1.
Geographic coordinate system
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A geographic coordinate system is a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols. The coordinates are chosen such that one of the numbers represents a vertical position. A common choice of coordinates is latitude, longitude and elevation, to specify a location on a two-dimensional map requires a map projection. The invention of a coordinate system is generally credited to Eratosthenes of Cyrene. Ptolemy credited him with the adoption of longitude and latitude. Ptolemys 2nd-century Geography used the prime meridian but measured latitude from the equator instead. Mathematical cartography resumed in Europe following Maximus Planudes recovery of Ptolemys text a little before 1300, in 1884, the United States hosted the International Meridian Conference, attended by representatives from twenty-five nations. Twenty-two of them agreed to adopt the longitude of the Royal Observatory in Greenwich, the Dominican Republic voted against the motion, while France and Brazil abstained. France adopted Greenwich Mean Time in place of local determinations by the Paris Observatory in 1911, the latitude of a point on Earths surface is the angle between the equatorial plane and the straight line that passes through that point and through the center of the Earth. Lines joining points of the same latitude trace circles on the surface of Earth called parallels, as they are parallel to the equator, the north pole is 90° N, the south pole is 90° S. The 0° parallel of latitude is designated the equator, the plane of all geographic coordinate systems. The equator divides the globe into Northern and Southern Hemispheres, the longitude of a point on Earths surface is the angle east or west of a reference meridian to another meridian that passes through that point. All meridians are halves of great ellipses, which converge at the north and south poles, the prime meridian determines the proper Eastern and Western Hemispheres, although maps often divide these hemispheres further west in order to keep the Old World on a single side. The antipodal meridian of Greenwich is both 180°W and 180°E, the combination of these two components specifies the position of any location on the surface of Earth, without consideration of altitude or depth. The grid formed by lines of latitude and longitude is known as a graticule, the origin/zero point of this system is located in the Gulf of Guinea about 625 km south of Tema, Ghana. To completely specify a location of a feature on, in, or above Earth. Earth is not a sphere, but a shape approximating a biaxial ellipsoid. It is nearly spherical, but has an equatorial bulge making the radius at the equator about 0. 3% larger than the radius measured through the poles, the shorter axis approximately coincides with the axis of rotation
2.
BBC London
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BBC London is the BBC English Region producing local radio, television, teletext and online services in London and parts of the surrounding area. Its output includes the daily BBC London News and weekly Sunday Politics on television, the regions headquarters are situated in the new eastern extension of Broadcasting House. The flagship programme is broadcast between 18,30 and 19,00 each weekday evening, following the end of the BBC News at Six and is presented by Riz Lateef. Comparisons are inevitably made to the commercial TV regional competition, in this case ITV News London, BBC London can be viewed in any part of the UK on digital satellite channel 974 on the BBC UK regional TV on satellite service. BBC Radio London combines speech and music based programmes 24 hours a day, Broadcasting across London on 94.9 FM, DAB, Virgin Media Channel 930, Sky Channel 0152, Freeview Channel 721 and also online. The station was known as BBC London Live, GLR. The current Breakfast show presenters are Penny Smith and Paul Ross, the Breakfast and Drivetime shows feature a wealth of local London news and comment with roving reporters out and about. Other programmes such as JoAnne Good or Robert Elms include varied speech and music with local news bulletins every half-hour. The travel news on BBC Radio London is updated at 31 and 58 minutes past each hour during off peak times and its one of the few radio stations to have access to TfL cameras. The travel news online is updated from an independent travel information supplier and this data is fed from their main system onto BBC Londons website, via the BBC Travel News portal. The online section also has features on aspects of travel in London. Sport is a major part of the radio schedule, with a 3-hour sports based programme each weeknight evening. This is considerably more than most other BBC local radio stations and reflects Londons large number of sporting teams, BBC London News launched on 1 October 2001 following changes to the coverage areas of BBC transmitters allowing for the establishment of new editorial areas. BBC London, as it came to be called, replaced the long-running Newsroom South East, there were many incarnations of regional news programmes in this area before the current programme was introduced in 2001. Other identities for the London area coverage were London Plus, and this meant that sizeable communities which probably deserved dedicated programming of their own - such as Oxford, Luton, Crawley and Medway - were often ill-served by a London-biased programme. There is also overlap with the editorial areas of other BBC regions in this part of England. The previous new services for the area, in the old BBC South East region, were based in Shepherds Bush, White City. Following the launch of BBC London, the moved into facilities in Marylebone High Street, where the news service was based alongside BBC London News
3.
ITV London
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ITV London is the on-air brand name used by ITV Broadcasting Limited for the two ITV broadcast franchises, Carlton Television and London Weekend Television in the London ITV region. Its terrestrial digital signal is transmitted from Crystal Palace in South London, ITV London was formed on 28 October 2002 as a unified on-screen brand for both of the Carlton and LWT franchises, running on weekdays and weekends respectively. It replaced the unique branding used by both franchisees with a service, offering the same service and news all week round. Legally, both franchises remained separate, but they are run by the operating board and from the same facilities. Both licences are now held by ITV Broadcasting Ltd, but the two companies still legally exist as Carlton Television Ltd and London Weekend Television Ltd. Each of these companies is, along with most other companies owned by ITV plc. ITV London is also unique in that it supplies the feed for the other franchises and is the sole alternative ITV region to Sky, Freesat. Other regional variants are available by manually searching, but London is the region to be given an exclusive EPG slot. ITV London is based at The London Studios, on the bank of the River Thames. The centre was due to both companies presence in the centre, Carlton having leased space within the facility, alongside GMTV. The contracted news service London News Network was also based, produced, any reference to the service being in London is made in the voiceover alone, or through the programme titles, such as London Tonight. The LWT logo was laid out in a purple box clearly at the top, with the caption An LWT Production beneath. This was replaced in 2006 by a caption featuring the new ITV1 logo with the words a production for above it. In 2013 it was replaced by a white ITV News caption with the words ©year ITN, to align with ITNs, on 14 January 2013, the stations on-air identity was changed to ITV, along with all other ITV plc-owned franchises. ITV London itself doesnt make any programmes, as all productions were completed by external companies, Carlton, Carlton Television London Weekend Television ITV History of ITV ITV London at itv. com
4.
Arqiva
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The company headquarters is located at Crawley Court in the village of Crawley, Hampshire. Its main customers are broadcasters and mobile network operators, and its main asset is a network of over 1,000 radio. It is owned by a consortium of investors led by CPP, Arqiva is a patron of The Radio Academy. Through its NOW Digital subsidiary, it operates various local digital radio ensembles, the company, which has a history that dates back to the beginning of regular public broadcasting in the United Kingdom, was actually only formed in 2005. Below is a history of the various organisations that are now part of Arqiva. The assets were split into a separate company, prior to being sold. The domestic transmitter network was purchased by a US company, Crown Castle, subsequently, in 2004, this was purchased by National Grid plc, which merged in its own private communication network, the name changing to National Grid Wireless in October 2005. This company developed on the back of the growth in mobile phones and this was added to by the purchase of the former BBC network National Grid Wireless, as it became, led a consortium bidding for the second UK national DAB multiplex licence, but was unsuccessful. The licence was awarded instead to 4 Digital Group in July 2007, the Television Act 1954 gave birth to the Independent Television Authority. The ITA appointed and regulated a number of regional programme contractors, the Sound Broadcasting Act 1972 created legal commercial radio in the UK for the first time. It was modelled on ITA, in that programmes were made by local contractors while the regulator, renamed the Independent Broadcasting Authority, the Broadcasting Act 1990 split the IBA into three bodies. The Independent Television Commission regulated commercial TV and the Radio Authority regulated commercial radio, at this point, technical standards regulation, previously carried out in accordance with the IBA engineering Code of Practice, seems to have disappeared from the regulatory landscape. Transcom was acquired by International CableTel Inc. which subsequently built its brand around the NTL name and it ran up huge debts during the dot-com boom which crippled the company for many years. In 1998, NTL acquired the UK antenna sites business of Simoco, in 1999 NTL acquired the UK field service operations business of Simoco. In 2004, NTL sold its broadcast unit to Macquarie Communications Infrastructure Group, in January 2005, Macquarie Communications Infrastructure Group renamed its new subsidiary Arqiva. Inmedia was owned by Kingston Communications and known as Kingston inmedia before being bought by the Carlyle Group in 2004. Arqiva announced the signing of a Sale & Purchase Agreement with BT to acquire the full-time service components of BT’s Satellite Broadcast Services business for £25 million in cash in November 2006. The deal will include long-term customer contracts, operations and personnel located in the USA, France, Italy, deal completion is subject to regulatory approval in the UK and Germany
5.
