Mobile communication systems Cellular telephone services industry 3 Cellular telephone systems 3 Cellular telephones 2 Wireless communication systems 2 Broadband communication systems 1 Cell phones 1 Cellular telephone equipment industry 1 Code division multiple access 1 Design and construction 1 Digital communications 1 Dissertations 1 Dissertations, Academic 1 Equipment and supplies 1 Forecasting 1 Gateways (Computer networks) 1 Industrial productivity 1 Instant messaging 1 Interface circuits 1 Packet switching (Data transmission) 1 Public key infrastructure (Computer security) 1 Radio circuits 1 Security measures 1 Social aspects 1 Technology and state 1 Telephone, Wireless 1