@inproceedings{FritzscheFestag2018, author = {Fritzsche, Richard and Festag, Andreas}, title = {Location-Based Scheduling for Cellular V2V Systems in Highway Scenarios}, booktitle = {2018 IEEE 87th Vehicular Technology Conference (VTC Spring) Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6355-4}, doi = {https://doi.org/10.1109/VTCSpring.2018.8417744}, year = {2018}, language = {en} } @article{BazziSepulcreDeloozetal.2024, author = {Bazzi, Alessandro and Sepulcre, Miguel and Delooz, Quentin and Festag, Andreas and Vogt, Jonas and Wieker, Horst and Berens, Friedbert and Spaanderman, Paul}, title = {Multi-Channel Operation for the Release 2 of ETSI Cooperative Intelligent Transport Systems}, volume = {8}, journal = {IEEE Communications Standards Magazine}, number = {1}, publisher = {IEEE}, address = {New York}, issn = {2471-2833}, doi = {https://doi.org/10.1109/MCOMSTD.0001.2200080}, pages = {28 -- 35}, year = {2024}, abstract = {Vehicles and road infrastructure are starting to be equipped with vehicle-to-everything (V2X) communication solutions to increase road safety and provide new services to drivers and passengers. In Europe, the deployment is based on a set of Release 1 standards developed by ETSI to support basic use cases for cooperative intelligent transport systems (C-ITS). For them, the capacity of a single 10 MHz channel in the ITS band at 5.9 GHz is considered sufficient. At the same time, the ITS stakeholders are working toward several advanced use cases, which imply a significant increment of data traffic and the need for multiple channels. To address this issue, ETSI has recently standardized a new multi-channel operation (MCO) concept for flexible, efficient, and future-proof use of multiple channels. This new concept is defined in a set of new specifications that represent the foundation for the future releases of C-ITS standards. The present article provides a comprehensive review of the new set of specifications, describing the main entities that extend the C-ITS architecture at the different layers of the protocol stack. In addition, the article provides representative examples that describe how these MCO standards will be used in the future and discusses some of the main open issues arising. The review and analysis of this article facilitate the understanding and motivation of the new set of Release 2 ETSI specifications for MCO and the identification of new research opportunities.}, language = {en} } @article{SongZhouLyuetal.2023, author = {Song, Rui and Zhou, Liguo and Lyu, Lingjuan and Festag, Andreas and Knoll, Alois}, title = {ResFed: Communication-Efficient Federated Learning With Deep Compressed Residuals}, volume = {11}, journal = {IEEE Internet of Things Journal}, number = {6}, publisher = {IEEE}, address = {New York}, issn = {2327-4662}, doi = {https://doi.org/10.1109/JIOT.2023.3324079}, pages = {9458 -- 9472}, year = {2023}, abstract = {Federated learning allows for cooperative training among distributed clients by sharing their locally learned model parameters, such as weights or gradients. However, as model size increases, the communication bandwidth required for deployment in wireless networks becomes a bottleneck. To address this, we propose a residual-based federated learning framework (ResFed) that transmits residuals instead of gradients or weights in networks. By predicting model updates at both clients and the server, residuals are calculated as the difference between updated and predicted models and contain more dense information than weights or gradients. We find that the residuals are less sensitive to an increasing compression ratio than other parameters, and hence use lossy compression techniques on residuals to improve communication efficiency for training in federated settings. With the same compression ratio, ResFed outperforms current methods (weight- or gradient-based federated learning) by over 1.4× on federated data sets, including MNIST, FashionMNIST, SVHN, CIFAR-10, CIFAR-100, and FEMNIST, in client-to-server communication, and can also be applied to reduce communication costs for server-to-client communication.