Abstract: A seismic marine vibrator (100) may comprises first plates (102) and second plates (104) arranged along a longitudinal axis (101), longitudinal and peripheral first (106) and second (108) elements respectively secured to the first (102) and second (104) plates, and an actuator (112) operable to reciprocate the first elements (106) relative to the second elements (108) along the longitudinal axis (101) so as to reciprocate the first plates (102) relative to the second plates (104). The seismic marine vibrator further comprises peripherally closed air-filled chambers (109) and peripherally open chambers (111), the volume of said open chambers (111) being varied when the first plates (102) are reciprocated so as to take in and expel water radially to generate an acoustic wave. This forms an improved seismic marine vibrator.

Abstract: A method is provided for assembling a 3D sensing apparatus that comprises at least two projectors, wherein the assembling of the apparatus is carried out by ensuring that a pattern formed from a combination of images projected by each of the at least two projectors, is not formed along an epi-polar line or part thereof more than once. The method comprises the steps of: placing the at least two projectors at initial approximate physical positions within the 3D sensing apparatus; and, placing one or more projectors' protectors on top of the at least two projectors, thereby changing the projectors initial positions and automatically positioning them accurately in their pre-defined position and orientation by using the one or more projectors' protectors.

Abstract: A sound source includes a first gas filled underwater resonator, a second gas filled underwater resonator connected to the first resonator and at least one excitation member configured to excite the first gas filled underwater resonator and the second gas filled underwater resonator, where the first gas filled underwater resonator is permanently tuned to produce a first resonant frequency upon excitation by the at least one excitation member, where the gas filled underwater second resonator is permanently tuned to produce a second resonant frequency upon excitation by the at least one excitation member, and where the first resonant frequency is different from the second resonant frequency.

Abstract: A method for generating acoustic waves under water includes actuating first and second pistons with an actuator system provided inside an enclosure of a source element, to generate a wave having a first frequency, and actuating the first and second pistons with a pressure mechanism attached to the enclosure, to control a pressure of a fluid inside the enclosure such that a pressure of the fluid is substantially equal to an ambient pressure of the enclosure. The enclosure has first and second openings and the first and second pistons are configured to close the first and second openings.

Abstract: A mobile device with an underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms. The portable device may be wearable.

Abstract: The output spectrum of a controllable swept-frequency acoustic source at a given frequency can be controlled by making the rate of change of frequency equal to the desired output power spectrum divided by the squared envelope amplitude of the source output signal, both measured at the time after the start of its frequency sweep at which the sweep frequency passes through the given frequency. The system and method can also be used to correct for propagation effects outside the source by dividing the desired spectrum by the propagation effect. The method can further be used either to obtain an output spectrum of a desired shape from a source operating at maximum output or to design a sweep of a minimum feasible duration that will result in an output spectrum of a specified shape and with a specified amplitude.

Abstract: A variable shock wave bio-oil extraction system and method utilizes shock waves to separate oil, water, and biomass from feedstock in a single step. In one embodiment, at least one pair of opposing transducer arrays are arranged in a shock wave extraction housing and collectively powered by a pulse controller to create controllable shearing planes and/or shearing regions and/or shock stem zones to interact upon a flow path of feedstock as the feedstock travels through the shock wave housing.

Abstract: Method, source and seismic vibro-acoustic source element configured to generate acoustic waves under water. The seismic vibro-acoustic source element includes an enclosure having first and second openings; first and second pistons configured to close the first and second openings; an actuator system provided inside the enclosure and configured to actuate the first and second pistons to generate a wave having first frequency; and a pressure mechanism attached to the enclosure and configured to control a pressure of a fluid inside the enclosure such that a pressure of the fluid is substantially equal to an ambient pressure of the enclosure.

Abstract: A technique includes determining at least one parameter to regulate actuation of a seismic source based on a frequency-based maximum deliverable output for the source. The technique includes using at least one sensor to acquire a measurement of an output of the source in response to the source being regulated using the at least one parameter and processing data representative of the measurement in a processor-based machine to selectively update the frequency-based maximum deliverable output and the at least one parameter based at least in part on the measurement.

Abstract: A device operable as a transducer is provided for use in which the device is mountable on a tow cable which in operation extends underwater substantially throughout the length thereof. The device comprises a head mass encompassing the tow cable wherein the head mass reacts to a wave-like strumming configuration about an axis of the tow cable thereby causing the tow cable to be displaced in one direction, along the axis and then in an opposite direction such that a low frequency continuous sound wave radiates from the head mass.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A sound source includes a bubble configured to be filled with a gas. The sound source also includes an actuator configured to perturb the gas within the bubble by changing the volume of the gas without adding gas to or removing gas from the bubble. The sound source also includes a processing circuit configured to provide a control signal to the actuator to cause the actuator to perturb the gas within the bubble at a frequency defined by the control signal.

