.Abstract – The goal of this research was to evaluate the potential of homopolar electrodynamic magnetic bearings for flywheel energy storage systems (FESSs). The primary target was a FESS for Low Earth Orbit (LEO) satellites, however, the design can also be easily adapted for Earth-based applications. The main advantages of Homopolar Electrodynamic Bearings compared to more conventional Active...

Due to the high mobility of low earth orbit (LEO) satellites, there is a significant number of handover attempts in a LEO satellite mobile communication system, causing a high handover failure rate. This paper proposes an Adaptive Channel Reservation Scheme (ACRS) which gives an overall optimal success rate for both handover and new call initialisation. ACRS is able to adapt to the local traffi...

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...

Next generation of wireless Internet scenarios include LEOs (Low Earth Orbit Satellites). Lower altitudes of LEO constellations could allow global coverage while offering: low end-to-end propagation delay, low power consumption, and effective frequency usage both for the users and the satellite network. LEOs rotate asynchronously to the earth rotation. Fast movement of LEOs makes it necessary t...

The Internet Engineering Task Force is working on extending the traditional TCP/IP model for supporting multimedia and real-time applications on the Internet. Thus, new protocols have been developed such as the Resource Reservation Protocol. With the rapid growth of mobile networks, the IETF is also working on creating and extending the existing protocols to support mobile users. This has led t...

Routing in Low-earth-orbit (LEO) satellite system involves the choice of inter-satellite links (ISLs) that connects two home satellites of the mobile terminals. We use a mesh model to formulate the LEO system and proposed 4 mesh-based algorithms. The objective is to minimize the new call blocking probability and the forced termination probability. Also, due to the dynamic topology of the LEO sy...

Mobile satellite systems (MSSs) are expected to play a significant role in providing users with communication services worldwide. In such context, low earth orbit (LEO) satellite constellations seem to be a good solution to attain a global coverage and to allow the use of low-power lightweight mobile terminals. This paper analyzes the performance of a novel medium access control (MAC) scheme su...

Low earth orbit (LEO) satellite systems gained considerable interest in the past decade and were expected to be instrumental in future telecommunications systems. Nevertheless, the first two LEO satellite networks that are currently in operation have not come to fruition on account of the limited spectrum of services that they provide. In this context, future LEO satellite networks will be gear...

When working with space systems the keyword is resources. For a satellite in orbit all resources are sparse and the most critical resource of all is power. It is therefore crucial to have detailed knowledge on how much power is available for an energy harvesting satellite in orbit at every time – especially when in eclipse, where it draws its power from onboard batteries. This paper addresses t...

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...