Alex Bendrick's research while affiliated with Technische Universität Braunschweig and other places

With research trending towards increasing amounts of Vehicle-to-Everything (V2X) applications that use a shared wireless medium for data exchange, the coordination of those applications gains more and more importance. Applicationcentric Resource Management (RM) is a promising candidate for that coordination. It allows to address both application constraints as well as network properties in order to guarantee adherence to real-time and safety constraints of critical applications, such as cooperative perception based on large data object streaming. These applications require the reliable and fast exchange of large data objects. We use earlier work on error correcting real-time protocols with a safe control protocol for application-aware dynamic network (re-)configuration. The RM mechanisms were evaluated using a physical wireless prototype that used commodity of the shelf hardware that resembles an automated valet parking use case. The RM proved highly effective in preventing constraint violations. Meanwhile, it did so in a predictable and synchronized manner even if the wireless channel is subject to non-negligible error rates.

There is a trend towards communication of larger data objects in wireless vehicle communication. In many cases, communication uses publish-subscribe protocols. Data rate requirements of such protocols are best addressed by wireless multicast protocols, but the existing protocols lack an error protection that is suitable for real-time and safety-critical applications. We present an application-aware protocol that supports the popular DDS (Data Distribution Service) middleware. By exploiting data object deadlines and slack for retransmissions and employing an adaptable, multicast-aware prioritization mechanism the reliable exchange of large data objects is enabled. The protocol is sufficiently general to be used on top of different communication standards such as 802.11- and cellular-based V2X (Vehicle-to-Everything) technologies. The protocol was implemented in an OMNeT++ simulation model and evaluated against recent state-of-the-art alternatives using parameters and constraints taken from a motivational truck platooning example. Furthermore, the protocol was implemented using an open-source DDS implementation as the basis and tested on a physical wireless demonstrator setup. The evaluation shows that the presented multicast protocol substantially outperforms the alternatives keeping streaming applications operational even under high frame error rates.

This paper summarizes the talks of a special session on the IPF 2.0 project, a collaborative German-US research project that leverages self-awareness principles for the self-management of distributed systems of autonomous multiprocessor systems-on-chip (MPSoCs).

In automotive and industrial real-time software systems, the primary timing constraints relate to cause-effect chains. A cause-effect chain is a sequence of linked tasks and it typically implements the process of reading sensor data, computing algorithms, and driving actuators. The classic timing analysis computes the maximum end-to-end latency of a given cause-effect chain to verify that its end-to-end deadline can be satisfied in all cases. This information is useful but not sufficient in practice: Software is usually evolving and updates may always alter the maximum end-to-end latency. It would be desirable to judge the quality of a software design a priori by quantifying how robust the timing of a given cause-effect chain will be in the presence of software updates. In this paper, we derive robustness margins which guarantee that if software extensions stay within certain bounds, then the end-to-end deadline of a cause-effect chain can still be satisfied. Robustness margins are also useful to know if the system model has uncertain parameters. A robust system design can tolerate bounded deviations from the nominal system model without violating timing constraints. The results are applicable to both the bounded execution time programming model and the (system-level) logical execution time programming model. In this paper, we study both an industrial use case from the automotive industry and analyze synthetically generated experiments with our open-source tool TORO.

The current roadmaps and surveys for future wireless networking typically focus on communication and networking technologies and use representative applications to derive future network requirements. Such a benchmarking approach, however, does not cover the application integration challenge that arises from the many distributed applications sharing a network infrastructure, each with their individual topology and data structure. The paper addresses V2X networks as an important example. Crucial end-to-end application constraints including real-time and safety encourage a closer look at application interference and systematic integration. This perspective paper proposes a two-layer resource management that divides the problem into an application integration and a network management task. Valet parking with high-resolution infrastructure camera support is elaborated as a use case that overarches vehicle network and wireless network management. Experiments demonstrate the benefits of complementing the current network-centric management by an application-centric integration.