Band I

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Band I is a range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum. The first time there was defined "for simplicity" in Annex 1 of "Final acts of the European Broadcasting Conference in the VHF and UHF bands - Stockholm, 1961" [1] . Band I ranges from 47 to 68 MHz for the European Broadcasting Area, [2] and from 54 to 88 MHz for the Americas [3] and it is primarily used for television broadcasting in line to ITU Radio Regulations (article 1.38). Channel spacings vary from country to country, with spacings of 6, 7 and 8 MHz being common.

Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around twenty thousand times per second to around three hundred billion times per second. This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range.

Very high frequency The range 30-300 MHz of the electromagnetic spectrum

Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).

The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies.

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Television broadcasting usage

In the UK, Band I was originally used by the BBC for monochrome 405-line television; [4] likewise, the French former 455-line (1937-1939) then 441-line (1943-1956) transmitter on the Eiffel Tower in Paris, and some stations of the French monochrome 819-line system used Band I. Both 405-line and 819-line systems were discontinued in the mid-1980s. Other European countries used Band I for 625-line analogue television, first in monochrome and later in colour.

The British Broadcasting Corporation (BBC) is a British public service broadcaster. Its headquarters are at Broadcasting House in Westminster, London, and it is the world's oldest national broadcasting organisation and the largest broadcaster in the world by number of employees. It employs over 20,950 staff in total, 16,672 of whom are in public sector broadcasting. The total number of staff is 35,402 when part-time, flexible, and fixed-contract staff are included.

Monochrome shades of one color; describes paintings, drawings, design, or photographs in one color or values of one color, having only one colour

A monochromic image is composed of one color. The term monochrome comes from the Ancient Greek: μονόχρωμος, romanized: monochromos, lit. 'having one color'.

The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting.

This was being gradually phased out with the introduction of digital television in the DVB-T standard, which is not defined for VHF Band I, though some older receivers and some modulators do support it.

Digital television transmission of audio and video by digitally processed and multiplexed signal

Digital television (DTV) is the transmission of television signals, including the sound channel, using digital encoding, in contrast to the earlier television technology, analog television, in which the video and audio are carried by analog signals. It is an innovative advance that represents the first significant evolution in television technology since color television in the 1950s. Digital TV transmits in a new image format called HDTV, with greater resolution than analog TV, in a wide screen aspect ratio similar to recent movies in contrast to the narrower screen of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit multiple channels, up to 7, in the same bandwidth occupied by a single channel of analog television, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2006 in some countries, and many industrial countries have now completed the changeover, while other countries are in various stages of adaptation. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widely used standards:

DVB-T is an abbreviation for "Digital Video Broadcasting — Terrestrial"; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998. This system transmits compressed digital audio, digital video and other data in an MPEG transport stream, using coded orthogonal frequency-division multiplexing modulation. It is also the format widely used worldwide for Electronic News Gathering for transmission of video and audio from a mobile newsgathering vehicle to a central receive point.

In the United States, use of this band is for analog NTSC (ended June 12, 2009) and digital ATSC (current). Digital television has problems with impulse noise interference, particularly in this band.

Europe

In European countries that use System B for television broadcasting, the band is subdivided into three channels, each being 7 MHz wide:

ChannelFrequency range
E247-54 MHz
E2A48.5-55.5 MHz
E354-61 MHz
E461-68 MHz
C82.25-87.75 MHz

Italy also uses a "outband" "channel C" (video : 82.25 MHz - audio : 87.75 MHz). It was used by the first transmitter brought in service by the RAI in Torino in the Fifties which was previously used in WW2 by the US to broadcast NTSC TV on channel A6 for military purposes, later donated to Italy, it had its video carrier shifted 1 MHz lower to accommodate the System B standard. This channel was also widely used by private local stations until the switch over to DVB-T.

RAI Italys national public service

RAI – Radiotelevisione italiana (Italian pronunciation: [ˈrai ˌradjoteleviˈzjoːne itaˈljaːna]; commercially styled as Rai since 2000; known until 1954 as Radio Audizioni Italiane is the national public broadcasting company of Italy, owned by the Ministry of Economy and Finance.

Some countries use slightly different frequencies or don't use Band 1 at all for terrestrial broadcast television. The fast growing of digital television as well as the susceptibility of this band to interference during E skip events in all European countries is accompanied by the progressive closedown of band I analog transmitters, e.g. former French-language Swiss Television transmitter at La Dôle near Geneva on channel E4 or French analog transmitters used by Canal Plus for its Pay-TV VHF network, e.g. Besançon (Lomont) and Carcassonne (Pic de Nore) both on French channel "L-3". Swiss VHF Band I transmitters are switched off untile 25/06/2007( Barillette ), and 26/11/2007, for Uetliberg, and Bantiger( German speaking area) French analog Canal Plus VHF band I are switched off until 2010.

