Shrief Rizkalla, Adrian Kliks, Nila Bagheri
et al.
This white paper aims to comprehensively analyze and consolidate the state of the art in communication technologies supporting modern and future Information and Communication Technology (ICT). Its primary objective is to establish a common understanding of how communication solutions enable automation, safety, and efficiency across multiple transport domains, including railways, road vehicles, aircraft, and unmanned aerial vehicles. The document seeks to identify key communication requirements and technological enablers necessary for interoperable and reliable ITS operation. It also assesses the limitations of current systems and proposes pathways for integrating emerging technologies such as 5G, Sixth Generation (6G), and Artificial Intelligence (AI)-driven network control. The white paper also intends to support harmonization between different transport modes through a unified framework for communication modeling, testing, and standardization. It highlights the importance of accurate channel modeling and empirical validation to design efficient, robust, and scalable systems. Another objective is to explore the use of reconfigurable intelligent surfaces, integrated sensing and communication, and digital twin concepts within ITS. The document emphasizes the role of spectrum management and standardization efforts in ensuring interoperability among diverse communication systems. Finally, the paper seeks to stimulate collaboration among academia, industry, and standardization bodies to advance the design of resilient and adaptive communication infrastructures for future transportation systems.
The ultimate goal of next-generation vehicle-toeverything (V2X) communication systems is enabling accident-free, cooperative automated driving that uses the available roadway efficiently. To achieve this goal, the communication system will need to enable a diverse set of use cases, each with a specific set of requirements. We discuss the main usecase categories, analyze their requirements, and compare them against the capabilities of currently available communication technologies. Based on the analysis, we identify a gap and indicate possible system designs for the fifth-generation (5G) V2X that could close the gap. Furthermore, we discuss an architecture of the 5G V2X radio access network (RAN) that incorporates diverse communication technologies, including current and cellular systems in centimeter wave (cm-wave) and millimeter wave (mm-wave), IEEE Standard 802.11p [1], and vehicular visible light communications (VVLC). Finally, we discuss the role of future 5G V2X systems in enabling more efficient vehicular transportation: from improved traffic flow and reduced intervehicle spacing on highways to coordinated intersections in cities (the cheapest way to increasing the road capacity) to automated smart parking (no more visits to the parking garage!), all of which will ultimately enable seamless end-to-end personal mobility.
Ahmed Danladi Abdullahi, Erfan Bahrami, Tooska Dargahi
et al.
The advancement of 6G technology has the potential to revolutionize the transportation sector and significantly improve how we travel. 6G-enabled Intelligent Transportation Systems (ITS) promise to offer high-speed, low-latency communication and advanced data analytics capabilities, supporting the development of safer, more efficient, and more sustainable transportation solutions. However, various security and privacy challenges were identified in the literature that must be addressed to enable the safe and secure deployment of 6G-ITS and ensure people's trust in using these technologies. This paper reviews the opportunities and challenges of 6G-ITS, particularly focusing on trust, security, and privacy, with special attention to quantum technologies that both enhance security through quantum key distribution and introduce new vulnerabilities. It discusses the potential benefits of 6G technology in the transportation sector, including improved communication, device interoperability support, data analytic capabilities, and increased automation for different components, such as transportation management and communication systems. A taxonomy of different attack models in 6G-ITS is proposed, and a comparison of the security threats in 5G-ITS and 6G-ITS is provided, along with potential mitigating solutions. This research highlights the urgent need for a comprehensive, multi-layered security framework spanning physical infrastructure protection, network protocol security, data management safeguards, application security measures, and trust management systems to effectively mitigate emerging security and privacy risks and ensure the integrity and resilience of future transportation ecosystems.
