Low Earth Orbit (LEO) satellites are an essential complement of the cellular radio infrastructure, especially the Universal Mobile Telecommunications System (UMTS), for mobile (pedestrian and, more important, vehicular) access to the Internet in sparsely populated areas, where high bandwidth UMTS cells cannot be economically deployed. LEO users would eventually switch between the satellite segm...

Low earth orbit (LEO) satellite systems allow a broad range of services to be provided using small, lightweight, cellular-like portable telephones. Exploiting LEO satellites to support distress signals for aircrafts, ships and international travelers is explored in the current paper. A multi-service priority-oriented algorithm is proposed for handling voice, data and emergency signals over LEO ...

Among satellite systems, low earth orbit (LEO) satellite system will make an important role in new fiture communication services, because of its less propagation delay, less power consumption in the user terminal and the satellites, and efficient spectrum utilization using smaller coverage area for each satellite than geostationa y (GEO) counterpart. However, a number of mobility problems that ...

Low Earth Orbit Satellite Networks can augment terrestrial wireless networks to provide global broadband services to users regardless of the users’ locations. Delivering QoS guarantees to the users of LEO satellite networks is complicated since footprints of LEO satellites move as the satellites traverse their orbits, and thus, causing frequent user handovers between the satellites. Traffic on ...

Long Range-Frequency Hopping Spread Spectrum (LR-FHSS) has been recently introduced into the LoRaWAN protocol specification to increase network capacity and collision robustness, enable direct connectivity between machine devices Low Earth Orbit (LEO) satellites. In this letter, we first construct analytical simulation models for packet delivery over LR-FHSS from ground nodes a LEO satellite, t...

As part of the Materials on The International Space Station Experiment (MISSE), aromatic polymers containing phenylphosphine oxide groups were exposed to low Earth orbit (LEO) for approximately 4 years. All of the aromatic polymers containing phenylphosphine oxide groups survived the exposure despite the high fluence of atomic oxygen that completely eroded other polymer films such as Kapton and...

| We propose a new framework for the link assignment (i.e., topological design) problem that arises from the use of inter-satellite links (ISL's) in Low-Earth Orbit (LEO) satellite networks. In the proposed framework, we model a LEO satellite network as a Finite State Automaton (FSA) where each state corresponds to an equal-length interval in the system period of the LEO satellite network. This...

Spaceborne GNSS-R (global navigation satellite system reflectometry) is an innovative and powerful bistatic radar remote sensing technique that uses specialized GNSS-R instruments on LEO (low Earth orbit) satellites to receive GNSS L-band signals reflected by the Earth’s surface. Unlike monostatic radar, the illuminated areas are elliptical regions centered on specular reflection points. Evalua...

the low earth orbiting (leo) satellites are widely used for geosciences applications. for most applications, precise orbital information of the satellites is required. a combination of the in suite observations and dynamic orbit yields the optimum solution. in order to obtain the combined optimal solution, one needs to analytically or numerically propagate the state vector epoch by an epoch bas...

A set of Global Navigation Satellite Systems (GNSS) satellite orbit and clock offset are an essential prerequisite for precise application. However, abrupt changes in accuracy at the boundaries prevalent products provided by international GNSS services, resulting decreased interpolation precision near daily boundary. In addition, effect this phenomenon is reflected deterioration fluctuations su...