Sporadic E propagation

Sporadic E or Es is an unusual form of radio propagation using characteristics of the Earth's ionosphere. Whereas most forms of skywave propagation use the normal and cyclic ionization properties of the ionosphere's F region to refract radio signals back toward the Earth's surface, sporadic E propagation bounces signals off smaller "clouds" of unusually ionized atmospheric gas in the lower E region. This occasionally allows for long-distance communication at VHF frequencies not usually well-suited to such communication.

La Dôle mountain

La Dôle is a mountain of the Jura, overlooking Lake Geneva in the westernmost part of the canton of Vaud. Rising to an altitude of 1677 meters, it is the second highest peak in the Swiss portion of the Jura, after Mont Tendre. Administratively, the summit is split between the municipalities of Gingins, Chéserex and La Rippe. The mountain is also close to and easily accessible from Saint-Cergue and the Col de la Givrine to the north, both above 1000 meters and connected to Nyon on Lake Geneva by road and by the Nyon–St-Cergue–Morez Railway. A paved road also climbs to the Chalet de la Dôle below the summit from Gingins.

Geneva Large city in Switzerland

Geneva is the second-most populous city in Switzerland and the most populous city of Romandy, the French-speaking part of Switzerland. Situated where the Rhône exits Lake Geneva, it is the capital of the Republic and Canton of Geneva.

Russia and other former members of OIRT

In the countries that use System D television broadcast system, the channel allocation in the VHF-I band is as follows:

ChannelFrequency range
148.5-56.5 MHz
258-66 MHz

North America

The band is subdivided into five channels for television broadcasting, each occupying 6 MHz (System M). Channel 1 is not being used for broadcasting anymore.

ChannelFrequency range
1*44-50 MHz
A254-60 MHz
A360-66 MHz
A466-72 MHz
A576-82 MHz
A682-88 MHz
A6A81.5-87.5 MHz

FM Radio Usage

The upper end of this band, 87.5 to 88 MHz, is the lower end of the FM radio band. In the United States, the FCC will occasionally issue a license for 87.9 MHz (though it only does so on rare occurrences and special circumstances; KSFH is the only standalone station that uses 87.9 currently); 87.7, which is approximately the same frequency as the audio feed of channel 6, is used by some television licenses to broadcast primarily to radio, such as Pulse 87's stations. In Japan and some former Soviet republics frequencies lower than 87MHz are still used for FM radio broadcasting.

See also

Related Research Articles

NTSC analog television system

NTSC, named after the National Television System Committee, is the analog television color system that was used in North America from 1954 and until digital conversion, was used in most of the Americas ; Myanmar; South Korea; Taiwan; Philippines; Japan; and some Pacific island nations and territories.

PAL Colour encoding system for analogue television

Phase Alternating Line (PAL) is a colour encoding system for analogue television used in broadcast television systems in most countries broadcasting at 625-line / 50 field per second (576i). Other common colour encoding systems are NTSC National Television Standards Committee, ATSC Advanced Television Systems Committee, and SECAM.

Terrestrial television television content transmitted via signals in the air

Terrestrial television is a type of television broadcasting in which the television signal is transmitted by radio waves from the terrestrial (Earth-based) transmitter of a television station to a TV receiver having an antenna. The term terrestrial is more common in Europe and Latin America, while in the United States it is called broadcast or over-the-air television (OTA). The term "terrestrial" is used to distinguish this type from the newer technologies of satellite television, in which the television signal is transmitted to the receiver from an overhead satellite, and cable television, in which the signal is carried to the receiver through a cable.

The FM broadcast band, used for FM broadcast radio by radio stations, differs between different parts of the world. In Europe, Australia and Africa ( ), it spans from 87.5 to 108 megahertz (MHz) - also known as VHF Band II - while in the Americas it ranges from 88 to 108 MHz. The FM broadcast band in Japan uses 76 to 95 MHz. The International Radio and Television Organisation (OIRT) band in Eastern Europe is from 65.8 to 74.0 MHz, although these countries now primarily use the 87.5 to 108 MHz band, as in the case of Russia. Some other countries have already discontinued the OIRT band and have changed to the 87.5 to 108 MHz band.

Digital Radio Mondiale Digital radio broadcasting standard

Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for analogue radio broadcasting including AM broadcasting, particularly shortwave, and FM broadcasting. DRM is more spectrally efficient than AM and FM, allowing more stations, at higher quality, into a given amount of bandwidth, using various MPEG-4 audio coding formats.

Terrestrial television systems are the encoding or formatting standards for the transmission and reception of terrestrial television signals. There were three main analog television systems in use around the world until the late 2010s (expected): NTSC, PAL, and SECAM. Now in digital terrestrial television (DTT), there are four main systems in use around the world: ATSC, DVB, ISDB and DTMB.

Amateur television

Amateur television (ATV) is the transmission of broadcast quality video and audio over the wide range of frequencies of radio waves allocated for radio amateur (Ham) use. ATV is used for non-commercial experimentation, pleasure, and public service events. Ham TV stations were on the air in many cities before commercial television stations came on the air. Various transmission standards are used, these include the broadcast transmission standards of NTSC in North America and Japan, and PAL or SECAM elsewhere, utilizing the full refresh rates of those standards. ATV includes the study of building of such transmitters and receivers, and the study of radio propagation of signals travelling between transmitting and receiving stations.