Crystal Palace, London
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Crystal Palace is a residential area in South London, England, within the London Boroughs of Bromley, Croydon, Lambeth, Lewisham, and Southwark. It is named after the local landmark, the Crystal Palace. The area is located eight miles south east of Charing Cross and includes one of the highest points in London, at 367 feet. It is contiguous with Anerley, Dulwich Wood, Gipsy Hill, Penge, South Norwood, Sydenham, the district was a natural oak forest until development began in the 19th century, and before the arrival of the Crystal Palace the area was known as Sydenham Hill. The Norwood Ridge and an oak tree were used to mark parish boundaries. Today, the area is represented by three different parliamentary constituencies, four London Assembly constituencies and fourteen local authority councillors, Crystal Palace Park has also been the setting for a number of concerts and films, including scenes from The Italian Job and The Pleasure Garden. Two television transmitter masts make the district a landmark location, visible from parts of Greater London. A pneumatic railway was briefly trialled in the area in 1864, after the palace was destroyed by fire, and with railway travel declining in the UK more generally, passenger numbers fell and the high level station was closed in 1954 and demolished 7 years later. Rail services gradually declined, and for a period in the 1960s and 1970s there were plans to construct a motorway through the area as part of the London Ringways plan. In 2016, Crystal Palace was named as one of the best places to live in London, the ridge and the historic oak tree known as The Vicars Oak were used to mark parish boundaries. This has led to the Crystal Palace area straddling the boundaries of five London Boroughs, Bromley, Croydon, Lambeth, Southwark, the area also straddles three postcode districts, SE19, SE20, and SE26. The ancient boundary between Surrey and Kent passes through the area and from 1889 to 1965 the area lay on the eastern boundary of the County of London. It included parts of Kent and Surrey until 1889 and then parts of Kent, London and Surrey between 1889 and 1965. For centuries the area was occupied by the Great North Wood, the forest was a popular area for Londoners recreation right up to the 19th century, when it began to be built over. It was also a home of Gypsies, with local street names. The area still retains vestiges of woodland, the third quarter of the 19th Century brought the Crystal Palace and the railways. The Crystal Palace was a cast-iron and glass building originally erected in Hyde Park to house the Great Exhibition of 1851. Following the success of the exhibition, the palace was moved and reconstructed in 1854 in a modified and enlarged form in the grounds of the Penge Place estate at Sydenham Hill
6.
London Borough of Bromley
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The London Borough of Bromley /ˈbrɒmli/ is one of the 32 London boroughs which make up Greater London. The London Borough of Bromley is south of the River Thames which flows through London, the borough is named after Bromley, its principal town. The local authority is Bromley London Borough Council, the borough is the largest in Greater London by area and occupies 59 square miles, of which the majority is Metropolitan Green Belt land. It is also perhaps the most rural, most of the population lives in the north and west of the borough, with an outlier at Biggin Hill in the far south. The borough shares borders with the London Boroughs of Lewisham and Greenwich to the North, Bexley to the North East, Southwark and Lambeth to the North West, as well as Croydon to the West. It also borders the Sevenoaks District of Kent to the East and South, westerham Heights, the highest point in London at an altitude of 804 feet, is located on the southern boundary. The Prime Meridian passes through Bromley, about 30% of the land in Bromley is farmland, the highest figure of a London Borough. The borough was formed, as were all other London boroughs, in 1969, after a local campaign, the village of Knockholt was transferred back to Kent to become part of the Sevenoaks Rural District and later Sevenoaks District. Before 1965 it had part of the Orpington Urban District. The borough is partly urban and partly rural, the former to the north, other smaller suburban areas include Anerley and nearby Crystal Palace, and Penge. In addition, parts of Mottingham, Sydenham, Swanley and Ruxley lie within the borough boundaries, there are two main built-up areas in the southern part of the borough, Hayes and West Wickham. Biggin Hill, Downe and Keston with Leaves Green and Nash are separate, smaller, local attractions include Down House, Chislehurst Caves, Holwood House, Crofton Roman Villa, and the site of The Crystal Palace. Bromley is divided into 22 wards with a total of 60 council seats, after a number of by-elections and a defection, the Conservatives regained control on 5 July 2001. The 22 wards are shown on the accompanying map, ward names often straddle the named settlements and suburban areas above, their boundaries are fixed, whereas the latter are not. In 1801, the parishes that form the modern borough had a total population of 8,944. This rose slowly throughout the 19th century, as the district built up. When the railways arrived the rate of growth increased. The population peaked in the 1970s, when began to relocate from London
7.
Ordnance Survey National Grid
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The Ordnance Survey National Grid reference system is a system of geographic grid references used in Great Britain, different from using Latitude and Longitude. It is often called British National Grid, the Ordnance Survey devised the national grid reference system, and it is heavily used in their survey data, and in maps based on those surveys. Grid references are commonly quoted in other publications and data sources. The Universal Transverse Mercator coordinate system is used to provide references for worldwide locations. European-wide agencies also use UTM when mapping locations, or may use the Military Grid Reference System system, the grid is based on the OSGB36 datum, and was introduced after the retriangulation of 1936–1962. It replaced the previously used Cassini Grid which, up to the end of World War Two, had issued only to the military. The Airy ellipsoid is a regional best fit for Britain, more modern mapping tends to use the GRS80 ellipsoid used by the GPS, the British maps adopt a Transverse Mercator projection with an origin at 49° N, 2° W. Over the Airy ellipsoid a straight grid, the National Grid, is placed with a new false origin. This false origin is located south-west of the Isles of Scilly, the distortion created between the OS grid and the projection is countered by a scale factor in the longitude to create two lines of longitude with zero distortion rather than one. Grid north and true north are aligned on the 400 km easting of the grid which is 2° W. 2° 0′ 5″ W. OSGB36 was also used by Admiralty nautical charts until 2000 after which WGS84 has been used, a geodetic transformation between OSGB36 and other terrestrial reference systems can become quite tedious if attempted manually. The most common transformation is called the Helmert datum transformation, which results in a typical 7 m error from true, the definitive transformation from ETRS89 that is published by the OSGB is called the National Grid Transformation OSTN02. This models the detailed distortions in the 1936–1962 retriangulation, and achieves backwards compatibility in grid coordinates to sub-metre accuracy, the difference between the coordinates on different datums varies from place to place. The longitude and latitude positions on OSGB36 are the same as for WGS84 at a point in the Atlantic Ocean well to the west of Great Britain. In Cornwall, the WGS84 longitude lines are about 70 metres east of their OSGB36 equivalents, the smallest datum shift is on the west coast of Scotland and the greatest in Kent. But Great Britain has not shrunk by 100+ metres, a point near Lands End now computes to be 27.6 metres closer to a point near Duncansby Head than it did under OSGB36. For the first letter, the grid is divided into squares of size 500 km by 500 km, there are four of these which contain significant land area within Great Britain, S, T, N and H. The O square contains an area of North Yorkshire, almost all of which lies below mean high tide
8.
The Crystal Palace
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The Crystal Palace was a cast-iron and plate-glass structure originally built in Hyde Park, London, to house the Great Exhibition of 1851. More than 14,000 exhibitors from around the world gathered in its 990, designed by Joseph Paxton, the Great Exhibition building was 1,851 feet long, with an interior height of 128 feet. It stood there from 1854 until its destruction by fire in 1936, Crystal Palace F. C. were founded at the site in 1905 and played at the Cup Final venue in their early years. The park still contains Benjamin Waterhouse Hawkinss Crystal Palace Dinosaurs which date back to 1854, the Commission in charge of mounting the Great Exhibition was established in January 1850, and it was decided at the outset that the entire project would be funded by public subscription. Within three weeks, the committee had received some 245 entries, including 38 international submissions from Australia, turner was furious at the rejection, and reportedly badgered the commissioners for months afterwards, seeking compensation, but at an estimated £300,000, his design was too expensive. Opponents of the scheme lobbied strenuously against the use of Hyde Park, the most outspoken critic was arch-conservative Col. At this point renowned gardener Joseph Paxton became interested in the project, the lily and its house led directly to Paxtons design for the Crystal Palace and he later cited the huge ribbed floating leaves as a key inspiration. Paxton left his 9 June 1850 meeting with Henry Cole fired with enthusiasm and he immediately went to Hyde Park, where he walked the site earmarked for the Exhibition. Two days later, on 11 June, while attending a meeting of the Midland Railway, Paxton made his original concept drawing. In the event, Paxtons design fulfilled and surpassed all the requirements, would cover roughly twenty-five times the ground area of its progenitor. He was exultant, but now had less than eight months to finalize his plans, manufacture the parts and erect the building in time for the Exhibitions opening, which was scheduled for 1 May 1851. Paxton was able to design and build the largest glass structure yet created, from scratch, in less than a year, Paxtons modular, hierarchical design reflected his practical brilliance as a designer and problem-solver. These were the largest available at the time, measuring 10 inches wide by 49 inches long, the original Hyde Park building was essentially a vast, flat-roofed rectangular hall. A huge open gallery ran along the axis, with wings extending down either side. The main exhibition space was two stories high, with the upper floor stepped in from the boundary. Most of the building had a roof, except for the central transept. Both the flat-profile sections and the transept roof were constructed using the key element of Paxtons design - his patented ridge-and-furrow roofing system. The basic roofing unit, in essence, took the form of a triangular prism
9.
