It amends the Federal Mine Safety and Health Act of and is intended to improve the safety of miners. Among other things, it provides updated requirements for emergency response, incident command and control, mine rescue teams, and incident notification. One of the goals of the MINER Act is to provide wireless communications and location information between underground workers and surface personnel following an underground accident. The CT technology that is available, or anticipated to be available soon, to meet these goals may be unfamiliar to the mining professionals who need to purchase or use this technology. The purpose of this tutorial is to introduce the different types of CT technologies, describe how they work, and provide guidelines that allow the reader to evaluate and compare systems.
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Wireless Glossary and Dictionary [A-B]VIDEO ON THE TOPIC: Basic VHF and UHF Fundamentals
Radio is the technology of signaling and communicating using radio waves. They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by a radio receiver connected to another antenna.
Radio is very widely used in modern technology, in radio communication, radar , radio navigation , remote control , remote sensing and other applications.
In radio communication , used in radio and television broadcasting , cell phones , two-way radios , wireless networking and satellite communication among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal impressing an information signal on the radio wave by varying some aspect of the wave in the transmitter.
In radar , used to locate and track objects like aircraft, ships, spacecraft and missiles, a beam of radio waves emitted by a radar transmitter reflects off the target object, and the reflected waves reveal the object's location.
In radio navigation systems such as GPS and VOR , a mobile receiver receives radio signals from navigational radio beacons whose position is known, and by precisely measuring the arrival time of the radio waves the receiver can calculate its position on Earth.
In wireless radio remote control devices like drones , garage door openers , and keyless entry systems , radio signals transmitted from a controller device control the actions of a remote device. Applications of radio waves which do not involve transmitting the waves significant distances, such as RF heating used in industrial processes and microwave ovens , and medical uses such as diathermy and MRI machines , are not usually called radio.
The noun radio is also used to mean a broadcast radio receiver. Radio waves were first identified and studied by German physicist Heinrich Hertz in The first practical radio transmitters and receivers were developed around by Italian Guglielmo Marconi , and radio began to be used commercially around To prevent interference between users, the emission of radio waves is strictly regulated by law, coordinated by an international body called the International Telecommunications Union ITU , which allocates frequency bands in the radio spectrum for different uses.
Radio waves are radiated by electric charges undergoing acceleration. In transmission, a transmitter generates an alternating current of radio frequency which is applied to an antenna. The antenna radiates the power in the current as radio waves.
When the waves strike the antenna of a radio receiver , they push the electrons in the metal back and forth, inducing a tiny alternating current. The radio receiver connected to the receiving antenna detects this oscillating current and amplifies it.
As they travel farther from the transmitting antenna, radio waves spread out so their signal strength intensity in watts per square meter decreases, so radio transmissions can only be received within a limited range of the transmitter, the distance depending on the transmitter power, antenna radiation pattern , receiver sensitivity, noise level, and presence of obstructions between transmitter and receiver.
An omnidirectional antenna transmits or receives radio waves in all directions, while a directional antenna or high gain antenna transmits radio waves in a beam in a particular direction, or receives waves from only one direction. Radio waves travel through a vacuum at the speed of light , and in air at very close to the speed of light, so the wavelength of a radio wave, the distance in meters between adjacent crests of the wave, is inversely proportional to its frequency.
The other types of electromagnetic waves besides radio waves; infrared , visible light , ultraviolet , X-rays and gamma rays , are also able to carry information and be used for communication.
The wide use of radio waves for telecommunication is mainly due to their desirable propagation properties stemming from their large wavelength. In radio communication systems, information is carried across space using radio waves. At the sending end, the information to be sent is converted by some type of transducer to a time-varying electrical signal called the modulation signal.
The modulation signal is applied to a radio transmitter. In the transmitter, an electronic oscillator generates an alternating current oscillating at a radio frequency , called the carrier wave because it serves to "carry" the information through the air. The information signal is used to modulate the carrier, varying some aspect of the carrier wave, impressing the information on the carrier.
Different radio systems use different modulation methods:. Many other types of modulation are also used. In some types a carrier wave is not transmitted but just one or both modulation sidebands. The modulated carrier is amplified in the transmitter, and applied to a transmitting antenna which radiates the energy as radio waves.
The radio waves carry the information to the receiver location. At the receiver, the radio wave induces a tiny oscillating voltage in the receiving antenna which is a weaker replica of the current in the transmitting antenna. The modulation signal is converted by a transducer back to a human-usable form: an audio signal is converted to sound waves by a loudspeaker or earphones, a video signal is converted to images by a display , while a digital signal is applied to a computer or microprocessor, which interacts with human users.
