Inter-Vehicular Communication - From Edge Support to Vulnerable Road Users

Summary

Looking back at the last decade, one can observe enormous progress in the domain of vehicular networking. In this growing community, many ongoing activities focus on the design of communication protocols to support safety applications, intelligent navigation, cooperative driving and others. Using the terms Vehicular Ad-hoc Networks (VANETs), Inter-Vehicle Communication (IVC), Car-2-X (C2X), or Vehicle-2-X (V2X), many applications – as interesting as challenging – have been envisioned and (at least) partially realized. Very large projects have been initiated to validate the theoretic work in field tests and protocols are being standardized. With the increasing interest from industry, security and privacy have also become crucial aspects in the stage of protocol design in order to support a smooth and carefully planned roll-out. We are now entering an era that might change the game in road traffic management. Many car makers already supply their recent brands with cellular and WiFi modems, some also adding vehicular WLAN (DSRC, ITS-G5) and/or C-V2X technologies, which focus on V2V and V2I communication.

The management and control of network connections among vehicles and between vehicles and an existing network infrastructure is currently one of the most challenging and active research fields in the networking domain. There is a long list of desirable applications that can be grouped into four IVC categories:

1. e-Safety applications that try to make driving safer, e.g., road hazard warning, collision warning;
2. traffic efficiency applications aiming at more efficient and thus greener traffic, e.g., detection of traffic jams, traffic distribution;
3. manufacturer oriented applications, e.g., automatic software updates; and
4. convenience applications, e.g., automatic map updates.

We initiated the “Inter-Vehicular Communication” Dagstuhl Series back in 2010, when a first Dagstuhl Seminar was organized on this topic. The motivation was to bring together experts in this field to investigate the state of the art and to highlight where sufficient solutions already existed. The main outcome of this very inspiring seminar series was that there are indeed areas within this research field where scientific findings are being consolidated and adopted by industry. This was the consensus of quite intriguing discussions among participants from both industry and academia. Yet, even more aspects have been identified where substantial research is still needed.

Some of the findings of the first three seminars in this series have been published not only in the related Dagstuhl reports but also in widely visible magazine articles:

1. Falko Dressler, Frank Kargl, Jörg Ott, Ozan K. Tonguz and Lars Wischhof, “Research Challenges in Inter-Vehicular Communication – Lessons of the 2010 Dagstuhl Seminar,” IEEE Communications Magazine, vol. 49 (5), pp. 158-164, May 2011.
2. Falko Dressler, Hannes Hartenstein, Onur Altintas and Ozan K. Tonguz, “Inter-Vehicle Communication – Quo Vadis,” IEEE Communications Magazine, vol. 52 (6), pp. 170-177, June 2014.
3. Onur Altintas, Suman Banerjee, Falko Dressler and Geert Heijenk, “Executive Summary – Inter-Vehicular Communication Towards Cooperative Driving,” Proceedings of Dagstuhl Seminar 18202 on Inter-Vehicular Communication – Towards Cooperative Driving, Schloss Dagstuhl, Germany, May 2018, pp. 31–59.

Seminars in this series focused on general vehicular communication technologies, security and safety impact, cooperative driving concepts and its implications on communication protocol design, and many more.

We now shifted the focus of this seminar from basic networking principles to open challenges in edge computing support and, as a novel aspect, on how to integrate so called vulnerable road users (VRU) into the picture. Edge computing is currently becoming one of the core building blocks of cellular networks, including 5G, and it is necessary to study how to integrate ICT components of moving systems. The trade-offs of computation distribution, system aspects, and the impact on end-to-end latency are still unanswered. Also, vehicular networking and cooperative driving focuses almost exclusively on cars but leaves out communication and coordination with, for example, pedestrians and bicyclists. For example, many of the existing communication solutions for this scenario were designed without having battery constraints in mind. In the mean-time, some early research has been initiated on this topic, we organized a workshop at INFORMATIK 2019 on VRUs and initial projects report very interesting results on safety features for VRUs. Building upon the great success of the first two seminars, with this follow-up seminar, our goal was to once again bring together experts from all these fields from both academia and industry. The seminar focused intensively on discussions in several working groups. To kick-off these discussions, we invited three keynote talks:

• Distributed machine learning in the vehicle-to-edge continuum by Carla-Fabiana Chiasserini (Polytechnic University of Turin, IT)
• A TechCity Living lab for vehicular-based mobility services in the road by Susana Sargento (Institute of Telecommunications, PT)
• Edge-based increase of awareness and support for all traffic participants by Lars Wolf (TU Braunschweig, DE)

We finally organized the following working groups on some of the most challenging issues related to inter-vehicular communication and cooperative driving:

• Edge Computing: A multi-dimensional techno-economic outlook (i.e., latency, cost, deployment issues, etc.)
• Cooperative Driving Again: Where are we now after 2018? What about vehicular platooning: Is it still alive? What are still unsolved challenges?
• How do we support VRU detection/warning?
• Forget about V2V, we have V2C: Is Vehicle-to-Cloud the Way to Go?

References

1. Falko Dressler, Frank Kargl, Jörg Ott, Ozan K. Tonguz and Lars Wischhof, “Research Challenges in Inter-Vehicular Communication – Lessons of the 2010 Dagstuhl Seminar,” IEEE Communications Magazine, vol. 49 (5), pp. 158-164, May 2011.
2. Falko Dressler, Hannes Hartenstein, Onur Altintas and Ozan K. Tonguz, “Inter-Vehicle Communication – Quo Vadis,” IEEE Communications Magazine, vol. 52 (6), pp. 170-177, June 2014.
3. Onur Altintas, Suman Banerjee, Falko Dressler and Geert Heijenk, “Executive Summary – Inter-Vehicular Communication Towards Cooperative Driving,” Proceedings of Dagstuhl Seminar 18202 on Inter-Vehicular Communication – Towards Cooperative Driving, Schloss Dagstuhl, Germany, May 2018, pp. 31–59.