John Logie Baird
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In 1928 the Baird Television Development Company achieved the first transatlantic television transmission. Bairds early technological successes and his role in the introduction of broadcast television for home entertainment have earned him a prominent place in televisions history. Baird was ranked number 44 in the BBCs list of the 100 Greatest Britons following a UK-wide vote in 2002. In 2006, Baird was named as one of the 10 greatest Scottish scientists in history, in 2015 he was inducted into the Scottish Engineering Hall of Fame. He was educated at Larchfield Academy in Helensburgh, the Glasgow and West of Scotland Technical College, while at college Baird undertook a series of engineering apprentice jobs as part of his course. The conditions in industrial Glasgow at the time helped form his socialist convictions and he became an agnostic, though this did not strain his relationship with his father. His degree course was interrupted by the First World War and he never returned to graduate, at the beginning of 1915 he volunteered for service in the British Army but was classified as unfit for active duty. Unable to go to the Front, he took a job with the Clyde Valley Electrical Power Company, the development of television was the result of work by many inventors. Among them, Baird was a prominent pioneer and made advances in the field. Many historians credit Baird with being the first to produce a live, moving, Baird achieved this, where other inventors had failed, by obtaining a better photoelectric cell and improving the signal conditioning from the photocell and the video amplifier. Between 1902 and 1907, Arthur Korn invented and built the first successful signal-conditioning circuits for image transmission, the circuits overcame the image-destroying lag effect that is part of selenium photocells. Korns success at transmitting halftone still images suggested that such compensation circuits might work in television, Baird was the direct beneficiary of Korns research and success. In his first attempts to develop a television system, Baird experimented with the Nipkow disk. Paul Gottlieb Nipkow had invented this scanning system in 1884. Television historian Albert Abramson calls Nipkows patent the master television patent, Nipkows work is important because Baird and many others chose to develop it into a broadcast medium. In early 1923, and in health, Baird moved to 21 Linton Crescent, Hastings. He later rented a workshop in the Queens Arcade in the town, in February 1924, he demonstrated to the Radio Times that a semi-mechanical analogue television system was possible by transmitting moving silhouette images. In July of the year, he received a 1000-volt electric shock, but survived with only a burnt hand
10.
One Canada Square
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One Canada Square, often referred to simply as Canary Wharf, is a skyscraper in Canary Wharf, London. It was the tallest building in the United Kingdom from 1990 to 2010, standing at 770 feet above ground level, in late 2010, it was surpassed by the Shard. The building is clad with stainless steel rather than natural stone. One of the predominant features of the building is the roof, which contains a flashing aircraft warning light. The distinctive pyramid pinnacle is 800 feet above sea level, One Canada Square is primarily used for offices, though there are some retail units on the lower ground floor. It is a location for offices and as of November 2015 was 100% let. The building is recognised as a London landmark, and it has gained attention through film, television. The original plans for a district on Canary Wharf came from G Ware Travelstead. He proposed three 260 m towers, Travelstead was unable to find the money for his project, so he sold the plans to Olympia & York in 1987. Olympia & York grouped all three towers into a known as Docklands Square, and the main tower was designated DS7 during planning. Docklands Square was later renamed Winston Square before finally being renamed as Canada Square, the architects chosen to design One Canada Square were Cesar Pelli & Associates, Adamson Associates, and Frederick Gibberd Coombes & Partners. They designed the tower with a shape to Three World Financial Center, New York City. The shape was also reminiscent of Big Ben. To comply with air safety regulations, the architects took five floors off the tower. The final height of 824 feet was permitted, otherwise, the developers would have had to dismantle what was necessary to fit the height restriction, the design of the tower received a fair share of criticism. According to Cesar Pelli, the most damaging criticism came from Prince Charles, other criticisms came from former Prime Minister Margaret Thatcher, who said that the building was not quite stunning. Construction on the began in 1988. Lehrer McGovern contracted out most of the work to Balfour Beatty because the Canary Wharf Tower was a building to build
11.
Canary Wharf
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Canary Wharf is a major business district located in Tower Hamlets, East London. Canary Wharf contains around 16,000,000 square feet of office and retail space, Morgan, KPMG, MetLife, Moodys, Morgan Stanley, RBC, S&P Global, Skadden, State Street, and Thomson Reuters. Canary Wharf is located on the West India Docks on the Isle of Dogs, from 1802 to 1939, the area was one of the busiest docks in the world. After the 1960s, the industry began to decline, leading to all the docks being closed by 1980. Canary Wharf itself takes its name from No.32 berth of the West Wood Quay of the Import Dock and this was built in 1936 for Fruit Lines Ltd, a subsidiary of Fred Olsen Lines for the Mediterranean and Canary Islands fruit trade. The Canary islands were so named after the dogs found there by the Spanish and as it is located on the Isle of Dogs. The Canary Wharf of today began when Michael von Clemm, former chairman of Credit Suisse First Boston, further discussions with G Ware Travelstead led to proposals for a new business district. The first buildings were completed in 1991, including One Canada Square, which became the UKs tallest building at the time, by the time it opened, the London commercial property market had collapsed, and Olympia and York Canary Wharf Limited filed for bankruptcy in May 1992. Initially, the City of London saw Canary Wharf as an existential threat and it modified its planning laws to expand the provision of new offices in the City of London, for example, creating offices above railway stations and roads. The resulting oversupply of office space contributed to the failure of the No 1 Canada Square project, in 1997, some residents living on the Isle of Dogs launched a lawsuit against Canary Wharf Ltd for private nuisance because the tower interfered with television signals. In December 1995 an international consortium, backed by the owners of Olympia & York and other investors. The new company was called Canary Wharf Limited, and later became Canary Wharf Group, recovery in the property market generally, coupled with continuing demand for large floorplate Grade A office space, slowly improved the level of interest. A critical event in the recovery was the start of work on the Jubilee Line Extension. At the peak of property prices in 2007, the HSBC building sold for a record £1.1 billion, in March 2014 planning permission was granted for the second residential building on the Canary Wharf estate, a 58-storey tower including 566 apartments plus shops and a health club. In July 2014 Canary Wharf Group was granted planning permission for a major expansion of the Canary Wharf estate. The plans include the construction of 30 buildings comprising a total of 4.9 million square feet, construction is planned to commence in autumn 2014 with the first buildings to be occupied at the end of 2018. In 2014, Singapore listed Oxley Holdings, together with developer Ballymore UK, have a joint venture to set up a new waterfront township of Royal Wharf with 3385 new homes housing over 10,000 people. This table lists completed buildings in Canary Wharf that are over 60 metres tall, the Canary Wharf developers played a pro-active role in improving transport links, which they recognised as essential to the success of the project
12.
Alexandra Palace television station
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The Alexandra Palace television station in North London is one of the oldest television transmission sites in the world. What was at the time called high definition TV broadcasts on VHF were beamed from this mast from 1936 until the outbreak of World War II. It then lay dormant until it was used successfully to foil the German Y-Gerät radio navigation system during the last stages of the Battle of Britain. After the war, it was reused for television until 1956, the transmitter is owned and maintained by Arqiva. Digital television replaced the television signals during the digital switchover of April 2012. However, only 3 of the 6 multiplexes are available, BBC A & B, BBC A launched on UHF61 on 4 April 2012, before moving to its final allocation of UHF49 on 18 April, when BBC B and Digital 3&4 launched. Analogue television is no longer transmitted from Alexandra Palace, BBC Two was closed on UHF64 on 4 April 2012, when ITV1 temporarily moved into its frequency. The remaining three analogue services closed down on 18 April 2012, aerial group, C/D Polarisation, horizontal The Transmission Gallery, Photographs and Information
13.
