Terrestrial Networks Research Articles

Analysing Roman itineraries using GIS tooling: the case of the road XIX (mansions from Tude to Luco Augusti)

Reconstruction of the Roman road network must be approached from different methodologies of multidisciplinary character. Once the traditional approaches have been exhausted without achieving a historiographical consensus, the problem may appear insurmountable. However, leveraging Geographic Information Systems (GIS) provides an avenue for re-evaluating existing proposals and suggesting more fitting layouts. This can be accomplished through a meticulous analysis that incorporates topographic and non-Euclidean correlations; allowing a more nuanced and accurate understanding of the subject matter than conventional methods might offer. In this context, the aim of this article is to discuss intriguing research points. But also emphasize the importance of multidisciplinary and multi-proxy studies in relation with the Roman terrestrial networks. We explore a case study in the Galician territory, where we have detected methodological shortcomings reconstructing the route of the XIX road: Item Bracaram Asturicam. One of the sections, from Tude to Luco Augusti, has aroused a greater debate, based on several basic problems: (1) the identification of the mansions, (2) the lack of consensus in the measurements of the distances, (3) the miles referred to in the classical sources, and (4) the complex orography of this territory. To propose answers and theories, that may solve the current problems of the description of this route of the XIX road, a multi- proxy approached methodology is proposed. Thus, by applying Geographic Information Systems techniques, we will be able to calculate the optimal path, and compare the results with historical data and archaeological evidence.

Hierarchical Resource Management for Mega-LEO Satellite Constellation

The mega-low Earth orbit (LEO) satellite constellation is pivotal for the future of satellite Internet and 6G networks. In the mega-LEO satellite constellation system (MLSCS), which is the spatial distribution of satellites, global users, and their services, along with the utilization of global spectrum resources, significantly impacts resource allocation and scheduling. This paper addresses the challenge of effectively allocating system resources based on service and resource distribution, particularly in hotspot areas where user demand is concentrated, to enhance resource utilization efficiency. We propose a novel three-layer management architecture designed to implement scheduling strategies and alleviate the processing burden on the terrestrial Network Control Center (NCC), while providing real-time scheduling capabilities to adapt to rapid changes in network topology, resource distribution, and service requirements. The three layers of the resource management architecture—NCC, space base station (SBS), and user terminal (UT)—are discussed in detail, along with the functions and responsibilities of each layer. Additionally, we explore various resource scheduling strategies, approaches, and algorithms, including spectrum cognition, interference coordination, beam scheduling, multi-satellite collaboration, and random access. Simulations demonstrate the effectiveness of the proposed approaches and algorithms, indicating significant improvements in resource management in the MLSCS.

Dimensioning Space-Air-Ground Integrated Networks for In-Flight 6G Slice Orchestration

In this study, we present an in-depth analysis of communication services for commercial airline passengers, focusing on the challenges posed by increasing internet traffic demand. We explore the integration of satellite, airborne, and terrestrial networks, emphasizing the roles of Low Earth Orbit (LEO) satellites, High-Altitude Platform Station (HAPS), and Terrestrial Aviation Network (TAN)-based services. Our contribution includes a theoretical model for optimizing resource allocation and capacity planning in non-terrestrial wireless networks, using a bipartite graph approach and linear programming techniques. The model shows adaptability and efficiency, providing key insights through numerical analysis. Leveraging a detailed air traffic dataset, a machine learning-based aggregation method, and real-world network parameters, our research addresses current challenges, such as scalable network capacity dimensioning in high-density airspaces and meeting the demand for quality of service by robust resource provisioning, and advances the design of communication networks for Space–Air–Ground Integrated Network (SAGIN). Numerical results from European airspace suggest that complementing TAN and LEO satellite networks with HAPS-based services will be essential as airline passengers adopt ground-level internet usage patterns.

UAV Communication in Space–Air–Ground Integrated Networks (SAGINs): Technologies, Applications, and Challenges

With the continuous advancement of 6G technology, SAGINs provide seamless coverage and efficient connectivity for future communications by integrating terrestrial, aerial, and satellite networks. Unmanned aerial vehicles (UAVs), owing to their high maneuverability and flexibility, have emerged as a critical component of the aerial layer in SAGINs. In this paper, we systematically review the key technologies, applications, and challenges of UAV-assisted SAGINs. First, the hierarchical architecture of SAGINs and their dynamic heterogeneous characteristics are elaborated on, and this is followed by an in-depth discussion of UAV communication. Subsequently, the core technologies of UAV-assisted SAGINs are comprehensively analyzed across five dimensions—routing protocols, security control, path planning, resource management, and UAV deployment—highlighting the progress and limitations of existing research. In terms of applications, UAV-assisted SAGINs demonstrate significant potential in disaster recovery, remote network coverage, smart cities, and agricultural monitoring. However, their practical deployment still faces challenges such as dynamic topology management, cross-layer protocol adaptation, energy-efficiency optimization, and security threats. Finally, we summarize the applications and challenges of UAV-assisted SAGINs and provide prospects for future research directions.

