ADVERTISING AND THE RADIO BROADCASTING

In the evaluating radio along with other media of communication, such as newspapers, magazines, billboards, skywriting, weekly supplement match cover, etc., the advertiser is concerned with the following criteria: 1). Circulation, 2). Effectiveness of the medium to sell his product, and Cost.

Circulation

When advertiser buy time on radio they do so because they are impressed with the wide circulation that radio can give to their advertising message. A commercial message delivered on a popular radio program. In Local advertising, the advertiser compares the circulation offered by the local radio stations with that offered by local newspapers. Circulation related to the number of people who are exposed to the advertiser's message. In Radio, circulation is influenced by the potential coverage offered by the station by virtue of its transmitting power, the general programming popularity of the station, the popularity of the program on which the advertising message is presented, the popularity of adjacent program and the attractiveness of the advertising message itself. It is therefore be expected that advertisers who buy radio time will generally seek to have commercial messages appear on program that reach the largest audience.

Effectiveness

Each advertising medium has its own special characteristic of communication that make advertising in it more less effective. Some advertising media are better for certain types of advertising than other media. Brand-name identification is often sought through repeated radio announcements. No advertising medium, however, can show a product to potential buyers. Many advertiser have found that radio provided them wth an opportunity to demonstrate their product and deliver a sales mesagge to millions of people that otherwise can only be done over the counter to a few people at a time. Moreover, the association of the advertising message with a popular program can give the advertiser additional values : goodwill engendered by the program itself ; identification with the program and the program talent that often is used for point-of-sales merchandising purpose; direct sales appeals by the stars, special attention to the advertiser's message through lead-ins designed to invited attention; and strategic placement of the message.

Cost

In evaluation the cost of advertising in relation to its effectiveness, advertisers are often forced to work with variable factors that make its very difficult to arrive at a scientific judgement. Ideallym the advertiser desires to know which methode of advertising producers the greates number of sales of his products at the smalles cost. Because he ussually has several different advertising campaigns proceeding simultaneously and beacause the effectiveness of his own commercial message is not a controlled factor when different media are compared, the advertiser generally contents himself with taking the simple circulation fidures, dividing them by thousand. and dividing that fidure into the cost of buying the broadcast time and the program arrive at a figure representing how much it costs to reach 1000 people.

PROGRAMMING

Radio Programming

The Key Factor in determining public acceptance of radio is programming-the determination of what programs to put on the air and at what points in the program schedule. Only though successful programming that wins large audiences do radio become attractive to advertiser seeking mass circulation, and it is only through income obtained from these advertisers that commercial station program operations are financed. The production, technical, and sales staffs of networks and stations work to little avail if they do not have effective programming leadership.

The Programming Function

To understand radio programming, we must first have some insight into its scope and nature. (1). The programming function in radio is of such vast proportions that it is difficult to convey its size accurately. As far as commercial operation is concerned, each of station plans a program schedule for every day of the week; many stations program 18 to 20 hours per day, and some more. The national radio networks program from 10 to 15 hours a day and offer these programs ti affiliated stations which are then relieved of the necessity to produce program for those hours. A single network presents different program in the course of a single season. Counting both network and local station offerings in both radio are broadcast each day throughout the country. (2). The programming functions is continuous. Station do not go on the air to broadcast only one or two program at a time. Once they sign on in the morning, with few exceptions they program without interruption until sign-off. (3) The programming function is extremely competitive-it ism indeed, the most competitive aspect of radio. In the constant search to find to develop “hit” programs, each network is in vigorous competition with other networks, and every station competes with other stations in the same market. (4) The programming function, is a very costly on the time, effort, money, and creative ability. (5). The programming function, especially network, is extremely complex, because it is interrelated with almost all the other functions and operating processes of radio-the simultaneous availability of performing, writing, and production talent, production facilities, including studios, technical crew, etc. (6) The programming function tends to seek stability in program schedule that will develop and listening habit with the audiences, in order to be able to make long-term sales and advertiser, and to obtain relief from the relentless pressure of building new program. (7) The programming function draws its creative ideas, materials, and talent from all possible sources, professional radio performers. Writers, journalism, etc. (8) The programming function is highly speculative, there are no sure rules for predicting which program ideas will result in program the audience will like or which new performers will develop into radio star talent.

BROADCASTING DEFINED

For the sake of convenience in this discussion, we may defined broadcasting as the transmission through space, by mean of radio frequencies, of signal capable of being received either aurally or visually or both aurally and visually by the general public. There are several types of broadcasting : standard or AM (Amplitude Modulation) broadcasting of sound; FM (Frequency Modulation) broadcasting a higher fidelity form of sound transmission,; television, the transmission of pictures and sound; facsimile, the transmission of still pictures and writing, with or without sound, to be received on photographic paper; and numerous other type of broadcasting, including shortwave transmissions overseas, police radio, Army and Navy radio, microwave relays, and highly specialized forms of broadcasting such as radar. When we use the term ‘broadcasting’ in this volume, it should be understood to include only AM dan FM radio, and television.

Transmission Of Broadcasting

One way to gauge the scope of Indonesia broadcasting is to note how much effort and money go into operations of our broadcasting system. In the 2000’s, there were in operations one national radio network (Radio of Indonesia Republic), more than 3000 individual radio stations. Most of the se stations transmit program from sunup to midnight, and many continue later. To produce income the commercial station sell program and time to advertiser.

