초록 ▼

A self-contained personal alarm device capable of signaling its location to a remote site such as a security station. The personal alarm device includes a housing enclosing a controller, an antenna, a cellular transmitter and a cellular receiver. The controller is coupled to the transmitter and rece

A self-contained personal alarm device capable of signaling its location to a remote site such as a security station. The personal alarm device includes a housing enclosing a controller, an antenna, a cellular transmitter and a cellular receiver. The controller is coupled to the transmitter and receiver, which are in turn coupled to the antenna. The controller controls the transmitter and the receiver to receive position location signals such as Global Positioning System signals (GPS), establish a cellular connection with a remote site, and transmit device location data to the remote site on the cellular connection, wherein the device location data indicates the location of the device. The cellular connection is established via a cellular telecommunication network that includes an array of cell base stations. The GPS signals are transmitted to the device over the cellular network by providing each cell base station with a Differential Global Positioning System (DGPS) receiver. Using the DGPS receivers, GPS signals are repeated over the cellular network.

대표청구항 ▼

[ What is claimed is:] [1.] A method of providing the location of a device to a remote site, wherein the device includes a transmitter and a receiver, comprising the steps of:(a) establishing a connection with the remote site using the transmitter, wherein the connection is established on a cellular

[ What is claimed is:] [1.] A method of providing the location of a device to a remote site, wherein the device includes a transmitter and a receiver, comprising the steps of:(a) establishing a connection with the remote site using the transmitter, wherein the connection is established on a cellular frequency;(b) receiving position location signals with the receiver, the signals being GPS signals modified for transmission at a cellular frequency and combined with cellular communication control data from a cellular signal and from a cellular site controller;(c) communicating device location data to the remote site over the cellular frequency connection, wherein the device location data is derived from the position location signals;(d) terminating the cellular connection after step (d); and(e) periodically repeating steps (a)-(e), such that the connection is discontinuous and the device location data is intermittently communicated to the remote site.