Survey of Inter-satellite Communication for Small Satellite Systems: Physical Layer to Network Layer View

Small satellite systems enable whole new class of missions for navigation, communications, remote sensing and scientific research for both civilian and military purposes. As individual spacecraft are limited by the size, mass and power constraints, mass-produced small satellites in large constellations or clusters could be useful in many science missions such as gravity mapping, tracking of forest fires, finding water resources, etc. Constellation of satellites provide improved spatial and temporal resolution of the target. Small satellite constellations contribute innovative applications by replacing a single asset with several very capable spacecraft which opens the door to new applications. With increasing levels of autonomy, there will be a need for remote communication networks to enable communication between spacecraft. These space based networks will need to configure and maintain dynamic routes, manage intermediate nodes, and reconfigure themselves to achieve mission objectives. Hence, inter-satellite communication is a key aspect when satellites fly in formation. In this paper, we present the various researches being conducted in the small satellite community for implementing inter-satellite communications based on the Open System Interconnection (OSI) model. This paper also reviews the various design parameters applicable to the first three layers of the OSI model, i.e., physical, data link and network layer. Based on the survey, we also present a comprehensive list of design parameters useful for achieving inter-satellite communications for multiple small satellite missions. Specific topics include proposed solutions for some of the challenges faced by small satellite systems, enabling operations using a network of small satellites, and some examples of small satellite missions involving formation flying aspects.Comment: 51 pages, 21 Figures, 11 Tables, accepted in IEEE Communications Surveys and Tutorial

Small satellites and CubeSats: survey of structures, architectures, and protocols

The space environment is still challenging but is becoming more and more attractive for an increasing number of entities. In the second half of the 20th century, a huge amount of funds was required to build satellites and gain access to space. Nowadays, it is no longer so. The advancement of technologies allows producing very small hardware components able to survive the strict conditions of the outer space. Consequently, small satellites can be designed for a wide set of missions keeping low design times, production costs, and deployment costs. One widely used type of small satellite is the CubeSat, whose different aspects are surveyed in the following: mission goals, hardware subsystems and components, possible network topologies, channel models, and suitable communication protocols. We also show some future challenges related to the employment of CubeSat networks

Distributed computing in space-based wireless sensor networks

This thesis investigates the application of distributed computing in general and wireless sensor networks in particular to space applications. Particularly, the thesis addresses issues related to the design of "space-based wireless sensor networks" that consist of ultra-small satellite nodes flying together in close formations. The design space of space-based wireless sensor networks is explored. Consequently, a methodology for designing space-based wireless sensor networks is proposed that is based on a modular architecture. The hardware modules take the form of 3-D Multi-Chip Modules (MCM). The design of hardware modules is demonstrated by designing a representative on-board computer module. The onboard computer module contains an FPGA which includes a system-on-chip architecture that is based on soft components and provides a degree of flexibility at the later stages of the design of the mission.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Development and Investigation of Communication Issues on a CubeSat-onboard Amateur Radio Payload with APRS Digipeater and Store-and-Forward Capabilities

Automatic Packet Reporting System (APRS) is originally a terrestrial packet communication system widely utilized by amateur radio stations to exchange various information. To extend this capability over a geographically broad coverage, a few microsatellites previously carried an APRS digipeater payload for global amateur community use, and then there have been proposals to do this on smaller nanosatellite platforms, such as the CubeSat. Although CubeSat is an attractive platform for this application – due to its substantially simpler design, lower cost, and faster development time – it also presents several technical challenges such as tight space, power, and communication link budgets. In this paper, we discuss the design, development and testing of an amateur radio payload that operates in the 145.825 MHz amateur frequency, consists of mostly commercial-of-the-shelf components and supports both APRS digipeater and store-and-forward (S&F) communication for remote data collection. The payload was carried as a technology demonstration mission of a 1U CubeSat constellation developed at the Kyushu Institute of Technology under the BIRDS-2 Project. Several amateur operators confirmed reception of the payload’s beacon message but full two-way communication failed due to uplink communication problems. This paper also tackles the investigation on the causes of failure through ground-based communication tests, as well as the recommendations from the findings