}, language = {en} } @article{HegdeSongFestag2023, author = {Hegde, Anupama and Song, Rui and Festag, Andreas}, title = {Radio Resource Allocation in 5G-NR V2X: A Multi-Agent Actor-Critic Based Approach}, volume = {11}, journal = {IEEE Access}, publisher = {IEEE}, address = {New York}, issn = {2169-3536}, doi = {https://doi.org/10.1109/ACCESS.2023.3305267}, pages = {87225 -- 87244}, year = {2023}, abstract = {The efficiency of radio resource allocation and scheduling procedures in Cellular Vehicle-to-X (Cellular V2X) communication networks directly affects link quality in terms of latency and reliability. However, owing to the continuous movement of vehicles, it is impossible to have a centralized coordinating unit at all times to manage the allocation of radio resources. In the unmanaged mode of the fifth generation new radio (5G-NR) V2X, the sensing-based semi-persistent scheduling (SB-SPS) loses its effectiveness when V2X data messages become aperiodic with varying data sizes. This leads to misinformed resource allocation decisions among vehicles and frequent resource collisions. To improve resource selection, this study formulates the Cellular V2X communication network as a decentralized multi-agent networked markov decision process (MDP) where each vehicle agent executes an actor-critic-based radio resource scheduler. Developing further the actor-critic methodology for the radio resource allocation problem in Cellular V2X, two variants are derived: independent actor-critic (IAC) and shared experience actor-critic (SEAC). Results from simulation studies indicate that the actor-critic schedulers improve reliability, achieving a 15-20\% higher probability of reception under high vehicular density scenarios with aperiodic traffic patterns.}, language = {en} } @inproceedings{LoboFestagFacchi2025, author = {Lobo, Silas and Festag, Andreas and Facchi, Christian}, title = {Adaptive Message Prioritization: How to Prioritize VRU Awareness Messages in a Congested V2X Network}, booktitle = {2024 IEEE 27th International Conference on Intelligent Transportation Systems (ITSC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3315-0592-9}, doi = {https://doi.org/10.1109/ITSC58415.2024.10919704}, pages = {423 -- 430}, year = {2025}, language = {en} } @inbook{DeloozMaksimovskiFestagetal.2024, author = {Delooz, Quentin and Maksimovski, Daniel and Festag, Andreas and Facchi, Christian}, title = {Design and Evaluation of V2X Communication Protocols for Cooperatively Interacting Automobiles}, booktitle = {Cooperatively Interacting Vehicles: Methods and Effects of Automated Cooperation in Traffic}, editor = {Stiller, Christoph and Althoff, Matthias and Burger, Christoph and Deml, Barbara and Eckstein, Lutz and Flemisch, Frank}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-60494-2}, doi = {https://doi.org/10.1007/978-3-031-60494-2_6}, pages = {159 -- 199}, year = {2024}, abstract = {This chapter studies two key communication services for the support of cooperative driving capabilities using Vehicle-to-Everything (V2X) communications: sensor data sharing and maneuver coordination. Based on the current state of the art in research and pre-standardization of V2X communications, we enhance the protocol design for both services and assess their performance by discrete-event simulations in highway and city scenarios. The first part of this chapter addresses the performance improvement of sensor data sharing by two complementary strategies. The shared sensor data are adapted to the available resources on the used channel. Furthermore, the redundancy of the transmitted information is reduced to lower the load on the wireless channel, whereas several approaches are proposed and assessed. The second part of the chapter analyzes cooperative maneuver coordination protocols. We propose a distributed approach based on the explicit exchange of V2X messages, which introduces priorities in maneuver coordination and studies several communication patterns for the negotiation and coordination of maneuvers among two and more vehicles. The results demonstrate the potential of V2X communications for automated driving, showcase several approaches for enhancements of sensor data sharing and maneuver coordination, and indicate the performance of these enhancements.}, language = {en} } @unpublished{SongZhouLyuetal.2022, author = {Song, Rui and Zhou, Liguo and Lyu, Lingjuan and Festag, Andreas and Knoll, Alois}, title = {ResFed: Communication Efficient Federated Learning by Transmitting Deep Compressed Residuals}, publisher = {arXiv}, address = {Ithaca}, doi = {https://doi.org/10.48550/arXiv.2212.05602}, year = {2022}, language = {en} } @inproceedings{FestagUdupaGarciaetal.2021, author = {Festag, Andreas and Udupa, Shrivatsa and Garcia, Lourdes and Wellens, Ralf and Hecht, Matthias and Ulfig, Pierre}, title = {End-to-End Performance Measurements of Drone Communications in 5G Cellular Networks}, booktitle = {2021 IEEE 94th Vehicular Technology Conference (VTC2021-Fall): Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-1368-8}, doi = {https://doi.org/10.1109/VTC2021-Fall52928.2021.9625429}, year = {2021}, language = {en} } @inproceedings{MaksimovskiFacchiFestag2024, author = {Maksimovski, Daniel and Facchi, Christian and Festag, Andreas}, title = {Packet Rate Control for Maneuver Coordination in Congested V2X Communication