Rain attenuation statistics for mobile satellite communications estimated from radar measurements in Malaysia

Mobile satellite communications will play a significant role in the next 5th generation mobile services. The use of high-frequency bands will be the enabler of this advancement. However, at high frequencies, excess rain attenuation causes severe signal losses and presents a major threat for the system availability, especially in the tropical region. To that end, this study presents the rain attenuation impact on mobile satellite communications estimated using long-term radar measurements in Malaysia, by exploiting the horizontal structure of rain from the radar database and simulating inner-city and highway mobile terminals scenarios. Additionally, a scaling factor was presented to scale available fixed satellite terminals measurements to mobile terminals operating at the same locality under similar conditions. In comparison to the available link measurements, the radar database was reliable enough to provide highly accurate estimates. In all simulation scenarios, the mobile terminal will depart the rainy area soon enough and experience lower attenuation statistics in comparison with the fixed terminal. The provided results will help determine the overall future system performance, especially in tropical regions

Satellite Communications

This study is motivated by the need to give the reader a broad view of the developments, key concepts, and technologies related to information society evolution, with a focus on the wireless communications and geoinformation technologies and their role in the environment. Giving perspective, it aims at assisting people active in the industry, the public sector, and Earth science fields as well, by providing a base for their continued work and thinking

Proceedings of the Seventeenth NASA Propagation Experimenters Meeting (NAPEX 17) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

The NASA Propagation Experimenters Meeting (NAPEX) is convened annually to discuss studies made on radio wave propagation by investors from domestic and international organizations. NAPEX 17 was held on 15 June 1993. The meeting was organized into two technical sessions. The first session was dedicated to slant path propagation studies and experiments. The second session focused on propagation studies for mobile and personal communications. Preceding NAPEX 17, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop was held on 14 June 1993 to review ACTS propagation activities with emphasis on ACTS experiments status and data collection, processing, and exchange

Proceedings of the 19th NASA Propagation Experimenters Meeting (NAPEX 19) and the 7th Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop (APSW 7)

The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. NAPEX 19 was held on 14 Jun. 1995, in Fort Collins, Colorado. Participants included representatives from Canada, Japan, and the United States, including researchers from universities, government agencies, and private industry. The meeting focused on mobile personal satellite systems and the use of 20/30-GHz band for fixed and mobile satellite applications. In total, 18 technical papers were presented. Following NAPEX 19, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop 7 (APSW 7) was held on 15-16 Jun. 1995, to review ACTS propagation activities with emphasis on the experimenters' status reports and dissemination of propagation data to industry

Standardized testing conditions for satellite communications on-the-move (SOTM) terminals

