Digital communications Mobile communication systems 6 Radio 6 Transmitters and transmission 6 Fading 5 Data transmission systems 4 Error-correcting codes (Information theory) 2 Mathematical models 2 Multiplexing 2 Technological innovations 2 Telecommunication 2 Artificial satellites in telecommunication 1 Automatic speech recognition 1 Cellular telephone services industry 1 Coding theory 1 Computer simulation 1 Deaf 1 Decoders (Electronics) 1 Design 1 Design and construction 1 Digital electronics 1 Digital techniques 1 Digital video 1 English language 1 Fifth generation computers 1 Grammar 1 Information display systems 1 Information visualization 1 Instant messaging 1 Interactive video 1