Low earth orbit (LEO) satellite has the advantages of global coverage, low propagation delay and low path losses, etc. Combined with orthogonal frequency division multiplexing (OFDM) transmission, LEO satellite system can support very high capacity suitable for wideband multimedia traffic. This paper analyzes the channel model and throughput for LEO OFDM satellite communication system. First, s...

The performance of sensors for Earth Observation Missions is constantly improving. This drives the need for a reliable, high-speed data transfer capability from a Low Earth Orbit (LEO) spacecraft (S/C) to ground. In addition, for the transfer of time-critical data to ground, a low latency between data generation in orbit and data reception at the respective mission control center is of high imp...

Introduction GPS receivers are now widely used for Low Earth Orbit (LEO) spacecraft applications for both scientific and commercial programmes. New applications are also under study, such as navigation in Geostationary Earth Orbit (GEO) and Geostationary Transfer Orbit (GTO), space rendezvous manoeuvres and atmospheric reentry, for which GPS receivers are promising candidates as navigation sens...

The challenge of future mobile multimedia networks is to provide worldwide tetherless communication services. Low Earth Orbit-Mobile Satellite Systems (LEO-MSSs) will play a significant role by filling the coverage gaps of future generation terrestrial cellular networks. This lecture presents research results on demand-assignment Medium Access Control (MAC) schemes able to share efficiently LEO...

The NASA Exploration Systems Architecture Study (ESAS) produced a transportation architecture for returning humans to the moon affordably and safely while using commercial services for tasks such as cargo delivery to low earth orbit (LEO). Another potential utilization of commercial services is the delivery of cryogenic propellants to LEO for use in lunar exploration activities. With in-space p...

In this paper, we survey techniques for routing and performance analysis of Low Earth Orbit (LEO) systems. We first review the basic structure of LEO satellite communications and present the main characteristics of LEO systems. The dynamic characteristics of LEO systems make the performance analysis and routing problem quite complicated. In this study, we review some of the proposed solutions t...

Based on the study of HLA (High Level Architecture) and OPNET-HLA interface, the dynamic control of simulation process and the real-time update of simulation for LEO (Low-Earth-Orbit) satellite communication system were achieved on multiple computers. In the distributed interactive simulation, a satellite’s location is controlled, then the end-to-end delay time and the routing table of Iridium ...

Future satellite communication systems proposed use geosynchronous (GEO) satellites, medium earth orbit (MEO), and low earth orbit (LEO) constellations with fast packet switching and quality of service (QoS) provisioning. In this paper, we present broadband GEO, MEO and LEO satellite network QoS models and simulated performance results. This paper proposes a new method of bandwidth allocation d...

The Internet Engineering Task Force (IETF) 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 (RSVP). At the same time, there has been a growing interest in using Low Earth Orbit (LEO) satellites. In the near future, when the Internet with mul...