Due to population distribution and economic flourish diversity, the low earth orbit (LEO) satellite network carries unbalanced traffic load, which leads that parts of satellite links are congested while others are underutilized. Furthermore, the congested inter-satellite links result in high queuing delay and packet dropping ratio. To ensure an intelligent scheduling of traffic over entire sate...

We investigate a topological design and routing problem for Low-Earth Orbit (LEO) satellite communication networks where each satellite can have a limited number of direct inter-satellite links (ISL's) to a subset of satellites within its line-of-sight. First, we model LEO satellite network as a FSA (Finite State Automaton) using satellite constellation information. Second, we solve a combined ...

Future satellite communication systems proposed use geosynchronous (GEO) satellites, medium earth orbit (MEO), and low earth orbit (LEO) constellations. Most of the next generation satellite systems will use fast packet switching with onboard processing to provide full two-way services to and from earth stations. One of the major service drivers is a high data rate internet access carried over ...

Low Earth Orbit (LEO) satellite networks are foreseen to complement terrestrial networks in future global mobile networks. Although space segment topology of a LEO network is characterized by periodic variations, connections of mobile stations (MS’s) to the satellite backbone network alter stochastically. As a result the quality of service delivered to users may degrade. Different procedures ha...

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...

User terminals for Communications-On-The-Move (COTM) systems and Low Earth Orbit (LEO) and Medium Earth Orbit (MEO) satellite ground terminals require antennas with high gain and steerable beams. LEO cubesats offer unprecedented opportunities for scientific discoveries as well as commercial space adventures. Internet is provided to aeroplanes, ships and defence and other vehicles by COTM system...

Many Transmission Control Protocol (TCP) versions have been proposed for terrestrial wired networks over the Internet Protocol (IP), e.g. Tahoe and Reno. TCP/IP is being studied to overcome its limitations within the satellite medium and to allow its efficient use in hybrid terrestrial/satellite networks. So far studies have been mainly directed to the use of Geostationary Earth Orbit (GEO) con...

In this paper, we propose a new channel estimation algorithm for low earth orbit satellite digital communications. Low earth orbit satellite channels impart severe spreading in delay and Doppler on the transmitted signal. We model the channel as a tapped-delay-line lter with time-varying complex coe cients. The time evolution of the taps is described by an auto-regressive model. A coupled lter ...

Abstract A model for the Low Earth Orbit (LEO) satellite communications channel is proposed in this paper. This model is validated through real measurements gathered from a satellite in LEO for a wide range of elevation angles. It is shown that that the burst statistics of the channel are sufficiently described by a multiplestate Fritchman model and four-state Markov model. This model has been ...

Mobility management is an important aspect in LEO (low earth orbit) systems. In terrestrial wireless networks, the movement of the user triggers location updating and determines the paging scheme, while in LEO satellite systems, the location updating and paging is mainly based on the movement of satellite. Terrestrial location management techniques must be altered to fit the LEO systems. This p...