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

Satellite Networks: Architectures, Applications, and Technologies

Since global satellite networks are moving to the forefront in enhancing the national and global information infrastructures due to communication satellites' unique networking characteristics, a workshop was organized to assess the progress made to date and chart the future. This workshop provided the forum to assess the current state-of-the-art, identify key issues, and highlight the emerging trends in the next-generation architectures, data protocol development, communication interoperability, and applications. Presentations on overview, state-of-the-art in research, development, deployment and applications and future trends on satellite networks are assembled

Kapeankaistan LTE koneiden välisessä satelliittitietoliikenteessä

Recent trends to wireless Machine-to-Machine (M2M) communication and Internet of Things (IoT) has created a new demand for more efficient low-throughput wireless data connections. Beside the traditional wireless standards, focused on high bandwidth data transfer, has emerged a new generation of Low Power Wide Area Networks (LPWAN) which targets for less power demanding low-throughput devices requiring inexpensive data connections. Recently released NB-IoT (Narrowband IoT) specification extends the existing 4G/LTE standard allowing more easily accessible LPWAN cellular connectivity for IoT devices. Narrower bandwidth and lower data rates combined to a simplified air interface make it less resource demanding still benefiting from the widely spread LTE technologies and infrastructure. %% Applications & Why space Applications, such as wide scale sensor or asset tracking networks, can benefit from a global scale network coverage and easily available low-cost user equipment which could be made possible by new narrowband IoT satellite networks. In this thesis, the NB-IoT specification and its applicability for satellite communication is discussed. Primarily, LTE and NB-IoT standards are designed only for terrestrial and their utilization in Earth-to-space communication raises new challenges, such as timing and frequency synchronization requirements when utilizing Orthogonal Frequency Signal Multiplexing (OFDM) techniques. Many of these challenges can be overcome by specification adaptations and other existing techniques making minimal changes to the standard and allowing extension of the terrestrial cellular networks to global satellite access.Viimeaikaiset kehitystrendit koneiden välisessä kommunikaatiossa (Machine to Machine Communication, M2M) ja esineiden Internet (Internet of Things, IoT) -sovelluksissa ovat luoneet perinteisteisten nopean tiedonsiirron langattomien standardien ohelle uuden sukupolven LPWAN (Low Power Wide Area Networks) -tekniikoita, jotka ovat tarkoitettu pienitehoisille tiedonsiirtoa tarvitseville sovelluksille. Viimeaikoina yleistynyt NB-IoT standardi laajentaa 4G/LTE standardia mahdollistaen entistä matalamman virrankulutuksen matkapuhelinyhteydet IoT laitteissa. Kapeampi lähetyskaista ja hitaampi tiedonsiirtonopeus yhdistettynä yksinkertaisempaan ilmarajapintaan mahdollistaa pienemmän resurssivaatimukset saman aikaan hyötyen laajalti levinneistä LTE teknologioista ja olemassa olevasta infrastruktuurista. Useissa sovelluskohteissa, kuten suurissa sensoriverkoissa, voitaisiin hyötyä merkittävästi globaalista kattavuudesta yhdistettynä edullisiin helposti saataviin päätelaitteisiin. Tässä työssä käsitellään NB-IoT standardia ja sen soveltuvuutta satellittitietoliikenteeseen. LTE ja NB-IoT ovat kehitty maanpääliseen tietoliikenteeseen ja niiden hyödyntäminen avaruuden ja maan välisessä kommunikaatiossa aiheuttaa uusia haasteita esimerkiksi aika- ja taajuussynkronisaatiossa ja OFDM (Orthogonal Frequency Signal Multiplexing) -tekniikan hyödyntämisessä. Nämä haasteet voidaan ratkaista soveltamalla spesifikaatiota sekä muilla jo olemassa olevilla tekniikoilla tehden mahdollisimman vähän muutoksia alkuperäiseen standardiin, ja täten sallien maanpäälisten IoT verkkojen laajenemisen avaruuteen

Software Defined Radio Implementation Of Ds-Cdma In Inter-Satellite Communications For Small Satellites