State of the Art: Small Spacecraft Technology

This report provides an overview of the current state-of-the-art of small spacecraft technology, with particular emphasis placed on the state-of-the-art of CubeSat-related technology. It was first commissioned by NASAs Small Spacecraft Technology Program (SSTP) in mid-2013 in response to the rapid growth in interest in using small spacecraft for many types of missions in Earth orbit and beyond, and was revised in mid-2015 and 2018. This work was funded by the Space Technology Mission Directorate (STMD). For the sake of this assessment, small spacecraft are defined to be spacecraft with a mass less than 180 kg. This report provides a summary of the state-of-the-art for each of the following small spacecraft technology domains: Complete Spacecraft, Power, Propulsion, Guidance Navigation and Control, Structures, Materials and Mechanisms, Thermal Control, Command and Data Handling, Communications, Integration, Launch and Deployment, Ground Data Systems and Operations, and Passive Deorbit Devices

Adaptation of the IEEE 802.11 protocol for inter-satellite links in LEO satellite networks

Knowledge of the coefficient of thermal expansion (CTE) of a ceramic material is important in many application areas. Whilst the CTE can be measured, it would be useful to be able to predict the expansion behaviour of multiphase materials.. There are several models for the CTE, however, most require a knowledge of the elastic properties of the constituent phases and do not take account ofthe microstructural features of the material. If the CTE could be predicted on the basis of microstructural information, this would then lead to the ability to engineer the microstructure of multiphase ceramic materials to produce acceptable thermal expansion behaviour. To investigate this possibility, magnesia-magnesium aluminate sp~el (MMAS) composites, consisting of a magnesia matrix and magnesium aluminate s~ne'l (MAS) particles, were studied. Having determined a procedure to produce MAS fr alumina and magnesia, via solid state sintering, magnesia-rich compositions wit ~ various magnesia contents were prepared to make the MMAS composites. Further, the l\.1MAS composites prepared from different powders (i.e. from an alumina-magnesia mixture ahd from a magnesia-spinel powder) were compared. Com starch was added into the powder mixtures before sintering to make porous microstructures. Microstructural development and thermal expansion behaviour ofthe MMAS composites were investigated. Microstructures of the MAS and the MMAS composites as well as their porous bodies were quaritified from backscattered electron micrographs in terms of the connectivity of solids i.e. solid contiguity by means of linear intercept counting. Solid contiguity decreased with increasing pore content and varied with pore size, pore shape and pore distribution whereas the phase contiguity depended strongly on the chemical composition and was less influenced by porosity. ' The thermal expansion behaviour of the MAS and the MMAS composites between 100 and 1000 °C was determined experimentally. Variation in the CTE ofthe MAS relates to the degree of spinel formation while the thermal expansion of the MMAS composites depends strongly on phase content. However, the MMAS composites with similar phase compositions but made from different manufacturing processes showed differences in microstructural features and thermal expansion behaviour. Predictions of the CTE values for composites based on a simple rule-of-mixtures (ROM) using volume fraction were compared with the measured data. A conventional ROM accurately predicted the effective CTE of a range of dense alumina-silicon carbide particulate composites but was not very accurate for porous multiphase structures. It provided an upper bound prediction as all experimental values were lower. Hence, the conventional ROM was modified to take account of quantitative microstructural parameters obtained from solid contiguity. The modified ROM predicted lower values and gave a good agreement with the experimental data. Thus, it has been shown that quantitative microstructural information can be used to predict the CTE of multiphase ceramic materials with complex microstructures.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Nanosatellite Store-and-Forward Communication Systems for Remote Data Collection Applications

