A security system (52) using cellular wireless half duplex communication call (62) is provided. The security system (52) comprises a set of monitored resources (10), group of owners (48) and group of helpers (50) connected using said cellular wireless half duplex call (52). The monitored resource (10)...http://www.google.es/patents/US7577420?utm_source=gb-gplus-sharePatente US7577420 - Instant help security system for emergency help using 2G, 2.5G and 3G cellular wirelesses half duplex call
Instant help security system for emergency help using 2G, 2.5G and 3G ...
