Markus Mazzola

Exploration of Centralized Car2X-Systems over LTE

Car2X-Communication is a method for data exchange between vehicles and infrastructure units to increase traffic safety and efficiency. Usually data processing and control is performed within the vehicle i.e decentralized. Centrally organized systems hardly get any attention in latest research, although they have many advantages. Since communication systems are improving, even safety-critical centralized systems become realistic. In this paper we present the technical feasibility of centralized Car2X-Systems based on LTE. Exemplarily, we investigate a Server-based Adaptive Cruise Control System (SbACC), whereby the longitudinal behavior of vehicles is controlled by a central server over LTE. Additionally we identify several methods with which the requirements for delay and bandwidth can be relaxed, such that a sufficient performance of the SbACC can still be guaranteed. The evaluation is then performed based on the simulation of scenarios with realistic movement and communication, yielding a maximum required bandwidth of the SbACC in downlink of 2.15% in an urban and 9.6% in a suburban scenario.

Safety-Critical Driver Assistance Over LTE: Toward Centralized ACC

Cooperative advanced driver assistance systems (ADAS) have the potential to increase traffic efficiency and safety beyond the level of sensor-based systems. Further development toward centralized cooperative systems is motivated by the improving performance of cellular technologies. However, the suitability of cellular communication, up to now, remains an unresolved topic in current research due to high system requirements (on, e.g., latency). In a centralized system design, the control algorithm is located at a central unit and the system input, as well as the measured output, is transmitted over the cellular network. This paper addresses the technical feasibility and practicability of centralized longitudinal control of vehicles and vehicle platoons with communication over long-term evolution (LTE). The focus is laid on the investigation of the system in disturbed situations, as well as on the evaluation and optimization of the required LTE resources. Therefore, a novel design of a centralized adaptive cruise control is developed, which satisfies required stability properties and optimizes the resource usage. The evaluation is based on simulation studies since it requires a large number of devices, as well as deep data logging within LTE. In summary, system safety can be achieved with moderate requirements on the cellular technology in the case of high localization accuracy. Considering the objectives of LTE, the communication requirements should be satisfied in areas with gapless coverage and with dedicated resources in the case of saturated channel conditions.