Satellite transmissions have an important role in telephone communications, television broadcasting, computer communications, maritime navigation, and military command and control. Moreover, in many situations they may be the only possible communication set-up. Recent trends in telecommunications indicate that four major growth market/service areas are: messaging and navigation services (wirele...

In the Data AirWaves Project at University of Maryland, we are integrating Direct Broadcast Satellite (DBS) systems with terrestrial networks to provide a hybrid and e ective communication substrate lying between data resources and remote/mobile user applications. Smooth integration of these two media balances the need for rapid data dissemination to very large numbers of clients and on{demand ...

In the past, digital transmission of video and audio has required a broader frequency bandwidth than analog transmission to transmit the same information. Recent progress in source coding technology for video and audio, however, has made it possible to reduce the bit rate while keeping the quality deterioration to a minimum. The frequency bandwidth required for digital transmission has conseque...

In this paper we address the problem of propagating data updates to a large number of mobile clients Typically mobile clients operate autonomously i e disconnected from data servers for prolonged periods of time relying on locally replicated corporate data e g database views le systems From time to time they need to refresh their replicas with data changes registered at a central data repositor...

background :people are increasingly interested in health news. as a mass media, the ‘islamic republic of iran broadcasting’ (irib) has the highest number of target audiences. in iran, some people follow health news via health programs on satellites and other means of communication. however, all of these programs do not live up to the standards of scientific evidence. in this study, we examined ...

This contribution is focused on simulation of the DVB-S2 (Digital Video Broadcasting – Satellite 2nd generation) digital television transmission. For this simulation an application in MATLAB has been developed. It can be use for simulation of whole processing in DVB-S2 transmitter including stream adaptation, FEC (Forward Error Correction) coding with interleaving, modulation, channel distortio...

In Austria like in many other countries nearly all school have an internet connection. This offers a lot of new possibilities in communication and information retrieval. The authors believe that streaming and broadcasting technology which require broadband access will lead to a major step forward in the use of IT in classroom. The prime aim of the AVD project is to investigate the potentialitie...

In this paper, we propose a low-power adaptive low-density parity check (LDPC) decoder that utilizes dynamic voltage and frequency scaling to reduce power consumption. Most existing adaptive LDPC decoders have focused only on the decoding performance based on the signal-to-noise ratio (SNR) estimation. However, significant idle power is consumed when the decoder awaits the next frame after proc...