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...

The tropospheric channel models developed for earth-GEO satellite links are not directly applicable for LEO satellites. In the absence of significant propagation datasets, reasonable models are developed for the simulation of earth-LEO link. This paper presents preliminary models for the simulation of the effect of turbulence on earth-LEO links.

A system to provide non-realtime short message transmission service to a wide-area of users via Low Earth Orbit (LEO) micro-satellite is developed. To increase the system capacity, a novel and efficient slotted quasi-synchronous CDMA access protocol is specially designed to deal with the serious Doppler shift and propagation delay variation. Before each message burst transmission, the user will...

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 ...

An analytical framework for the efficient evaluation of the performance of complete sharing (CS) and complete partitioning (CP) resource sharing policies under a newly proposed general channel management strategy for multi-class traffic in Low Earth Orbit-Mobile Satellite Systems (LEO-MSS) is presented. This strategy gives a higher priority to handover calls over new calls by combine the guard ...

Future Low Earth Orbit (LEO) satellite networks are envisioned as distributed architectures of autonomous data processing nodes. Such ad hoc networks should deliver reliable communication channels for control commands and data among ground stations and satellites minimizing delay and power. The LEO satellite networks are different from the generic ad hoc scenario. In this paper, we first analyz...

A technique for satellite formation flying modelling in LEO is applied at L2. Analytical solutions to the equations of motion of a hub satellite relative to L2 are used to define a halo reference orbit. An expression for the gravity gradient is obtained at the hub and the linearised equations of motion of the mirror satellites relative to the hub are derived. The relative motion model is implem...

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 ...

—W-band (75-110 GHz) is proposed nowadays as a valuable alternative to intensively-exploited Ku and Ka bands for high-speed transmission over satellite networks. In such a framework, some experiments are being carried out, which are targeted to verify the feasibility of exploitation of W-band for broadband service deployment. From a theoretical viewpoint, the large bandwidth availability and th...

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...