Mobile satellite systems are a crucial component of the future global telecommunications infrastructure. An important aspect of the future system is to manage the location of both users and satellites. This paper presents a strategy for location registration (update) and paging in Low Earth Orbit (LEO) mobile satellite systems. First, we discuss the tradeoff that exists between four proposed sa...

In this paper the main performances of communication services based on low earth orbit satellites (LEOs) have been analyzed in order to evaluate their suitability for a typical set of power system monitoring functionalities. As an experimental test bed, an intelligent electronic device (IED) for remote monitoring and protection of power components equipped with a bi-directional communication sy...

In this paper, the performance of a parallel acquisition scheme is evaluated for a direct-sequence/codedivision-multiple-access (DS/CDMA) system with imperfect power control in a low-earth-orbit (LEO) mobile satellite environment. The acquisition scheme consists of a parallel matched-filter and a FFT processor. The uplink of mobile satellite channel is modeled as a shadowed Rician fading channe...

Earth rotation parameters (ERP) are one of the key in realization International Terrestrial Reference Frames (ITRF). At present, Laser Ranging Service (ILRS) generates satellite laser ranging (SLR)-based ERP products only using SLR observations to Geodynamics Satellite (LAGEOS) and Etalon satellites. Apart from these geodetic satellites, many low orbit (LEO) satellites observation missions also...

The global navigation satellite systems (GNSSs) are increasingly suffering from interferences, such as coming jammers and spoofers, their performance is still modest in challenging urban indoor scenarios. Therefore, there efforts worldwide to develop complementary positioning, navigation, timing (PNT) solutions. One method under current research the so-called LEO-PNT, namely, PNT solutions base...

At present, a large number of surveillance, scientific, and commercial communications constellations are being actively pmsued by DoD, NASA, and the commercial space community. In many cases, these constellations will be made up of "LightSats" or small, low cost spacecraft. F or such systems, operations costs, which are large in traditional systems, can become a dominant element of total system...

Satellite communication promises potential methods for providing global communication. In particular, by the development of a Low Earth Orbital (LEO) satellite constellation, both global coverage and broadband communication will be accessible. Problems arise in situations where various tra¢ c types in broadband communication require di¤erent levels of quality of service (QoS). Tra¢ c control is...

Modern low earth orbit (LEO) satellites that require multi-mission flexibility are highly likely to be repositioned between different operational orbits. While executing this process the satellite may experience high levels of vibration and environmental hazards, exposing the deployed solar panel to dangerous stress levels, fatigue and space debris, hence it is desirable to retract the solar sa...

A low Earth orbit (LEO) satellite constellation could be used to provide network coverage for the entire globe. This study considers multi-beam frequency reuse in LEO systems. In such a system, channel is time-varying due fast movement of satellite. proposes an efficient power and bandwidth allocation method that employs two linear machine learning algorithms take conditions traffic demand (TD)...

The GPS meteorology (GPS/MET) experiment, led by the Universities Corporation for Atmospheric Research (UCAR), consists of a GPS receiver aboard a low earth orbit (LEO) satellite which was launched on 3 April 1995. During a radio occultation the LEO satellite rises or sets relative to one of the 24 GPS satellites at the Earth's horizon. Thereby the atmospheric layers are successively sounded by...