Matches 1 - 45 out of 45
Match Document Document Title
7376385 Repeaters sharing a common medium for communications  
A system for communications on a bi-directional medium includes a first repeater, a second repeater, a third repeater and a fourth repeater, each of which is coupled to the medium. The first...
7336079 Aerial electronic detection of surface and underground threats  
An aerial electronic system for detection of surface and underground threats comprises an electromagnetic (EM) gradiometer flown aloft over the possible ground and underground threats to a convoy....
7286812 Coupling between power line and customer in power line communication system  
Apparatus for coupling communication signal modulated radio frequency signals between an electrical power distribution line and the electrical power wiring at a customer's premises which includes a...
EP0954910B1 RF COMMUNICATION SIGNAL DISTRIBUTION SYSTEM AND METHOD  
Abstract not available for EP0954910 Abstract of corresponding document: US5774789 A system and method for distribution of RF communication signals. First RF communication signals are...
7149472 Through-the-earth radio  
A through-the-earth communication system that includes a digital signal input device; a transmitter operating at a predetermined frequency sufficiently low to effectively penetrate useful distances...
7050831 Through-the-earth communication system  
A method and system for communication within an energy-transmission-limited environment. RF transceivers throughout the site are located site-wide such that areas within the site in which...
7043204 Through-the-earth radio  
A method and apparatus for effective through-the-earth communication involves a signal input device connected to a transmitter operating at a predetermined frequency sufficiently low to effectively...
7043195 Communications system  
A communications system, including at least one base station ( 8 ) at the surface, at least one repeater station ( 6 ) below the surface, and at least one mobile station ( 4 ) below the surface,...
6997418 Methods and apparatus for testing a train control system  
A method is described for testing a train control system configured to control at least two locomotives. The train control system includes a control unit on each locomotive and is configured to...
6934511 Integrated repeater  
An integrated repeater includes a housing having opposing sides, a donor antenna mounted on one of the opposing sides, a null antenna mounted on the other of the opposing sides, and repeater...
6927698 Shuttle-in receiver for radio-imaging underground geologic structures  
A coal bed anomaly detection and imaging system comprises a synchronous transmitter and receiver that are separated by a geologic structure with embedded and hidden anomalies. The receiver is...
6892815 Coal bed methane borehole pipe liner perforation system  
A coalbed methane borehole pipe liner perforation system comprises a plastic pipe punch that slips down inside a coalbed methane production borehole lined with a non-perforated plastic pipe. A...
6856799 Communications system, communication method and corresponding devices  
Communications system in which at least certain mobile devices ( 1 ) are each able to be connected to a power supply network ( 4 ) via a connecting module ( 2 ), which connecting modules ( 2 )...
6813324 Synchronized communication system  
A synchronized communication system for communicating signals into and from a medium is disclosed. The communication system utilizes a transmitter located at a central station external to the...
6778127 Drillstring radar  
A drillstring radar comprises a measurements-while-drilling instrument for mounting just behind the drill bit and downhole motor of a drill rod. The instrument includes a radar system connected to...
6745003 Adaptive cancellation for wireless repeaters  
A repeater system has at least one donor antenna element for communicating with a base station and at least one link antenna element for communicating with a remote station. A radio frequency...
6744253 Synchronous radio-imaging of underground structures  
A coal bed anomaly detection and imaging system comprises a synchronous transmitter and receiver that are separated by a geologic structure with embedded and hidden anomalies. The transmitter sends...
6731904 Side-to-side repeater  
A modular repeater includes a housing having a pair of substantially 180° oppositely facing surfaces. At least one antenna element is mounted to each of these surfaces for radiating energy in a...
6633252 Radar plow drillstring steering  
A radar-plow drillstring steering system comprises a steering plow and a measurements-while-drilling instrument for mounting just behind the drill bit and downhole motor of a drill rod. The...
6593746 Method and system for radio-imaging underground geologic structures  
A coal bed anomaly detection and imaging system comprises a synchronous transmitter and receiver that are separated by a geologic structure with embedded and hidden anomalies. The transmitter sends...
6549012 Radio system for characterizing and outlining underground industrial developments and facilities  
Most mines and underground facilities employ standardized construction techniques and materials. Such also cannot avoid having some above ground openings to receive utilities, fresh air, supplies,...
6497457 Drilling, image, and coal-bed methane production ahead of mining  
A coal mining operation begins by using directional drilling to bore several horizontal shafts through a coal deposit with its natural overburden still intact. Any methane gas permeating the coal...
EP1232568A1 HIGHLY RELIABLE POWER LINE COMMUNICATIONS SYSTEM  
Abstract not available for EP1232568 Abstract of corresponding document: WO0137438 An electric power line communication system (20) operates with an electric power distribution system to provide...