Environments}, booktitle = {2024 IEEE 100th Vehicular Technology Conference (VTC2024-Fall), Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3315-1778-6}, doi = {https://doi.org/10.1109/VTC2024-Fall63153.2024.10758036}, year = {2024}, language = {en} } @inproceedings{FestagSong2021, author = {Festag, Andreas and Song, Rui}, title = {Analysis of Existing Approaches for Information Sharing in Cooperative Intelligent Transport Systems}, booktitle = {FISITA World Congress 2021}, subtitle = {SENSORIS and V2X Messaging}, publisher = {FISITA}, address = {Bishops Stortford}, url = {https://www.fisita.com/library/f2020-acm-012}, year = {2021}, language = {en} } @inproceedings{SongHegdeSeneletal.2022, author = {Song, Rui and Hegde, Anupama and Senel, Numan and Knoll, Alois and Festag, Andreas}, title = {Edge-Aided Sensor Data Sharing in Vehicular Communication Networks}, booktitle = {2022 IEEE 95th Vehicular Technology Conference: (VTC2022-Spring) Proceedings}, publisher = {IEEE}, address = {Piscataway (NJ)}, isbn = {978-1-6654-8243-1}, issn = {2577-2465}, doi = {https://doi.org/10.1109/VTC2022-Spring54318.2022.9860849}, year = {2022}, language = {en} } @inproceedings{MaksimovskiFacchiFestag2021, author = {Maksimovski, Daniel and Facchi, Christian and Festag, Andreas}, title = {Priority Maneuver (PriMa) Coordination for Connected and Automated Vehicles}, booktitle = {2021 IEEE International Intelligent Transportation Systems Conference (ITSC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-9142-3}, doi = {https://doi.org/10.1109/ITSC48978.2021.9564923}, pages = {1083 -- 1089}, year = {2021}, language = {en} } @article{DeloozFestagVinel2021, author = {Delooz, Quentin and Festag, Andreas and Vinel, Alexey}, title = {Congestion Aware Objects Filtering for Collective Perception}, volume = {80}, journal = {Electronic Communications of the EASST}, publisher = {TU Berlin}, address = {Berlin}, issn = {1863-2122}, doi = {http://dx.doi.org/10.14279/tuj.eceasst.80.1160}, year = {2021}, abstract = {This paper addresses collective perception for connected and automated driving. It proposes the adaptation of filtering rules based on the currently available channel resources, referred to as Enhanced DCC-Aware Filtering (EDAF).}, language = {en} } @inproceedings{VolkDeloozSchieggetal.2021, author = {Volk, Georg and Delooz, Quentin and Schiegg, Florian and Bernuth, Alexander von and Festag, Andreas and Bringmann, Oliver}, title = {Towards Realistic Evaluation of Collective Perception for Connected and Automated Driving}, booktitle = {2021 IEEE International Intelligent Transportation Systems Conference (ITSC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-9142-3}, doi = {https://doi.org/10.1109/ITSC48978.2021.9564783}, pages = {1049 -- 1056}, year = {2021}, language = {en} } @inproceedings{HegdeFestag2021, author = {Hegde, Anupama and Festag, Andreas}, title = {Mode Switching Performance in Cellular-V2X}, booktitle = {2020 IEEE Vehicular Networking Conference (VNC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-9221-5}, doi = {https://doi.org/10.1109/VNC51378.2020.9318394}, year = {2021}, language = {en} } @inproceedings{DeloozRieblFestagetal.2021, author = {Delooz, Quentin and Riebl, Raphael and Festag, Andreas and Vinel, Alexey}, title = {Design and Performance of Congestion-Aware Collective Perception}, booktitle = {2020 IEEE Vehicular Networking Conference (VNC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-9221-5}, doi = {https://doi.org/10.1109/VNC51378.2020.9318335}, year = {2021}, language = {en} } @inproceedings{SenelElgerFestag2020, author = {Senel, Numan and Elger, Gordon and Festag, Andreas}, title = {Sensor Time Synchronization in Smart Road Infrastructure}, booktitle = {FISITA Web Congress 2020}, publisher = {FISITA}, address = {Bishops Stortford}, url = {https://www.fisita.com/library/f2020-acm-083}, year = {2020}, language = {en} } @inproceedings{DeloozFestag2020, author = {Delooz, Quentin and Festag, Andreas}, title = {Network Load Adaptation for Collective Perception in V2X Communication}, booktitle = {2019 IEEE ICCVE, The 8th IEEE International Conference on Connected Vehicles and Expo (ICCVE), November 4-8, 2019, 2019 Conference Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-7281-0142-2}, doi = {https://doi.org/10.1109/ICCVE45908.2019.8964988}, year = {2020}, language = {en} } @article{HungZhangFestagetal.2019, author = {Hung, Shao-Chou and Zhang, Xin and Festag, Andreas and Chen, Kwang-Cheng and Fettweis, Gerhard}, title = {Vehicle-Centric Network Association in Heterogeneous Vehicle-to-Vehicle Networks}, volume = {68}, journal = {IEEE Transactions on Vehicular Technology}, number = {6}, publisher = {IEEE}, address = {New York}, issn = {1939-9359}, doi = {https://doi.org/10.1109/TVT.2019.2910324}, pages = {5981 -- 5996}, year = {2019}, language = {en} } @article{HegdeFestag2019, author = {Hegde, Anupama and Festag, Andreas}, title = {Mode Switching Strategies in Cellular-V2X}, volume = {52}, journal = {IFAC-PapersOnLine}, number = {8}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8963}, doi = {https://doi.org/10.1016/j.ifacol.2019.08.052}, pages = {81 -- 86}, year = {2019}, language = {en} } @article{KuehlmorgenLuFestagetal.2019, author = {K{\"u}hlmorgen, Sebastian and Lu, Hongsheng and Festag, Andreas and Kenney, John and Gemsheim, Sebastian and Fettweis, Gerhard}, title = {Evaluation of Congestion-Enabled Forwarding With Mixed Data Traffic in Vehicular Communications}, volume = {21}, journal = {IEEE Transactions on Intelligent Transportation Systems}, number = {1}, publisher = {IEEE}, address = {New York}, issn = {1558-0016}, doi = {https://doi.org/10.1109/TITS.2018.2890619}, pages = {233 -- 247}, year = {2019}, language = {en} } @inproceedings{MaksimovskiFacchiFestag2022, author = {Maksimovski, Daniel and Facchi, Christian and Festag, Andreas}, title = {Cooperative Driving: Research on Generic Decentralized Maneuver Coordination for Connected and Automated Vehicles}, booktitle = {Smart Cities, Green Technologies, and Intelligent Transport Systems: 10th International Conference, SMARTGREENS 2021, and 7th International Conference, VEHITS 2021, Virtual Event, April 28-30, 2021, Revised Selected Papers}, editor = {Klein, Cornel and Jarke, Matthias and Helfert, Markus and Berns, Karsten and Gusikhin, Oleg}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-17097-3}, doi = {https://doi.org/10.1007/978-3-031-17098-0_18}, pages = {348 -- 370}, year = {2022}, language = {en} } @inproceedings{KuehlmorgenSchmagerFestagetal.2018, author = {K{\"u}hlmorgen, Sebastian and Schmager, Patrick and Festag, Andreas and Fettweis, Gerhard}, title = {Simulation-Based Evaluation of ETSI ITS-G5 and Cellular-VCS in a Real-World Road Traffic Scenario}, booktitle = {2018 IEEE 88th Vehicular Technology Conference (VTC-Fall) Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-5386-6358-5}, issn = {2577-2465}, doi = {https://doi.org/10.1109/VTCFall.2018.8691011}, year = {2018}, language = {en} } @inproceedings{SongZhouLakshminarasimhanetal.2022, author = {Song, Rui and Zhou, Liguo and Lakshminarasimhan, Venkatnarayanan and Festag, Andreas and Knoll, Alois}, title = {Federated Learning Framework Coping with Hierarchical Heterogeneity in Cooperative ITS}, booktitle = {2022 IEEE 25th International Conference on Intelligent Transportation Systems (ITSC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-6880-0}, pages = {3502 -- 3508}, year = {2022}, language = {en} } @inproceedings{DeloozFestagVineletal.2023, author = {Delooz, Quentin and Festag, Andreas and Vinel, Alexey and Lobo, Silas}, title = {Simulation-Based Performance Optimization of V2X Collective Perception by Adaptive Object Filtering}, booktitle = {2023 IEEE Intelligent Vehicles Symposium (IV): Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3503-4691-6}, doi = {https://doi.org/10.1109/IV55152.2023.10186788}, year = {2023}, language = {en} } @article{GoeckenjanFestagKather2023, author = {Goeckenjan, Maren and Festag, Andreas and Kather, Jakob Nikolas}, title = {Entscheidungsfindungen in der Reproduktionsmedizin}, volume = {21}, journal = {Gyn{\"a}kologische Endokrinologie}, subtitle = {von der menschlichen zur k{\"u}nstlichen Intelligenz}, number = {1}, publisher = {Springer}, address = {Heidelberg}, issn = {1610-2908}, doi = {https://doi.org/10.1007/s10304-022-00489-9}, pages = {72 -- 77}, year = {2023}, language = {de} } @article{ZhouSongChenetal.2023, author = {Zhou, Liguo and Song, Rui and Chen, Guang and Festag, Andreas and Knoll, Alois}, title = {Residual encoding framework to compress DNN parameters for fast transfer}, volume = {2023}, pages = {110815}, journal = {Knowledge-Based Systems}, number = {277}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7409}, doi = {https://doi.org/10.1016/j.knosys.2023.110815}, year = {2023}, language = {en} } @unpublished{BazziSepulcreDeloozetal.2023, author = {Bazzi, Alessandro and Sepulcre, Miguel and Delooz, Quentin and Festag, Andreas and Vogt, Jonas and Wieker, Horst and Berens, Friedbert and Spaanderman, Paul}, title = {Multi-Channel Operation for the Release 2 of ETSI Cooperative Intelligent Transport Systems}, publisher = {arXiv}, address = {Ithaca}, doi = {https://doi.org/10.48550/arXiv.2305.19863}, year = {2023}, abstract = {Vehicles and road infrastructure are starting to be equipped with vehicle-to-everything (V2X) communication solutions to increase road safety and provide new services to drivers and passengers. In Europe, the