Mobile communication systems Wireless communication systems 39 Mobile computing 12 Radio 11 Design and construction 8 Fading 8 Transmitters and transmission 8 Security measures 7 Digital communications 6 Instant messaging 6 Long-Term Evolution (Telecommunications) 6 Technological innovations 6 Telecommunication 6 Cell phone systems 5 Code division multiple access 5 Computer networks 5 IEEE 802.16 (Standard) 5 Roaming (Telecommunication) 5 TCP/IP (Computer network protocol) 5 Wireless LANs 5 Antennas (Electronics) 4 Cell phones 4 Design 4 Equipment and supplies 4 Multimedia systems 4 Orthogonal frequency division multiplexing 4 Packet switching (Data transmission) 4 Routing protocols (Computer network protocols) 4 Wireless Internet 4 Access control 3