Abstract: A cellphone Presence and Locating system includes antenna(s) with associated receiver(s) extracting user information, presence and location data from a plurality of mobile cellphones with a Subscriber Identity Module (SIM) card containing a low duty cycle transmitter. The transmitter communicates with the SIM processor and extracts user and configuration information. The transmitter broadcast messages containing selected SIM and other information at intervals or on demand. These transmissions are processed by a receiving station, and additional information such as signal strength, time of arrival and direction is extracted. This data is used to determine local presence or a more accurate location within the coverage area and is added to the specific SIM information before being passed on to an information processing server. The information processing server selects relevant prestored files and delivers these to the originating cellphone via a mobile communication network.

Abstract: A cellphone Presence and Locating system includes antenna(s) with associated receiver(s) extracting user information, presence and location data from a plurality of mobile cellphones with a Subscriber Identity Module (SIM) card containing a low duty cycle transmitter. The transmitter communicates with the SIM processor and extracts user and configuration information. The transmitter broadcast messages containing selected SIM and other information at intervals or on demand. These transmissions are processed by a receiving station, and additional information such as signal strength, time of arrival and direction is extracted. This data is used to determine local presence or a more accurate location within the coverage area and is added to the specific SIM information before being passed on to an information processing server. The information processing server selects relevant prestored files and delivers these to the originating cellphone via a mobile communication network.