deployment is based on a set of Release 1 standards developed by ETSI to support basic use cases for cooperative intelligent transport systems (C-ITS). For them, the capacity of a single 10 MHz channel in the ITS band at 5.9 GHz is considered sufficient. At the same time, the ITS stakeholders are working towards several advanced use cases, which imply a significant increment of data traffic and the need for multiple channels. To address this issue, ETSI has recently standardized a new multi-channel operation (MCO) concept for flexible, efficient, and future-proof use of multiple channels. This new concept is defined in a set of new specifications that represent the foundation for the future releases of C-ITS standards. The present paper provides a comprehensive review of the new set of specifications, describing the main entities extending the C-ITS architecture at the different layers of the protocol stack, In addition, the paper provides representative examples that describe how these MCO standards will be used in the future and discusses some of the main open issues arising. The review and analysis of this paper facilitate the understanding and motivation of the new set of Release 2 ETSI specifications for MCO and the identification of new research opportunities.}, language = {en} } @inproceedings{MaksimovskiFacchiFestag2024, author = {Maksimovski, Daniel and Facchi, Christian and Festag, Andreas}, title = {A Framework of Use Cases, Scenarios, and Metrics for Evaluation of V2X Maneuver Coordination}, booktitle = {2024 IEEE Vehicular Networking Conference (VNC)}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3503-6270-1}, doi = {https://doi.org/10.1109/VNC61989.2024.10575992}, pages = {1 -- 8}, year = {2024}, language = {en} } @inproceedings{SongLyuJiangetal.2023, author = {Song, Rui and Lyu, Lingjuan and Jiang, Wei and Festag, Andreas and Knoll, Alois}, title = {V2X-Boosted Federated Learning for Cooperative Intelligent Transportation Systems with Contextual Client Selection}, booktitle = {CoPerception: Collaborative Perception and Learning, ICRA 2023 workshop}, url = {https://drive.google.com/file/d/1-OQAeNryd7-lksCTuWnhhyydpFSnw5On/view?usp=share_link}, year = {2023}, language = {en} } @unpublished{SongLiangCaoetal.2024, author = {Song, Rui and Liang, Chenwei and Cao, Hu and Yan, Zhiran and Zimmer, Walter and Gross, Markus and Festag, Andreas and Knoll, Alois}, title = {Collaborative Semantic Occupancy Prediction with Hybrid Feature Fusion in Connected Automated Vehicles}, publisher = {arXiv}, address = {Ithaca}, doi = {https://doi.org/10.48550/arXiv.2402.07635}, year = {2024}, abstract = {Collaborative perception in automated vehicles leverages the exchange of information between agents, aiming to elevate perception results. Previous camera-based collaborative 3D perception methods typically employ 3D bounding boxes or bird's eye views as representations of the environment. However, these approaches fall short in offering a comprehensive 3D environmental prediction. To bridge this gap, we introduce the first method for collaborative 3D semantic occupancy prediction. Particularly, it improves local 3D semantic occupancy predictions by hybrid fusion of (i) semantic and occupancy task features, and (ii) compressed orthogonal attention features shared between vehicles. Additionally, due to the lack of a collaborative perception dataset designed for semantic occupancy prediction, we augment a current collaborative perception dataset to include 3D collaborative semantic occupancy labels for a more robust evaluation. The experimental findings highlight that: (i) our collaborative semantic occupancy predictions excel above the results from single vehicles by over 30\%, and (ii) models anchored on semantic occupancy outpace state-of-the-art collaborative 3D detection techniques in subsequent perception applications, showcasing enhanced accuracy and enriched semantic-awareness in road environments.}, language = {en} } @article{BauderFestagKubjatkoetal.2024, author = {Bauder, Maximilian and Festag, Andreas and Kubjatko, Tibor and Schweiger, Hans-Georg}, title = {Data accuracy in Vehicle-to-X cooperative awareness messages: An experimental study for the first commercial deployment of C-ITS in Europe}, volume = {2024}, pages = {100744}, journal = {Vehicular Communications}, number = {47}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2214-2096}, doi = {https://doi.org/10.1016/j.vehcom.2024.100744}, year = {2024}, abstract = {Cooperative Intelligent Transportation Systems have achieved a mature technology stage and are in an early phase of mass deployment in Europe. Relying on Vehicle-to-X communication, these systems were primarily developed to improve traffic