The necessity of simultaneous access to one communication channel by many users, e.g., in satellite communication systems or cellular telephony, has led to the development of the corresponding standards: FDMA (Frequency Division Multiple Access) and TDMA (Frequency Division Multiple Access). Increasing requirements to the communication channel transmission rates gave rise to the appearance of C...

Satellite communications and relaying techniques have been receiving the attention of the research community over the last years. This paper proposes a terrestrial to satellite communication system aided by terrestrial relay nodes to facilitate a robust, reliable, and efficient communication link and improve the spectral efficiency. In particular, this paper concentrates on evaluating the spect...

This paper presents a combination of Free Space Optic systems with WLAN and Satellite Communications to provide Video conferencing and data transfer for use in Civil Military Cooperation and disaster recovery applications. A modular communication system developed at TU Graz is described, which facilitates worldwide access to the Internet or any other network (depending on the particular applica...

Monitoring of land surface albedo dynamics is important for the understanding of observed climate trends. Recently developed multidecadal surface albedo data products, derived from a series of geostationary satellite data, provide the opportunity to study long term surface albedo dynamics at the regional to global scale. Reliable estimates of temporal trends in surface albedo require carefully ...

A general conceptual approach to measuring innovation in complex systems is developed; specifically defining innovation as a measure of the rate of change of function per cost over time. This notion is applied in the context of communication satellites with the associated challenges discussed. Given the constraints on data availability, a highest-lowerbound estimator is proposed as a surrogate ...

The tropospheric channel models developed for earth-GEO satellite links are not directly applicable for LEO satellites. In the absence of significant propagation datasets, reasonable models are developed for the simulation of earth-LEO link. This paper presents preliminary models for the simulation of the effect of turbulence on earth-LEO links.

Today, leisure time is changing by globalization and using of information technology. Most of people especially women prefer to spend their leisure time by modern technologies. Thus, they spend their leisure time to look up satellite programs and use of the internet. This research has done for sociological consideration of the globalization of communications (internet  & satellite) on leisure t...

Fixed GEO satellite communications are impaired by long RTTs (especially GEO) and the possible presence of packet losses on the satellite radio channels. Moreover, when the satellite receiver is mobile, short and long disruptions due to line of sight obstructions associated with the presence of shadowing can cause further performance deterioration. In this paper, we evaluate the impact of a dis...

In the context of next generation 5G networks, the satellite industry is clearly committed to revisit and revamp the role of satellite communications. As major drivers in the evolution of (terrestrial) fixed and mobile networks, Software Defined Networking (SDN) and Network Function Virtualisation (NFV) technologies are also being positioned as central technology enablers towards improved and m...