Mobile phones, phone systems, and emergency location systems are described with features that assist rescue teams in locating survivors in a disaster situation where a phone user and their mobile phone are buried under rubble. To enable the phone's battery charge to last longer, an emergency power conservation mode (E-mode) is activated by either receiving a command from an external source via RF transmission, or by noticing a rapid reduction in signal strength from a tower without changing the phone's physical location. Transmissions are also made by the phone from time to time indicating the user's health condition including providing an indication of life. Portable RF devices may be deployed at grid positions to locate mobile phones by triangulation based on signals received from mobile phones while battery charge still exists for the mobile phones immediately following the disaster.

A software-defined radio system has a plurality of fixed radio receivers each operable to receive radio signals in a receiving band, to sample a received radio signal to produce a sample stream, and to send the sample stream over a network. The radio system includes at least one fixed sync signal transmitter operable to transmit predetermined sync signals in said receiving band to receivers of the aforementioned plurality. The radio system further comprises a data processing system which is connected to the network for receiving sample streams from the receivers. The data processing system is operable to align samples of a data signal contained in sample streams from different receivers by: detecting a sync signal in those sample streams; determining a timing offset between samples of the sync signal in those sample streams in dependence on predetermined locations of the different receivers and the transmitter of that sync signal; and aligning the samples of the data signal in dependence on the timing offset.

A software-defined radio system has a plurality of fixed radio receivers each operable to receive radio signals in a receiving band, to sample a received radio signal to produce a sample stream, and to send the sample stream over a network. The radio system includes at least one fixed sync signal transmitter operable to transmit predetermined sync signals in said receiving band to receivers of the aforementioned plurality. The radio system further comprises a data processing system which is connected to the network for receiving sample streams from the receivers. The data processing system is operable to align samples of a data signal contained in sample streams from different receivers by: detecting a sync signal in those sample streams; determining a timing offset between samples of the sync signal in those sample streams in dependence on predetermined locations of the different receivers and the transmitter of that sync signal; and aligning the samples of the data signal in dependence on the timing offset.

A light source emits a modulated light, and a radio-frequency transceiver disposed therewith emits a radio-frequency signal. A mobile device may receive either or both signals and determine its position based thereon. The light and radio-frequency sources may be disposed in node in a network of said sources, and the nodes may communicate via the radio-frequency transceivers.

Systems and methods are provided that include a transceiver system. The transceiver system is configured to (i) transmit a location request signal to a user identification device (UID), (ii) receive, in response to the UID receiving the location request signal, a position signal transmitted from the UID, and (iii) measure angles of arrival of the position signal for each transceiver of the transceiver system. A controller is in communication with the transceivers and is configured to (i) receive the angles of arrival, (ii) determine a location of the UID based on the angles of arrival, and (iii) activate at least one of an ignition system of a vehicle and a locking system of the vehicle based on the location of the UID.

A system for multi-ship geolocation of a signal emitter of interest uses differential GPS (DGPS) to determine the relative positions of two or more receivers in order to determine baseline vectors between them. The geolocation of the signal emitter is then determined as a function of the baseline vectors. The use of DGPS allows for more efficient and useful geometries between the receivers as two receivers can both be in a mainlobe of an emitted signal and still provide increased geolocation accuracy.

A system for multi-ship geolocation of a signal emitter of interest uses differential GPS (DGPS) to determine the relative positions of two or more receivers in order to determine baseline vectors between them. The geolocation of the signal emitter is then determined as a function of the baseline vectors. The use of DGPS allows for more efficient and useful geometries between the receivers as two receivers can both be in a mainlobe of an emitted signal and still provide increased geolocation accuracy.

Drone-based wireless communications systems are provided, as are methods carried-out by such wireless communications systems. In one embodiment, the wireless communications system includes a Satellite Signal Transformation (SST) unit and a plurality of aerial network drones, which can be deployed over a designated geographical area to form a multi-drone network thereover. During operation, the SST unit transmits a network source signal, which contains content extracted from a satellite signal. The multi-drone network receives the network source signal, disseminates drone relay signals containing the content through the multi-drone network, and broadcastings user device signals containing the content over the designated geographical area. In embodiments, the multi-drone network may broadcast multiple different types of user device signals for reception by various different types of user devices located within the designated geographical area, such as an arear containing communication infrastructure disabled by a natural disaster, a hostile attack, or other catastrophic event.

Drone-based wireless communications systems are provided, as are methods carried-out by such wireless communications systems. In one embodiment, the wireless communications system includes a Satellite Signal Transformation (SST) unit and a plurality of aerial network drones, which can be deployed over a designated geographical area to form a multi-drone network thereover. During operation, the SST unit transmits a network source signal, which contains content extracted from a satellite signal. The multi-drone network receives the network source signal, disseminates drone relay signals containing the content through the multi-drone network, and broadcastings user device signals containing the content over the designated geographical area. In embodiments, the multi-drone network may broadcast multiple different types of user device signals for reception by various different types of user devices located within the designated geographical area, such as an arear containing communication infrastructure disabled by a natural disaster, a hostile attack, or other catastrophic event.

A method is provided for determining a current position of at least one industrial truck having a mobile radio station and positioned in an area having a plurality of stationary radio stations. The method comprises determining vehicle data pertaining to at least one of a vehicle speed and a steering angle of the at least one industrial truck. A position-determining signal is transmitted from the mobile radio station and received by the plurality of stationary radio stations. A position signal is then transmitted from each of the plurality of the stationary radio stations to the mobile radio station. Additional data is appended to at least one of the position-determining signal and the position signal and the current position of the at least one industrial truck is determined from at least three position signals received by the mobile radio station.