Improving the Hybrid FSO/LI-FI/UWOC Network's

Abstract: Optical wireless communications are an alternative approach to address the challenges in completing the deployment of terrestrial networks to underwater optical wireless communication (UWOC) environments. This study aims to investigate the effectiveness of a free-space optical (FSO) channel system to feed light-fidelity Li-Fi-closed underwater platforms that, in turn, supply the non-line-of-sight (NLOS) link with the proper communications. The FSO link faces the challenge of attenuation due to the surrounding environment, which in turn negatively affects the communication link reaching the end user underwater via Li-Fi underwater platforms according to the proposed scenario. measurements show a strong signal at the receiver, it indicates that the reflection is effective and that the system can successfully transmit information using NLOS methods. Multipath with apt transmit power and NLOS transmission surface incident angle selection achieved ambitious results and sustainable connectivity even in rainy situations surrounding the FSO system.

Joint Interference Management and Traffic Offloading in Integrated Terrestrial and Non-Terrestrial Networks

Joint Interference Management and Traffic Offloading in Integrated Terrestrial and Non-Terrestrial Networks

Energy‐Aware Protocol Design and Evaluation of the PHY Layer in Satellite IoT

ABSTRACTDirect‐to‐satellite communication for the Internet of Things (IoT) has attracted significant interest from both the scientific community and major telecommunications players. The integration of satellite connectivity in smartphones and IoT devices promises a transformative impact on critical applications such as environmental monitoring, asset tracking, agriculture, and nature conservation. These applications require reliable and energy‐efficient technologies for transmitting sensor data from regions without terrestrial networks, necessitating robust design of waveforms and protocols. This work investigates the most suitable IoT protocols for direct‐to‐satellite communication, emphasizing overhead, spectral, and energy efficiency. By introducing a framework and evaluation metrics that incorporate physical layer overhead into the evaluation, a comprehensive analysis of the effective energy efficiency in satellite IoT systems is conducted. Our findings highlight substantial differences among the Low Power Wide Area Network (LPWAN) protocols. Consequently, we propose a new classification for the most energy‐efficient protocols, termed Massive Multiple Access very Low Power Wide Area Networks (MMA‐vLPWANs). This classification aims to streamline the selection process for energy‐conscious satellite IoT waveforms for deployments in remote areas. The results not only advance the understanding of protocol efficiency in satellite IoT communications but also offer a guideline for optimizing power usage in IoT devices, extending their operational life and enhancing their utility in inaccessible regions.

Model‐based impact analysis of climate change and land‐use intensification on trophic networks

There is well‐established evidence that land use is the main driver of terrestrial biodiversity loss. In contrast, the combined effects of land‐use and climate changes on food webs, particularly on terrestrial trophic networks, are understudied. In this study, we investigate the combined effects of climate change (temperature, precipitation) and land‐use intensification on food webs using a process‐based general mechanistic ecosystem model (‘MadingleyR'). We simulated the ecosystem dynamics of four regions in different climatic zones (Brazil, Namibia, Finland and France) according to trait‐based functional groups of species (ectothermic and endothermic herbivores, carnivores and omnivores). The simulation results were consistent across the selected regions, with land‐use intensification negatively affecting endotherms, whereas ectotherms were under increased pressure from rising temperatures. Land‐use intensification led to the downsizing of endotherms, and thus, to smaller organisms in the food web. In combination with climate change, land‐use intensification had the greatest effect on higher trophic levels, culminating in the extinction of endothermic carnivores in Namibia and Finland and endothermic omnivores in Namibia. Arid and tropical regions showed a slightly higher response of total biomass to climate change under a high‐emissions scenario with rising temperatures, whereas areas with low net primary productivity showed the most negative response to land‐use intensification. Our results suggest that 1) further land‐use intensification will significantly affect larger organisms and predators, leading to a major restructuring of global food webs. 2) Arid low‐productivity regions will experience significant changes in community composition due to global change. 3) Climate changes appear to have slightly greater effects in tropical and arid climates, whereas land‐use intensification tends to affect less productive environments. This paper shows how general ecosystem models deepen our understanding of multitrophic interactions and how climate change or land‐use drivers affect ecosystems in different biomes.