Treatment Of News and Public Events

NEWS

1). A Radio Station's news schedule should be adequate and well-balanced. 2). News reporting should be factual, fair and without bias. 3). A Radio Station's broadcaster should exercise articular discrimination in the acceptance, placement and presentation of advertising in news program so that such advertising should be distinguishable from the news content. 4). At all times, pictorial and verbal material for both news and comment ahould conform to other sections of these standards, wherever such sections are reasonably applicable. 5). Good taste should prevail in the selection and handling of news : Morbid, sensational or alarming detail not essential to the factual report, especially in connection with stories of crime or sex, should be avoided. News Should be telecast in such a manner as to avoid panic and unneccessary alarm. 6). Commentary and analysis shoul be clearly identified as such. 7). Pictorial material should be chosen with care and not presented in a misleding manner. 8. All News interview program should be governed by accepted standards of ethical jounalism, under which the interviewer selects the questions to be asked. Where there is advance agreement materially restricting an important or newsworthy area questioning, the interviewer will state on the program that such limitation has been agreed upon. Such disclosure should be made if the person being interviewed requires that question be submitted in advance or if the participates in editing a recording of the interview prior to its use on the air. 9). A Radio broadcaster should exercise due care in his supervision of content, format, and presentation of newscast originated by his station, and in this selection of newscasters, commentators, and analysis.

PUBLIC EVENTS

1). A Radio broadcaster has an affirmative responsibility at all times to be informed of public, event, and to provide coverage consonant with the ends of an informed and enlightened citizenry. 2). The treatment of such events by a radio broadcaster should provide adequate and informed coverage.

Presenting On Radio

It is the lot of broadcasters, as most will admit, constantly to be seen as inferior to television presenters. Sadly they often secretly beleive it themselves and struggle desperately to get in front of a camera, regardless of their suitability. The two mediums, whilst requiring many of the same skills, also demand different abilities. Television is technically more complicated and, I beleive, more stressful and cumbersome; it is certainly not true that because you have mastered it you can slip easily in to radio. There is a closeners to the audience which the presenter, potentially, much loved but also extremely vulnerable. Radio is not just TV without the picture.

Creating A Sound And Style

Radio is a remarkably intimate medium. Every presenter says you should imaging you mum, partner or friend and talk only to them. If there is a golden rule, this is it. But you need to do more than this. A presenter either spontaneously, or else deliberately, will create a sound that will become a 'USP' (unique selling point)- something that marks you out from the rest. Since you can only be yourself this involves developing certain of your prefered characteristics. Maybe you are forth- right by nature or maybe gentle and coaxing with people; these traits will form a style that 'brands' you. At the same time, when you're starting out it's as well to be able to adapt your sound so that you maximize your job oppotunities and get heaps of experience.

Interactive Media

Interactive media refers to media that allows for active participation by the recipient, hence interactivity. Traditional information theory would describe interactive media as those media that establish two-way communication. In media theory, interactive media are discussed along their cultural implications. The field of Human Computer Interaction deals with aspects of interactivity and design in digital media. Other areas that deal with interactive media are new media art, interactive advertising and video game production.

While much traditional analog electronic media and print media qualifies as interactive media, the term is sometimes misunderstood as exclusive to digital media. The significant increase in possibilities for interactivity (especially over vast distances) brought by the internet boosted the availability of digital interactive media. Still, e.g. language in face-to-face communication would formally belong to the category of interactive media.

Interactive media are often designed by information designers. As all media they rely on communication. In the case of e.g. computer games this is visual, acoustic, and haptic communication between the user (player) and the game. In Mobile telephony, the communication happens between two people and is purely acoustic at the first glance. Yet, according to media theory the cultural implications of the medium have to be taken into account. Thus, aspects like constant availability, customization of the mobile phone and Short Message Service are also part of the interactive medium called Mobile telephony. Media restrain from being translated to technological entities.

Terminology

Any form of interface between the end user/audience and the medium may be considered interactive. Interactive media is not limited to electronic media or digital media. Board games, pop-up books, gamebooks, flip books and constellation wheels are all examples of printed interactive media. Books with a simple table of contents or index may be considered interactive due to the non-linear control mechanism in the medium, but are usually considered non-interactive since the majority of the user experience is non-interactive sequential reading.

Examples of interactive media

• World Wide Web
• Computer games
• Online games
• Video games
• Interactive television
• Interactive radio
• Mobile telephony
• E-Mail
• E-Commerce
• Short Message Service
• electronic literature
• Some developments in pervasive computing
• Shadow Monsters

Music Radio

Music radio is a radio format in which music is the main broadcast content. After television replaced old time radio's dramatic content, music formats became dominant in many countries. Radio drama and comedy continue, often on public radio Music drives radio technology, including wide-band FM and modern digital radio systems such as digital radio mondiale.

