Network systems provider Nokia, the Fraunhofer Institute for Embedded Systems and Communications Technology (Fraunhofer ESK) and Smart Mobile Labs are developing a concept to relay safety-critical data very quickly to vehicles within the V2X scheme, utilising LTE mobile radio networks. At the recent ITS World Congress in Detroit, the group proved the feasibility of such an approach by transmitting braking alert messages of a driving vehicle to other traffic participants over an LTE network. "Thanks to very low signal propagation delay and its widely available infrastructure, LTE can complement other technologies and help to introduce the V2X (also known as C2X) technology faster to the market", says Dirk Lindemeier, Head of Liquid Applications at Nokia Networks.
Hitherto, LTE was regarded as a potential technology for infotainment connectivity in the first place. The collaboration between Fraunhofer ESK and the other two project partners however aims clearly to safety-related applications, said Karsten Roscher, project manager Car2X Hybrid at Fraunhofer ESK. The innovative approach in this context is to relay time-critical messages directly from base station to base station instead implement them on a backend server or even in the cloud.
At the trials, the group used real vehicles as well as a vehicle simulator which was equipped with an on-board unit transmitting real-time brake warnings over an LTE connection. In the base station, the Radio Applications Cloud Server developed by Nokia processed these data telegrams and relayed it to other stations instead of sending them to the backbone infrastructure. Through this measure, transfer times of 20 to 50 milliseconds were realised - significantly faster than human response time. The systems integration was done by Smart Mobile Labs which also developed a test app.
The successful test makes LTE available (at the technology level) for V2X applications. So far, the V2X world was based primarily on the ETSI ITS-G5 wireless technology, a European standard closely related to its international variant IEEE 802.11p. Both