Very high frequency
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Very high frequency is the ITU designation for the range of radio frequency electromagnetic waves from 30 MHz to 300 MHz, with corresponding wavelengths of ten to one meters. Frequencies immediately below VHF are denoted high frequency, and the higher frequencies are known as ultra high frequency. Air traffic control communications and air navigation systems work at distances of 100 kilometres or more to aircraft at cruising altitude, some older DVB-T receivers included channels E2 to E4 but newer ones only go down to channel E5. VHF propagation characteristics are suited for terrestrial communication, with a range generally somewhat farther than line-of-sight from the transmitter. VHF waves are restricted to the radio horizon less than 100 miles. VHF is less affected by noise and interference from electrical equipment than lower frequencies. Unlike high frequencies, the ionosphere does not usually reflect VHF waves, the distance to the radio horizon is slightly extended over the geometric line of sight to the horizon, as radio waves are weakly bent back toward the Earth by the atmosphere. These approximations are only valid for antennas at heights that are compared to the radius of the Earth. They may not necessarily be accurate in mountainous areas, since the landscape may not be transparent enough for radio waves, in engineered communications systems, more complex calculations are required to assess the probable coverage area of a proposed transmitter station. The accuracy of calculations for digital TV signals is being debated. Portable radios usually use whips or rubber ducky antennas, while base stations usually use larger fiberglass whips or collinear arrays of vertical dipoles, for directional antennas, the Yagi antenna is the most widely used as a high gain or beam antenna. For television reception, the Yagi is used, as well as the log periodic antenna due to its wider bandwidth, helical and turnstile antennas are used for satellite communication since they employ circular polarization. For even higher gain, multiple Yagis or helicals can be mounted together to make array antennas, vertical collinear arrays of dipoles can be used to make high gain omnidirectional antennas, in which more of the antennas power is radiated in horizontal directions. Television and FM broadcasting stations use arrays of specialized dipole antennas such as batwing antennas. Certain subparts of the VHF band have the same use around the world, some national uses are detailed below. 108–118 MHz, Air navigation beacons VOR and Instrument Landing System localiser, 118–137 MHz, Airband for air traffic control, AM,121.5 MHz is emergency frequency 144–146 MHz, Amateur radio. Other capital cities and regional areas used a combination of these, the initial commercial services in Hobart and Darwin were respectively allocated channels 6 and 8 rather than 7 or 9. By the early 1960s it became apparent that the 10 VHF channels were insufficient to support the growth of television services and this was rectified by the addition of three additional frequencies—channels 0, 5A and 11
14.
405-line television system
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The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting. It was introduced with the BBC Television Service in 1936, suspended for the duration of World War II and it was also used between 1961 and 1982 in Ireland, as well as from 1957 to 1973 for the Rediffusion Television cable service in Hong Kong. Sometimes called the Marconi-EMI system, it was developed in 1934 by the EMI Research Team led by Sir Isaac Shoenberg, the figure of 405 lines had been chosen following discussions over Sunday lunch at the home of Alan Blumlein. The system used interlacing, EMI had been experimenting with a 243 line all-electronic interlaced system since 1933, in the 405 system the scanning lines were broadcast in two complementary fields,50 times per second, creating 25 frames per second. At the time of its introduction the 405-line system was referred to as high definition, in 1934 the British government set up a committee to advise on the future of TV broadcasting. The committee recommended that a high service to be run by the BBC be established. The recommendation was accepted and tenders were sought from industry, two tenders were received, one from the Baird company offering a 240 line mechanical system, and the other from EMI offering a 405-line all-electronic one. The Television Committee advised that they were unable to choose between the two systems and that both tenders should be accepted, the two systems to be run together for an experimental period and this became the standard for all British TV broadcasts until the 1960s. It soon became apparent that television reception was also well outside the original intended service area. A few minutes of programming were recorded on 16 mm movie film and this is now considered to be the only surviving example of pre-war, live British television. The BBC temporarily ceased transmissions on 1 September 1939, the day of the German invasion of Poland, in 1954 the BBC lost its monopoly of the British television market, and the following year the commercial network ITV, comprising a consortium of regional companies, was launched. In 1964 the BBC launched its BBC2 service on UHF using only a 625-line system, the introduction of colour on BBC2 in 1967 necessitated an even more complex dual-standard set to receive all three channels. In November 1969 BBC1 and ITV also started broadcasting in 625-line PAL colour on UHF, as their programming was now entirely produced using the new standard, the 405-line broadcasts served only as a rebroadcast in monochrome for people who did not have the newer receivers. Thereafter, receivers were of a single standard design which could not receive the legacy 405 line transmissions. The last 405-line transmissions were seen on 3 January 1985, in Scotland and this left only the UHF PAL system in operation in the UK. The frequencies used by the 405-line system were left empty. This was because people in these areas already had 405-line sets for receiving UK broadcasts from Wales or Northern Ireland. Telefís Éireanns primary standard was 625-line which began in the summer of 1962, the service of 405-line system ended in 1973, replaced by 625-line PAL system free-to-air broadcast
15.
Croydon transmitting station
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The Croydon transmitting station is a broadcasting and telecommunications facility on Beulah Hill in Upper Norwood, London, England, in the London Borough of Croydon, owned by Arqiva. It was established in 1955 and initially used a lattice tower. The present tower is 152 metres high and was built in 1962 and it was originally used to broadcast the London ITV signal on VHF Band III. When UHF broadcasting began, the nearby Crystal Palace transmitting station was used and it carried Channel 5s analogue signal, and the digital terrestrial signal is transmitted from Crystal Palace. Croydon also had reserve transmitters for BBC1, BBC2, ITV and Channel 4, the site is also a maintenance base for transmitter maintenance teams and used to house one of four Regional Operations Centres. The past ITV franchises which originally served London were Associated-Rediffusion and Associated Television began transmitting on VHF9 on 22 September 1955, the transmitters power was originally 60 kW but after the new tower was built in 1962 this was increased to 400 kW. Thames Television and London Weekend Television took over the London franchise area in 1968, the VHF analogue service closed down, along with the rest of the UK, on 3 January 1985. Channel 5 launched on 30 March 1997 with transmissions from Croydon, backup for ITV and Channel 4 was later added in case they were not available from Crystal Palace and some time later, BBC1 and BBC2. Since 18 April 2012, no television has been broadcast from Croydon, however, backup for the PSB1,2 and 3 and COM4,5 and 6 multiplexes are available should there be a problem at Crystal Palace. Wrotham transmitting station, Brookmans Park transmitting station and Droitwich transmitting station - the main radio transmitters serving London on VHF, mediumwave and longwave respectively
16.
ITV (TV network)
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ITV is a commercial TV network in the United Kingdom. Since the passing of the Broadcasting Act 1990 its legal name has been Channel 3, to distinguish it from the analogue channels at the time, namely BBC1, BBC2. ITV is a network of channels that operate regional television services as well as sharing programmes between each other to be displayed on the entire network. In recent years, several of companies have merged so currently the fifteen franchises are in the hands of two companies. With the exception of Northern Ireland, the ITV brand is the used by ITV plc for the Channel 3 service in these areas. In Northern Ireland, ITV plc uses the brand name UTV, STV Group plc, uses the STV brand for its two franchises of central and northern Scotland. The origins of ITV lie in the passing of the Television Act 1954, the act created the Independent Television Authority to heavily regulate the industry and to award franchises. The first six franchises were awarded in 1954 for London, the Midlands, the first ITV network to launch was Londons Associated-Rediffusion on 22 September 1955, with the Midlands and North services launching in February 1956 and May 1956 respectively. Following these launches, the ITA awarded more franchises until the country was covered by fourteen regional stations. Following the 1993 changes, ITV as a network began to consolidate with several companies doing so to save money by ceasing the duplication of services present when they were all separate companies. The ITV Network is not owned or operated by one company, since 2016 the fifteen licences are held by two companies, with the majority held by ITV Broadcasting Limited, part of ITV plc. The network is regulated by the media regulator Ofcom who is responsible for awarding the broadcast licences, the last major review of the Channel 3 franchises was in 1991, with all operators licences having been renewed between 1999 and 2002 and again from 2014 without a further contest. However, due to amalgamation of several of companies since the creation of ITV Network Limited. Approved by Ofcom, this results in ITV plc commissioning and funding the network schedule, all licensees have the right to opt out of network programming, however many do not due to pressures from the parent company or because of limited resources. The network also needs to produce accessible output containing subtitles, signing, in exchange for this programming, the ITV network is available on all platforms free to air and can be found at the top of the EPG of all providers. Since the launch of the platform in 1998, all of the ITV licensees have received gifted capacity on the terrestrial television platform. At present, the companies are able to broadcast additional channels and all choose to broadcast the ITV plc owned ITV2, ITV3, ITV4 and CITV in their region. UTV and STV previously broadcast their own services – UTV2 in Northern Ireland and S2 in central and northern Scotland – until 2002, the broadcasters all make use of the Digital 3&4 multiplex, shared with Channel 4
17.
