FSSCat Mission description and first scientific results of the FMPL-2 onboard 3CAT-5/A
Camps Carmona, Adriano José; Muñoz Martin, Joan Francesc; Ruiz De Azúa Ortega, Juan Adrián; Fernandez Capon, Lara Pilar; Pérez Portero, Adrián; Llaveria Godoy, David; Herbert, Christoph Josef; Pablos Hernández, Miriam; Golkar, Alessandro; Gutiérrez Peña, Antonio
FSSCat, the “Federated Satellite Systems/ 3 Cat-5” mission was the winner of the 2017 ESA S^3 (Sentinel Small Satellite) Challenge and overall winner of the Copernicus Masters competition. FSSCat consists of two 6 unit cubesats carrying on board UPC's Flexible Microwave Payload - 2 (FMPL-2), an L-band microwave radiometer and GNSS-Reflectometer implemented in a software defined radio, and Cosine's HyperScout-2 visible and near infrared + thermal infrared hyperspectral imager, enhanced with PhiSat-1, a on board Artificial intelligence experiment for cloud detection. Both spacecrafts include optical and UHF inter-satellite links technology demonstrators, provided by Golbriak Space and UPC, respectively. This paper describes the mission, and the main scientific results of the FMPL-2 obtained during the first three months of the mission, notably the sea ice concentration and thickness, and the downscaled soil moisture products over the Northern hemisphere.
FSSCat Mission description and first scientific results of the FMPL-2 onboard 3CAT-5/A
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Genetic algorithm-based grouping strategy for IEEE 802.11ah networks
Genetic algorithm-based grouping strategy for IEEE 802.11ah networks
García Villegas, Eduard; López García, Alejandro; López Aguilera, M. Elena
The IEEE 802.11ah standard is intended to adapt the specifications of IEEE 802.11 to the Internet of Things (IoT) scenario. One of the main features of IEEE 802.11ah consists of the Restricted Access Window (RAW) mechanism, designed for scheduling transmissions of groups of stations within certain periods of time or windows. With an appropriate configuration, the RAW feature reduces contention and improves energy efficiency. However, the standard specification does not provide mechanisms for the optimal setting of RAW parameters. In this way, this paper presents a grouping strategy based on a genetic algorithm (GA) for IEEE 802.11ah networks operating under the RAW mechanism and considering heterogeneous stations, that is, stations using different modulation and coding schemes (MCS). We define a fitness function from the combination of the predicted system throughput and fairness, and provide the tuning of the GA parameters to obtain the best result in a short time. The paper also includes a comparison of different alternatives with regard to the stages of the GA, i.e., parent selection, crossover, and mutation methods. As a proof of concept, the proposed GA-based RAW grouping is tested on a more constrained device, a Raspberry Pi 3B+ , where the grouping method converges in around 5 s. The evaluation concludes with a comparison of the GA-based grouping strategy with other grouping approaches, thus showing that the proposed mechanism provides a good trade-off between throughput and fairness performance.
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Enabling multi-tenant cellular IoT services over LEO constellations in future 6G networks
Enabling multi-tenant cellular IoT services over LEO constellations in future 6G networks
Kellermann, Timo Nicolas; Calveras Augé, Anna M.; Pueyo Centelles, Roger; Camps, Dani; Ferrús Ferré, Ramón Antonio; Guadalupi, Marco
Satellite-based, non-terrestrial networks (NTN) are crucial in providing global connectivity coverage, supporting important use cases in future 3rd Generation Partnership Project (3GPP) 6th generation networks (6G). Existing systems stand out due to their high complexity and specialized user equipment (UE) that comes with high operational costs. The rise of CubeSat and SmallSat spacecraft technology drastically cuts the cost of deployment, especially in Low Earth Orbits (LEO). Possible access architectures for NTN include repeater-like architectures with transparent payloads, where the gNB/eNB is located on the ground segment, or regenerative payloads, with a full gNB/eNB located on the satellite. A key NTN service is expected to be based on the extension of the NB-IoT (NarrowBand Internet of Things) protocol deployed over low-density LEO constellations using regenerative payloads, that are able to operate without having an active feeder link connection with a ground station. Enabling this service requires solving two key architectural challenges, namely the operation of the NB-IoT protocol in store and forward mode and supporting multi-tenancy, with multiples service providers using the same LEO constellation to extend their service footprint. The main contribution of this paper is the capacity analysis of a revised 3GPP architecture for NB-IoT services with a regenerative NTN architecture supporting discontinuous service and feeder link connectivity, by adding store and forward functionality. The assesment is supported by analysing the information flow of the revised architecture. Based on that architecture, we present a practical NB-IoT constellation and provide a capacity analysis. That constellation enabling for NB-IoT coverage across the globe may be possible with as little as one satellite, assuming its orbit covers the whole globe. Furthermore, we analyze authentication and user data transport with the maximum number of supported UE per satellite due to capacity constraints in the feeder link under typical data patterns. We find that variations in revisit and visibility times for both UEs and ground stations significantly impact the maximum number of supported users. Finally, the paper points out that new architectures for discontinuous backhauling, as one of the key NTN challenges, must be solved by future 6G networks.
