Publications
1.
Lobo, S.; Facchi, C.; Festag, A.
Adaptive Message Prioritization: How to Prioritize VRU Awareness Messages in a Congested V2X Network Proceedings Article
In: IEEE International Conference on Intelligent Transportation Systems (ITSC), Edmonton, Canada, 2024.
Abstract | Links | BibTeX | Tags: Intelligent Transport Systems, safety, V2X communication, vulnerable road users
@inproceedings{lobo:ITSC:2024,
title = {Adaptive Message Prioritization: How to Prioritize VRU Awareness Messages in a Congested V2X Network},
author = {S. Lobo and C. Facchi and A. Festag},
url = {https://ieee-itsc.org/2024/},
doi = {10.1109/ITSC58415.2024.10919704},
year = {2024},
date = {2024-07-18},
urldate = {2024-07-18},
booktitle = {IEEE International Conference on Intelligent Transportation Systems (ITSC)},
address = {Edmonton, Canada},
abstract = {The safety of Vulnerable Road Users (VRUs) can be improved through the utilization of Vehicle-to-Everything (V2X) communication, enabling the exchange of the VRUs' position and kinematic data. In the European V2X system, the dissemination relies on a dedicated message type, the VRU Awareness Message (VAM), which integrates VRUs into the V2X network as active transceivers. However, in the long term, the high number of V2X nodes transmitting messages poses challenges in the wireless resource allocation, which may result in safety-critical situations. To mitigate this issue, the current standardization of VRU awareness services in Europe, considers clustering VRUs with similar kinematic pattern. Nevertheless, the VRU process for joining a cluster may encounter errors, resulting in high channel load due to multiple requests. In this paper, an adaptive message prioritization is proposed to reduce this impact. This method is triggered only under heavy network load and takes into account the number of potential V2X senders. Via simulations based on a crossing scenario, improvements in network performance are observed, as well as an increase in VRU awareness measured by vehicles, i.e. more VRUs being detected.},
keywords = {Intelligent Transport Systems, safety, V2X communication, vulnerable road users},
pubstate = {published},
tppubtype = {inproceedings}
}
The safety of Vulnerable Road Users (VRUs) can be improved through the utilization of Vehicle-to-Everything (V2X) communication, enabling the exchange of the VRUs' position and kinematic data. In the European V2X system, the dissemination relies on a dedicated message type, the VRU Awareness Message (VAM), which integrates VRUs into the V2X network as active transceivers. However, in the long term, the high number of V2X nodes transmitting messages poses challenges in the wireless resource allocation, which may result in safety-critical situations. To mitigate this issue, the current standardization of VRU awareness services in Europe, considers clustering VRUs with similar kinematic pattern. Nevertheless, the VRU process for joining a cluster may encounter errors, resulting in high channel load due to multiple requests. In this paper, an adaptive message prioritization is proposed to reduce this impact. This method is triggered only under heavy network load and takes into account the number of potential V2X senders. Via simulations based on a crossing scenario, improvements in network performance are observed, as well as an increase in VRU awareness measured by vehicles, i.e. more VRUs being detected.
2.
Hegde, A.; Lobo, S.; Festag, A.
Cellular-V2X for Vulnerable Road User Protection in Cooperative ITS Proceedings Article
In: 2022 18th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), Thessaloniki, Greece, 2022.