The radio waves from many transmitters pass through the air simultaneously without interfering with each other because each transmitter's radio waves oscillate at a different rate, in other words each transmitter has a different frequency , measured in kilohertz kHz , megahertz MHz or gigahertz GHz. The receiving antenna typically picks up the radio signals of many transmitters. The receiver uses tuned circuits to select the radio signal desired out of all the signals picked up by the antenna, and reject the others.
A tuned circuit also called resonant circuit or tank circuit acts like a resonator , similarly to a tuning fork. The resonant frequency of the receiver's tuned circuit is adjusted by the user to the frequency of the desired radio station; this is called "tuning". The oscillating radio signal from the desired station causes the tuned circuit to resonate , oscillate in sympathy, and it passes the signal on to the rest of the receiver.
Radio signals at other frequencies are blocked by the tuned circuit and not passed on. A modulated radio wave, carrying an information signal, occupies a range of frequencies. See diagram. The information modulation in a radio signal is usually concentrated in narrow frequency bands called sidebands SB just above and below the carrier frequency. The width in hertz of the frequency range that the radio signal occupies, the highest frequency minus the lowest frequency, is called its bandwidth BW.
The bandwidth required by a radio transmission depends on the data rate of the information modulation signal being sent, and the spectral efficiency of the modulation method used; how much data it can transmit in each kilohertz of bandwidth.
Different types of information signals carried by radio have different data rates. For example, a television video signal has a greater data rate than an audio signal. The radio spectrum , the total range of radio frequencies that can be used for communication in a given area, is a limited resource.
Radio bandwidth is regarded as an economic good which has a monetary cost and is in increasing demand. In some parts of the radio spectrum the right to use a frequency band or even a single radio channel is bought and sold for millions of dollars. So there is an incentive to employ technology to minimize the bandwidth used by radio services.
In recent years there has been a transition from analog to digital radio transmission technologies. Part of the reason for this is that digital modulation can often transmit more information a greater data rate in a given bandwidth than analog modulation , by using data compression algorithms, which reduce redundancy in the data to be sent, and more efficient modulation. Other reasons for the transition is that digital modulation has greater noise immunity than analog, digital signal processing chips have more power and flexibility than analog circuits, and a wide variety of types of information can be transmitted using the same digital modulation.
Because it is a fixed resource which is in demand by an increasing number of users, the radio spectrum has become increasingly congested in recent decades, and the need to use it more effectively is driving many additional radio innovations such as trunked radio systems , spread spectrum ultra-wideband transmission, frequency reuse , dynamic spectrum management , frequency pooling, and cognitive radio.
It can be seen that the bandwidth , the range of frequencies, contained in each band is not equal but increases exponentially as the frequency increases; each band contains nine times the bandwidth of the preceding band.
The greater bandwidth available has motivated a continuing trend to exploit higher frequencies throughout radio's history. The airwaves are a resource shared by many users. Two radio transmitters in the same area that attempt to transmit on the same frequency will interfere with each other, causing garbled reception, so neither transmission may be received clearly.
To prevent interference between different users, the emission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunications Union ITU , which allocates bands in the radio spectrum for different uses. In some classes, such as radio and television broadcasting stations, the transmitter is given a unique identifier consisting of a string of letters and numbers called a callsign , which must be used in all transmissions.
The radio operator must hold a government license, such as the general radiotelephone operator license in the US, obtained by taking a test demonstrating adequate technical and legal knowledge of safe radio operation.
Exceptions to the above rules allow the unlicensed operation by the public of low power short range transmitters in consumer products such as cell phones , cordless phones , wireless devices , walkie-talkies , citizens band radios , wireless microphones , garage door openers , and baby monitors. Many of these devices use the ISM bands , a series of frequency bands throughout the radio spectrum reserved for unlicensed use.
Although they can be operated without a license, like all radio equipment these devices generally must be type-approved before sale. Broadcasting is the one-way transmission of information from a radio transmitter to receivers belonging to a public audience. Since the radio waves become weaker with distance, a broadcasting station can only be received within a limited distance of its transmitter. Systems which broadcast from satellites can generally be received over an entire country or continent.
Older terrestrial radio and television is paid for by commercial advertising or governments. In subscription systems like satellite television and satellite radio the customer pays a monthly fee. In these systems the radio signal is encrypted and can only be decrypted by the receiver, which is controlled by the company and can be deactivated if the customer doesn't pay his bill.
Broadcasting uses several parts of the radio spectrum, depending on the type of signals transmitted and the desired target audience.