How it works

The radio station provides programming to attract listeners, and profits by selling advertising. Young people are targeted by advertisers because their product preferences can be changed more easily. Therefore, the most commercially successful stations target young audiences. The programming usually cycles from the least attractive item, to most attractive, followed by commercials. The purpose of this plan is to build listener interest during the programming. Because dead air does not attract listeners, the station tries to fill its broadcast day with sound. Audiences will only tolerate a certain number of commercials before tuning away. In some regions, government regulators specify how many commercials can be played in a given hour.Music is the main program item. There are several standard ways of selecting the music, such as free-form, top-40, album-oriented rock, and Jack. These can be applied to all types of music. Jingles are radio's equivalent of neon signs. Jingles are brief, bright pieces of choral music that promote the station's call letters, frequency and sometimes disc-jockey or program segment. Jingles are produced for radio stations by commercial specialty services such as JAM[1], in Texas. Jingles are often replaced by recorded voiceovers (called "stingers"). In order to build station loyalty, the station announces time, station call letters and frequency as often as six times per hour. Jingles and stingers help give the station a branded sound in a pleasant, minimal amount of air-time. The legal requirement for station identification in the U.S. is once per hour, approximately at the top of the hour, or at the conclusion of a transmission.News, time-checks, real-time travel advice and weather reports are often valuable to listeners. The news headlines and station identification are therefore given just before a commercial. Time, traffic and weather are given just after. The engineer typically sets the station clocks to standard local time each day, by listening to WWV or WWVH (see atomic clock). These segments are less valued by the most targeted market, young people, so many stations shorten or omit these segments in favor of music. While most music stations that offer news reports simply "tear and read" news items (from the newswires or the Internet), larger stations (generally those affiliated with news/talk stations) may employ an editor to rewrite headlines, and provide summaries of local news. Summaries fit more news in less air-time. Some stations share news collection with TV or newspapers in the same media conglomerate. An emerging trend is to use the radio station's web site to provide in-depth coverage of news and advertisers headlined on the air. Many stations contract with agencies such as Smartraveler and AccuWeather for their weather and traffic reports instead of using in-house staff. Most radio stations maintain a call-in telephone line for promotions and gags, or to take record requests. DJs generally answer the phone and edit the call during music plays. Some stations take requests by e-mail and online chat. The value of a station's advertising is set by the number, age and wealth of its listeners. Arbitron, a commercial statistical service, historically used listener diaries to statistically measure the number of listeners. Arbitron diaries were collected on Thursdays, and for this reason, most radio stations have run special promotions on Thursdays, hoping to persuade last-minute Arbitron diarists to give them a larger market-share. Arbitron contractually prevents mention of its name on the air. Promotions are the on-air equivalent of lotteries for listeners. Promotional budgets usually run about $1 per listener per year. In a large market, a successful radio station can pay a full time director of promotions, and run several lotteries per month of vacations, automobiles and other prizes. Lottery items are often bartered from advertisers, allowing both companies to charge full prices at wholesale costs. For example, cruising companies often have unused capacity, and when given the choice, prefer to pay their bills by bartering cruise vacations. Since the ship will sail in any case, bartered vacations cost the cruise company little or nothing. The promotion itself advertises the company providing the prize.

Radio Broadcasting

Radio broadcasting is an audio (sound) broadcasting service, traditionally broadcast through the air as radio waves (a form of electromagnetic radiation) from a transmitter to an antenna and a thus to a receiving device. Stations can be linked in radio networks to broadcast common programming, either in syndication or simulcast or both. Audio broadcasting also can be done via cable FM, local wire networks, satellite and the Internet.

History

The earliest radio stations were simply radiotelegraphy systems and did not carry audio. The first claimed audio transmission that could be termed a broadcast occurred on Christmas Eve in 1906, and was made by Reginald Fessenden. While many early experimenters attempted to create systems similar to radiotelephone devices where only two parties were meant to communicate, there were others who intended to transmit to larger audiences. Charles Herrold started broadcasting in California in 1909 and was carrying audio by the next year.

For the next decade, radio tinkerers had to build their own radio receivers. Dr. Frank Conrad began broadcasting from his Wilkinsburg, Pennsylvania garage with the call letters KDKA. Later, the equipment was moved to the top of an office building in Pittsburgh, Pennsylvania and purchased by Westinghouse). KDKA of Pittsburgh, under Westinghouse's ownership, started broadcasting as the first licensed "commercial" radio station on November 2, 1920.[1] The commercial designation came from the type of license—they didn't start airing advertisements until a few years later. The first broadcast was the results of the U.S. presidential election, 1920. The Montreal station that became CFCF began program broadcasts on May 20, 1920, and the Detroit station that became WWJ began program broadcasts beginning on August 20, 1920, although neither held a license at the time.

Radio Argentina began regularly scheduled transmissions from the Teatro Coliseo in Buenos Aires on August 27, 1920, making its own priority claim. The station got its license on November 19, 1923. The delay was due to the lack of official Argentine licensing procedures before that date. This station continued regular broadcasting of entertainment and cultural fare for several decades.[1][2]

When internet based radio became feasible in the mid '90s, the new medium required no licensing and the stations could broadcast from anywhere in the world without the need for "over the air" transmitters. This greatly reduced the overhead for establishing a station, and in 1996, George Maat started 'A' Net Station (A.N.E.T.)[3] and began broadcasting commercial free from Antarctica.

MIT developed the "Radio Locator" List of Radio Stations.[4]. After stations started streaming audio on the internet, Radio-Locator added this to their search engine so anyone could locate a station's website and listen to a station offering a worldwide stream. This list also tracks "terrestrial" radio stations who may not have live audio on the net, or even a website, but are able to find station information by various other search queries.

Types

The best known type of radiostation are the ones that broadcast via radiowaves. These include foremost AM and FM stations. There are several subtypes, namely commercial, public and nonprofit varieties as well as student-run campus radio stations and hospital radio stations can be found throughout the developed world.
Although now being eclipsed by internet-distributed radio, there are many stations that broadcast on shortwave bands using AM technology that can be received over thousands of miles (especially at night). For example, the BBC has a full schedule transmitted via shortwave. These broadcasts are very sensitive to atmospheric conditions and sunspots.