Ultra high frequency
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Ultra high frequency is the ITU designation for radio frequencies in the range between 300 MHz and 3 GHz, also known as the decimetre band as the wavelengths range from one meter to one decimetre. Radio waves with frequencies above the UHF band fall into the 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, the IEEE defines the UHF radar band as frequencies between 300 MHz and 1 GHz. Two other IEEE radar bands overlap the ITU UHF band, the L band between 1 and 2 GHz and the S band between 2 and 4 GHz. Radio waves in the UHF band travel almost entirely by propagation and ground reflection, there is very little reflection from the ionosphere. They are blocked by hills and cannot travel far beyond the horizon, atmospheric moisture reduces, or attenuates, the strength of UHF signals over long distances, and the attenuation increases with frequency. UHF TV signals are generally more degraded by moisture than lower bands, occasionally when conditions are right, UHF radio waves can travel long distances by tropospheric ducting as the atmosphere warms and cools throughout the day. The length of an antenna is related to the length of the radio waves used, the UHF antenna is stubby and short, at UHF frequencies a quarter-wave monopole, the most common omnidirectional antenna is between 2.5 and 25 cm long for example. UHF is widely used in telephones, cell phones, walkie-talkies and other two-way radio systems from short range up to the visual horizon. Their transmissions do not travel far, allowing frequency reuse, public safety, business communications and personal radio services such as GMRS, PMR446, and UHF CB are often found on UHF frequencies as well as IEEE802.11 wireless LANs. The widely adapted GSM and UMTS cellular networks use UHF cellular frequencies, radio repeaters are used to retransmit UHF signals when a distance greater than the line of sight is required. Omnidirectional UHF antennas used on mobile devices are usually short whips, higher gain omnidirectional UHF antennas can be made of collinear arrays of dipoles and are used for mobile base stations and cellular base station antennas. The short wavelengths also allow high gain antennas to be conveniently small, high gain antennas for point-to-point communication links and UHF television reception are usually Yagi, log periodic, corner reflectors, or reflective array antennas. At the top end of the band slot antennas and parabolic dishes become practical, for television broadcasting specialized vertical radiators that are mostly modifications of the slot antenna or helical antenna are used, the slotted cylinder, zig-zag, and panel antennas. UHF television broadcasting fulfilled the demand for additional over-the-air television channels in urban areas, today, much of the bandwidth has been reallocated to land mobile, trunked radio and mobile telephone use. UHF channels are used for digital television. UHF spectrum is used worldwide for mobile radio systems for commercial, industrial, public safety. Many personal radio services use frequencies allocated in the UHF band, major telecommunications providers have deployed voice and data cellular networks in UHF/VHF range
18.
BBC One
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BBC One is the flagship television channel of the British Broadcasting Corporation in the United Kingdom, Isle of Man and Channel Islands. It was launched on 2 November 1936 as the BBC Television Service and it was renamed BBC TV in 1960, using this name until the launch of sister channel BBC2 in 1964, whereupon the BBC TV channel became known as BBC1, with the current spelling adopted in 1997. The channels annual budget for 2012–13 is £1.14 billion, the channel is funded by the television licence fee together with the BBCs other domestic television stations, and therefore shows uninterrupted programming without commercial advertising. It is currently the most watched channel in the United Kingdom, ahead of its traditional rival for ratings leadership. As of June 2013 the channel controller for BBC One is Charlotte Moore, the BBC began its own regular television programming from the basement of Broadcasting House, London, on 22 August 1932. BBC Television returned on 7 June 1946 at 15,00, Jasmine Bligh, one of the original announcers, made the first announcement, saying, Good afternoon everybody. Do you remember me, Jasmine Bligh, the Mickey Mouse cartoon of 1939 was repeated twenty minutes later. The competition quickly forced the channel to change its identity and priorities following a reduction in its audience. The 1962 Pilkington Report on the future of broadcasting noticed this, and it therefore decided that Britains third television station should be awarded to the BBC. The station, renamed BBC TV in 1960, became BBC1 when BBC2 was launched on 20 April 1964 transmitting an incompatible 625-line image on UHF. The only way to all channels was to use a complex dual-standard 405- and 625-line, VHF and UHF, receiver. Old 405-line-only sets became obsolete in 1985, when transmission in the standard ended, although standards converters have become available for enthusiasts who collect, BBC1 was based at the purpose-built BBC Television Centre at White City, London between 1960 and 2013. In the weeks leading up to 15 November 1969, BBC1 unofficially transmitted the occasional programme in its new colour system, to test it. At midnight on 15 November, simultaneously with ITV and two years after BBC2, BBC1 officially began 625-line PAL colour programming on UHF with a broadcast of a concert by Petula Clark, colour transmissions could be received on monochrome 625-line sets until the end of analogue broadcasting. In terms of share, the most successful period for BBC1 was under Bryan Cowgill between 1973 and 1977, when the channel achieved an average audience share of 45%. On 30 December 1980, the BBC announced their intention to introduce a new breakfast television service to compete with TV-am. On 17 January 1983, the first edition of Breakfast Time was shown on BBC One, becoming the first UK wide breakfast television service and continued to lead in the rating until 1984. The first major overhaul was to axe the deeply unpopular Sixty Minutes current affairs programme and its replacement was the BBC Six OClock News, a straight new programme in a bid to shore up its failing early evening slot
19.
BBC Two
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BBC Two is the second television channel operated by the British Broadcasting Corporation in the United Kingdom, Isle of Man and Channel Islands. It covers a range of subject matter, but tending towards more highbrow programmes than the more mainstream. Like the BBCs other domestic TV and radio channels, it is funded by the television licence and it is a comparatively well-funded public service network, regularly attaining a much higher audience share than most public service networks worldwide. Originally styled BBC2, it was the third British television station to be launched, a high-definition version of the channel launched on 26 March 2013, replacing BBC HD. British television at the time of BBC2s launch consisted of two channels, the BBC Television Service and the ITV network made up of regional companies. Both channels had existed in a state of competition since ITVs launch in 1955, the 1962 Pilkington Report on the future of broadcasting noticed this, and that ITV lacked any serious programming. It therefore decided that Britains third television station should be awarded to the BBC, prior to its launch, the new BBC2 was promoted on the BBC Television Service, the soon to be renamed BBC1. The animated adverts featured the campaign mascots Hullabaloo, a mother kangaroo, however, at around 18,45 a huge power failure, originating from a fire at Battersea Power Station, caused Television Centre, and indeed much of west London, to lose all power. BBC1 was able to continue broadcasting via its facilities at Alexandra Palace, associated-Rediffusion, the London weekday ITV franchise-holder, offered to transmit on the BBCs behalf, but their gesture was rejected. At 22,00 programming was officially postponed until the following morning, there was believed to be no recording made of this bulletin, but a videotape was discovered in early 2003. By 11,00 on 21 April, power had restored to the studios and programming began. The launch schedule, postponed from the night before, was successfully shown that evening. In reference to the cut, the transmission opened with a shot of a lit candle which was then sarcastically blown out by presenter Denis Tuohy. To establish the new identity and draw viewers to it. The production chosen was The Forsyte Saga, a adaptation of the novels by John Galsworthy, featuring well-established actors Kenneth More. Unlike BBC1 and ITV, BBC2 was broadcast only on the 625 line UHF system and this created a market for dual standard receivers which could switch between the two systems. On 1 July 1967, during the Wimbledon Championships, BBC2 became the first channel in Europe to begin broadcasts in colour. The thirteen part series Civilisation was created as a celebration of two millennia of western art and culture to showpiece the new colour technology, BBC1 and ITV later joined BBC2 on 625-line UHF band, but continued to simulcast on 405-line VHF until 1985
20.
ITV (TV channel)
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ITV is a commercial television channel in the United Kingdom. Previously a network of regional television channels, ITV currently operates in England, Wales, Scotland, the Isle of Man. From 2001 until 2013, the channel was called ITV1, in 2004, Granada Television acquired Carlton Communications to form ITV plc. ITV is the biggest and most popular television channel in the United Kingdom. ITV and its channels have contended with BBC One for the status of the UKs most watched television channel since the 1950s. However, in line with other channels, ITVs audience share has fallen in the era of multi-channel television. Following the creation of the Television Act 1954, the establishment of a television service in the UK began. The Independent Television service, or ITV, was made up of regions, the three largest regions were subdivided into weekday and weekend services, with a different company running each. ITV existed in a form from its inception to the 2000s. ITV1 became the generic brand name used by the twelve franchises of the ITV Network in the United Kingdom. The brand was introduced in 2001 by Carlton- and Granada-owned franchises, however, it became the sole on-air identity in 2002 when the two companies decided to create a single unified playout of the channel, with regional references only used prior to regional programming. Carlton and Granada went on to merge in 2004, creating ITV plc which now owns thirteen of the fifteen regional ITV licences. The ITV1 name was used in England, Wales, Southern Scotland and Isle of Man until Channel Television adopted the name in January 2006. It should be noted, however, that as national continuity is used on Channel Television. ITV Wales & West was the exception, using the name ITV1 Wales at all times for the Welsh part of its broadcast area as it has a higher regional commitment. Latterly the ITV1 Wales name was used on breakbumpers and regionally advertised programmes till 2013. Non ITV plc-owned licencees on the network generally did not refer to the ITV name, the network production arms of the ITV-plc owned licencees have been gradually combined since 1993 to eventually form ITV Studios. ITV was formed by the unification of eleven of the ITV licences, the Broadcasting Act 1990 changed many of the rules regulating the ITV Network, which most notably relaxed franchise ownership and hours of production
21.