Longwave and medium wave signals can give reliable coverage of areas several hundred kilometres across, but have more limited information carrying capacity and so work best with audio signals speech and music , and the sound quality can be degraded by radio noise from natural and artificial sources.
The shortwave bands have greater potential range, but are more subject to interference by distant stations and varying atmospheric conditions that affect reception. In the very high frequency band, greater than 30 megahertz, the Earth's atmosphere has less of an effect on the range of signals, and line-of-sight propagation becomes the principle mode.
These higher frequencies permit the great bandwidth required for television broadcasting. Since natural and artificial noise sources are less present at these frequencies, high-quality audio transmission is possible, using frequency modulation.
Radio broadcasting means transmission of audio sound to radio receivers belonging to a public audience. Analog audio is the earliest form of radio broadcast. AM broadcasting began around FM broadcasting was introduced in the late s with improved fidelity. Digital audio broadcasting DAB debuted in some countries in It transmits audio as a digital signal rather than an analog signal as AM and FM do. DAB has the potential to provide higher quality sound than FM although many stations do not choose to transmit at such high quality , has greater immunity to radio noise and interference, makes better use of scarce radio spectrum bandwidth, and provides advanced user features such as electronic program guides.
Its disadvantage is that it is incompatible with previous radios so that a new DAB receiver must be purchased. Broadcasters can transmit a channel at a range of different bit rates , so different channels can have different audio quality. Digital Radio Mondiale DRM is a competing digital terrestrial radio standard developed mainly by broadcasters as a higher spectral efficiency replacement for legacy AM and FM broadcasting.
Mondiale means "worldwide" in French and Italian, and DRM, developed in , is currently supported by 23 countries and has been adopted by some European and Eastern broadcasters beginning in It is incompatible with existing radio receivers and requires listeners to purchase a new DRM receiver.
The DRM system is designed to be as compatible as possible with existing AM and FM radio transmitters, so much of the equipment in existing radio stations will not have to be replaced.
Satellite radio is a subscription radio service that broadcasts CD quality digital audio direct to subscribers' receivers using a microwave downlink signal from a direct broadcast communication satellite in geostationary orbit 22, miles above the Earth. It is mostly intended for car radios in vehicles. Satellite radio uses the 2. Television broadcasting is the transmission of moving images by radio, which consist of sequences of still images, which are displayed on a screen on a television receiver a "television" or TV along with a synchronized audio sound channel.
Television video signals occupy a wider bandwidth than broadcast radio audio signals. The current television standard, introduced beginning in , is a digital format called HDTV high definition television , which transmits pictures at higher resolution, typically pixels high by pixels wide, at a rate of 25 or 30 frames per second.
Digital television DTV transmission systems, which replaced older analog television in a transition beginning in , use image compression and high efficiency digital modulation such as OFDM and 8VSB to transmit HDTV video within a smaller bandwidth than the old analog channels, saving scarce radio spectrum space. Digital television receivers have a different behavior in the presence of poor reception or noise than analog television, called the " digital cliff " effect.
A minor amendment has been made to section 3. Radio Standards Specification RSS-Gen, General Requirements for Compliance of Radio Apparatus, sets out general and certification requirements for licensed and licence-exempt radio apparatus Footnote 1 used for radiocommunication other than broadcasting. However, a transition period of six 6 months following its publication will be provided, within which compliance with RSS-Gen, issue 4 or issue 5, will be accepted. After this period, only applications for certification of equipment that complies with the requirements in RSS-Gen, issue 5, will be accepted. Inquiries may be submitted online using the General Inquiry form.
Basic Tutorial on Wireless Communication and Electronic Tracking: Technology Overview
In addition, adaptive antenna systems offer the potential of increased spectrum efficiency, extended range of coverage and higher rate of frequency reuse. Depending on whether the processing is performed at the transmitter, receiver, or both ends of the communication link, the adaptive antenna technique is defined as multiple-input single-output MISO , single-input multiple-output SIMO , or multiple-input multiple-output MIMO. Absorption Spectrum A-key is a secret number issued to a cellular phone that is used in conjunction with a subscriber's shared secret data information for authentication. An encryption key is also generated that is subsequently used to encrypt all wireless communications voice, SMS, etc.