safety, efficiency, and driving comfort. However, they also offer great opportunities for other use cases. One of them is forensic accident analysis, where the received data provide details about the status of other traffic participants, give insights into the accident scenario, and therefore help in understanding accident causes. A high accuracy of the sent information is essential: For safety use cases, such as traffic jam warning, a poor accuracy of the data may result in wrong driver information, undermine the usability of the system and even create new safety risks. For accident analysis, a low accuracy may prevent the correct reconstruction of an accident. This paper presents an experimental study of the first generation of Cooperative Intelligent Transportation Systems in Europe. The results indicate a high accuracy for most of the data fields in the Vehicle-to-X messages, namely speed, acceleration, heading and yaw rate information, which meet the accuracy requirements for safety use cases and accident analysis. In contrast, the position data, which are also carried in the messages, have larger errors. Specifically, we observed that the lateral position still has an acceptable accuracy. The error of the longitudinal position is larger and may compromise safety use cases with high accuracy requirements. Even with limited accuracy, the data provide a high value for the accident analysis. Since we also found that the accuracy of the data increases for newer vehicle models, we presume that Vehicle-to-X data have the potential for exact accident reconstruction.}, language = {en} } @article{SongXuFestagetal.2023, author = {Song, Rui and Xu, Runsheng and Festag, Andreas and Ma, Jiaqi and Knoll, Alois}, title = {FedBEVT: Federated Learning Bird's Eye View Perception Transformer in Road Traffic Systems}, volume = {9}, journal = {IEEE Transactions on Intelligent Vehicles}, number = {1}, publisher = {IEEE}, address = {New York}, issn = {2379-8904}, doi = {https://doi.org/10.1109/TIV.2023.3310674}, pages = {958 -- 969}, year = {2023}, abstract = {Bird's eye view (BEV) perception is becoming increasingly important in the field of autonomous driving. It uses multi-view camera data to learn a transformer model that directly projects the perception of the road environment onto the BEV perspective. However, training a transformer model often requires a large amount of data, and as camera data for road traffic are often private, they are typically not shared. Federated learning offers a solution that enables clients to collaborate and train models without exchanging data but model parameters. In this paper, we introduce FedBEVT, a federated transformer learning approach for BEV perception. In order to address two common data heterogeneity issues in FedBEVT: (i) diverse sensor poses, and (ii) varying sensor numbers in perception systems, we propose two approaches - Federated Learning with Camera-Attentive Personalization (FedCaP) and Adaptive Multi-Camera Masking (AMCM), respectively. To evaluate our method in real-world settings, we create a dataset consisting of four typical federated use cases. Our findings suggest that FedBEVT outperforms the baseline approaches in all four use cases, demonstrating the potential of our approach for improving BEV perception in autonomous driving.}, language = {en} } @unpublished{SongLyuJiangetal.2023, author = {Song, Rui and Lyu, Lingjuan and Jiang, Wei and Festag, Andreas and Knoll, Alois}, title = {V2X-Boosted Federated Learning for Cooperative Intelligent Transportation Systems with Contextual Client Selection}, publisher = {arXiv}, address = {Ithaca}, doi = {https://doi.org/10.48550/arXiv.2305.11654}, year = {2023}, abstract = {Machine learning (ML) has revolutionized transportation systems, enabling autonomous driving and smart traffic services. Federated learning (FL) overcomes privacy constraints by training ML models in distributed systems, exchanging model parameters instead of raw data. However, the dynamic states of connected vehicles affect the network connection quality and influence the FL performance. To tackle this challenge, we propose a contextual client selection pipeline that uses Vehicle-to-Everything (V2X) messages to select clients based on the predicted communication latency. The pipeline includes: (i) fusing V2X messages, (ii) predicting future traffic topology, (iii) pre-clustering clients based on local data distribution similarity, and (iv) selecting clients with minimal latency for future model aggregation. Experiments show that our pipeline outperforms baselines on various datasets, particularly in non-iid settings.