Abstract | Links | BibTeX | Tags: Intelligent Transport Systems, safety, V2X communication, vulnerable road users
@inproceedings{Hegde:WiMob:2022,
title = {Cellular-V2X for Vulnerable Road User Protection in Cooperative ITS},
author = {A. Hegde and S. Lobo and A. Festag},
url = {http://www.wimob.org/wimob2022},
doi = {10.1109/WiMob55322.2022.9941707},
year = {2022},
date = {2022-12-31},
urldate = {2022-10-12},
booktitle = {2022 18th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)},
address = {Thessaloniki, Greece},
abstract = {Cooperative Intelligent Transport Systems (C-ITS) play a significant role in improving road traffic safety and efficiency. Primary use cases rely on vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication. In C-ITS, the safety of vulnerable road users (VRUs) such as pedestrians, motorists and other users with reduced mobility is being increasingly considered. A warning system, where VRUs actively send and receive messages instead of being passively monitored as road traffic objects, can play an important role in detecting risky situations and allowing the warning of vehicle drivers. However, in a dense urban traffic scenario with closely moving vehicles and pedestrians, the communication network can face severe resource constraints. Considering Cellular-V2X communication systems, the user equipments (UEs) may have to use the unmanaged mode of the sidelink interface. This paper analyzes the limitations of the existing radio resource allocation mechanisms and proposes adaptive strategies to ensure fairness in the distribution of radio resources between vehicles and VRUs. In addition, this work addresses the question about the situations in which VRU safety, being subject to a resource-constrained Cellular-V2X network, can be ensured.},
keywords = {Intelligent Transport Systems, safety, V2X communication, vulnerable road users},
pubstate = {published},
tppubtype = {inproceedings}
}
Cooperative Intelligent Transport Systems (C-ITS) play a significant role in improving road traffic safety and efficiency. Primary use cases rely on vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication. In C-ITS, the safety of vulnerable road users (VRUs) such as pedestrians, motorists and other users with reduced mobility is being increasingly considered. A warning system, where VRUs actively send and receive messages instead of being passively monitored as road traffic objects, can play an important role in detecting risky situations and allowing the warning of vehicle drivers. However, in a dense urban traffic scenario with closely moving vehicles and pedestrians, the communication network can face severe resource constraints. Considering Cellular-V2X communication systems, the user equipments (UEs) may have to use the unmanaged mode of the sidelink interface. This paper analyzes the limitations of the existing radio resource allocation mechanisms and proposes adaptive strategies to ensure fairness in the distribution of radio resources between vehicles and VRUs. In addition, this work addresses the question about the situations in which VRU safety, being subject to a resource-constrained Cellular-V2X network, can be ensured.
3.
Lobo, S.; Festag, A.; Facchi, C.
Enhancing the Safety of Vulnerable Road Users: Messaging Protocols for V2X Communication Proceedings Article
In: IEEE 96th Vehicular Technology Conference (VTC2022-Fall), London UK and Beijing, China, 2022.
Abstract | Links | BibTeX | Tags: Intelligent Transport Systems, safety, V2X communication, vulnerable road users
@inproceedings{Lobo:VTCFall:2022,
title = {Enhancing the Safety of Vulnerable Road Users: Messaging Protocols for V2X Communication},
author = {S. Lobo and A. Festag and C. Facchi},
url = {https://ieeexplore.ieee.org/document/10012775},
doi = {10.1109/VTC2022-Fall57202.2022.10012775},
year = {2022},
date = {2022-09-05},
urldate = {2022-09-05},
booktitle = {IEEE 96th Vehicular Technology Conference (VTC2022-Fall)},
address = {London UK and Beijing, China},
abstract = {The protection of vulnerable road users (VRUs) by means of V2X communication is increasingly considered for the next generation of cooperative safety systems. Two messaging protocols are being standardized: (i) With collective perception for sensor data sharing: VRUs can be passively perceived by the local sensors in vehicles and roadside units, which disseminate this information in dedicated messages carrying lists with VRU and other objects. (ii) VRUs can actively transmit messages in order to make other road users in their vicinity aware of their presence. This paper carries out a performance evaluation of a scenario with the two main messaging protocols and also their combined deployment, and compares them with two baseline approaches. Simulation results for a representative roundabout scenario with manifold interaction among vehicles and pedestrians indicate that the combination of sensor data sharing and active VRU transmissions performs best: It provides the highest VRU detection rate and the shortest VRU detection latency. This approach keeps the channel busy ratio below a critical threshold, which prevents the data congestion control of the V2X communication system from its activation.},
keywords = {Intelligent Transport Systems, safety, V2X communication, vulnerable road users},
pubstate = {published},
tppubtype = {inproceedings}
}
The protection of vulnerable road users (VRUs) by means of V2X communication is increasingly considered for the next generation of cooperative safety systems. Two messaging protocols are being standardized: (i) With collective perception for sensor data sharing: VRUs can be passively perceived by the local sensors in vehicles and roadside units, which disseminate this information in dedicated messages carrying lists with VRU and other objects. (ii) VRUs can actively transmit messages in order to make other road users in their vicinity aware of their presence. This paper carries out a performance evaluation of a scenario with the two main messaging protocols and also their combined deployment, and compares them with two baseline approaches. Simulation results for a representative roundabout scenario with manifold interaction among vehicles and pedestrians indicate that the combination of sensor data sharing and active VRU transmissions performs best: It provides the highest VRU detection rate and the shortest VRU detection latency. This approach keeps the channel busy ratio below a critical threshold, which prevents the data congestion control of the V2X communication system from its activation.