Due to compact design, cost-effectiveness and shorter development time, a nanosatellite constellation is seen as a viable space-based data-relay asset to collect data from remote places that are rather impractical to be linked by terrestrial means. While nanosatellites have these advantages, they have more inherent technical limitations because of limited space for subsystems and payloads. Nanosatellite S&F communication systems are notably challenging in this respect due to requirements on antennas, transceivers, and signal processing. Although nanosatellites can be scaled up for better resources and capabilities, smaller platforms (i.e., ≤6U CubeSat) tend to be used for cost-effectiveness and lower risk. This thesis dealt with the problem of designing a nanosatellite S&F communication system for delay-tolerant remote data collection applications considering: (a) technical constraints in hardware, processing capabilities, energy budget and space in both the nanosatellite and ground sensor terminal (GST) sides; (b) physical communication layer characteristics and constraints such as limited available bandwidth, LEO channel Doppler, attenuation and fading/shadowing effects, low transmit power and data rate, and multi-user interference among asynchronously transmitting terminals. We designed, developed, and operated an amateur radio payload with S&F communication and APRS-DP capabilities, and performed a post-launch communication failure investigation. We also investigated suitability of E-SSA protocol for IoT/M2M terminals to nanosatellite communication by analyzing performance and energy efficiency metrics. The thesis comprises nine chapters. Chapter 1 describes the research background, problem, objectives, state of research, potential contributions of this thesis, and a gist of methodology detailed in later chapters. Chapter 2 and 3 provide an extensive literature review. Chapter 2 reviews the previous research works on using nanosatellites for S&F communication for remote data collection, and the previous nanosatellite S&F missions. Such research works and nanosatellite missions were undertaken primarily in the context of non-commercial/civil applications. Then, Chapter 2 surveys the recent commercial nanosatellite IoT/M2M players and examines their proposed systems in terms of satellite platform, constellation design, communication technology, targeted applications, requirements, and performance. Chapter 3 presents a literature review on communication system architecture, physical layer and random-access schemes, protocols, and technologies relevant to satellite IoT/M2M systems. In the context of IoT/M2M applications, the constraints in energy budget, transmit power and available bandwidth limit the system’s capacity in terms of amount of data that can be received and number of GSTs that can be supported. In both nanosatellite and GST sides, there are stringent limitations in hardware complexity, processing capabilities and energy budget. Addressing these challenges requires a simple, spectrally and energy efficient asynchronous random-access communication protocol. This research investigated using the enhanced spread spectrum Aloha (E-SSA) protocol for satellite IoT/M2M uplink (terminal to satellite) communication and analyzed its performance and suitability for the said application. Chapter 4 discusses the BIRDS-2 CubeSat S&F remote data collection system, payload design, development, tests, and integration with the BIRDS-2 CubeSats. Chapter 5 discusses the investigation on communication design issues of BIRDS-2 CubeSat S&F payload, tackling both the methodology and findings of investigation. It is noted that there are only a few satellites that have carried an APRS-DP payload but even some of these failed due to communication, power, or software issues. In BIRDS-2 Project, considering tight constraints in a 1U CubeSat equipped with