Anubhab Chowdhury, Sai Subramanyam Thoota, Erik G. Larsson
This paper studies integrated sensing and communication (ISAC) with dynamic time division duplex (DTDD) cell-free (CF) massive multiple-input multiple-output~(mMIMO) systems. DTDD enables the CF mMIMO system to concurrently serve both uplink~(UL) and downlink~(DL) users with spatially separated \emph{half-duplex~(HD)} access points~(APs) using the same time-frequency resources. Further, to facilitate ISAC, the UL APs are utilized for both UL data and target echo reception, while the DL APs jointly transmit the precoded DL data streams and target signal. In this context, we present centralized and distributed generalized likelihood-ratio tests~(GLRTs) for target detection treating UL users' signals as sensing interference. We then quantify the optimality and complexity trade-off between distributed and centralized GLRTs and benchmark the respective estimators with the Bayesian Cramér-Rao lower bound for target radar-cross section~(RCS). Then, we present a unified framework for joint UL users' data detection and RCS estimation. Next, for communication, we derive the signal-to-noise-plus-interference~(SINR) optimal combiner accounting for the cross-link and radar interference for UL data processing. In DL, we use regularized zero-forcing for the users and propose two types of precoders for the target: one ``user-centric" that nullifies the interference caused by the target signal to the DL users and one ``target-centric" based on the dominant eigenvector of the composite channel between the target and the APs. Finally, numerical studies corroborate with our theoretical findings and reveal that the \emph{GLRT is robust to inter-AP interference, and DTDD doubles the $90\%$-likely sum UL-DL SE compared to traditional TDD-based CF-mMIMO ISAC systems}; while using HD hardware.
With both regional authorities and corporate entities declaring net-zero greenhouse gas ambitions over the last decade, the assessment and development of potential solutions has accelerated. One of the key sectors emitting around 25 % of energy-related greenhouse gases is transportation. Although some segments of the transportation sector have instituted concrete plans with strict regulatory requirements, the maritime sector faces significant challenges in decarbonization, driven by the limited availability of low-emission fuels and commercialized zero-emission vessels compared to its high energy demand. In this work, we develop the Mobility and Energy Transportation Analysis Model, a python-based optimization model to investigate the maritime sector’s current and projected energy demand and a technology sales forecast based on different scenarios, including the latest IMO aspirations to reach carbon neutrality by 2050 on a Well to Wake basis. Along with introducing lower carbon fuels as alternative refueling options for conventional vessels, we explore the market opportunities of mobile carbon capture (MCC), also referred to as Onboard Carbon Capture (OCC) through 2050. To accurately assess this technology, a techno-economic analysis is essential to determine marginal abatement costs compared to alternative decarbonization technologies. Considering consumer decision making as a key factor in shaping the future of marine vessels represents the novelty of our methodology. An additional novelty of this work comes from the detailed cost categories taken into consideration in the analysis, including intangible costs associated with MCC system cost components for different capture rates, as well as the total cost of owning each vessel technology. Based on the study results, MCC could be a viable alternative technology to decarbonize the marine fleet towards complying with IMO’s regulations.
[Objective] Evacuation bottlenecks for subway stations in flood scenarios are investigated to enhance subway station personnel evacuation efficiency under water inundation and backflow conditions, and provide insights for developing subway evacuation emergency plans. [Method] Pedestrian walking tests are conducted using drone aerial footage. OpenCV (open source computer vision) library image processing algorithms are employed to analyze pedestrians walking paths and calculate their walking speeds in carious water depth scenarios. Based on the social force model and in line with subway safety evacuation standards, an emergency evacuation simulation model for subway stations in flood scenarios is established and then simulated using Anylogic. [Result & Conclusion] The test results show that the deeper the water depth, the slower the pedestrian passage speed, and the greater the amplitude of the left-right swing of the pedestrians to maintain balance. If support structures are added in critical areas, pedestrian walking efficiency can be effectively improved. Taking a sunken plaza subway station in a coastal city as an example, different degrees of inundation and backflow are analyzed through simulation. Results show that the water depth has a significant impact on the walking speed and evacuation efficiency of pedestrians. When water depth is over 5 cm, the evacuation time may exceed the requirements of evacuation specifications. When water depth reaches 20 cm, the proportion of people safely evacuated within 6 minutes is 26.38%. Failure to organize timely and effective evacuation during the flood event will seriously threaten the evacuation safety of the subway station.
Improving public transport connectivity is crucial for decarbonisation and economic growth. Current transport planning approaches to addressing connectivity problems rely on trial-and-error approaches to identify problems and generate options, limited by planners' incomplete knowledge and the overwhelming volume of available travel data.We introduce a machine-assisted approach to identify opportunities for connectivity enhancements from origin-destination data and generate prioritised intervention options. Using an origin-destination matrix for Greater London covering approximately 1200 activity centres, our method applies trajectory clustering to identify potential high-demand corridors with poor public transport quality.Our prototype automatically generates multiple public transport scheme options (local bus, express bus, metro) within these corridors along with approximate operating costs. These options are batch-tested using accelerated assignment modelling that optimises mode choice, frequency, and route generation, and the results are given ordered according to benefit-cost ratios.This approach is now being used to supplement human planners’ knowledge in the development of new express bus services in London.
