Band IV is the name of a radio frequency range within the ultra high frequency part of the electromagnetic spectrum.
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.
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter. Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range. Lower frequency signals fall into the VHF or lower bands. UHF radio waves propagate mainly by line of sight; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for television broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones, and numerous other applications.
The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies.
Sources differ on the exact frequency range of the band. For example, the Swiss Federal Office of Communications, MHz, whilst the BBC define the range as 470 to 614 MHz. Band IV is primarily used for analogue and digital (DVB-T, ATSC and ISDB) television broadcasting, as well as services intended for mobile devices such as DVB-H.the Broadcast engineer's reference book and Ericsson India Ltd all define the range of Band IV from 470 to 582 MHz. An EICTA paper defines the range as 474 to 602
Ericsson is a Swedish multinational networking and telecommunications company headquartered in Stockholm. The company offers services, software and infrastructure in information and communications technology for telecommunications operators, traditional telecommunications and Internet Protocol (IP) networking equipment, mobile and fixed broadband, operations and business support services, cable television, IPTV, video systems, and an extensive services operation.
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.
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 Australia UHF channel allocations are 7 MHz wide. Band IV includes channels 28 to 35, with base frequencies of 529.5 MHz to 578.5 MHz. More details are available on the television frequencies page.
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It is the largest country in Oceania and the world's sixth-largest country by total area. The neighbouring countries are Papua New Guinea, Indonesia and East Timor to the north; the Solomon Islands and Vanuatu to the north-east; and New Zealand to the south-east. The population of 25 million is highly urbanised and heavily concentrated on the eastern seaboard. Australia's capital is Canberra, and its largest city is Sydney. The country's other major metropolitan areas are Melbourne, Brisbane, Perth and Adelaide.
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.
In New Zealand UHF channel allocations are 8 MHz wide. Band IV includes channels 25 to 35, with base frequencies of 506.0 MHz to 586.0 MHz. More details are available on the television frequencies page.
New Zealand is a sovereign island country in the southwestern Pacific Ocean. The country geographically comprises two main landmasses—the North Island, and the South Island —and around 600 smaller islands. New Zealand is situated some 2,000 kilometres (1,200 mi) east of Australia across the Tasman Sea and roughly 1,000 kilometres (600 mi) south of the Pacific island areas of New Caledonia, Fiji, and Tonga. Because of its remoteness, it was one of the last lands to be settled by humans. During its long period of isolation, New Zealand developed a distinct biodiversity of animal, fungal, and plant life. The country's varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealand's capital city is Wellington, while its most populous city is Auckland.
In the UK, Band IV allocations are 8 MHz wide, traditionally consisting of 14 channels from UHF 21 to 34 inclusive. However, in the mid-1990s the squeezing of analogue Channel 5 broadcasts into the existing national terrestrial TV transmitter network effectively closed a gap between bands IV and V, which was previously reserved for radar applications and home consumer devices. This stretched the practical definition of Band IV in the UK to cover 18 channels from UHF 21 to 38 inclusive. Aerials of the group A type cover this band.
Radar is a detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna and a receiver and processor to determine properties of the object(s). Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.
The following table covers the most inclusive definition of Band IV in the UK. Rows with a yellow background indicate channels which were not traditionally (before the mid-1990s) considered part of Band IV for TV broadcasting purposes and may not be considered part of the band in other countries (e.g. Switzerland).
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).
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.
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.
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 30 Hertz to 300 GHz. Electromagnetic waves in this frequency range, called radio waves, are extremely widely used in modern technology, particularly in telecommunication. To prevent interference between different users, the generation and transmission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU).
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.
In North American broadcast television frequencies, channel 1 is a former broadcast (over-the-air) television channel. During the experimental era of TV operation, Channel 1 was moved around the lower VHF spectrum repeatedly, with the entire band displaced upward at one point due to an early 40 MHz allocation for the FM broadcast band.
Digital terrestrial television in the United Kingdom encompasses over 100 television, radio and interactive services broadcast via the United Kingdom's terrestrial television network and receivable with a standard television set. The majority of digital terrestrial television (DTT) services, including the five former analogue channels, are broadcast free-to-air, and a further selection of encrypted pay TV services are also available.
The Llanddona transmitting station is a broadcasting and telecommunications facility, situated at Llanddona, near Beaumaris, on the isle of Anglesey, Wales. It comprises a 106.7 metres (350 ft) guyed mast with antennas attached at various heights. It is owned and operated by Arqiva.
The Wenvoe transmitting station is a facility for broadcasting and telecommunications situated close to the village of Wenvoe in the Vale of Glamorgan, Wales, in the UK. It comprises a 260.7-metre (855 ft) guyed mast with antennas attached at various heights. The mast plus the Main UHF (TV) antenna on top gives a height of 260.7 metres (869 ft). The average height above sea level is 392 metres for the television antennas. It is owned and operated by Arqiva. The mast sways 10 feet, or 4 meters, which is quite high for a mast this size.
Channel 37 is a purposefully 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.
The Oxford transmitting station is a broadcasting and telecommunications facility, situated on land 129.5 metres (425 ft) above Ordnance Datum to the north east of the city of Oxford, in Oxfordshire, England. It has a guyed steel lattice mast which is 154.4 metres (507 ft) in height to the top of the main steel structure. The UHF television antenna, which consist of a vertical array of transmitting panels, is mounted above the steel structure. The total height of the mast to the top of this UHF antenna is 165.7 metres (544 ft). It is owned and operated by Arqiva.
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.
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". Band I ranges from 47 to 68 MHz for the European Broadcasting Area, and from 54 to 88 MHz for the Americas and it is primarily used for television broadcasting in line to ITU Radio Regulations. Channel spacings vary from country to country, with spacings of 6, 7 and 8 MHz being common.
China Mobile Multimedia Broadcasting (CMMB) is a mobile television and multimedia standard developed and specified in China by the State Administration of Radio, Film, and Television (SARFT). It is based on the Satellite and Terrestrial Interactive Multiservice Infrastructure (STiMi), developed by TiMiTech, a company formed by the Chinese Academy of Broadcasting Science. Announced in October 2006, it has been described as being similar to Europe's DVB-SH standard for digital video broadcast from both satellites and terrestrial repeaters to handheld devices.
Band V is the name of a radio frequency range within the ultra high frequency part of the electromagnetic spectrum. It is not to be confused with the V band in the extremely high frequency part of the spectrum.
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.
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