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IPv6 over cross-technology communication with wake-up radio
IPv6 over cross-technology communication with wake-up radio
Aguilar Romero, Sergio; Vidal Ferré, Rafael; Gómez Montenegro, Carlos
A variety of wireless (and wired) technologies are being used to enable Internet of Things (IoT) device connectivity. Two examples of popular technologies in some crucial IoT domains (e.g., smart home, smart factories and smart cities, among others) are IEEE 802.15.4 and IEEE 802.11. However, IoT devices supporting different wireless technologies are not interoperable without a gateway. One solution to this problem is exploiting bidirectional Cross-Technology Communication with Wake-up Radio (WuR-CTC). Nevertheless, existing WuR-CTC approaches do not support IPv6, and therefore cannot offer full Internet protocol stack interoperability. For the first time to our knowledge, in this paper, we present the design, implementation and evaluation of an adaptation layer to provide IPv6 support over WuR-CTC, by leveraging the IETF Static Context Header Compression and fragmentation (SCHC) framework. Among others, experimental results show that our solution allows transferring a 127-byte IPv6 packet from an IEEE 802.15.4 device to an IEEE 802.11 device, without a gateway, in 69 ms (in average). Therefore, the designed solution supports latency-stringent applications in smart environments, where a human in the loop expects real-time interaction between devices.
© 2023 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
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Deep learning TCP for mitigating NLoS impairments in 5G mmWave
Deep learning TCP for mitigating NLoS impairments in 5G mmWave
Poorzare, Reza; Calveras Augé, Anna M.
5G and beyond 5G are revolutionizing cellular and ubiquitous networks with new features and capabilities. The new millimeter-wave frequency band can provide high data rates for the new generations of mobile networks but suffers from NLoS caused by obstacles, which causes packet drops that mislead TCP because the protocol interprets all drops as an indication of network congestion. The principal flaw of TCP in such networks is that the root for packet drops is not distinguishable for TCP, and the protocol takes it for granted that all losses are due to congestion. This paper presents a new TCP based on deep learning that can outperform other common TCPs in terms of throughput, RTT, and congestion window fluctuation. The primary contribution of deep learning is providing the ability to distinguish various conditions in the network. The simulation results revealed that the proposed protocol could outperform conventional TCPs such as Cubic, NewReno, Highspeed, and BBR.
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Design and validation of a dual-band circular polarization patch antenna and stripline combiner for the FSSCat mission
Design and validation of a dual-band circular polarization patch antenna and stripline combiner for the FSSCat mission
Fernandez Capon, Lara Pilar; Muñoz Martín, Joan Francesc; Ruiz de Azua, Joan Adria; Calveras Augé, Anna M.; Camps Carmona, Adriano José
The FMPL-2 payload on board the 3Cat-5/A 6 Unit CubeSat, part of the FSSCat CubeSat mission, includes a dual L-Band Microwave Radiometer and a Global Navigation Satellite System Reflectometer, in one instrument, implemented in a Software Defined Radio. One of the design challenges of this payload was its Nadir looking Antenna, which had to be directive (> 12 dB), dual-band at 1400–1427 MHz and 1575.42 MHz, left-hand circularly polarized, and with important envelope restrictions, notably with a low profile. After a trade-off analysis, the best design solution appeared to be an array of six elements each of them being a stacked dual-band patch antenna, with diagonal feed to create the circular polarization, and a six to one stripline combiner. The design process of the elementary antennas first includes a theoretical analysis, to obtain the approximate dimensions. Then, by means of numerical simulations, prototyping, and adjusting the results in the simulations, the manufacturing errors and dielectric constant tolerances, to which patch antennas are very sensitive, can be characterized. A similar approach is taken with the combiner. This article includes the theoretical analysis, simulations, and prototype results, including the Flight Model assembly and characterization
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Deployment of NB-IoT NTN core network functions on Software Defined Radio (SDR) nanosatellites: approach and performance assessment
Deployment of NB-IoT NTN core network functions on Software Defined Radio (SDR) nanosatellites: approach and performance assessment
Montilla, Víctor; Ferrer, Josep; Guadalupi, Marco; Ferrús Ferré, Ramón Antonio; Calveras Augé, Anna M.; Ruiz de Azua, Joan Adria
According to forecasts, around 10 billion connected devices in the world will exchange data over the Internet by2028 and the significant connections increase threatens to congest terrestrial networks. These devices will mainly beembedded, controlled by smart software and operated in the cloud, integrating the Internet of Things ecosystem. Addi-tionally, current terrestrial infrastructures do not meet novel IoT requirements: remote access areas, multiple networkdomains crossing and adaptable latency and bandwidth. To provide global and ubiquitous coverage, the 3GPP stan-dardizes in rel-17 the concept of Non-Terrestrial-Networks. The term includes, among others, Non-Terrestrial nodessuch as GEO, MEO and LEO satellites. Lately, LEO satellites have contributed to consolidate the New Space indus-try opening new business opportunities by providing services using low-cost CubeSats. Despite offering importantbenefits compared to GEO (e.g. lower latency and propagation loss), LEO still has challenges to face related to com-munication discontinuity (intermittent satellite-to-ground links). Global region coverage is achieved through satelliteconstellations; however, the main concern is the non-guarantee of simultaneous contact from UE to the Ground StationNetwork via the satellite. While 3GPP rel-17 specs have centered on the specification of satellites using transparentpayload, the use of regenerative payloads has not precluded and has a central role in the technology roadmap. Re-generative payloads envision to embark part of the NF within the satellite, giving multiple enhancements (e.g. lowerlatencies, Store-and-Forward operation, in-satellite local loop communications and edge computing). Onboard func-tions may include radio access functions, such as eNB/gNB, as well as core NF, which enables direct satellite responseto UE. This paper provides a performance analysis of a deployment of core NF in a regenerative payload with a Soft-ware Defined Radio based on FPGA technology for nanosatellites. Measures are obtained and contrasted against aRPi4 board by running a tailored Evolved Packet Core (EPC) with NB-IoT NTN support.