Also, many other non-broadcast types of radio stations exist. These include:
•base stations for police, fire and ambulance networks
•military base stations
•dispatch base stations for taxis, trucks, and couriers
•emergency broadcast systems
•amateur radio stations

Data (digital radio)

Most new radio systems are digital, see also: Digital TV, Satellite Radio, Digital Audio Broadcasting. The oldest form of digital broadcast was spark gap telegraphy, used by pioneers such as Marconi. By pressing the key, the operator could send messages in Morse code by energizing a rotating commutating spark gap. The rotating commutator produced a tone in the receiver, where a simple spark gap would produce a hiss, indistinguishable from static. Spark gap transmitters are now illegal, because their transmissions span several hundred megahertz. This is very wasteful of both radio frequencies and power.

The next advance was continuous wave telegraphy, or CW (Continuous Wave), in which a pure radio frequency, produced by a vacuum tube electronic oscillator was switched on and off by a key. A receiver with a local oscillator would "heterodyne" with the pure radio frequency, creating a whistle-like audio tone. CW uses less than 100 Hz of bandwidth. CW is still used, these days primarily by amateur radio operators (hams). Strictly, on-off keying of a carrier should be known as "Interrupted Continuous Wave" or ICW or on-off keying (OOK).

Radio teletypes usually operate on short-wave (HF) and are much loved by the military because they create written information without a skilled operator. They send a bit as one of two tones. Groups of five or seven bits become a character printed by a teletype. From about 1925 to 1975, radio teletype was how most commercial messages were sent to less developed countries. These are still used by the military and weather services.

Aircraft use a 1200 Baud radioteletype service over VHF to send their ID, altitude and position, and get gate and connecting-flight data. Microwave dishes on satellites, telephone exchanges and TV stations usually use quadrature amplitude modulation (QAM). QAM sends data by changing both the phase and the amplitude of the radio signal. Engineers like QAM because it packs the most bits into a radio signal when given an exclusive (non-shared) fixed narrowband frequency range. Usually the bits are sent in "frames" that repeat. A special bit pattern is used to locate the beginning of a frame.

Communication systems that limit themselves to a fixed narrowband frequency range are vulnerable to jamming.

A variety of jamming-resistant spread spectrum techniques were initially developed for military use, most famously for Global Positioning System satellite transmissions. Commercial use of spread spectrum begin in the 1980s.
Bluetooth, most cell phones, and the 802.11b version of Wi-Fi each use various forms of spread spectrum.

Systems that need reliability, or that share their frequency with other services, may use "coded orthogonal frequency-division multiplexing" or COFDM. COFDM breaks a digital signal into as many as several hundred slower subchannels. The digital signal is often sent as QAM on the subchannels. Modern COFDM systems use a small computer to make and decode the signal with digital signal processing, which is more flexible and far less expensive than older systems that implemented separate electronic channels. COFDM resists fading and ghosting because the narrow-channel QAM signals can be sent slowly. An adaptive system, or one that sends error-correction codes can also resist interference, because most interference can affect only a few of the QAM channels. COFDM is used for WiFi, some cell phones, Digital Radio Mondiale, Eureka 147, and many other local area network, digital TV and radio standards.

Audio

AM broadcast radio sends music and voice in the Medium Frequency (MF—0.300 MHz to 3 MHz) radio spectrum. AM radio uses amplitude modulation, in which the amplitude of the transmitted signal is made proportional to the sound amplitude captured (transduced) by the microphone while the transmitted frequency remains unchanged. Transmissions are affected by static and interference because lightning and other sources of radio that are transmitting at the same frequency add their amplitudes to the original transmitted amplitude. The most wattage an AM radio station in the United States and Canada is allowed to use is 50,000 watts and the majority of stations that emit signals this powerful were grandfathered in; these include WGN (AM), WJR, KGA and CKLW. In 1986 KTNN received the last granted 50,000 watt license.
FM broadcast radio sends music and voice with higher fidelity than AM radio. In frequency modulation, amplitude variation at the microphone causes the transmitter frequency to fluctuate. Because the audio signal modulates the frequency and not the amplitude, an FM signal is not subject to static and interference in the same way as AM signals. Due to its need for a wider bandwidth, FM is transmitted in the Very High Frequency (VHF—30 MHz to 300 MHz) radio spectrum. VHF radio waves act more like light, traveling in straight lines, hence the reception range is generally limited to about 50-100 miles. During unusual upper atmospheric conditions, FM signals are occasionally reflected back towards the Earth by the ionosphere, resulting in Long distance FM reception. FM receivers are subject to the capture effect, which causes the radio to only receive the strongest signal when multiple signals appear on the same frequency. FM receivers are relatively immune to lightning and spark interference.