Optimized Dynamic Deployment of UAVs in Maritime Networks with Route Prediction

The limited coverage of terrestrial base stations and the limited transmission distance and onboard resources of satellite communications make it difficult to ensure the quality of communication services for marine users by relying only on satellites and terrestrial base stations. In contrast, UAVs, as flexible mobile communication nodes, have the capacity for dynamic deployment and real-time adjustment. They can effectively make up for the communication blind spots of traditional satellites and ground base stations in the marine environment, especially in the vast and unpredictable marine environment. Considering the mobility of maritime users, one can effectively reduce the communication delay and optimize the deployment scheme of UAVs by predicting their sailing trajectories in advance, thus enhancing the communication service quality. Therefore, this paper proposes a communication coverage model based on mobile user route prediction and a UAV dynamic deployment algorithm (RUDD). It aims to optimize the coverage efficiency of the maritime communication network, minimize the communication delay, and effectively reduce the energy consumption of UAVs. In this algorithm, the RUDD algorithm employs a modified Long Short-Term Memory (LSTM) network to predict the maritime user’s trajectory, utilizing its strengths in processing time-series data to provide accurate predictions. The prediction results are then used to guide the Proximal Policy Optimization (PPO) algorithm for the dynamic deployment of UAVs. The PPO algorithm can optimize the deployment strategy in dynamic environments, improve communication coverage, and reduce energy consumption. Simulation results show that the proposed algorithm can complement the existing satellite and terrestrial networks well in terms of coverage, with a communication coverage rate of more than 95%, which significantly improves the communication quality of marine users in areas far from land and beyond the reach of traditional networks, and enhances network reliability and user experience.

SDN-Based Integrated Satellite Terrestrial Cyber–Physical Networks with 5G Resilience Infrastructure: Future Trends and Challenges

This paper reviews the state-of-the art technologies and techniques for integrating satellite and terrestrial networks within a 5G and Beyond Networks (5GBYNs). It highlights key limitations in existing architectures, particularly in addressing interoperability, resilience, and Quality of Service (QoS) for real-time applications. In response, this work proposes a novel Software-Defined Networking (SDN)-based framework for reliable satellite–terrestrial integration. The proposed framework leverages intelligent traffic steering and dynamic access network selection to optimise real-time communications. By addressing gaps in the literature with a distributed SDN control approach spanning terrestrial and space domains, the framework enhances resilience against disruptions, such as natural disasters, while maintaining low latency and jitter. Future research directions are outlined to refine the design and explore its application in 6G systems.

Pre-calculated space-ground integrated structure (P-SGIS) against link cut set (LCS) failures in space-ground integrated optical networks.

Fiber link failure is a common and frequent failure type in terrestrial optical networks (TONs). To guarantee the stable operation of the TON against single or multi-link failures, various kinds of survivability technologies have been proposed. Although these survivability technologies are effective in many cases, a link cut set (LCS), which is a set of fiber links whose simultaneous failures can disconnect the TON, presents an extreme situation of network partitioning that these technologies cannot address. Recently, the satellite network has obtained rapid development and various types of satellite constellations are being constructed. Moreover, the laser inter-satellite link (LISL) is studied deeply and verified widely. The satellite optical network (SON) is gradually formed and can be integrated with the TON together into the space-ground integrated optical network (SGION). In the SGION, the LCS failure in the TON can be addressed by the SON. This paper focuses on space-ground integrated protection. A pre-calculated space-ground integrated structure (P-SGIS) is designed. "Pre-calculated" refers to extracting reliable, low-redundant backup protection structures in advance from the physical topology of the SGION, based on prior knowledge, such as satellite movement regularity, failure distribution, and so on. Heuristic algorithms are developed for P-SGIS construction and backup resource reservation. Numerical results show that the P-SGIS-based protection scheme has high resource efficiency and protection success rate.

