Telephone 35 Cellular telephone systems 26 Wireless communication systems 18 Cellular telephones 15 Social aspects 14 Telecommunication 14 Mobile communication systems 13 History 12 Telecommunication systems 8 Telephone systems 8 Radio 7 Security measures 6 Design and construction 5 Management 5 Telephone switching systems, Electronic 5 Cellular telephone equipment industry 4 Communication 4 Digital communications 4 Equipment and supplies 4 Mobile computing 4 Standards 4 Adaptive antennas 3 Broadband communication systems 3 Cellular telephone services industry 3 Computer crimes 3 Computer networks 3 Digital telephone systems 3 Interference 3 Interpersonal communication 3 Prevention 3