High power is useful in penetrating buildings, diffracting around hills, and refracting for some distance beyond the horizon. Consequently, 100,000 watt FM stations can regularly be heard up to 100 miles (160 km) away, and farther (e.g., 150 miles, 240 km) if there are no competing signals. A few old, "grandfathered" stations do not conform to these power rules. WBCT-FM (93.7) in Grand Rapids, Michigan, USA, runs 320,000 watts ERP, and can increase to 500,000 watts ERP by the terms of its original license. Such a huge power level does not usually help to increase range as much as one might expect, because VHF frequencies travel in nearly straight lines over the horizon and off into space. Nevertheless, when there were fewer FM stations competing, this station could be heard near Bloomington, Illinois, USA, almost 300 miles (500 km) away.[citation needed]

FM subcarrier services are secondary signals transmitted in a "piggyback" fashion along with the main program. Special receivers are required to utilize these services. Analog channels may contain alternative programming, such as reading services for the blind, background music or stereo sound signals. In some extremely crowded metropolitan areas, the sub-channel program might be an alternate foreign language radio program for various ethnic groups. Sub-carriers can also transmit digital data, such as station identification, the current song's name, web addresses, or stock quotes. In some countries, FM radios automatically re-tune themselves to the same channel in a different district by using sub-bands.
Aviation voice radios use VHF AM. AM is used so that multiple stations on the same channel can be received. (Use of FM would result in stronger stations blocking out reception of weaker stations due to FM's capture effect). Aircraft fly high enough that their transmitters can be received hundreds of miles (or kilometres) away, even though they are using VHF.

Marine voice radios can use single sideband voice (SSB) in the shortwave High Frequency (HF—3 MHz to 30 MHz) radio spectrum for very long ranges or narrowband FM in the VHF spectrum for much shorter ranges. Narrowband FM sacrifices fidelity to make more channels available within the radio spectrum, by using a smaller range of radio frequencies, usually with five kHz of deviation, versus the 75 kHz used by commercial FM broadcasts, and 25 kHz used for TV sound.

Government, police, fire and commercial voice services also use narrowband FM on special frequencies. Early police radios used AM receivers to receive one-way dispatches.

Civil and military HF (high frequency) voice services use shortwave radio to contact ships at sea, aircraft and isolated settlements. Most use single sideband voice (SSB), which uses less bandwidth than AM. On an AM radio SSB sounds like ducks quacking. Viewed as a graph of frequency versus power, an AM signal shows power where the frequencies of the voice add and subtract with the main radio frequency. SSB cuts the bandwidth in half by suppressing the carrier and (usually) lower sideband. This also makes the transmitter about three times more powerful, because it doesn't need to transmit the unused carrier and sideband.

TETRA, Terrestrial Trunked Radio is a digital cell phone system for military, police and ambulances. Commercial services such as XM, WorldSpace and Sirius offer encrypted digital Satellite radio.

Uses of radio

Early uses were maritime, for sending telegraphic messages using Morse code between ships and land. The earliest users included the Japanese Navy scouting the Russian fleet during the Battle of Tsushima in 1905. One of the most memorable uses of marine telegraphy was during the sinking of the RMS Titanic in 1912, including communications between operators on the sinking ship and nearby vessels, and communications to shore stations listing the survivors.

Radio was used to pass on orders and communications between armies and navies on both sides in World War I; Germany used radio communications for diplomatic messages once it discovered that its submarine cables had been tapped by the British. The United States passed on President Woodrow Wilson's Fourteen Points to Germany via radio during the war. Broadcasting began from San Jose in 1909[21], and became feasible in the 1920s, with the widespread introduction of radio receivers, particularly in Europe and the United States. Besides broadcasting, point-to-point broadcasting, including telephone messages and relays of radio programs, became widespread in the 1920s and 1930s. Another use of radio in the pre-war years was the development of detection and locating of aircraft and ships by the use of radar (RAdio Detection And Ranging).

Today, radio takes many forms, including wireless networks and mobile communications of all types, as well as radio broadcasting. Before the advent of television, commercial radio broadcasts included not only news and music, but dramas, comedies, variety shows, and many other forms of entertainment. Radio was unique among methods of dramatic presentation in that it used only sound. For more, see radio programming.

Radio History

Tesla demonstrating wireless transmissions during his high frequency and potential lecture of 1891. After continued research, Tesla presented the fundamentals of radio in 1893.

In 1893, in St. Louis, Missouri, Nikola Tesla made devices for his experiments with electricity. Addressing the Franklin Institute in Philadelphia and the National Electric Light Association, he described and demonstrated in detail the principles of his wireless work.[16] The descriptions contained all the elements that were later incorporated into radio systems before the development of the vacuum tube. He initially experimented with magnetic receivers, unlike the coherers (detecting devices consisting of tubes filled with iron filings which had been invented by Temistocle Calzecchi-Onesti at Fermo in Italy in 1884) used by Guglielmo Marconi and other early experimenters.[17]

The first radio couldn't transmit sound or speech and was called the "wireless telegraph." The first public demonstration of wireless telegraphy took place in the lecture theater of the Oxford University Museum of Natural History on August 14, 1894, carried out by Professor Oliver Lodge and Alexander Muirhead. During the demonstration a radio signal was sent from the neighboring Clarendon laboratory building, and received by apparatus in the lecture theater.

In 1895 Alexander Stepanovich Popov built his first radio receiver, which contained a coherer. Further refined as a lightning detector, it was presented to the Russian Physical and Chemical Society on May 7, 1895. A depiction of Popov's lightning detector was printed in the Journal of the Russian Physical and Chemical Society the same year. Popov's receiver was created on the improved basis of Lodge's receiver, and originally intended for reproduction of its experiments.

In 1896, Marconi was awarded the British patent 12039, Improvements in transmitting electrical impulses and signals and in apparatus there-for, for radio. In 1897 he established the world's first radio station on the Isle of Wight, England. Marconi opened the world's first "wireless" factory in Hall Street, Chelmsford, England in 1898, employing around 50 people.