Channel 4
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Channel 4 is a British public-service television broadcaster that began transmission on 2 November 1982. With the conversion of the Wenvoe transmitter group in Wales to digital on 31 March 2010, before Channel 4 and S4C, Britain had three terrestrial television services, BBC1, BBC2, and ITV. The Broadcasting Act 1980 began the process of adding a fourth, after some months of test broadcasts, it began scheduled transmissions on 2 November 1982. Indeed, television sets throughout the 1970s and early 1980s had a spare channel called ITV/IBA2. It was most likely politics which had the biggest impact in leading to a delay of almost three decades before the commercial channel became a reality. The campaign was taken so seriously by Gwynfor Evans, former president of Plaid Cymru, the result was that Channel 4 as seen by the rest of the United Kingdom would be replaced in Wales by Sianel Pedwar Cymru. Operated by a specially created authority, S4C would air programmes in Welsh made by HTV, since then, carriage on digital cable, satellite and digital terrestrial has introduced Channel 4 to Welsh homes where it is now universally available. The first programme to air on the channel was the game show Countdown. The first person to be seen on Channel 4 was Richard Whiteley with Ted Moult being the second, the first woman on the channel, contrary to popular belief, was not Carol Vorderman and was a lexicographer only ever identified as Mary. Whiteley opened the show with the words, On its first day, Channel 4 also broadcast controversial soap opera Brookside, which ran until 2003. On its launch, Channel 4 committed itself to providing an alternative to the existing channels, Channel 4 co-commissioned Robert Ashleys ground-breaking television opera Perfect Lives, which it premiered over several episodes in 1984. The channel often did not receive mass audiences for much of period, however. Channel 4 for many years had a poorer quality signal compared to other channels, Channel 4 also began the funding of independent films, such as the Merchant-Ivory docudrama The Courtesans of Bombay, during this time. In 1992, Channel 4 also faced its first libel case by Jani Allan, a South African journalist, who objected to her representation in the documentary The Leader, His Driver and the Drivers Wife. After control of the station passed from the Channel Four Television Company to the Channel Four Television Corporation in 1993, instead of aiming for the fringes of society, it began to focus on the edges of the mainstream, and the centre of the mass market itself. It began to show many US programmes in peak viewing time and it gave such shows as Friends and ER their UK premières. In the early 2000s, Channel 4 began broadcasting reality formats such as Big Brother and obtained the rights to broadcast mass appeal sporting events like cricket and this new direction increased ratings and revenues. In addition, the corporation launched a number of new channels through its new 4Ventures offshoot, including Film4, At the Races, E4
22.
Effective radiated power
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Effective radiated power, synonymous with equivalent radiated power, is an IEEE standardized definition of directional radio frequency power transmitted from a theoretical half-wave dipole antenna. It is differentiated from effective isotropic radiated power mainly by use of antenna gain instead of absolute gain in the calculation. The term antenna gain is assumed to be absolute unless specifically stated to be relative, the gain is then multiplied by the power actually accepted by the antenna to result in the actual ERP value. Power losses which occur prior to the antenna, e. g. in the line or from inefficiency in the generator itself are therefore not included in the calculation of ERP or EIRP. Antenna gain is closely related to directivity and often used interchangeably. However, gain is less than directivity by a factor called radiation efficiency. Whereas directivity is entirely a function of wavelength and the geometry and type of antenna, specifically, accelerating charge causes electromagnetic radiation per Maxwells equations. Therefore, antennas use a current distribution on radiating elements to generate electromagnetic energy that propagates away from the antenna and this coupling is never 100% efficient, and therefore antenna gain will always be less than directivity by this efficiency factor. The receiver would not be able to determine a difference, maximum directivity of an ideal half-wave dipole is a constant, i. e.0 dBd =2.15 dBi. Therefore, ERP is always 2.15 dB less than EIRP, the ideal dipole antenna could be further replaced by an isotropic radiator, and the receiver cannot know the difference so long as the input power is increased by 2.15 dB. Unfortunately, the distinction between dBd and dBi is often left unstated and the reader is forced to infer which was used. For example, a Yagi-Uda antenna is constructed from several dipoles arranged at intervals to create better energy focusing than a simple dipole. Since it is constructed from dipoles, often its antenna gain is expressed in dBd, obviously this ambiguity is undesirable with respect to engineering specifications. A Yagi-Uda antennas maximum directivity is 8.77 dBd =10.92 dBi and its gain necessarily must be less than this by the factor η, which must be negative in units of dB. Neither ERP nor EIRP can be calculated without knowledge of the power accepted by the antenna, let us assume a 100 Watt transmitter with losses of 6 dB prior to the antenna. ERP <22. 77dBW and EIRP <24. 92dBW, polarization has not been taken into account so far, but properly it must be. When considering the dipole radiator previously we assumed that it was aligned with the receiver. Now assume, however, that the antenna is circularly polarized
23.
Digital terrestrial television
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Digital terrestrial television is a technological evolution of broadcast television and an advancement over analog television. A terrestrial implementation of digital television uses a aerial to broadcast to a conventional television antenna instead of a satellite dish or cable television connection. The amount of data that can be transmitted is directly affected by channel capacity, the modulation method in DVB-T is COFDM with either 64 or 16-state Quadrature Amplitude Modulation. In general, a 64QAM channel is capable of transmitting a bit rate. 16 and 64QAM constellations can be combined in a single multiplex, the DVB-T standard is not used for terrestrial digital television in North America. Instead, the ATSC standard calls for 8VSB modulation, which has similar characteristics to the vestigial sideband modulation used for analog television. This provides considerably more immunity to interference, but is not immune — as DVB-T is — to multipath distortion, both systems use the MPEG transport stream and H. 262/MPEG-2 Part 2 video codec specified in MPEG-2, they differ significantly in how related services are encoded. DTTV is received either via a digital set-top box, TV gateway or integrated tuner included with television sets, some set-top-boxes and TV gateways include digital video recorder functionality. This is quite common in the UK, see external links, indoor aerials are even more likely to be affected by these issues and possibly need replacing. Main articles, List of digital television deployments by country, Digital television transition Afghanistan started digital transmissions in MPEG-4 on Sunday,31 August 2014, Afghanistan adopted DVB-T2 system for digital television. India adopted DVB-T system for television in July 1999. The first DVB-T transmission was started on 26 January 2003 in the four metropolitan cities by Doordarshan. Currently the terrestrial transmission is available in digital and analog formats. 4 high power DVB-T transmitters were set up in the top 4 cities, an additional 190 high power, and 400 low power DVB-T2 transmitters have been approved for Tier I, II and III cities of the country by 2017. The Indian telecom regulator, TRAI, had recommended the I&B to allow private broadcast companies to use the DTT technology, so far, the Indian I&B ministry only permits private broadcast companies to use satellite, cable and IPTV based systems. Israel started digital transmissions in MPEG-4 on Sunday,2 August 2009, Israel was the first nation in the Middle East and the first non-European nation to shut down its analogue TV distribution system. The new service which is operated by the Second Authority for Radio, according to government decisions, the system will expand to include two additional multiplexes that will carry new channels and HD versions of the existing channels. In this matter nothing has been decided upon until the end on 2012, on 20 March 2013 it was announced that Thomson Broadcast had won a major contract with The Second Authority for Television and Radio for the extension of its nationwide DVB-T/DVB-T2 network
24.
Decibel
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The decibel is a logarithmic unit used to express the ratio of two values of a physical quantity. One of these values is often a reference value, in which case the decibel is used to express the level of the other value relative to this reference. When used in way, the decibel symbol is often qualified with a suffix that indicates the reference quantity that has been used or some other property of the quantity being measured. For example, dBm indicates a power of one milliwatt. There are two different scales used when expressing a ratio in decibels depending on the nature of the quantities, when expressing power quantities, the number of decibels is ten times the logarithm to base 10 of the ratio of two power quantities. That is, a change in power by a factor of 10 corresponds to a 10 dB change in level, when expressing field quantities, a change in amplitude by a factor of 10 corresponds to a 20 dB change in level. The difference in scales relates to the square law of fields in three-dimensional linear space. The decibel scales differ so that comparisons can be made between related power and field quantities when they are expressed in decibels. The definition of the decibel is based on the measurement of power in telephony of the early 20th century in the Bell System in the United States. One decibel is one tenth of one bel, named in honor of Alexander Graham Bell, however, today, the decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory. In electronics, the gains of amplifiers, attenuation of signals, the decibel originates from methods used to quantify signal loss in telegraph and telephone circuits. The unit for loss was originally Miles of Standard Cable, the standard telephone cable implied was a cable having uniformly distributed resistance of 88 ohms per loop mile and uniformly distributed shunt capacitance of 0.054 microfarad per mile. 1 TU was defined such that the number of TUs was ten times the logarithm of the ratio of measured power to a reference power level. The definition was conveniently chosen such that 1 TU approximated 1 MSC, in 1928, the Bell system renamed the TU into the decibel, being one tenth of a newly defined unit for the base-10 logarithm of the power ratio. It was named the bel, in honor of the telecommunications pioneer Alexander Graham Bell, the bel is seldom used, as the decibel was the proposed working unit. However, the decibel is recognized by international bodies such as the International Electrotechnical Commission. The term field quantity is deprecated by ISO 80000-1, which favors root-power, in spite of their widespread use, suffixes are not recognized by the IEC or ISO. The ISO Standard 80000-3,2006 defines the following quantities, the decibel is one-tenth of a bel,1 dB =0.1 B
25.
