Low Earth Orbits (LEO) satellites are used for public communication and for scientific purposes. These satellites provide opportunities for investigations for which alternative techniques are either difficult or impossible to apply. Ground stations have to be established in order to communicate with such satellites. Usually these satellites communicate with ground stations at S-band. The commun...

Satellite network is the essential part of the future generation of hybrid communication networks. Considering the surging demands for multimedia traffic across the globe, the dynamic time-varying topology of low earth orbit (LEO) satellite network and the flaws of existing QoS (Quality of Service) routing algorithms, a novel QoS routing algorithm applying multi-agent system (MAQR) for LEO sate...

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...

Most recent satellite network research has focused on providing routing services without considering security. In this paper, for the sake of better global coverage, we introduce a novel triple-layered satellite network architecture including Geostationary Earth Orbit (GEO), Highly Elliptical Orbit (HEO), and Low Earth Orbit (LEO) satellite layers, which provides the near-global coverage with 2...

In this paper, for the sake of better global coverage, we introduce a novel triple-layered satellite network architecture including the Geostationary Earth Orbit (GEO), the Highly Elliptical Orbit (HEO), and the Low Earth Orbit (LEO) satellite layers, which provides the near-global coverage with 24 hour uninterrupted over the areas varying from 75° S to 90° N. On the basis of this satellite net...

Designing an efficient routing algorithm for LEO satellite constellations is crucial for optimizing IP over Satellite (IPoS) network resources. Since there could be many shortest paths between two satellites, an efficient routing algorithm should provide better utilization of these paths. For this purpose, we propose a Priority-based Adaptive Routing (PAR) technique, which distributedly sets th...

The GlobalstarTM system provides telephone and data services to and from mobile and fixed users in the area between ±70 degrees latitude. Connection between user terminals and the PSTN is established through fixed terrestrial gateways via a constellation of low earth orbiting (LEO) satellites. Globalstar uses an extension of the IS-95 CDMA standard that is used in terrestrial digital cellular s...

Due to the time-varying phase in frequency diverse arrays (FDAs), traditional phase-based secure communication (SC) methods cannot be utilized. In this reported work, automatic scanning property of FDAs (time-varying property) was rederived. This allows for presetting beam time towards desired receiver (Bob). Subsequently, time-carrying design applied Low Earth Orbit (LEO) satellites. A satelli...

Today most of the satellite systems are designed in Low Earth Orbit (LEO) satellite systems.Because the satellites which are located in these orbits have small propagation delays than the satellites in other orbits. And also the closeness of LEOs to the earth gives them an advantage that there isn’t any need to the more power for having a communication with earth stations.In this study, we cons...