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...

Notwithstanding the limited commercial success of the first narrowband Low Earth Orbit (LEO) satellite systems, the interest of the scientific community in this type of systems has been revived on the basis of the current trend toward the migration to all IP-based services. LEO systems can play a pivotal role in providing services to areas where there is no substantial terrestrial infrastructur...

Low Earth Orbit (LEO) satellite networks will play an important role in the evolving information infrastructure. Satellites in the low earth orbits provide communication with shorter end-to-end delays and efficient frequency usage. However, some problems need to be solved before LEO satellite systems can be successfully deployed. One of these problems is the handover management. The objective o...

The rapid growth of Internet-based applications pushes broadband satellite networks to carry on IP traffic. In previously proposed connectionless routing schemes in satellite networks, the metrics used to calculate the paths do not reflect the total delay a packet may experience. In this paper, a new Satellite Grouping and Routing Protocol (SGRP) is developed. In each snapshot period, SGRP divi...

satellite orbit determination is a method of determining the state vector, i.e., position and velocity, of a low earth orbiting (leo) satellite or interplanetary spacecraft. during the past two decades, many satellites with various applications including geodetic applications have been launched at low altitudes. for instance, topex / poseidon, champ, grace and goce are the examples of the geode...

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...

A new routing algorithm for Low-earth orbit (LEO) satellite networks is designed in this study. For this reason genetic algorithms are used. A new objective function is obtained to find the suitable path according to the criteria of the delay and an aging factor. Also Call Blocking Probabilities (CBPs) are considered due to the dynamic nature of the satellite systems. This dynamic routing type ...

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...

We study the problem of carrying voice calls over a LEO satellite network, and we present an analytical model for computing call blocking probabilities for a single orbit of a satellite constellation. We have devised a method to solve the corresponding Markov process eÆciently for up to 5-satellite orbits. For orbits consisting of a larger number of satellites, we have developed an approximate ...