FM broadcasting
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FM broadcasting is a method of radio broadcasting using frequency modulation technology. Invented in 1933 by American engineer Edwin Armstrong, it is used worldwide to provide high-fidelity sound over broadcast radio, FM broadcasting is capable of better sound quality than AM broadcasting, the chief competing radio broadcasting technology, so it is used for most music broadcasts. FM radio stations use the VHF frequencies, the term FM band describes the frequency band in a given country which is dedicated to FM broadcasting. Throughout the world, the FM broadcast band falls within the VHF part of the radio spectrum. Usually 87.5 to 108.0 MHz is used, or some portion thereof, with few exceptions, In the former Soviet republics, and some former Eastern Bloc countries, assigned frequencies are at intervals of 30 kHz. This band, sometimes referred to as the OIRT band, is slowly being phased out in many countries, in those countries the 87. 5–108.0 MHz band is referred to as the CCIR band. In Japan, the band 76–95 MHz is used, the frequency of an FM broadcast station is usually an exact multiple of 100 kHz. In most of South Korea, the Americas, the Philippines, in some parts of Europe, Greenland and Africa, only even multiples are used. In the UK odd or even are used, in Italy, multiples of 50 kHz are used. There are other unusual and obsolete FM broadcasting standards in countries, including 1,10,30,74,500. Random noise has a triangular spectral distribution in an FM system and this can be offset, to a limited extent, by boosting the high frequencies before transmission and reducing them by a corresponding amount in the receiver. Reducing the high frequencies in the receiver also reduces the high-frequency noise. These processes of boosting and then reducing certain frequencies are known as pre-emphasis and de-emphasis, the amount of pre-emphasis and de-emphasis used is defined by the time constant of a simple RC filter circuit. In most of the world a 50 µs time constant is used, in the Americas and South Korea,75 µs is used. This applies to both mono and stereo transmissions, for stereo, pre-emphasis is applied to the left and right channels before multiplexing. They cannot be pre-emphasized as much because it would cause excessive deviation of the FM carrier, systems more modern than FM broadcasting tend to use either programme-dependent variable pre-emphasis, e. g. dbx in the BTSC TV sound system, or none at all. Long before FM stereo transmission was considered, FM multiplexing of other types of audio level information was experimented with. Edwin Armstrong who invented FM was the first to experiment with multiplexing and these original FM multiplex subcarriers were amplitude modulated
26.
BBC Radio London
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BBC Radio London is Londons BBC Local Radio station and part of the broader BBC London network. The station broadcasts across Greater London and beyond, on the 94.9 FM frequency, DAB, Virgin Media Channel 937, Sky Channel 0152, Freeview Channel 721 and online. The stations output is similar to that of other BBC Local Radio stations and targets a broad. Test transmissions for the new radio station were carried out from Wrotham, Kent, on 95.3 MHz in FM mono, relaying BBC Radio 1. On 6 October 1970 BBC Radio London was launched, three years before commercial radio for Greater London in the guise of LBC, an additional medium wave frequency was allocated on 1457 kHz from Brookmans Park. It took on a lively sound and featured extensive traffic reports, phone-in programmes — it pioneered the daily phone-in in the UK — and much contemporary. A phone-in programme, Sounding Brass, was pioneered, devised, listeners were invited to choose a Christmas carol or hymn while a Salvation Army brass band stood by in the studio to play their request live. It later moved to BBC Radio 2 and was presented by Gloria Hunniford, as soon as Independent Local Radio stations LBC and Capital Radio went on air, public attention to Radio London declined, with the station attempting to copy both. Tests for FM stereo began in 1981 with Music on the Move, the FM transmitter was shortly moved to Crystal Palace. This coincided with the relaunch in 1981, which saw the station take on a style that was softer than BBC Radio 2 - a station predominantly playing easy listening music. Music ranged from contemporary pop, such as The Carpenters. This move was unpopular with employed staff, who thought it very un-hip, however, the relaunch led to improved audience figures and a string of awards and accolades. The programmes title was changed to Black London shortly before Radio London closed and it was revived for a short time in 2003, with Pascall returning as presenter. The forerunner to the BBC Asian Network was a hugely popular Asian programme, London Sounds Eastern, pandit Ravi Shankar, Indian pop star Usha Uthup, were among those interviewed for London Sounds Eastern, launched on BBC Radio London in 1976 and produced by Keith Yeomans. The programme introduced the Bollywood music of Asha Bhosle and Lata Mangeshkar to new London audiences, a programming relaunch in 1984 saw Radio London adopt the tagline The Heart and Soul of London, with more soul music being played during the day. He was sacked in 1988 crossing the line of taste and decency, regular Soul Night Outs were held initially in Kilburn but later in other venues, such as Ilford. This was where Dave Pearce, later of BBC Radio 1 fame, BBC Radio London closed on 7 October 1988. The final programme, just before its 18th birthday, was presented by Mike Sparrow, immediately after closedown at 7pm, test transmissions began for the next 17 days, preparing for a new radio station for London
27.
Radio X (United Kingdom)
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Radio X is a commercial radio station brand focused on alternative music, primarily indie rock, which is owned by Global Radio. Radio X launched nationally on 21 September 2015 as a rebrand of Xfm and superseded Xfm London, Xfm was created in London in 1992 by Sammy Jacob and Chris Parry. The station became full-time on 1 September 1997, during the following year the station played a range of music from its studios in 97 Charlotte Street, but mass appeal was thwarted by the lack of awareness due to an unsuccessful marketing campaign. Jacob would later go on to co-found NME Radio and CDNX in 2008 and 2015 respectively, in 1998, Xfm was acquired by the Capital Radio Group and was relocated from Charlotte Street to Capitals headquarters at Leicester Square, where Radio X remains based today. On 23 August of that year was closed down for four days, the station subsequently relaunched with a more mainstream format, and a new advert featuring a cartoon radio saying Dont be afraid. Which referred to the inaccessibility of its old format. The soft-rock revamp was not a success, culminating in listener-led protests outside the Capital Radio studios, following the take-over by Capital, the station became more male-orientated and featured football coverage and laddish output. This came to an end when the Radio Authority fined XFM £50,000 for breakfast presenter Tom Binnss joking about beastiality on air. This yielded good results for the station in a period in which it could boast growing listening figures and talent such as Zane Lowe, the music was, and is today, a play-listed mix of popular indie and soft rock. XFM has held 28-day Restricted Service Licence FM broadcasts in a number of British cities, including Manchester, Birmingham, Cardiff and Glasgow. It was at one point reported that this version of XFM London would have local content drop-ins within it over time. Most DAB coverage of XFM carried the London version of the station, in 2001, XFM rehired Ricky Gervais and Steve Merchant to run the Saturday afternoon show. Karl Pilkington joined them to just push the buttons but eventually became the point of the show. The trio often called the station a tin pot station, shoddy and not just a station in London. On 9 June 2005, the group was awarded a permanent FM broadcasting licence to serve the city of Manchester as XFM Manchester and this station went on air in March 2006. Also in 2005, XFM was among the bidders for the regional North East franchise on 97.5 FM, on 4 January 2006, GCap Media relaunched its Central Scotland regional station Beat 106 as XFM Scotland. In 2007, a fourth station joined the network with the launch of a new regional XFM for south Wales, on 6 March 2008 an announcement was made reversing the decision to remove daytime presenters. From 25 March 2008 a new schedule restoring daytime schedules was put in place, a new schedule was launched on 12 January 2009
28.