Transportation and communications, Transportation engineering
Mateusz Zajac, Tomislav Rožić, Justyna Swieboda-Kutera
et al.
<i>Background</i>: The increasing complexity of global supply chains and environmental expectations has highlighted the strategic importance of digital transformation in the transport, forwarding, and logistics (TFL) sector. Despite a growing portfolio of available tools, adoption rates—particularly among small and medium-sized enterprises (SMEs) in Central and Eastern Europe—remain low. This study investigates the barriers and motivations related to the implementation of digital planning tools supporting intermodal transport planning. <i>Methods</i>: A structured online survey was conducted among 80 Polish TFL enterprises, targeting decision-makers responsible for operational and digital strategies. The questionnaire included 17 closed and semi-open questions grouped into three thematic sections: tool usage, implementation barriers, and digital readiness. <i>Results</i>: The findings indicate that only 20% of respondents use dedicated route planning tools, and merely 10% report satisfaction with their performance. Key barriers include lack of awareness, organizational inertia, and the prioritization of other initiatives, with financial cost cited less frequently. While environmental sustainability is declared as a priority by most enterprises, digital support for emission tracking is limited. The results highlight the need for targeted education, integration support, and differentiated platform functionalities for SMEs and larger firms. <i>Conclusions</i>: This study offers evidence-based recommendations for developers, policymakers, and logistics managers aiming to accelerate digital adoption in the intermodal logistics landscape.
Transportation and communication, Management. Industrial management
This study introduces a novel dataset of parking lot boundaries covering fifteen US cities. We generate this dataset using a deep learning segmentation model described in Qiam et al. (2025), and a subsequent post-processing workflow. The dataset, publicly available in shapefile format, enables spatial analysis of parking land use at both inter- and intra-city levels. To estimate the share of off-street land used for off-street parking, we link these polygons with tax parcel datasets, in order to exclude streets and public sidewalks. Off-street surface parking accounts for as little as 3.4% of parcel land in Oakland and as much as 10.7% in Anaheim, with central business districts ranging from 2.3% in Boston to 31.7% in Tulsa.
Transportation and communications, Urban groups. The city. Urban sociology
Vehicular communications, referring to information exchange among vehicles, infrastructures, etc., have attracted a lot of attention recently due to great potential to support intelligent transportation, various safety applications, and on-road infotainment. In this paper, we provide a comprehensive overview of a recent research on enabling efficient and reliable vehicular communications from the network layer perspective. First, we introduce general applications and unique characteristics of vehicular communication networks and the corresponding classifications. Based on different driving patterns, we categorize vehicular networks into manual driving vehicular networks and automated driving vehicular networks, and then discuss the available communication techniques, network structures, routing protocols, and handoff strategies applied in these vehicular networks. Finally, we identify the challenges confronted by the current vehicular networks and present the corresponding research opportunities.
The Rydberg atomic quantum receivers (RAQR) are emerging quantum precision sensing platforms designed for receiving radio frequency (RF) signals. It relies on creation of Rydberg atoms from normal atoms by exciting one or more electrons to a very high energy level, thereby making the atom sensitive to RF signals. RAQRs realize RF-to-optical conversions based on light-atom interactions relying on the so called electromagnetically induced transparency (EIT) and Aulter-Townes splitting (ATS), so that the desired RF signal can be read out optically. The large dipole moments of Rydberg atoms associated with rich choices of Rydberg states and various modulation schemes facilitate an ultra-high sensitivity ($\sim$ nV/cm/$\sqrt{\text{Hz}}$) and an ultra-broadband tunability (direct-current to Terahertz). RAQRs also exhibit compelling scalability and lend themselves to the construction of innovative, compact receivers. Initial experimental studies have demonstrated their capabilities in classical wireless communications and sensing. To fully harness their potential in a wide variety of applications, we commence by outlining the underlying fundamentals of Rydberg atoms, followed by the principles and schemes of RAQRs. Then, we overview the state-of-the-art studies from both physics and communication societies. Furthermore, we conceive Rydberg atomic quantum single-input single-output (RAQ-SISO) and multiple-input multiple-output (RAQ-MIMO) schemes for facilitating the integration of RAQRs with classical wireless systems. Finally, we conclude with a set of potent research directions.