Induced geoelectric field: influence of polarization in coast effect and proximity effect

During a magnetic storm, the induced geoelectric field drives induced currents that couple with artificial metallic networks such as power lines, pipelines, telecommunication cables and railway lines with the consequent risk, in case of strong events, of possible blackouts, damages and impairments of those systems. It is known that magnetic storms are global phenomena and their effects in specific regions with specific ground conductivity may be different; in particular, when a magnetic storm involves regions composed of two adjacent media characterized by very large difference of conductivity between them (e. g. sea and land) the induced geoelectric field is largely influenced by this conductivity contrast and depends, primarily, on its orientation with respect to the discontinuity line. By representing the source as an incident plane wave normally directed with respect to the air-land/sea interface, two kinds of polarizations are usually considered in literature: H/E polarization i.e. with the incident magnetic/electric field parallel to the discontinuity. In this paper, we wish to study a more general case i.e. when the source is characterized by an electric field forming a generic angle with the discontinuity line so that the resulting field is a combination of both H and E polarizations; to do this, and by adopting a 2D approach based on the generalized thin sheet model, the paper combines, published formulas for H polarization while new approximated analytic formulas for E polarization are derived. Moreover, we express the induced geoelectric field as a function of a generic direction which represents the layout orientation of a potentially affected plant (power line, pipeline…); this is important, because that is the first step necessary to evaluate the level of geomagnetically induced currents (GIC) in the plant itself. In conclusion, the novelty of this approach is that the resulting induced geoelectric field on the Earth’s surface can be expressed using only analytical formulas; a further advantage of the proposed approach to the problem is that it is quite simple and particularly suitable for the evaluation of GIC in terrestrial conductor networks.

Performance Optimization of 5G–Satellite Integrated Networks for IoT Applications in Smart Cities: A Two-Ray Propagation Model Approach

The convergence of 5G terrestrial networks with satellite systems offers a revolutionary approach to achieving global, seamless connectivity, particularly for Internet of Things (IoT) applications in urban and rural settings. This paper investigates the implications of this 5G–satellite integrated network architecture, specifically through the application of the two-ray propagation model and the free-space path loss (FSPL) model. By simulating signal characteristics over varying distances, altitudes, and environmental parameters, we explore how factors such as transmitter height, satellite altitude, and frequency impact received power, path loss, channel capacity, and outage probability. The key findings indicate that received power decreases significantly with increasing distance, with notable oscillations in the two-ray model due to interference from ground reflections, particularly evident within the first 100 km. For example, at 50 km, a 300 km satellite altitude yields approximately −115 dBm in received power, while at 1000 km altitude, this power drops to around −136 dBm. Higher frequencies (e.g., 32 GHz) exhibit greater path loss than lower frequencies (e.g., 24 GHz), with a 5 dB difference observed at 1000 km, reinforcing the need for frequency considerations in long-range communication design. In terms of channel capacity, increasing bandwidth enhances achievable data rates but declines with distance due to diminishing received power. At 100 km, a 50 MHz bandwidth supports up to 4500 Mbps, while at 3000 km, capacity drops to around 300 Mbps. The outage probability analysis shows that higher signal-to-noise ratio (SNR) thresholds substantially increase the likelihood of communication failures, especially at distances exceeding 2000 km. For instance, at 3000 km, the outage probability for a 15 dB SNR threshold reaches approximately 25%, compared to less than 5% for a 5 dB threshold. These results underscore the critical trade-offs in designing 5G–satellite IoT networks, balancing bandwidth, frequency, SNR thresholds, and satellite altitudes for optimal performance across diverse IoT applications. The analysis provides valuable insights for enhancing connectivity and reliability in 5G–satellite integrated networks, especially in remote and underserved regions.

Full-Scale Assessment of the “5GT System” for Tracking and Monitoring of Multimodal Dry Containers

A novel tracking and monitoring system for ISO 668 dry containers was realized by the ESA-funded “5G SENSOR@SEA” project, integrating 5G cellular technologies for massive Internet of Things with a GEO satellite-optimized backhauling link. The scope is the development of monitoring and tracking new services for multimodal container shipping. With the cooperation of four industrial partners and a telecommunication research center, the so-called “5GT System” was designed, developed, tested and validated up to field trials. Several modules of the system were designed, built and finally installed on the ship and in the teleport: the container tracking devices placed on the containers, the NB-IoT cellular network with optimized satellite backhauling, the Ku-band satellite terminals and the maritime service platform based on the OneM2M standard. The field trial conducted during the intercontinental liner voyage of a container ship showed primary technical achievements, including fair switching between terrestrial and satellite networks, reduction in packet loss in the open sea scenario and seamless integration of the BLE mesh network over the container tracking devices as NB-IoT/BLE LE Mesh gateways.