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Understanding the impact of packet size on the energy efficiency of LoRaWAN
Understanding the impact of packet size on the energy efficiency of LoRaWAN
Casals Ibáñez, Lluís; Gómez Montenegro, Carlos; Vidal Ferré, Rafael
LoRaWAN has become a flagship LPWAN technology, and one of the main connectivity alternatives for IoT devices. Since LoRaWAN was designed for low energy consumption, it is fundamental to understand its energy performance. In this paper, we study the impact of packet size on LoRaWAN device energy consumption per delivered data bit (EPB). By means of extensive simulations, we show that, when network performance is very high or very low, EPB decreases steadily with packet size; otherwise, EPB may show an “asymmetric U” shape as a function of packet size, with a minimum EPB value that is achieved for a medium packet size. We also provide detailed insights on the reasons that produce the observed behaviors.
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Improving road safety and user experience by employing dynamic in-vehicle information systems
Improving road safety and user experience by employing dynamic in-vehicle information systems
Galarza Osio, Miguel Ángel; Paradells Aspas, Josep
Modern vehicular infotainment systems are becoming increasingly complex and are embracing a wide range of functionalities. Interacting with some of these functionalities, while driving, may increase the driver's workload and affect the execution of primary driving tasks. This article addresses this issue and proposes a practical application that could help overcome the problem as well as improve the driving experience. The applied method consists of developing a system capable of estimating the driving complexity in real time using variables already available in current vehicles, and responding according to the complexity reference, to apply countermeasures to the infotainment system. The intended purpose is to facilitate the interaction with the functionalities and reducing the amount of information offered to the driver in complex scenarios. A baseline system was built and tested, demonstrating the feasibility of its implementation in current vehicles.
This is the peer reviewed version of the following article: Galarza, M.; Paradells, J. Improving road safety and user experience by employing dynamic in-vehicle information systems. "IET intelligent transport systems", 1 Abril 2019, vol. 13, núm. 4, p. 738-744, which has been published in final form at https://doi.org/10.1049/iet-its.2018.5022. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
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A high-accuracy, scalable and affordable indoor positioning system using visible light positioning for automated guided vehicles
A high-accuracy, scalable and affordable indoor positioning system using visible light positioning for automated guided vehicles
Boixader Coma, Aleix; Labella, Carlos; Catalán, Marisa; Paradells Aspas, Josep
Indoor Positioning Systems (IPSs) have multiple applications. For example, they can be used to guide people, to locate items in a warehouse and to support the navigation of Automated Guided Vehicles (AGV). Currently most AGVs use local pre-defined navigation systems, but they lack a global localisation system. Integrating both systems is uncommon due to the inherent challenge in balancing accuracy with coverage. Visible Light Position (VLP) offers accurate and fast localisation, but it encounters scalability limitations. To overcome this, this paper presents a novel Image Sensor-based VLP (IS-VLP) identification method that harnesses existing Light Emitting Diode (LED) lighting infrastructure to substitute both navigation and localisation systems effectively in the whole area. We developed an IPS that achieves six-axis positioning at 90 Hz refresh rate using OpenCV’s solvePnP algorithm and embedded computing. This IPS has been validated in a laboratory environment and successfully deployed in a real factory to position an operative AGV. The system has resulted in accuracies better than 12 cm for 95% of the measurements. This work advances towards positioning VLP as an appealing choice for IPS in industrial environments, offering an inexpensive, scalable, accurate and robust solution.
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