4: Operational structure of the use case ”Vehicles and Roadside Unit (RSU) interaction” with communication to the cloud using 3G/4G, and IEEE 802.11p and 3G/4G for communication between vehicles and roadside units. (ARS) programmes will strongly benefit from this integration, which enables, via VCA, the early-detection of possible dangerous road events/situations (e.g., vehicles slowing down, vehicles queue, motionless objects) and, via TM applications, the fast drivers' alert of such traffic anomalies [51; 52]. The probability of traffic accidents will decrease by providing assistance to drivers exploiting both ARS (e.g., collision avoidance systems) and other management applications, like Adaptive Traffic Light Systems (A-TLSs) and dedicated wireless sensor networks (WSNs). A-TLSs change the traffic lights signaling plan (the duration of red, yellow and green phases) according to a set of control parameters, e.g., the time and the day. A-TLS improvements enabled by VCA allow the optimization of the signaling plan according to the changing traffic conditions, usually by extending the green phase when vehicles are closely spaced. Figure 6 shows the architecture of the envisaged system. It integrates several SafeCOP framework components, including runtime mechanisms for safety assurance and distributed safety-critical cooperation techniques (based on extensions to IEEE 802.11p), into a Traffic Management Application, which runs in a distributed way.