The next great invention was the vacuum tube detector, invented by Westinghouse engineers. On Christmas Eve, 1906, Reginald Fessenden used a synchronous rotary-spark transmitter for the first radio program broadcast, from Ocean Bluff-Brant Rock, Massachusetts. Ships at sea heard a broadcast that included Fessenden playing O Holy Night on the violin and reading a passage from the Bible. The first radio news program was broadcast August 31, 1920 by station 8MK in Detroit, Michigan. The first college radio station began broadcasting on October 14, 1920, from Union College, Schenectady, New York under the personal call letters of Wendell King, an African-American student at the school.[18] That month 2ADD, later renamed WRUC in 1940, aired what is believed to be the first public entertainment broadcast in the United States, a series of Thursday night concerts initially heard within a 100-mile (160 km) radius and later for a 1,000-mile (1,600 km) radius. In November 1920, it aired the first broadcast of a sporting event.[19][20] At 9 pm on August 27, 1920, Sociedad Radio Argentina aired a live performance of Richard Wagner's Parsifal opera from the Coliseo Theater in downtown Buenos Aires, only about twenty homes in the city had a receiver to tune in. Meanwhile, regular entertainment broadcasts commenced in 1922 from the Marconi Research Centre at Writtle, England.

One of the first developments in the early 20th century (1900-1959) was that aircraft used commercial AM radio stations for navigation. This continued until the early 1960s when VOR systems finally became widespread (though AM stations are still marked on U.S. aviation charts). In the early 1930s, single sideband and frequency modulation were invented by amateur radio operators. By the end of the decade, they were established commercial modes. Radio was used to transmit pictures visible as television as early as the 1920s. Commercial television transmissions started in North America and Europe in the 1940s. In 1954, Regency introduced a pocket transistor radio, the TR-1, powered by a "standard 22.5 V Battery".

In 1960, Sony introduced its first transistorized radio, small enough to fit in a vest pocket, and able to be powered by a small battery. It was durable, because there were no tubes to burn out. Over the next 20 years, transistors replaced tubes almost completely except for very high-power uses. By 1963 color television was being regularly transmitted commercially, and the first (radio) communication satellite, TELSTAR, was launched. In the late 1960s, the U.S. long-distance telephone network began to convert to a digital network, employing digital radios for many of its links. In the 1970s, LORAN became the premier radio navigation system. Soon, the U.S. Navy experimented with satellite navigation, culminating in the invention and launch of the GPS constellation in 1987. In the early 1990s, amateur radio experimenters began to use personal computers with audio cards to process radio signals. In 1994, the U.S. Army and DARPA launched an aggressive, successful project to construct a software defined radio that can be programmed to be virtually any radio by changing its software program. Digital transmissions began to be applied to broadcasting in the late 1990s.

Etymology & Invention

Etymology

Originally, radio or radiotelegraphy was called "wireless telegraphy", which was shortened to "wireless". The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, coined by the French physicist Edouard Branly in 1897 and based on the verb to radiate (in Latin "radius" means "spoke of a wheel, beam of light, ray"). "Radio" as a noun is said to have been coined by advertising expert Waldo Warren (White 1944). The word appears in a 1907 article by Lee de Forest, was adopted by the United States Navy in 1912 and became common by the time of the first commercial broadcasts in the United States in the 1920s. (The noun "broadcasting" itself came from an agricultural term, meaning "scattering seeds".) The term was then adopted by other languages in Europe and Asia, although British Commonwealth countries continued to use the term "wireless" until the mid-20th century.

In recent years the term "wireless" has gained renewed popularity through the rapid growth of short-range computer networking, e.g., Wireless Local Area Network (WLAN), WiFi and Bluetooth, as well as mobile telephony, e.g., GSM and UMTS. Today, the term "radio" often refers to the actual transceiver device or chip, whereas "wireless" refers to the system and/or method used for radio communication, hence one talks about radio transceivers and Radio Frequency Identification (RFID), but about wireless devices and wireless sensor networks.

Invention

Although the invention of radio was long attributed to Guglielmo Marconi, the identity of the original inventor of radio (at the time called wireless telegraphy) is contentious.[12] Development from a laboratory demonstration to commercial utility spanned several decades and required the efforts of many practitioners. In 1943 Tesla was granted the patent for the invention of radio when the U.S. Supreme Court overturned many of Marconi's radio patents.