Derivation of the carbon dioxide total column in the atmosphere from satellite-based infrared fourier-transform spectrometer IKFS–2 measurements: analysis and application experience

The paper discusses the use of a new version of the regression technique for derivation the total content of carbon dioxide in the atmosphere XCO2 (column-averaged dry-air mole fraction) from measurements of the infrared Fourier-transform spectrometer IKFS–2 installed on board Russian meteorological satellite Meteor-M No. 2. To evaluate the accuracy of satellite-based XCO2 estimates the retrospective comparison was made with data from ground-based spectroscopic measurements at Peterhof site of St. Petersburg State University as well as with aircraft measurements of the V. E. Zuev Institute of Atmospheric Optics (IOA) in the area of the Novosibirsk Reservoir conducted in 2019-2022. A brief description of the regression technique modifications is given made to improve the accuracy of satellite – based XCO2 estimates. In particular, to compensate for the effect of changes in the IKFS-2 characteristics during a long flight, the XCO2 estimates calibration is realized using ground - based XCO2 measurements at the NOAA Observatory on Mauna Loa volcano (island of Hawaii). After calibration and cloud scenes filtering, the discrepancy between satellite estimates and ground-based / aircraft measurements is characterized by root mean square deviation of ~4 ppm or 1% of the CO2 total content. In order to accelerate the adjustment of the regression technique, used for estimating XCO2, to IKFS-2 data on new satellites, it is reasonable to use XCO2 observations at the TCCON terrestrial network in addition to conventional contact measurements of CO2 concentrations. Along with this, it seems rational to use the cryogenic film thickness on the glass of the IKFS-2 photodetector, characterizing the state of the instrument, as additional predictor in the regression model.

Interference mitigation method for LEO satellites with optimal dynamic switching array elements in co‐frequency beams

AbstractSatellite communication has rapidly advanced, from navigation to broadband Internet and direct mobile connectivity. Driven by low Earth orbit satellites, these networks are merging with terrestrial mobile networks, forming integrated space–air–ground systems. However, the growing scale of satellite constellations has intensified intra‐system interference, particularly among ground cells utilizing co‐frequency beams. A mitigation method based on switching array elements is proposed, optimizing their state by considering beamwidth and maximum sidelobe level. Simulations show that the proposed algorithm effectively reduces beam coverage widening and sidelobes, mitigating the interference between co‐frequency beams.

Performance analysis of terrestrial 6G networks in tropical region

Performance analysis of terrestrial 6G networks in tropical region

Mobility-Aware Congestion Control for Multipath QUIC in Integrated Terrestrial Satellite Networks

Mobility-Aware Congestion Control for Multipath QUIC in Integrated Terrestrial Satellite Networks

Application of 6G Technology in Satellite-Terrestrial Communications

In the contemporary digital era, the accelerated dissemination of data and pervasive interconnectivity have emerged as pivotal drivers of social advancement. The increasing demand for high-performance satellite-terrestrial communications systems, which are vital for achieving seamless global coverage, presents a significant challenge. The advent of 6G technology offers a promising avenue for addressing the current limitations of satellite-terrestrial communications. This paper presents a comprehensive review of the potential applications of 6G technology in satellite-terrestrial communication systems, with a particular focus on its capacity to transform these systems. By achieving seamless global connectivity, 6G technology is positioned to address the limitations of current communication technologies and enhance communication speeds, reliability, and efficiency. This research indicates that the integration of satellite and terrestrial communication networks through 6G not only improves the overall efficiency and coverage of the communication network, but also addresses existing challenges such as limited coverage, high latency and scarce spectrum resources. As research and development progresses, it will be essential to facilitate the widespread adoption and evolution of 6G technology in satellite-terrestrial communications through strengthened global cooperation and standardisation.

Performance Analysis of Reconfigurable Intelligent Surface (RIS)-Assisted Satellite Communications: Passive Beamforming and Outage Probability

Reconfigurable intelligent surfaces (RISs), which consist of numerous passive reflecting elements, have emerged as a prominent technology to enhance energy and spectral efficiency for future wireless networks. RISs have the capability to intelligently reconfigure the incident wave, reflecting it towards the intended target without requiring energy for signal processing. Consequently, they have become a promising solution to support the demand for high-throughput satellite communication (SatCom) and enhanced coverage for areas inaccessible to terrestrial networks. This paper presents an asymptotic analysis of an RIS-assisted SatCom system. In this system, an unmanned aerial vehicle equipped with an RIS operates as a mobile reflector between a satellite and users. In particular, a passive beamformer is designed with the aim of asymptotically attaining optimal performance, considering the limitations imposed by practical SatCom systems. Moreover, the closed-form expressions for the ergodic achievable rate and outage probability are derived considering the proposed passive beamforming technique. Furthermore, we extend the system model to a multicast system and asymptotically analyze the optimality of the proposed scheme, leveraging the derived asymptotic results in the unicast system. The results of the simulations confirm that our analyses can precisely and analytically assess the performance of the RIS-assisted SatCom system, confirming the asymptotic optimality of the proposed scheme.