Internet radio device
Radio is the technology of signaling and communicating using radio waves. They are generated by an electronic device called a transmitter connected to an antenna which radiates the waves, and received by a radio receiver connected to another antenna. Radio is very widely used in modern technology, in radio communication, radar , radio navigation , remote control , remote sensing and other applications. In radio communication , used in radio and television broadcasting , cell phones , two-way radios , wireless networking and satellite communication among numerous other uses, radio waves are used to carry information across space from a transmitter to a receiver, by modulating the radio signal impressing an information signal on the radio wave by varying some aspect of the wave in the transmitter.SEE VIDEO BY TOPIC: Weekend Project: Aircraft Band Receiver
Automotive Infotainment and Telematics Minimize menu. After the merger of the two companies in , ST continued to be the main radio IC supplier of SiriusXM, which counts now over 30 million service subscribers. ST is very proud to have contributed to the most successful story in the Digital Radio market developing seven generations of radio ICs based on state-of-art CMOS technology to deliver features of increasing complexity with continuous improvement in power performance. For any questions about satellite radio solutions, please contact ST sales offices. Terrestrial radio receivers. Our multi-band audio receivers reduce system components count and cost, while ensuring best-in-class radio signal reception. Select a radio receiver or get in touch with our sales office for custom design requests. Visit the ST Community to tell us what you think about this website. This browser is out of date and not supported by st. As a result, you may be unable to access certain features.
The Universe is a laboratory holding undiscovered knowledge that may spawn unimagined new benefits and entirely new industries. Astronomy is our tool for unlocking that knowledge. To preserve our ability to discover this new knowledge, we must prevent interference that blocks the Universe from our view. For optical astronomers, that means reducing light pollution of the night sky.
An Internet radio device , also called network music player is a hardware device that is capable of receiving and playing streamed media from either Internet radio stations or a home network. The network music player is connected to a home router. For convenience a wireless router is often used. The router is connected to the internet and thus enables access to Internet streaming resources. Alternatively, the home network can access the user's collection of music on a computer or on a network-attached storage NAS device dedicated to store a user's music files. Audio streaming is one way of transmitting audio files on a continuous feed to a network music player. A common way today is to stream the audio from the computer to a network music player over the more convenient wireless technologies such as Wi-Fi in a networked environment. The computer, which is typically used for storing the music file, acts as a music server by means of server software, often compliant to DLNA Digital Living Network Alliance standard. And the network music player is a typical receiver which starts playing an audio file as soon as some of the data has been received so that one does not have to wait for the entire audio file to finish downloading. The MP3 music file is streamed to the network music player in digital format, commonly in the original MP3 format.
Audio and Radio Solutions
Chapter 7. Telecommunications, the Internet, and Information System Architecture. The electronic transmission of information over distances, called telecommunications, has become virtually inseparable from computers: Computers and telecommunications create value together. Components of a Telecommunications Network. Telecommunications are the means of electronic transmission of information over distances. The information may be in the form of voice telephone calls, data, text, images, or video. Today, telecommunications are used to organize more or less remote computer systems into telecommunications networks. These networks themselves are run by computers. A telecommunications network is an arrangement of computing and telecommunications resources for communication of information between distant locations. A telecommunications network includes the following components:.
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Call Us In modern society, radios are common technology in the car and in the home. In fact, in today's world one would be hard pressed to find anyone who has not heard of, seen, or used a radio during his or her life, regardless of how old or young they may be. This was not always the case, however. Before the 19th century, wireless radio communication in everyday life was a thing of fantasy. Even after the development of the radio in the late s, it took many years before radios went mainstream and became a household fixture. The history of the radio is a fascinating one that changed how the world connected and communicated from distances both far and near. While the radio enjoys a long and interesting history, its earliest beginnings are still quite controversial.
What Marine Communication Systems Are Used in the Maritime Industry?
Italian inventor and engineer Guglielmo Marconi developed, demonstrated and marketed the first successful long-distance wireless telegraph and in broadcast the first transatlantic radio signal. In he shared the Nobel Prize in Physics for his radio work. Guglielmo Marconi was born in in Bologna, Italy.
Radio telecommunication at sea had undergone a sea change in the last century. After the days of semaphores and flags which is still relevant today in some cases , radio brought about a drastic change in marine communication at sea. Radio telegraphy using Morse code was used in the early part of the twentieth century for marine communication.
In radio transmission a radiating antenna is used to convert a time-varying electric current into an electromagnetic wave or field , which freely propagates through a nonconducting medium such as air or space. In a broadcast radio channel, an omnidirectional antenna radiates a transmitted signal over a wide service area. In a point-to-point radio channel, a directional transmitting antenna is used to focus the wave into a narrow beam, which is directed toward a single receiver site.
Our highly-integrated, single-chip solutions provide reduced board space and easy implementation for multi-band audio receivers and consumer electronic applications. If you have any issues downloading, please contact sales support or product technical support. Audio and Radio Solutions Improve performance and reliability with scalable, industry-leading broadcast audio solutions.