Other significant contributions include:
•In 1887, David E. Hughes transmitted signals by radio using a clockwork-keyed Spark Transmitter, achieving a range of approximately 500 metres.
•In 1888, Heinrich Hertz produced and measured the Ultra High Frequency range (via a sparkgap transmitter).
•In 1891, Nikola Tesla began wireless research. He developed means to reliably produce radio frequencies, publicly demonstrated the principles of radio, and transmitted long-distance signals.
•Between 1893 and 1894, Roberto Landell de Moura, a Brazilian priest and scientist, conducted experiments. He did not publicise his achievement (publicly broadcasting human voice) until 1900 but later obtained a Brazilian patent.
•In 1894 in Kolkata (Calcutta), Sir Jagdish Chandra Bose (J. C. Bose) invented the mercury coherer, together with the telephone receiver.
•Alexander Stepanovich Popov, in 1894, built his first radio receiver, which contained a coherer, although in actuality the coherer was first invented by Edouard Branly. Popov demonstrated the coherer, further refined as a lightning detector, to the Russian Physical and Chemical Society on May 7, 1895.
•In 1894, Guglielmo Marconi read about Hertz's and Tesla's work on wireless telegraphy, and began his own experiments.
•In August 1894, Oliver Lodge, an English physicist and writer, transmitted radio signals at a meeting of the British Association for the Advancement of Science at the University of Oxford.[13]
•Late 1896 to early 1897, Tesla received wireless signals transmitted from the Houston Street lab in New York City to West Point, "a distance of about 30 miles."[14]
•In March 1897 Marconi transmitted wireless telegraphy signals over a distance of two miles on Salisbury Plains, followed in May 1897 by a test over water between Lavernock and Flat Holm in the Bristol Channel, a distance of just over three miles. He then moved the receiving equipment to Brean Down Fort and extended the range to just under ten miles.
•In December of 1901 Guglielmo Marconi received the first transatlantic radio communication over a distance of 2,000 miles (3,200 km) from Poldhu, UK, to St. Johns, Newfoundland. Marconi was celebrated worldwide for this achievement. Soon after the patent was given to Marconi. He later received the Nobel Prize.
•In early 1900s Canadian engineer-inventor Reginald Fessenden [1] and American engineer Lee de Forest invented amplitude-modulated (AM) radio, allowing an audio signal to be sent over the air.
•In 1935 Edwin H. Armstrong invented frequency-modulated (FM) radio, so that an audio signal can avoid "static," that is, interference from electrical equipment and atmospherics.
•In 1943, the U.S. Supreme Court acknowledged that Marconi's work wasn't original because he had used 17 of Tesla's patents to accomplish his broadcasts, and the patent ownership is given back to Nikola Tesla. However, Tesla died shortly before the decision was announced.[15]

Radio

Radio is the transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Information is carried by systematically changing (modulating) some property of the radiated waves, such as amplitude, frequency, or phase. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information.

The meaning and usage of the word "radio" has developed in parallel with developments within the field and can be seen to have three distinct phases: electromagnetic waves and experimentation; wireless communication and technical development; and radio broadcasting and commercialization. Many, many individuals -- inventors, engineers, developers, businessmen -- contributed to produce the modern idea of radio and thus the origins and 'invention' are multiple and controversial.
James Clerk Maxwell, a Scottish scientist, developed the theoretical basis for explaining electromagnetism. He predicted that electric and magnetic fields can couple together to form electromagnetic waves. Heinrich Hertz, a German scientist, is credited with being the first to produce and detect such waves at radio frequencies, in 1888, using a sparkgap transmitter in the Ultra High Frequency range.
In 1893, Nikola Tesla, in America, first demonstrated the principles of wireless communications.[1][2] Tesla would later ultimately hold the patent rights in the United States. Ignoring prior art, some have suggested that the U.S. Supreme Court was influenced in its decision by the fact that the Marconi Company was suing the United States Government for use of its patents in World War I at the time.[3] Physicists and inventors such as John Stone Stone and Alexander Stepanovich Popov have cited Tesla as the originator of wireless communications.[4] In August 1894, Oliver Lodge, an English physicist and writer, transmitted radio signals at a meeting of the British Association for the Advancement of Science at the University of Oxford.[5] In 1895, Guglielmo Marconi, an Italian inventor, began experimenting with wireless and went on to develop the world's first commercial system of radio communication. In 1896, Marconi was granted the world's first wireless telegraphy patent by the British Patent Office. Marconi has been generally credited with the development of radio by most scholars and historians.[6] [7] [8] [9] [10] In 1909, Marconi was jointly awarded the Nobel Prize for Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy."[11] In 1943 the U.S. Supreme Court overturned Marconi's wireless patents and granted patent ownership to Nikola Tesla

Over radiowaves

AM

AM stations were the earliest broadcasting stations to be developed. AM refers to amplitude modulation, a mode of broadcasting radio waves by varying the amplitude of the carrier signal in response to the amplitude of the signal to be transmitted.
One of the advantages of AM is that its unsophisticated signal can be detected (turned into sound) with simple equipment. If a signal is strong enough, not even a power source is needed; building an unpowered crystal radio receiver was a common childhood project in the early years of radio.

AM broadcasts occur on North American airwaves in the medium wave frequency range of 530 to 1700 kHz (known as the "standard broadcast band"). The band was expanded in the 1990s by adding nine channels from 1620 to 1700 kHz. Channels are spaced every 10 kHz in the Americas, and generally every 9 kHz everywhere else.

Many countries outside of the U.S. use a similar frequency band for AM transmissions. Europe also uses the long wave band. In response to the growing popularity of FM radio stereo radio stations in the late 1980s and early 1990s, some North American stations began broadcasting in AM stereo, though this never gained popularity, and very few receivers were ever sold.

AM radio has some serious shortcomings.

•The signal is subject to interference from electrical storms (lightning) and other EMI.
•AM transmissions cannot be ionospherically propagated during the day due to strong absorption in the D-layer of the ionosphere. During the night, this absorption largely disappears and permits signals to travel to much more distant locations via ionospheric reflections.
•Fading of the signal can be severe at night.
AM signals exhibit diurnal variation, traveling much longer distances at night. In a crowded channel environment this means that the power of regional channels which share a frequency must be reduced at night or directionally beamed in order to avoid interference, which reduces the potential nighttime audience. Some stations have frequencies unshared with other stations in North America; these are called clear channel stations. Many of them can be heard across much of the country at night. (This is not to be confused with Clear Channel Communications, merely a brand name, which currently owns many U.S. radio stations.)