other subsystems and payloads, we developed a S&F/APRS-DP payload and integrated it with each of the three 1U CubeSats of participating countries. After launching the CubeSats from the ISS, several amateur operators confirmed reception downlink beacon messages, but full two-way communication failed due to uplink communication failure. Thus, this research not only studied the design and development of a S&F/APRS-DP payload suitable for a CubeSat platform, but also systematically investigated the causes of communication failure by on-orbit observation results and ground-based tests. We found that uplink failure was caused by two design problems that were overlooked during development, namely, the poor antenna performance and increased payload receiver noise floor due to satellite-radiated EMI coupled to the antenna. Chapter 6 first describes the enhanced spread spectrum Aloha (E-SSA) based nanosatellite IoT/M2M communication model implemented in Matlab and derives the mathematical definitions of packet loss rate (PLR), throughput (THR) and energy efficiency (EE) metrics. Then, it tackles the formulated baseband signal processing algorithm for E-SSA, including packet detection, channel estimation, demodulation and decoding. Chapter 7 presents the simulation results and discussion for Chapter 6. Chapter 8 tackles the S&F nanosatellite constellation design for global coverage and presents the results and findings. Chapter 9 describes the laboratory setups for validating the E-SSA protocol and then presents the findings. Finally, Chapter 9 also gives the summary, conclusions, and recommendations. Simulation results showed that for E-SSA protocol with the formulated algorithm, THR, PLR and EE metrics are more sensitive to MAC load G, received power variation σLN and Eb/N0, due to imperfect detection and channel estimation. With loose power control (σLN=3dB), at Eb/N0=14 dB, the system can be operated up to a maximum load of 1.3 bps/Hz, achieving a maximum THR of 1.25 bps/Hz with PLR<0.03. Without power control (σLN=6dB,9dB), at Eb/N0=14 dB, maximum load is also 1.3 bps/Hz, but achievable THR is lower than ~1 bps/Hz and PLR values can be as high as ~0.23. Worse PLR results are attributed to misdetection of lower power packets and demodulation/decoding errors. Both are caused by the combined effects of MUI, channel estimation errors, imperfect interference cancellation residue power, and noise. The PLR and THR can be improved by operating with higher Eb/N0 at the expense of lower energy efficiency. Then, laboratory validation experiments using a SDR-based platform confirmed that with G=0.1, Eb/N0=14dB, σLN=6dB, the formulated algorithm for E-SSA protocol can still work even with inaccurate oscillator (±2 ppm) at GSTs, obtaining experimental PLR result of 0.0650 compared to simulation result of 0.0352. However, this requires lowering the detection thresholds and takes significantly longer processing time. For the S&F nanosatellite constellation design, it was found that to achieve the target percent coverage time (PCT) of more than 95% across all latitudes, a 9x10 Hybrid constellation or a 10x10 Walker Delta constellation would be required.九州工業大学博士学位論文 学位記番号：工博甲第506号 学位授与年月日：令和2年9月25日1: Introduction|2: Nanosatellite S&F Research, Missions and Applications|3: Satellite S&F Communication Systems and Protocols|4: BIRDS-2 CubeSat S&F Data Collection System, Payload Design and Development|5: Investigation on Communication Design Issues of BIRDS-2 CubeSat APRS-DP/S&F Payload, Results and Discussion|6: E-SSA-based Nanosatellite IoT/M2M Communication System Model and Signal Processing Algorithm|7: Simulation Results and Discussion for E-SSA-based Nanosatellite IoT/M2M Communication System|8: Nanosatellite Constellation for Global Coverage|9: Experimental Laboratory Validation for E-SSA Protocol, Research Summary, Conclusions and Recommendations九州工業大学令和2年

