• Ross Gotfredsen posted an update 3 days, 16 hours ago

    Among the reviewed applications, TOCADAS and CADAS systems act upon detecting the risk of collision. Similarly, Road-Accident, CAGFP, and IR-CAS ACN systems perform action after detecting an accident. DBD system starts action once it order Prostaglandin E2 detects the abnormal behavior of the driver. In Overtaking system, when the driver\’s intent to overtake is perceived, the driving scene is analyzed and the reasoning process gets initiated. In CAISA system, the vehicle\’s acceleration is controlled as the gears are switched. When the driver switches gears, the current revolution of the engine is compared with the engine\’s max revolution, and regulated as required. Similarly, Gas-Station system initiates to act when the fuel level of the vehicle has considerably decreased by indicating the available cheap gas stations. Finally, CFMS system acts whenever the user reports breakdown or an accident to the central server.7. Prominent projects review: context-awarenessSince context-awareness is an important aspect of the VANET applications, we devote the third dimension to it. This dimension includes the parameters of “context type” and “context gathering method”, as follows:7.1. Context typeContext-aware applications in vehicular network are based on contextual information. In other words, each application relies on particular context types. Before investigating the required contextual information of the projects, we generally categorize context in transportation domain into four groups including “local”, “external”, “general-related to transportation”, and “general-unrelated to transportation”. Afterward, we review the required context elements of the projects according to the categorization.? Local context: This type of context information describes a local entity, i.e., the driver or his vehicle. Such context information as the location, speed, and acceleration of the vehicle, and the driver\’s age and gender are considered as local contextual information. All of applications use local context information except for TCE system. Some of the local context including speed, acceleration, location, direction, and distance to neighboring vehicles or objects are used by most of the applications. For instance, the vehicle\’s speed and acceleration are used by TOCADAS, Road-Accident, DBD, Electric-Vehicle, CAGFP, Overtaking, CADAS, IDB, CAISA, and CATE. Similarly, the location of the vehicle is utilized by On-Street-Parking, Road-Accident, DBD, CAGFP, Gas-Station, IDB, CAPM, CFMS, and CAISA. Other local context including type and size of the vehicle, mass and frontal area of the vehicle, the vehicle\’s number, behavior and sleepiness of the driver, and type and level of the vehicle\’s fuel are rarely used. For example, the context information of type and size of the vehicle is used by On-Street-Parking system, the mass and frontal area of the vehicle is used in Electric-Vehicle system, the type of fuel, the level of fuel and amount of fuel consumption are used by Gas-Station system.? External context: This context describes other vehicles or drivers (external nodes) such as the location, speed and acceleration of other vehicles or information about other drivers. From among the studied projects, only a few of them utilized external context; reductional division include CADAS, DBD, CAGFP, Overtaking, and CFMS systems. As elaborated in Table 4, the context information of speed, acceleration, distance, location, and direction of other vehicles are generally used in these applications. Table 4. Context information used by context-aware vehicular applications. Project name Context type Local context External context General-related to transportation General-unrelated to transportation On-Street-Parking[40] Driver profile, vehicle profile, vehicle location, gap space between vehicle and adjacent vehicles in parking space, driver parking preferences, driver parking destination and duration Size and location of the available parking spaces, parking policies, parking prices, serial number and location of InfoStations