•AM radio transmitters can transmit audio frequencies up to 15 kHz (now limited to 10 kHz in the US due to FCC rules designed to reduce interference), but most receivers are only capable of reproducing frequencies up to 5 kHz or less. At the time that AM broadcasting began in the 1920s, this provided adequate fidelity for existing microphones, 78 rpm recordings, and loudspeakers. The fidelity of sound equipment subsequently improved considerably, but the receivers did not. Reducing the bandwidth of the receivers reduces the cost of manufacturing and makes them less prone to interference. AM stations are never assigned adjacent channels in the same service area. This prevents the sideband power generated by two stations from interfering with each other. Bob Carver created an AM stereo tuner employing notch filtering that demonstrated that an AM broadcast can meet or exceed the 15 kHz baseband bandwidth allocted to FM stations without objectionable interference. After a several years, the tuner was discontinued. Bob Carver had left the company and the Carver Corporation later cut the number of models produced before discontinuing production completely. AM stereo broadcasts declined with the advent of HD Radio.


FM

FM refers to frequency modulation, and occurs on VHF airwaves in the frequency range of 88 to 108 MHz everywhere (except Japan and Russia). Japan uses the 76 to 90 MHz band. FM stations are much more popular in economically developed regions, such as Europe and the United States, especially since higher sound fidelity and stereo broadcasting became common in this format.

FM radio was invented by Edwin H. Armstrong in the 1930s for the specific purpose of overcoming the interference (static) problem of AM radio, to which it is relatively immune. At the same time, greater fidelity was made possible by spacing stations further apart. Instead of 10 kHz apart, they are 200 kHz apart. (For example, the difference between the lowest current FM frequency in the U.S., 88.1 MHz, and the next lowest, 88.3 MHz. This was far in advance of the audio equipment of the 1940s, but wide interchannel spacing was chosen to take advantage of the noise-suppressing feature of wideband FM.

In fact, 200 kHz is not needed to accommodate an audio signal — 20 kHz to 30 kHz is all that is necessary for a narrowband FM signal. The 200 kHz bandwidth allowed room for ±75 kHz signal deviation from the assigned frequency plus a 20 kHz guardband to eliminate adjacent channel interference. The larger bandwidth allows for broadcasting a 15 kHz bandwidth audio signal plus a 38 kHz stereo "subcarrier" — a piggyback signal that rides on the main signal. Additional unused capacity is used by some broadcasters to transmit utility functions such as background music for public areas, GPS auxiliary signals, or financial market data.

The AM radio problem of interference at night was addressed in a different way. At the time FM was set up, the available frequencies were far higher in the spectrum than those used for AM radio - by a factor of approximately 100. Using these frequencies meant that even at far higher power, the range of a given FM signal was much lower, thus its market was more local than for AM radio. The reception range at night is the same as at daytime.

The original FM radio service in the U.S. was the Yankee Network, located in New England (see [5][6][7]). Regular FM broadcasting began in 1939, but did not pose a significant threat to the AM broadcasting industry. It required purchase of a special receiver. The frequencies used, 42 to 50 MHz, were not those used today. The change to the current frequencies, 88 to 108 MHz, began after the end of World War II, and it was to some extent imposed by AM radio owners so as to attempt to cripple what was by now realized to be a potentially serious threat.

FM radio on the new band had to begin from the ground floor. As a commercial venture it remained a little-used audio enthusiasts' medium until the 1960s. The more prosperous AM stations, or their owners, acquired FM licenses and often broadcast the same programming on the FM station as on the AM station ("simulcasting"). The FCC limited this practice in the 1970s. By the 1980s, since almost all new radios included both AM and FM tuners (without any government mandate), FM became the dominant medium, especially in cities. Because of its greater range, AM remained
more common in rural environments.


Other types of radio communication over radiowaves

An early form of digital radio broadcasting was packet radio, which combines digital information with traditional radio broadcasting over the air.
Digital radio broadcasting has emerged, first in Europe (the UK in 1995 and Germany in 1999), and later in the United States, France, Holland, South Africa and many other countries worldwide. The most simple system is named DAB Digital Radio, for Digital Audio Broadcasting, and uses the public domain EUREKA 147 (Band III) system. DAB is used mainly in the UK and South Africa. Germany and Holland use the DAB and DAB+ systems, and France use the L-Band system of DAB Digital Radio.

In the United States digital radio isn't used in the same way as Europe and South Africa - instead the IBOC system is named HD Radio and owned by a consortium of private companies called iBiquity. An international non-profit consortium Digital Radio Mondiale (DRM), has introduced the public domain DRM system.
It is expected that by the end of 2008 a digital radio will be available that can receive all these systems, in the same way that FM and AM can be received on the same radio. It is expected that for the next 10 to 20 years, all these systems will co-exist, while by 2015 to 2020 digital radio may predominate, at least in the developed countries.

Satellite

Satellite radiobroadcasters are slowly emerging, but the enormous entry costs of space-based satellite transmitters, and restrictions on available radio spectrum licenses has restricted growth of this market. In the USA and Canada, just two services, XM Satellite Radio and Sirius Satellite Radio exist.


Program formats

Radio program formats differ by country, regulation and markets. For instance, the U.S. Federal Communications Commission designates the 88–92 megahertz band in the U.S. for non-profit or educational programming, with advertising prohibited.
In addition, formats change in popularity as time passes and technology improves. Early radio equipment only allowed program material to be broadcast in real time, known as live broadcasting. As technology for sound recording improved, an increasing proportion of broadcast programming used pre-recorded material. A current trend is the automation of radio stations. Some stations now operate without direct human intervention by using entirely pre-recorded material sequenced by computer control.