The increased usage of CubeSats recently has changed the communication philosophy from long-range point-to-point propagations to a multi-hop network of small orbiting nodes. Separating system tasks into many dispersed satellites can increase system survivability, versatility, configurability, adaptability, and autonomy. Inter-satellite links (ISL) enable the satellites to exchange information and share resources while reducing the traffic load to the ground. Establishment and stability of the ISL are impacted by factors such as the satellite orbit and attitude, antenna configuration, constellation topology, mobility, and link range. Software Defined Radio (SDR) is beginning to be heavily used in small satellite communications for applications such as base stations. A software-defined radio is a software program that does the functionality of a hardware system. The digital signal processing blocks are incorporated into the software giving it more flexibility and modulation. With this, the idea of a remote upgrade from the ground as well as the potential to accommodate new applications and future services without hardware changes is very promising. Realizing this, my idea is to create an inter-satellite link using software defined radio. The advantages of this are higher data rates, modification of operating frequencies, possibility of reaching higher frequency bands for higher throughputs, flexible modulation, demodulation and encoding schemes, and ground modifications. However, there are several challenges in utilizing the software-defined radio to create an inter-satellite link communication for small satellites. In this paper, we designed and implemented a multi-user inter-satellite communication network using SDRs, where Code Division Multiple Access (CDMA) technique is utilized to manage the multiple accesses to shared communication channel among the satellites. This model can be easily reconfigured to support any encoding/decoding, modulation, and other signal processing schemes

Software Defined Radio Implementation Of Ds-Cdma In Inter-Satellite Communications For Small Satellites

The increased usage of CubeSats recently has changed the communication philosophy from long-range point-to-point propagations to a multi-hop network of small orbiting nodes. Separating system tasks into many dispersed satellites can increase system survivability, versatility, configurability, adaptability, and autonomy. Inter-satellite links (ISL) enable the satellites to exchange information and share resources while reducing the traffic load to the ground. Establishment and stability of the ISL are impacted by factors such as the satellite orbit and attitude, antenna configuration, constellation topology, mobility, and link range. Software Defined Radio (SDR) is beginning to be heavily used in small satellite communications for applications such as base stations. A software-defined radio is a software program that does the functionality of a hardware system. The digital signal processing blocks are incorporated into the software giving it more flexibility and modulation. With this, the idea of a remote upgrade from the ground as well as the potential to accommodate new applications and future services without hardware changes is very promising. Realizing this, my idea is to create an inter-satellite link using software defined radio. The advantages of this are higher data rates, modification of operating frequencies, possibility of reaching higher frequency bands for higher throughputs, flexible modulation, demodulation and encoding schemes, and ground modifications. However, there are several challenges in utilizing the software-defined radio to create an inter-satellite link communication for small satellites. In this paper, we designed and implemented a multi-user inter-satellite communication network using SDRs, where Code Division Multiple Access (CDMA) technique is utilized to manage the multiple accesses to shared communication channel among the satellites. This model can be easily reconfigured to support any encoding/decoding, modulation, and other signal processing schemes

DYNAMIC EXTENSION OF NETWORK FOR CYBER AND COMMUNICATION

CubeSat-backboned networks maybe the key in providing access to highly dynamic networks since they are cost effective and durable. In this thesis, we examine the efficiency of a CubeSat network for an operational area with multiple unmanned aerial vehicles as relays. Also, we assume the vehicles are equipped with directed antenna technology. A successful communication link between the CubeSat and ground nodes is established using commercial off-the-shelf components. From our research results, we conclude that an advancement in directed antenna technology and more capable commercial-of-the-shelf transceivers are needed to achieve faster, more reliable, and more secure networks.Lieutenant Junior Grade, Turkish NavyApproved for public release; distribution is unlimited