6263189 Narrowband high temperature superconducting receiver for low frequency radio waves  
An underground communicating device has a low-noise SQUID using high temperature superconductor components connected to detect a modulated external magnetic flux for outputting a voltage signal...
6195561 Antenna system for two-way UHF underground radio system  
An antenna system for a multi-channel, two-way UHF underground communication includes a base radio station; a non-radiating coaxial cable attached to the transmit/receive connector on said base...
6041216 Radio communication system for use in tunnels  
A radio communications system is intended for use by trains in a tunnel. This system includes an antenna subsystem which incorporates a radiating coaxial cable disposed along the length of the...
6032020 Multi-repeater communication system  
A structure (24) includes a plurality of repeaters (34), each having a primary transceiver (36) and a secondary transceiver (38) electromagnetically located upon a clear side (30) and a blocked...
5832364 Distributing wireless system carrier signals within a building using existing power line wiring  
A radio-frequency (RF) distribution system carriers multi-carrier RF signals having frequencies above 500 Mb over existing electric power wiring between a transceiver and one or more antennas. The...
5689804 Medium-frequency radio transmission system  
A medium-frequency radio transmission system is formed by installing a receiving antenna for receiving an amplitude-modulated medium-frequency radio wave at the rooftop of an existing building,...
EP0772952A1 AN AUDIO INTERFACE GARMENT AND COMMUNICATION SYSTEM FOR USE THEREWITH  
Abstract not available for EP0772952 Abstract of corresponding document: US5563951 A personal communications apparatus using a garment-based audio interface. A garment member is worn on the upper...
5603080 Radio coverage in closed environments  
A repeater system in a communication system including a base station and a mobile unit provides a communications link between the base station and the mobile unit when the mobile unit is located in...
5553126 Secure anti-jamming wireless party line  
A secure wireless party line system that can be used by a group of mobile users to communicate with each other like a wired party line but without the cumbersome inconvenience of long wired tether....
5537637 Medium-frequency radio broadcasting retransmission system for confined and electromagnetically shielded areas  
A medium-frequency radio transmission system is formed by installing a receiving antenna for receiving an amplitude-modulated medium-frequency radio wave at the rooftop of an existing building,...
5504809 Communication system for use in a mine  
A communication system for use in a mine to provide two-way communication between a conveyance which moves in a mine and a communication network located in the mine. The system comprising: means...
5432838 Communication system  
A communication system, particularly for a mine, has a broad band distribution system. Antennas, which may comprise leaky coax feeders, are connected to this distribution system by interface units....
5404570 Radio coverage in closed environments  
A repeater system in a communication system including a base station and a mobile unit provides a communications link between the base station and the mobile unit when the mobile unit is located in...
5345473 Apparatus for providing two-way communication in underground facilities  
The invention relates to an apparatus which is desiged for underground use in order to facilitate a two-way communication. The apparatus is operated within the frequency band 0.1-2 MHz, in order to...
5230080 Ultra-high frequency communication installation  
A communication installation for use in a site having underground galleries, for information exchanges, comprises a repeater connected to a wired distribution network. The repeater is arranged for...
5206863 Processor-to-processor communications protocol for a public service trunking system  
A downlink between a communications dispatch console and a digitally trunked radio repeater system site controller efficiently transfers message data between the site controller and the console...
5146611 Mine communication cable and method for use  
A mine emergency communication cable and a method for use. The cable is comprised of a plurality of brightly colored, lightweight, strong synthetic fibers having a plurality of noninsulated tin...
5128930 Processor-to-processor communications protocol for a public service trunking system  
A downlink between a communications dispatch console and a digitally trunked radio repeater system site controller efficiently transfers message data between the site controller and the console...
5087099 Long range multiple point wireless control and monitoring system  
A method for remotely monitoring conditions such as carbon monoxide or methane gas concentration, longwall roof support pressure, machine parameters or uncut coal, trona or potash layer thickness...
4984292 Bandpass amplifier and receiver using bandpass amplifier  
The present application relates to an active bandpass amplifier comprising a single stage operational amplifier, a bridged "T" network single frequency elimination filter in the negative feedback...
4879755 Medium frequency mine communication system  
A method for using an underground mine communication system to effect minewide communication and an intrinsically safe current limiter circuit for insuring that electrical equipment in the system...
4835731 Processor-to-processor communications protocol for a public service trunking system  
A downlink between a communications dispatch console and a digitally trunked radio repeater system site controller efficiently transfers message data between the site controller and the console...
Matches 1 - 45 out of 45