Abstract: A system (10) and method delivers geolocation or other signals (26, 28) to a communication unit (24) located within an area (20) (e.g., a building) where an obstruction exists between the signal transmitter (12, 18) and the communication unit (24). The system (10) uses an infrastructure transceiver apparatus (14, 16, 22) to receive (204, 304, 604) the signals (26, 28) and retransmit (208, 310, 610) them within the area (20). A communication unit (24) calculates responsive data, such as its approximate position, from the retransmitted signals and reports (406, 704) the responsive data to a host system via the infrastructure transceiver apparatus (14, 16, 22).

Abstract: A system (10) and method delivers simplex signals (26, 28) to a communication unit (24) located within an area (20) (e.g., a building) where an obstruction exists between the signal transmitter (12, 18) and the communication unit (24). The system (10) uses an infrastructure retransmission apparatus (14, 16, 22) to receive (204, 304, 402, 404) the signals (26, 28) and retransmit (208, 310, 410) them within the area (20). Geolocation signals (26) from navigation satellites (12) can be retransmitted (208, 310) using the infrastructure retransmission apparatus (14, 16, 22), thus enabling a communication unit (24) located within an obstructed area (20) to calculate its position.

Abstract: Subscriber units (26) in a satellite communication system (10) send and receive data messages at optimum times. Each subscriber unit (26) has a pre-programmed database that includes a collection of messages (302), such as data (314), fax (316), pre-recorded voice (318), pager (320), or video files (322). Pre-programmed times include low traffic times (404) and/or most economical times (406) at the point of origination and/or destination. Low traffic time information (404) and most economical time information (406) are stored in the subscriber unit (26) and may be updated by the communication system (10). The subscriber unit (26) sends and receives messages at either a pre-programmed or low traffic time (404) or most economical time (406). The satellite communication system (10) calculates message delivery time when different from a user's time zone. A user is notified when a message is sent and received. The subscriber unit (26) stores the messages for future access.

Abstract: A constellation of satellites which are distributed around the earth serves as a communications infrastructure that supports autonomous position determination and reporting of that position to a remote location. Satellites continuously broadcast acquisition signals. Position determining units are remotely programmed to activate upon the occurrence of an activation event. If PDUs can capture an acquisition signal, then they engage in activities which lead to determining their position and they coordinate their communications with the requirements of the communications infrastructure. To determine position, a location pulse may be transmitted on a regular schedule. The location pulse is transported between a fast moving satellite and a PDU. The movement of the satellite causes different location pulses to have different propagation delays and Doppler characteristics. By analyzing changes in propagation delays and Doppler characteristics, a procedure determines a position for a PDU.