Tuner (radio) frequency selection subsystem for a radio receiver

A tuner is a subsystem that receives radio frequency (RF) transmissions like radio broadcasts and converts the selected carrier frequency and its associated bandwidth into a fixed frequency that is suitable for further processing, usually because a lower frequency is used on the output. Broadcast FM/AM transmissions usually feed this intermediate frequency (IF) directly into a demodulator that convert the radio signal into audio-frequency signals that can be fed into an amplifier to drive a loudspeaker.

Television channel frequencies Wikimedia list article

The following tables show the frequencies assigned to broadcast television channels in various regions of the world, along with the ITU letter designator for the system used. The frequencies shown are for the analogue video and audio carriers. The channel itself occupies several megahertz of bandwidth. For example, North American channel 2 occupies the spectrum from 54 to 60 MHz. See Broadcast television systems for a table of signal characteristics, including bandwidth, by ITU letter designator.

Multiplexed Analogue Components

Multiplexed analogue components (MAC) was a satellite television transmission standard, originally proposed for use on a Europe-wide terrestrial HDTV system, although it was never used terrestrially.

Channel 37 is an intentionally unused ultra-high frequency (UHF) television broadcasting television channel in the United States, Canada and Mexico. The frequency range allocated to this channel is important for radio astronomy, so broadcasting is not licensed.

Analog high-definition television was an analog video broadcast television system developed in the 1930s to replace early experimental systems with as few as 12-lines. On 2 November 1936 the BBC began transmitting the world's first public regular analog high-definition television service from the Victorian Alexandra Palace in north London. It therefore claims to be the birthplace of television broadcasting as we know it today. John Logie Baird, Philo T. Farnsworth, and Vladimir Zworykin had each developed competing TV systems, but resolution was not the issue that separated their substantially different technologies, it was patent interference lawsuits and deployment issues given the tumultuous financial climate of the late 1920s and 1930s.

Band III is the name of the range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum from 174 to 240 megahertz (MHz). It is primarily used for radio and television broadcasting. It is also called high-band VHF, in contrast to Bands I and II.

Television frequency allocation has evolved since the start of television in Australia in 1956, and later in New Zealand in 1960. There was no coordination between the national spectrum management authorities in either country to establish the frequency allocations. The management of the spectrum in both countries is largely the product of their economical and political situation. New Zealand didn't start to develop television service until 1965 due to World War 2 and its economic harm in the country's economy.

High Definition Television (HDTV) is a television system providing an image resolution that is of substantially higher resolution than that of standard-definition television. This can be either analog or digital. HDTV is the current standard video format used in most broadcasts: terrestrial broadcast television, cable television, satellite television, Blu-rays, and streaming video.

CCIR System B was the 625-line analog broadcast television system which at its peak was the system used in most countries. It is being replaced across Western Europe, part of Asia and Africa by digital broadcasting.

The Pan-American television frequencies are different for terrestrial and cable television systems. Terrestrial television channels are divided into two bands: the VHF band which comprises channels 2 through 13 and occupies frequencies between 54 through 216 MHz, and the UHF band, which comprises channels 14 through 83 and occupies frequencies between 470 and 890 MHz. These bands are different enough in frequency that they often require separate antennas to receive, and separate tuning controls on the television set. The VHF band is further divided into two frequency ranges: VHF low band between 54 and 88 MHz, containing channels 2 through 6, and VHF high band between 174 and 216 MHz, containing channels 7 through 13. The wide spacing between these frequency bands is responsible for the complicated design of rooftop TV antennas. The UHF band has higher noise and greater attenuation, so higher gain antennas are often required for UHF.

CCIR System A was the 405 line analog broadcast television system broadcast in the UK and Ireland. CCIR service was discontinued in 1985.

CCIR System I is an analog broadcast television system. It was first used in the Republic of Ireland starting in 1962 as the 625-line broadcasting standard to be used on VHF Band I and Band III, sharing Band III with 405-line System A signals radiated in the north of the country. The UK started its own 625-line television service in 1964 also using System I, but on UHF only - the UK has never used VHF for 625-line television except for some cable relay distribution systems.

References

  1. "Final acts of the European Broadcasting Conference in the VHF and UHF bands - Stockholm, 1961". www.ero.dk. Retrieved 2019-01-09.
  2. "FM / TV Regional Frequency Assignment Plans". ITU. Retrieved 20 February 2017.
  3. "Frequency Bands allocated to Terrestrial Broadcasting Services". ITU. Retrieved 20 February 2017.
  4. Paulu, Burton (1981-10-01). Television and Radio in the United Kingdom. U of Minnesota Press. p. 91. ISBN   9780816609413 . Retrieved 11 April 2012.