Von Beginn an haben Satelliten Kommunikationsdienste über große Distanzen bereitgestellt. Endgeräte für die mobile Satellitenkommunikation sind mit einer Nachführeinrichtung ausgestattet, um den verwendeten Satelliten bei Bewegung zu verfolgen. Für höchstmöglichen Datendurchsatz und um Störaussendungen zu benachbarten Satelliten zu vermeiden bedarf es akkurater Nachführalgorithmen. Die Prüfung solcher Satcom-On-The-Move (SOTM) Terminals wird dabei zunehmend wichtig, wie Betreiber von Satellitendiensten anhand des negativen Einflusses suboptimaler Geräte auf ihre Infrastruktur bemerken. Herkömmlich werden SOTM-Terminals im Rahmen von Feldtests mit operativen Satelliten geprüft. Solche Tests sind allerdings nicht exakt wiederholbar. Die Reproduzierbarkeit von Tests ist jedoch insbesondere beim Vergleichstest mehrerer Terminals wichtig. Dieser Beitrag widmet sich der Untersuchung eines umfassenden Qualifikationstests von SOTM-Terminals innerhalb einer Laborumgebung, welche Reproduzierbarkeit ermöglicht. Wesentlicher Vorteil der Laborumgebung ist die Möglichkeit, Terminals unter realitätsnahen Bedingungen zu testen - ohne dass reale Satelliten benötigt werden, was die Kosten reduziert. Diese Arbeit behandelt darüber hinaus die Testmethodik in der Fraunhofer-Testanlage ”Facility for Over-the-air Research and Testing (FORTE)”. Wichtige Leistungsparameter wie Nachführgenauigkeit (Antenna De-pointing) und Nachbarsatellitenstörung (Adjacent Satellite Interference, ASI) können akkurat gemessen und ausgewertet werden. Die verwendete Methodik zur Gewinnung der vorgeschlagenen Profile wird in der Arbeit ebenso behandelt wie Testergebnisse von Ka-Band-SOTM Terminals. Wesentlicher Beitrag dieser Arbeit ist die Entwicklung von Bewegungs- und Abschattungsprofilen für SOTM-Terminaltests. Bewegungsprofilen für die Landmobile und Maritime Umgebungen wurden entwickelt. Für jede Umgebung, zwei Klassen wurden definiert, Klasse A mit Profile die hohe Bewegungsdynamik haben und Klasse B mit Profile die relativ niedrige Bewegungsdynamik haben. Die vorgeschlagenen Bewegungsprofile wurden in der GVF-105 Standard des Global VSAT Forums berücksichtigt. Die Standardisierung solcher Profile ist notwendig, um einen fairen Leistungsvergleich verschiedener Terminals zu garantieren und solche Geräte sicher zu identifizieren, welche Interferenzen im Satellitennetz verursachen. Dies bedeutet im Ergebnis einen Gewinn für die gesamte Satellitenindustrie.Satellites have proven their success in providing communication services especially between distant locations. For Satellite Communication On-The-Move (SOTM) applications, accurate satellite tracking algorithms must be applied in order to ensure the highest possible throughput and also to avoid harmful interference to adjacent satellites. Performance validation of SOTM terminals is becoming more important as the satellite operators recognize the negative influence of suboptimal terminals on their satellite networks. Traditionally, SOTM testing is performed with actual operational satellites in field tests, which lack repeatability. The capability to repeat the conditions in which SOTM terminals are tested is important, especially when the performance of multiple terminals is compared. This contribution is dedicated to study how to conduct a comprehensive qualification test of SOTM terminals in a laboratory environment so that repeatability can be ensured. A major advantage of a laboratory environment is the ability to test the complete terminal as if it was in the field of operation, yet without the involvement of real satellites effectively reducing the costs of testing. This thesis presents the methodology for testing SOTM terminals at the Fraunhofer Facility for Over-the-air Research and Testing (FORTE). Important performance parameters, such as, antenna de-pointing and Adjacent Satellite Interference (ASI) can be accurately measured and evaluated. The procedure used to obtain the proposed profiles and results of testing a Ka-band SOTM terminal are also presented in this thesis. A major contribution of this thesis is represented by the development of motion and shadowing profiles suitable for standardization of SOTM testing. Motion profiles for the land mobile and the maritime environment have been developed. For each environment two classes were defined, Class A with rough motion conditions and Class B with more relaxed motion conditions. The proposed motion profiles were added to the well-known GVF-105 standard recommendations of the Global VSAT Forum. Shadowing profiles were defined for land mobile applications in different environment types, e.g., urban, suburban, highway, etc. Standardization of such profiles is necessary to guarantee a fair comparison of the performance of different terminals and therefore leading to sort out the bad performing terminals which cause harmful interference to the existing satellite networks. This will lead to an overall improvement in the performance of the satellite industry

Proceedings of the Mobile Satellite Conference

A satellite-based mobile communications system provides voice and data communications to mobile users over a vast geographic area. The technical and service characteristics of mobile satellite systems (MSSs) are presented and form an in-depth view of the current MSS status at the system and subsystem levels. Major emphasis is placed on developments, current and future, in the following critical MSS technology areas: vehicle antennas, networking, modulation and coding, speech compression, channel characterization, space segment technology and MSS experiments. Also, the mobile satellite communications needs of government agencies are addressed, as is the MSS potential to fulfill them

Proceedings of the Thirteenth NASA Propagation Experimenters Meeting (NAPEX 13)

The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. The meeting was organized into three technical sessions: the first focused on mobile satellite propagation; the second examined the propagation effects for frequencies above 10 GHz; and the third addressed studies devoted exclusively to the Olympus/Advanced Communications Technology Satellite (ACTS) Program

Proceedings of the Fifteenth NASA Propagation Experimenters Meeting (NAPEX 15) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. The meeting was organized into three technical sessions. The first session was dedicated to Olympus and ACTS studies and experiments, the second session was focused on the propagation studies and measurements, and the third session covered computer-based propagation model development. In total, sixteen technical papers and some informal contributions were presented. Following NAPEX 15, the Advanced Communications Technology Satellite (ACTS) miniworkshop was held on 29 Jun. 1991, to review ACTS propagation activities, with emphasis on ACTS hardware development and experiment planning. Five papers were presented

Proceedings of the Fifth International Mobile Satellite Conference 1997

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments