The objective of NOW is to specify and standardise a communication system for transmission of sensor data und further information between vehicles. The system is demonstrated in a reference implementation conducted by several German car manufacturers. Like warning calls in nature, the transmission of sensor data allow the driver's horizon of perception to be extended, which minimizes the risk of accidents. In the past, it has been shown that a system relying solely on active safety applications is not able to enter the market successfully. Therefore, the system to be specified must also support internet applications between vehicles and stationary units that have an immediate user benefit at low equipment rates.