Firmware de seleção de célula para redes 5G não-terrestres

The integration of satellite technology in 5G will enable networks to become more ubiquitous and reliable, extending coverage to previously underserved areas and making the network more resilient to natural catastrophes. The nonterrestrial networks (NTN) are expected to co-exist with the current terrestrial infrastructures, sharing much of the same requirements. This in turn will allow the User Equipment to connect to both, opening up new use cases and possibilities. The intent of this dissertation is to design a firmware that prepares these devices to take advantage of this new paradigm. This firmware implements an extended, radio access and backhaul-aware cell selection scheme, that chooses either to connect to terrestrial or non-terrestrial cells. The selection is based on metrics, such as, the latency and packet loss of the link, in addition to the traditional signal strength indicators. Testing the solution required deploying an end-to-end 5G network which includes not only a gNodeB (gNB) capable of simulating the propagation delay induced by long distances but also a terrestrial node. This deployment uses the OpenAirInterface (OAI) 5G software stack. With the use of this testbench, the implemented firmware was tested against key network degradation scenarios. These scenarios include, for example, the total failure of the terrestrial gNB and the steady increase of latency. The results show that this use of the firmware might help upkeep the quality of service for the User Equipment using it.A integração de tecnologias satélite nas redes 5G vai permitir que estas se tornem mais seguras e omnipresentes, estendendo a cobertura de forma a abranger áreas remotas e tornando estas redes mais resilientes contra catástrofes naturais. É expectado que as redes não-terrestres venham a coexistir com as atuais redes terrestres, partilhando os mesmos requisitos. Por sua vez isto vai permitir que os terminais se conectem a ambos, abrindo assim novas possibilidades e casos de uso. Com esta dissertação pretende-se projetar um firmware que prepare estes dispositivos para tomar partido deste novo paradigma. Este firmware funciona como uma versão estendida, ciente do backhaul, do esquema de cell selection, de forma a que este possa decidir entre conectar cells terrestres ou não terrestres. Esta decisão é informada por métricas como a latência e a perda de pacotes da ligação, além dos indicadores de força de sinal tradicionais. Para a validação desta solução foi necessário a instalação de uma rede 5G end-to-end que incluísse tanto um gNodeB (gNB) capaz de simular atraso de propagação induzido pelas longas distâncias, tal como um nó terrestre. Esta instalação usa o OpenAirInterface (OAI), uma implementação da stack 5G. Usando esta testbench, a implementação do firmware projetado foi testada face a cenários de degradação da rede. Estes incluem, por exemplo, a falha total do gNB terrestre ou um aumento crescente da latência. Os resultados obtidos mostram que o uso deste firmware poderá ajudar a manter a qualidade de serviço de um terminal que o utilize.Mestrado em Engenharia de Computadores e Telemátic

Wireless communication, identification and sensing technologies enabling integrated logistics: a study in the harbor environment

In the last decade, integrated logistics has become an important challenge in the development of wireless communication, identification and sensing technology, due to the growing complexity of logistics processes and the increasing demand for adapting systems to new requirements. The advancement of wireless technology provides a wide range of options for the maritime container terminals. Electronic devices employed in container terminals reduce the manual effort, facilitating timely information flow and enhancing control and quality of service and decision made. In this paper, we examine the technology that can be used to support integration in harbor's logistics. In the literature, most systems have been developed to address specific needs of particular harbors, but a systematic study is missing. The purpose is to provide an overview to the reader about which technology of integrated logistics can be implemented and what remains to be addressed in the future

A random access MAC protocol for MPR satellite networks

Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores, pela Universidade Nova de Lisboa, Faculdade de Ciências e TecnologiaRandom access approaches for Low Earth Orbit (LEO) satellite networks are usually incompatible with the Quality of Service (QoS) requirements of multimedia tra c, especially when hand-held devices must operate with very low power. Cross-Layered optimization architectures, combined with Multipacket Reception (MPR)schemes are a good choice to enhance the overall performance of a wireless system. Hybrid Network-assisted Diversity Multiple Access (H-NDMA) protocol, exhibits high energy e ciency, with MPR capability, but its use with satellites is limited by the high round trip time. This protocol was adapted to satellites, in Satellite-NDMA, but it required a pre-reservation mechanism that introduces a signi cant delay. This dissertation proposes a random access protocol that uses H-NDMA, for Low Earth Orbit (LEO) satellite networks, named Satellite Random-NDMA (SR-NDMA). The protocol addresses the problem inherent to satellite networks (large round trip time and signi cant energy consumption) de ning a hybrid approach with an initial random access plus possible additional scheduled retransmissions. An MPR receiver combines the multiple copies received, gradually reducing the error rate. Analytical performance models are proposed for the throughput, delay, jitter and energy e ciency considering nite queues at the terminals. It is also addressed the energy e ciency optimization, where the system parameters are calculated to guarantee the QoS requirements. The proposed system's performance is evaluated for a Single-Carrier with Frequency Domain Equalization (SC-FDE) receiver. Results show that the proposed system is energy e cient and can provide enough QoS to support services such as video telephony