Electronic alarm systems Electronic security systems 58 Design and construction 46 Microcontrollers 29 Programmable controllers 21 Ultrasonics 18 Security systems 15 Global system for mobile communications 14 Security measures 11 Anti-theft devices 6 Automobiles 6 Burglar alarms 6 Electronic apparatus and appliances 6 Mobile communication systems 6 Sensors 6 Control systems 5 Fire alarms 5 Identification 5 Cellular telephone systems 4 Computer networks 4 Electronics 4 Global Positioning System 4 Instant messaging 4 Microcontroller 4 Modem 4 Text messages (Telephone systems) 4 Tunnels 4 Dwellings 3 Radio frequency 3 Radio frequency identification systems 3