Abstract: The autonomous waterproof electronic signaling device disclosed comprises an activator; an audible signal emitter and a visual signal emitter, the audible signal emitter to emit a primary signal upon activation of the activator, the audible signal emitter comprising one or more of the following: a hydrophone, a siren, a speaker, or a transducer; and a head assembly, the head assembly positioned so as to alter at least a portion of the primary signal producing a notification signal. The visual signal emitter comprises at least one of incandescent bulbs, compact fluorescent bulbs, strobe bulbs, high intensity discharge (HID) bulbs, and light emitting diodes (LED) bulbs. The audible signal emitter and a visual signal emitter are operative singly or in combination, continuously or intermittently.

Abstract: A system for enhancing the separation of particles or fluids from water is disclosed. A settling tank or skim tank is provided with an open submersible acoustophoretic separator. In a skim tank, the separator captures and holds oil droplets or particles, permitting them to coalesce until they are large enough and have sufficient buoyant force to float to the top of the tank. In a settling or sediment tank, separator captures and holds particles until they are large enough that the force of gravity causes them to settle out of the water. The acoustophoretic device thus speeds up separation of the particles or droplets from the water.

Abstract: A forward and aft open-ended, towed underwater acoustic source having a hollow with a plurality of wires disposed in parallel across one or both of the end openings. In operation, water flows around the wires and proceeds through the hollow body, exiting the aft open end of the body. The tensioned wires are situated normal to the direction of flow in order to cause production of Strouhal vibration frequencies due to the vortex shedding action of the water flow behind the wires. The source transmits broadband acoustic energy without requiring heavy transducers.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A seismic source includes a flextensional shell defining a longer axis and a shorter axis and at least one driver coupled to the flextensional shell proximate an end of the shorter axis. The seismic source may be a component of a marine seismic survey system. The marine seismic survey system may be utilized in a method of marine seismic surveying.

Abstract: The invention concerns a device for emitting seismic waves designed to operate by being towed by a vessel. The device of the invention comprises a support of elongated shape; at least one seismic source connected to the support; means to tow the support whilst holding it in a substantially vertical position.

Abstract: A sound source includes a tubular resonator configured to be filled with a gas. The exterior of the resonator includes rigid and elastomeric portions. The interior of the resonator includes a first volume and a second volume. The volumes are separated by a rigid tubular wall containing at least one orifice. The at least one orifice enables a flow of gas between the volumes. The resonator also includes at least one rigid tubular member configured to move along the rigid tubular wall. The position of the at least one rigid tubular member regulates at least one dimension of the path between the volumes. The sound source also includes a volume velocity actuator disposed within the resonator. The sound source also includes a processing circuit configured to provide a control signal to cause the volume velocity actuator to perturb the gas within the resonator at a defined frequency.

Abstract: Method, source and seismic vibro-acoustic source element configured to generate acoustic waves under water. The seismic vibro-acoustic source element includes an enclosure having first and second openings; first and second pistons configured to close the first and second openings; an actuator system provided inside the enclosure and configured to actuate the first and second pistons to generate a wave having first frequency; and a pressure mechanism attached to the enclosure and configured to control a pressure of a fluid inside the enclosure such that a pressure of the fluid is substantially equal to an ambient pressure of the enclosure.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A sound source includes a bubble configured to be filled with a gas. The sound source also includes an actuator configured to perturb the gas within the bubble by changing the volume of the gas without adding gas to or removing gas from the bubble. The sound source also includes a processing circuit configured to provide a control signal to the actuator to cause the actuator to perturb the gas within the bubble at a frequency defined by the control signal.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A sound source comprises a bubble configured to be filled with a gas, an actuator configured to perturb the gas within the bubble, and a processing circuit configured to provide a control signal to the actuator to cause the actuator to perturb the gas within the bubble at a frequency defined by the control signal.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: An underwater navigation system comprising a transmitter having an electrically insulted magnetic coupled antenna for transmitting an electromagnetic and/or magneto-inductive signal, a receiver having an electrically insulated magnetic coupled antenna for receiving an electromagnetic and/or magneto-inductive signal from the transmitter, and determining means for determining the position of the receiver relative to the transmitter using the received electromagnetic and/or magneto-inductive signal.

Abstract: The systems described include a light-weight, low frequency (200 Hz-1000 Hz), broadband underwater sound sources that comprise an inner resonator tube with thin walls tuned to a certain frequency surrounded by a shorter, larger-diameter, lower frequency tuned outer resonator tube that has an acoustic source suspended off-center inside the inner resonator tube.

Abstract: The generator device is proposed for seabed survey, comprising a generator line, including electrodes, a hoist, hydraulic pump, air compressor, and at least one hose joined to the generator line, situated optionally inside or outside the line. The hose includes a through hydro-channel therein, a stationary end connected to the pump or alternatively to the compressor, and a running end furnished with a discharge valve. Connecting to the compressor ensures positive floatation of the generator line, whereas connecting to the pump ensures negative floatation thereof. In preferred embodiments, the device comprises a hydraulic clutch and a faucet. The hose communicates with the pump and compressor through the clutch and faucet, ensuring alternative communication of the hose's hydro-channel with water or air for filling thereof. The generator line comprises a dipole including one power braiding, and an initial part including two power braidings, the braidings are connected to the electrodes.