}, language = {en} } @inproceedings{JagtapSongSadashivaiahetal.2025, author = {Jagtap, Abhishek Dinkar and Song, Rui and Sadashivaiah, Sanath Tiptur and Festag, Andreas}, title = {V2X-Gaussians: Gaussian Splatting for Multi-Agent Cooperative Dynamic Scene Reconstruction}, booktitle = {2025 IEEE Intelligent Vehicles Symposium (IV)}, publisher = {IEEE}, address = {Piscataway}, isbn = {979-8-3315-3803-3}, doi = {https://doi.org/10.1109/IV64158.2025.11097436}, pages = {1033 -- 1039}, year = {2025}, language = {en} } @inproceedings{MaksimovskiFestagFacchi2021, author = {Maksimovski, Daniel and Festag, Andreas and Facchi, Christian}, title = {A Survey on Decentralized Cooperative Maneuver Coordination for Connected and Automated Vehicles}, booktitle = {Proceedings of the 7th International Conference on Vehicle Technology and Intelligent Transport Systems}, publisher = {SciTePress}, address = {Set{\´u}bal}, isbn = {978-989-758-513-5}, issn = {2184-495X}, doi = {https://doi.org/10.5220/0010442501000111}, pages = {100 -- 111}, year = {2021}, abstract = {V2X communications can be applied for maneuver coordination of automated vehicles, where the vehicles exchange messages to inform each other of their driving intentions and to negotiate for joint maneuvers. For motion and maneuver planning of automated vehicles, the cooperative maneuver coordination extends the perception range of the sensors, enhances the planning horizon and allows complex interactions among the vehicles. For specific scenarios, various schemes for maneuver coordination of connected automated vehicles exist. Recently, several proposals for maneuver coordination have been made that address generic instead of specific scenarios and apply different schemes for the message exchange of driving intentions and maneuver negotiation. This paper presents use cases for maneuver coordination and classifies existing generic approaches for decentralized maneuver coordination considering implicit and explicit trajectory broadcast, cost values and space-time reservation. We systematically describe the approaches, compare them and derive future research topics.}, language = {en} } @inproceedings{HegdeStahlLoboetal.2022, author = {Hegde, Anupama and Stahl, Ringo and Lobo, Silas and Festag, Andreas}, title = {Modeling Cellular Network Infrastructure in SUMO}, volume = {2}, booktitle = {SUMO Conference Proceedings}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2750-4425}, doi = {https://doi.org/10.52825/scp.v2i.97}, pages = {99 -- 113}, year = {2022}, abstract = {Communication networks are becoming an increasingly important part of the mobility system. They allow traffic participants to be connected and to exchange information related to traffic and roads. The information exchange impacts the behavior of traffic participants, such as the selection of travel routes or their mobility dynamics. Considering infrastructure-based networks, the information exchange depends on the availability of the network infrastructure and the quality of the communication links. Specifically in urban areas, today's 4G and 5G networks deploy small cells of high capacity, which do not provide ubiquitous cellular coverage due to their small range, signal blocking, etc. Therefore, the accurate modeling of the network infrastructure and its integration in simulation scenarios in microscopic traffic simulation software is gaining relevance. Unlike traffic infrastructure, such as traffic lights, the simulation of a cellular network infrastructure is not natively supported in SUMO. Instead, the protocols, functions and entities of the communication system with the physical wireless transmission are modeled in a dedicated and specialized network simulator that is coupled with SUMO. The disadvantage of this approach is that the simulated SUMO entities, typically vehicles, are not aware which portions of the roads are covered by wireless cells and what quality the wireless communication links have. In this paper, we propose a method for modeling the cellular infrastructure in SUMO that introduces a cellular coverage layer to SUMO. This layer models cell sites in a regular hexagonal grid, where each site is served by a base station. Following commonly accepted guidelines for the evaluation of cellular communication system, the method facilitates standardized and realistic modeling of the cellular coverage, including cell sites, antenna characteristics, cell association and handover. In order to ease the applicability of the method, we describe the work flow to create cell sites. As a representative case, we have applied the method to InTAS, the SUMO Ingolstadt traffic scenario and applied real data for the cellular infrastructure. We validate the approach by simulating a Cellular V2X system with sidelink connectivity in an urban macro cell environment by coupling SUMO enhanced by the proposed connectivity sublayer with ARTERY-C, a network simulator for Cellular V2X. As a proof-of-concept, we present a signal-to-interference noise ratio (SINR) coverage map and further evaluate the impact of different types of interference. We also demonstrate the effect of advanced features of cellular networks such as inter-cell interference coordination (ICIC) and sidelink communication modes of Cellular V2X with dynamic switching between the in-coverage and out-of-coverage mode.