MAGNETIC TRANSMISSION

Abstract: A system and a method for data transmission using a magnetic field. The system comprises means for generating a magnetic field and effecting variation of the magnetic field in correspondence with data to be transmitted. The varied magnetic field is then transmitted and subsequently received and decoded in order to retrieve the carried data.

Description: "Magnetic Transmission" This invention relates to a data transmission system. 5 More particularly, the invention relates to magnetic induction transmission, over a distance, of data such as voice, measurements^ computer bytes, video, etc, that is any analogue or digital signals that can be processed onto a modulated carrier or; in such configuration that it can be Q transmitted and recognised by the systems using this invention. According to the present invention there is provided a data transmission system comprising means for generating a S magnetic field means -for effecting variations to said magnetic field in correspondence with data to be transmitted, means for transmitting said varied magnetic field, and means for receiving and decoding said transmitted magnetic field in order to retrieve the transmitted data. D Further according to the present invention there is provided a method of transmitting data comprising the steps of generating a magnetic field; varying said magnetic field in correspondence with data to be transmitted, transmitting 5 said varied magnetic field and receiving and decoding said transmitted magnetic field in order to retrieve the carried data. Thus, the invention involves the transmission of signals by generation of a recognisable magnetic field (preferably by modulation) and reception of the signal by measurements of the transmitted magnetic field as a vehicle for transfer of information. ' Embodiments of the present invention will now be described, by way of example, with reference to the attached drawing which shows one implementation of the system of the invention. With reference to the drawing, a data transmission system comprises a magnetic field transmitter 1 which receives data from a number of data collection devices 2 which in the particular application illustrated could be temperature, pressure, flow rate; etc. The transmitter 1 is located in a bore hole 20 and encodes the data transmitting it through the creation of a modulated magnetic field, which is received by a receiver 10 located, for example, on the sea¬ bed. Alternatively, the receiver may be a receiver 11 located on a drilling platform, a receiver 12 located on a floating vessel or a receiver 13 located on-shore. The generation of the transmitted magnetic field may be provided, for example; by electrical coil induction within a body of matter; the reception being made by measurements with sensors responding to magnetic field variations such as magnetometers, Hall effect generators, fluxgates, induction coils, etc. As in the case of data and signals transmitted by means of electro-magnetic carriers, this invention has a large variety of applications making use of signal differentiation by frequency or amplitude modulation; phase shift or rotation, time delay, etc. The invention finds applications in the transmission of signals in environments not easily permeable to, or saturated by, electro-magnetic waves; such as environments buried within or shadowed by a large land mass, concrete shelters or other constructions; under water, etc. The invention is particularly useful for the transmission of data and information collected deep inside hydrocarbon or geothermic wells, where pressures, temperatures and flows are recorded for good management of the reservoirs; inside mines and natural caves for communication and safety; underwater for communication, navigation and data gathering between surface and submerged boats, beacons, automatic recording stations, remotely operated wellheads, etc. all without the use of hard wired links between the transmitter and receivers. The described mode of transmission is not limited to earth bound applicatons, and the invention has application in space or within or outside of anybody of matter, provided that this body of matter does not, by the physics of its properties, attenuate too quickly the magnetic field (principal mode of transfer of information) generated for the signal transmission. Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims: CLAIMS 1. A data transmission system comprising means for generating a magnetic field, means for effecting variations 5 to said magnetic field in correspondence with data to be transmitted, means for transmitting said varied magnetic field, and means for receiving and decoding said transmitted magnetic field in order to retrieve the transmitted data. 10 2. A system as claimed in Claim 1, wherein said means for generating a magnetic field comprises electrical coil induction within a body of matter. 3. A system as claimed in either preceding claim, wherein 15 . said variation in said magnetic field comprises frequency modulation, amplitude modulation, phase shift, phase rotation, or time delay. 4. A system as claimed in any preceding claim, wherein said 20 means for receiving and decoding said transmitted magnetic field is responsive to variations in said field. 5. A data transmission system substantially as hereinbefore described with reference to the accompanying drawing. 25 _ 6. A method of transmitting data comprising the steps of generating a magnetic field, varying said magnetic field in correspondence with data to be transmitted, transmitting said varied magnetic field and receiving and decoding said 30 transmitted magnetic field in order to retrieve the carried data. 7. A method of transmitting data substantially as hereinbefore described with reference to the accompanying 353 drawing.

Inventors: MISSON PIERRE, MISSON, PIERRE
Applicants: MISSON PIERRE, MISSON, PIERRE
Application year: 1986
Main classification: H04B5
IPC codes: E21B47, H04B5