Antenna and Random Access Solutions for nano-satellite and 5G networks operating in the millimiter-wave domain

L\u2019obiettivo di questa tesi \ue8 la discussione di soluzioni per reti satellitari basate su nano-satelliti e reti 5G, operanti in onde millimetriche. I contributi originali di questo lavoro interessano due settori che ricoprono un ruolo chiave nel contesto delle comunicazioni digitali ad alta velocit\ue0 e alta capacit\ue0: i meccanismi di condivisione del mezzo trasmissivo basati sull\u2019accesso casuale e le antenne a schiera riconfigurabili e compatte. I risultati ottenuti in questi due ambiti sono poi applicati in un\u2019architettura di rete che integra sistemi 5G terrestri e una costellazione di nanosatelliti in orbita bassa. Le comunicazioni satellitari sono sempre pi\uf9 parte integrante della vita quotidiana. Negli ultimi anni, si \ue8 registrata una crescita notevole dei piccoli satelliti (da 1 a 100 kg), sia in termini di tecnologia, che di frequenza di utilizzo. Non solo vengono lanciati in gran numero, ma si \ue8 iniziato ad utilizzarli in costellazioni da diverse decine di unit\ue0. Questa attivit\ue0 \ue8 l\u2019indicatore di una prospettiva ormai prossima: gli sviluppi nel settore dell\u2019Information and Communication Technology hanno avviato diverse iniziative che puntano ad utilizzare megacostellazioni di satelliti come reti per la fornitura di servizi di comunicazione a banda larga. Lo sfruttamento delle onde millimetriche rappresenta quindi un punto cardine per soddisfare la crescente richiesta di capacit\ue0 dei sistemi radio di prossima generazione. Inoltre, lo scenario che ne risulta \ue8 tale da richiedere una connettivit\ue0 completa, cos\uec che ogni satellite operi come un nodo di rete a tutto tondo, con possibilit\ue0 di collegamento tra la terra e lo spazio, e da satellite a satellite. In tale contesto, il ricorso a moderne tecniche di accesso casuale \ue8 particolarmente indicato. Negli ultimi anni si \ue8 assistito a un rinnovato interesse per i protocolli di tipo Aloha, grazie alla possibilit\ue0 di dotare i ricevitori di sistemi di cancellazione dell\u2019interferenza. A tale proposito, viene presentato un nuovo algoritmo che affianca alla cancellazione iterativa di interferenza lo sfruttamento dell\u2019effetto cattura, tenendo al tempo stesso presente la possibile non idealit\ue0 della cancellazione, e quindi la presenza di un residuo. Le sue prestazioni sono confrontate con i metodi attualmente adottati negli standard, mostrando un miglioramento del throughput pari al 31%. Viene inoltre presentata la sintesi di un\u2019antenna a schiera operante in banda Ka adatta per l\u2019uso su nanosatelliti. La schiera risultante offre interessanti benefici in termini di larghezza di banda, polarizzazione e versatilit\ue0, essendo possibile un utilizzo dual-task (downlink verso terra e collegamentointersatellitare). I risultati cos\uec ottenuti sono poi utilizzati per dimostrare, in un simulatore tempo discreto ed evento discreto, le prestazioni ottenibili da un\u2019architettura di rete integrante segmenti di rete radiomobile 5G con una dorsale costituita da una costellazione di nanosatellti. Il simulatore si avvale inoltre di un modello teorico per valutare l\u2019impatto della distribuzione geometrica dei nodi interferenti su una comunicazione in onde millimetriche di tipo line-of-sight. Tale modello, validato con simulazioni di tipo Monte Carlo, contempla i diagrammi di radiazione delle antenne e i recenti modelli di canale in onde millimetriche, che tengono in considerazione rumore, dispersione angolare, fading e bounded path loss. Sono state ricavate delle formulazioni analitiche per la distribuzione della potenza di rumore e interferenza, che consentono di valutare in forma chiusa la probabilit\ue0 di cattura. Tale impostazione \ue8 stata infine usata per discutere gli effetti dell\u2019interferenza sulla capacit\ue0 di Shannon di un collegamento in uplink operante in onde millimetriche, prendendo in considerazione delle condizioni realistiche per il canale

A Survey on Non-Geostationary Satellite Systems: The Communication Perspective

The next phase of satellite technology is being characterized by a new evolution in non-geostationary orbit (NGSO) satellites, which conveys exciting new communication capabilities to provide non-terrestrial connectivity solutions and to support a wide range of digital technologies from various industries. NGSO communication systems are known for a number of key features such as lower propagation delay, smaller size, and lower signal losses in comparison to the conventional geostationary orbit (GSO) satellites, which can potentially enable latency-critical applications to be provided through satellites. NGSO promises a substantial boost in communication speed and energy efficiency, and thus, tackling the main inhibiting factors of commercializing GSO satellites for broader utilization. The promised improvements of NGSO systems have motivated this paper to provide a comprehensive survey of the state-of-the-art NGSO research focusing on the communication prospects, including physical layer and radio access technologies along with the networking aspects and the overall system features and architectures. Beyond this, there are still many NGSO deployment challenges to be addressed to ensure seamless integration not only with GSO systems but also with terrestrial networks. These unprecedented challenges are also discussed in this paper, including coexistence with GSO systems in terms of spectrum access and regulatory issues, satellite constellation and architecture designs, resource management problems, and user equipment requirements. Finally, we outline a set of innovative research directions and new opportunities for future NGSO research

Compilation of thesis abstracts, September 2009

NPS Class of September 2009This quarter’s Compilation of Abstracts summarizes cutting-edge, security-related research conducted by NPS students and presented as theses, dissertations, and capstone reports. Each expands knowledge in its field.http://archive.org/details/compilationofsis109452751