Telecommunication Telecommunication systems 11 Management 8 Mobile communication systems 8 Equipment and supplies 7 Signals and signaling 6 Cell phone systems 4 Communication planning 4 Internet 4 Quality control 4 Integrated services digital networks 3 Internet telephony 3 Internetworking (Telecommunication) 3 Multimedia communications 3 Oral communication 3 Security measures 3 Switching systems 3 Video compression 3 Voice 3 Broadband communication systems 2 Computer network protocols 2 Computer networks 2 Computer storage devices 2 Data compression (Telecommunication) 2 Data transmission systems 2 Education 2 Optical fiber communication 2 Radio wave propagation 2 Streaming technology (Telecommunications) 2 System theory 2