Abstract: A subsea monitoring system.

Abstract: A sound source comprises a bubble configured to be filled with a gas, an actuator configured to perturb the gas within the bubble, and a processing circuit configured to provide a control signal to the actuator to cause the actuator to perturb the gas within the bubble at a frequency defined by the control signal.

Abstract: System for generating pressure waves for deep seismic surveys operating in an underwater environment below the surface, suitable for investigating subcrustal objectives for prospecting purposes in the search for hydrocarbons and/or minerals. The system comprises one or more autonomous underwater vehicles organized in swarms, independent and coordinated, each housing one or more autonomous acoustic sea sources with self-propelled striker pistons. This system is served by a system of supporting surface stations, for reprovisioning, recovery actions, checking the well-being of the single vehicles and swarms and maintenance. The system is capable of using both conventional and non-conventional self-charged acoustic sea seismic sources. The system is capable of replicating the effect of a conventional source operated from the surface.

Abstract: A method for electromagnetic surveying subsurface formations includes inducing an electromagnetic field in the subsurface formations by passing electric current through a transmitter. Response of the subsurface formations to the induced electromagnetic field is detected at a first plurality of spaced apart positions disposed longitudinally within a bipole length of the transmitter. A direct induction response is removed from the detected response.

Abstract: The present invention discloses a tagging and identification device and system for tracking and monitoring sea vessels as they enter sea ports, estuaries and/or other channels. The tagging device of the present invention comprises a receiver, for receiving an underwater electromagnetic signal transmitted by an underwater beacon. An acoustic transmitter is provided for transmitting an identification signal to an acoustic receiver deployed nearby. The acoustic identification signal is transmitted after an electromagnetic trigger signal is received from the underwater beacon. The tagging and device may further comprise a memory device which can store data relating to position and time of the see vessel to which it is attached. The tagging and identification device of the present invention is covert, compact and is capable of extended active deployment without replenishment of batteries etc.

Abstract: According to a preferred aspect of the instant invention, there is provided herein a system and method for creating low frequency seismic waves. In brief, the instant invention uses a rotary propeller-type system that has been mounted in, for example, a barge or other marine vessel as a seismic source. In the preferred arrangement, the instant source will generate a seismic signal that has greater low frequency content (e.g., frequencies that are less than about 10 Hz) than has been possible heretofore.

Abstract: An underwater remote sensing system comprising a transmitter for transmitting an electromagnetic signal, a receiver for receiving an electromagnetic signal reflected from an object and determining means for determining the location of the object, wherein at least one of the transmitter and receiver is underwater. The determining means may be operable to determine the location of the object using signals received at three or more receiver positions. To do this, three or more receiver antennas may be provided. Alternatively, a single receiver antenna may be provided and moved between three or more different measurement locations.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: The present invention provides a communication device and a communication method of an underwater vehicle, which use an electromagnetic field (electromagnetic wave), having a higher propagation speed than that of an acoustic wave, for communication between an underwater vehicle and a mother vessel or the like so as to allow real-time control of the underwater vehicle and the like and further to make the communication little sensitive to noise and the like. The communication device performs wireless communication between an underwater vehicle in water and an object on land or on water, and is configured to compress data to be transmitted and transmit/receive the compressed data by the use of a low-frequency electromagnetic field.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: The autonomous waterproof electronic signaling device disclosed comprises an activator; a signal emitter, said signal emitter to emit a primary signal upon activation of said activator, said signal emitter comprising one or more of the following: a hydrophone, a siren, a speaker, or a transducer; and a head assembly, said head assembly positioned so as to alter at least a portion of said primary signal producing a notification signal.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A system and method for relaying signals from a magneto-inductive system, which are normally used to communicate between magneto-inductive units using quasi-static magnetic fields, over a voice-band communication system. The magneto-inductive signals are modulated data signals having a carrier frequency typically between 300 Hz and 3 kHz. The voice-band communication system facilitates long distance communication of voice-band signals. By supplying the signals from one magneto-inductive unit to the voice-band communication system through an analog input port, the signals are transmitted through the voice-band communication system. They are output from the system through an analog audio output port to the other magneto-inductive unit.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A ballistic-acoustic transducer system includes a processor and one or more acoustic sensors. The sensors are positioned in a body of water and are in communication with the processor. The system is configured such that acoustic energy generated by a non-explosive projectile as it impacts the water, enters the water, and sinks through the water, is sensed by the one or more acoustic sensors, and the processor is configured to process the acoustic energy sensed by the one or more acoustic sensors.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.