More and more satellites are populating the sky nowadays in Low Earth orbits (LEO). Most of targeted applications related to broadband narrowband communications, observation, synthetic aperture radar, internet-of-Things (IoT) connectivity. In addition these applications, there is yet-to-be-harnessed potential for LEO positioning, navigation, timing (PNT) systems, or what referred as LEO-PNT. No...

This paper proposes a novel dynamic bandwidth assignment multiple access (DBAMA) protocol employing a dynamic packet reservation technique for direct user terminal access to a ATM-based low earth orbit (LEO) satellite communications system. Performance analyses by simulations are presented. Methods to efficiently integrate ATM-based BISDN traffic are considered.

A novel LEO/MEO two-tier satellite communication system with inter-satellite links ( I S L r ) is proposed for providing multimedia services to global mobile users. This two-tier syxtem architecture can reduce the transmission delay for long-distunce users via ME0 satellites while keeping the benefits of using LEO satellites as the service access nodes. The routing and re-routing during a hando...

In this paper the basic principles for the design and implementation of a wide-band statistical model for the LMS (land mobile satellite) channel at various frequency bands are presented. The model is valid for different services including communications, broadcast, navigation, etc. The simulator implementing the model is suitable of the study of new systems, including those using LEO and other...

We present an analytical model for calculating upper and lower bounds for call-blocking probabilities in a LEO satellite network that carries voice calls. The method is especially useful for large systems where calculation of call-blocking probabilities are too expensive. Our method calculates upper and lower bounds very easily and produces fairly accurate results.

In this letter, a handover scheme tailored for LEO satellite systems is proposed and evaluated. The proposed algorithm capitalizes upon the deterministic topology of this type of systems in order to increase channel utilization and diminish both blocking and forced termination probabilities.

In this chapter, we survey communication related issues arising in the context of Low Earth Orbit (LEO) satellite constellations. In particular, we study the impact of the predictable movement of the satellites on the techniques used in topological design, routing, and hand-over strategies.

Space is an unforgiving environment – one of harshest known to mankind. Yet, space is far less understood than other service environments in which DOD systems operate. It has been known to limit the useful life of satellites, with 20 to 25% of all mission failures being attributed to the effects of the space environment.[1] Since access to space is so costly, materials and components must funct...

Satellite networks offer a number of desirable characteristics including wide area coverage, unique broadcast capabilities, the ability to communicate with hand-held devices, and low cost-per-minute access time, among others. Low Earth Orbit (LEO) satellites are expected to support multimedia traffic and to provide their users with the appropriate Quality of Service (QoS). However, the limited ...