}, language = {en} } @inproceedings{DeloozFestagVinel2020, author = {Delooz, Quentin and Festag, Andreas and Vinel, Alexey}, title = {Revisiting Message Generation Strategies for Collective Perception in Connected and Automated Driving}, booktitle = {VEHICULAR 2020: The Ninth International Conference on Advances in Vehicular Systems, Technologies and Applications}, publisher = {IARIA}, address = {[s. l.]}, isbn = {978-1-61208-795-5}, url = {https://www.thinkmind.org/index.php?view=article\&articleid=vehicular_2020_1_80_30039}, pages = {46 -- 52}, year = {2020}, language = {en} } @article{MaksimovskiFestagFacchi2026, author = {Maksimovski, Daniel and Festag, Andreas and Facchi, Christian}, title = {Adaptive Message Generation Rules for V2X Maneuver Coordination Service}, volume = {14}, journal = {IEEE Access}, publisher = {IEEE}, address = {New York}, issn = {2169-3536}, doi = {https://doi.org/10.1109/ACCESS.2026.3652364}, pages = {6417 -- 6437}, year = {2026}, abstract = {Maneuver coordination enables connected and automated vehicles (CAVs) to collaboratively plan, negotiate, and execute driving maneuvers, aiming to enhance safety, traffic flow, and energy efficiency. As part of the Vehicle-to-Everything (V2X) communication system, it operates as a dedicated service that relies on detailed, bidirectional interactions between vehicles, unlike traditional broadcast-based V2X services. While maneuver coordination is the focus of ongoing research and standardization, the rules that govern when and how vehicles generate Maneuver Coordination Messages (MCMs) within the Maneuver Coordination Service (MCS) are still not fully defined. These rules are essential for ensuring timely and reliable coordination. This paper proposes three adaptive MCM generation strategies based on the operation mode of the MCS, maneuver priority, and current channel load. The first approach defines MCM rules for intent sharing, maneuver negotiation, and execution phases, factoring in maneuver importance. The second adjusts the frequency of intent MCMs when a negotiation message is received from another vehicle. The third adapts frequency based on real-time channel load during intent sharing. For comparison, two baseline strategies are also evaluated. The proposed rules are tested for highway merging and lane change use cases in traffic scenarios with increasing vehicle density and high channel loads. A comprehensive evaluation is conducted using metrics related to the network, message generation frequency, congestion control, and maneuver coordination. The results demonstrate significantly enhanced channel efficiency and communication reliability across all metrics. For example, under the final approach, maneuver negotiation time is reduced by a factor of five in congested V2X environments.}, language = {en} } @article{DeloozVinelFestag2023, author = {Delooz, Quentin and Vinel, Alexey and Festag, Andreas}, title = {Optimizing the channel resource usage for sensor data sharing with V2X communications}, volume = {71}, journal = {at - Automatisierungstechnik}, number = {4}, publisher = {De Gruyter}, address = {Berlin}, issn = {2196-677X}, doi = {https://doi.org/10.1515/auto-2022-0162}, pages = {311 -- 317}, year = {2023}, language = {en} } @inproceedings{HegdeFestag2020, author = {Hegde, Anupama and Festag, Andreas}, title = {Artery-C: An OMNeT++ Based Discrete Event Simulation Framework for Cellular V2X}, booktitle = {MSWiM '20: Proceedings of the 23rd International ACM Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems}, publisher = {ACM}, address = {New York}, isbn = {978-1-4503-8117-8}, doi = {https://doi.org/10.1145/3416010.3423240}, pages = {47 -- 51}, year = {2020}, language = {en} } @inproceedings{HegdeDeloozMariyakllaetal.2023, author = {Hegde, Anupama and Delooz, Quentin and Mariyaklla, Chethan L. and Festag, Andreas and Klingler, Florian}, title = {Radio Resource Allocation for Collective Perception in 5G-NR Vehicle-to-X Communication Systems}, booktitle = {2023 IEEE Wireless Communications and Networking Conference (WCNC): Proceedings}, publisher = {IEEE}, address = {Piscataway}, isbn = {978-1-6654-9122-8}, issn = {1558-2612}, doi = {https://doi.org/10.1109/WCNC55385.2023.10118606}, year = {2023}, language = {en} }