Capital XTRA
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Capital XTRA is an urban music radio station owned by Global Radio. It is anchored by an FM operation in London, and is also broadcast via DAB Digital Radio, Freesat, Sky, Virgin Media, Choice 96.9 began as an independent company in March 1990, broadcasting from studios in Trinity Gardens, Brixton. It was Britain’s first 24-hour black music station with a licence. The station was now broadcasting from Borough High Street, Borough, the move resulted in a community march from the coverage area and their studios. It was accused of selling out as some of their DJs were removed and replaced by their Kiss counterparts who play some electronic music, the DAB service also became a simulcast of the London station, with the demise of local drop-ins. Following their takeover of Choice, Capital Radio Group merged with GWR to form GCap Media in 2005, Choice was flagged up as one of the key brands of the new larger network, and the station was made available to digital TV viewers via its addition to Sky. GCap were subsequently taken over by Global Radio, who owned the Galaxy Network of dance/urban music stations. Despite the separate music format and branding, Choice was marketed to advertisers as part of the Galaxy network for package advertising deals, in 2010 Global Radio announced that the Galaxy network stations would be networked with 95.8 Capital FM, leaving Choice as a standalone brand again. On 3 October 2013, Global announced that Choice would be rebranded as Capital Xtra on 7 October, Capital Xtra reaches 680,000 listeners in London alone. Supporting Global Radios commitment to a Social Responsibility programme, Choice FM promoted social action campaigns, I Have a Choice and I Have a Choice - Music Potential. As of September 2016, schedule changes meant the departure of presenters E-Plus, Steve Clarke and DJ Woody, ras Kwame also lost his Tuesday-Friday 12-3am Midnight Mix slot and now only presents The Reggae Recipe from 12-2am on Sunday night/Monday mornings. Weekend overnights are currently presenter free, list of radio stations in the United Kingdom Official website
29.
Absolute Radio
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Absolute Radio is one of the UKs three Independent National Radio stations. The station rebranded to its current name at 7,45 am on 29 September 2008, the station is based in London and plays popular rock music. It currently broadcasts on medium wave and DAB across the UK, on 105.8 FM in London and 105.2 FM in the West Midlands, Sky, Virgin Media, Freeview and Freesat. It is also available in parts of the world via satellite, cable. As of 31 December 2013, international streaming via the internet has been discontinued, Absolute Radio is a patron of The Radio Academy. Absolute Radio is owned and operated by Bauer Radio of Hamburg based Bauer Media Group, the 1990 Broadcasting Act allowed for the launch of independent national radio stations in the United Kingdom. The Radio Authority was mandated to award three INR licences, one of which had to be for a station, and one of which had to be for a predominantly speech-based service. The remaining licence was to be open to all-comers, the licences were to be awarded to the highest cash bidder, providing that the applicant met criteria set down in the Broadcasting Act. The second national licence, INR2, would take over the 1197 kHz and 1215 kHz frequencies, later that year, TV-am lost its ITV license and its stake in the radio station was sold in March 1993 to Apax Partners, JP Morgan Investment Corporation and Sir David Frost. The station launched as Virgin 1215 at 12.15 pm on 30 April 1993, the original line-up of DJs included Richard Skinner, Russ Williams, Jono Coleman, Mitch Johnson, Graham Dene, Nick Abbot, Wendy Lloyd, Tommy Rivers, Emperor Rosko and Dave Fanning. Chris Evans was also hired to present a Saturday morning show, the Show, The Big Red Mug Show was sponsored by Nescafe. The first song was a version of the Steppenwolf song Born to be Wild. Richard Branson was the first voice to be heard, live from the Virgin Megastore in Manchester, Skinner was also Programme Director, a role he shared with John Revell. John Pearson, formerly Sales Director of LBC was launch Sales Director, andy Mollett was launch Finance Director. David Campbell, previously managing director of one of Virgins post-production television companies, was the executive at launch. From before its launch on AM, Virgin Radio was campaigning for a national FM network, Virgin Radio launched on 105.8 MHz FM in London on 10 April 1995 beginning with a message from broadcaster David Frost at 6 am followed by the Russ n’ Jono breakfast show. Part of the requirements for the London service meant that a daily London opt-out was broadcast on FM. Within a year, Virgin Group was considering the next steps for the station, including the option of a flotation or buying back the shares of JP Morgan, Apax
30.
Classic FM (UK)
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Classic FM is one of the United Kingdoms three Independent National Radio stations. Classic FM broadcasts nationally on FM, DAB digital radio, Freeview, satellite, in addition to playing older music, the station plays several modern film scores and video game music. The idea for a national, commercial FM network devoted to classical music originated with the management at GWR group and it had been operating a trial programme on its AM frequencies in Wiltshire and Bristol, testing audience reaction to a regular drive-time programme of popular classical music. It proved successful and the companys CEO, Ralph Bernard, and programme director, Michael Bukht, meanwhile, Brian Brolly, formerly the CEO of Andrew Lloyd Webbers Really Useful Group, had a similar idea in 1990. After failing to raise sufficient funds for the project Brollys consortium was approached by GWR Group, the UK Government had decided to award several new national radio licences and invited tenders. Brolly had brought the idea to Rick Senat, the head of business affairs in London for Warner Brothers. Initially rejected by Warner Brothers, Senat showed the project to the President of Time Warner International Broadcasting, Tom McGrath, Time Warner agreed to back the project but was prohibited under then current UK law from owning more than a 25% interest. GWR created a plan which was supported by its major shareholder. An internal dispute over ownership of the licence was resolved and the consortium was completed after Time Warner agreed to back GWRs plans for the station. The founding shareholder group that launched Classic FM was Sir Peter Michael and Time Warner, GWR, DMGT (5%, the Radio Authority had granted an exemption so that Time Warner could hold more than 25% provided a UK citizen/corporation was larger in the shareholding group. During the stations test transmissions between July and September 1992, Classic FM broadcast a continuous soundtrack of birds singing and other countryside sounds, the birdsong test transmissions attracted newspaper articles and comment prior to the stations launch. Consequently, the sound and style of the station was unknown until it launched at 6am on 7 September 1992 and this birdsong recording could later be heard on the temporary DAB station Birdsong, which replaced Oneword when it closed down. Global Radio, the UKs largest radio ownership group, now owns the station. Classic FM has broadcast from its current studios on the floor of 30 Leicester Square, central London. The first programme to be broadcast live from there was Mark Griffiths programme on Sunday,26 March 2006, Classic FMs Hall of Fame is broadcast annually over the four days of the Easter weekend. First broadcast in 1996 the show counts down the 300 most-popular pieces as voted for by listeners, the number one spot was occupied until 2001 by Max Bruchs Violin Concerto No. 1, and then by Rachmaninoffs Piano Concerto No.2, in 2006 the top spot was taken by Mozarts Clarinet Concerto. From 2007 to 2010, the top place on the Hall of Fame was taken by Ralph Vaughan Williams The Lark Ascending
31.
Medium wave
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Medium wave is the part of the medium frequency radio band used mainly for AM radio broadcasting. Practical groundwave reception typically extends to 200–300 miles, with distances over terrain with higher ground conductivity. Most broadcast stations use groundwave to cover their listening area, Medium waves can also reflect off charged particle layers in the ionosphere and return to Earth at much greater distances, this is called the skywave. At night, especially in winter months and at times of low solar activity, when this happens, MF radio waves can easily be received many hundreds or even thousands of miles away as the signal will be reflected by the higher F layer. This can allow very long-distance broadcasting, but can also interfere with distant local stations, due to the limited number of available channels in the MW broadcast band, the same frequencies are re-allocated to different broadcasting stations several hundred miles apart. On nights of good skywave propagation, the signals of distant station may interfere with the signals of local stations on the same frequency. These channels are called clear channels, and they are required to broadcast at higher powers of 10 to 50 kW and this arrangement had numerous practical difficulties. The Commerce Department rarely intervened in such cases but left it up to stations to enter into voluntary timesharing agreements amongst themselves, the addition of a third entertainment wavelength,400 meters, did little to solve this overcrowding. In 1923, the Commerce Department realized that as more and more stations were applying for commercial licenses, on 15 May 1923, Commerce Secretary Herbert Hoover announced a new bandplan which set aside 81 frequencies, in 10 kHz steps, from 550 kHz to 1350 kHz. Each station would be assigned one frequency, no longer having to broadcast weather, class A and B stations were segregated into sub-bands. Today in most of the Americas, mediumwave broadcast stations are separated by 10 kHz and have two sidebands of up to ±5 kHz in theory, in the rest of the world, the separation is 9 kHz, with sidebands of ±4.5 kHz. Both provide adequate quality for voice, but are insufficient for high-fidelity broadcasting. In the US and Canada the maximum power is restricted to 50 kilowatts. Those stations which shut down completely at night are known as daytimers. In most cases there are two limits, a lower one for omnidirectional and a higher one for directional radiation with minima in certain directions. The power limit can also be depending on daytime and it is possible, other countries may only operate low-powered transmitters on the same frequency, again subject to agreement. For example, Russia operates a transmitter, located in its Kaliningrad exclave and used for external broadcasting. Due to the demand for frequencies in Europe, many countries operate single frequency networks, in Britain
32.
Hertz
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The hertz is the unit of frequency in the International System of Units and is defined as one cycle per second. It is named for Heinrich Rudolf Hertz, the first person to provide proof of the existence of electromagnetic waves. Hertz are commonly expressed in SI multiples kilohertz, megahertz, gigahertz, kilo means thousand, mega meaning million, giga meaning billion and tera for trillion. Some of the units most common uses are in the description of waves and musical tones, particularly those used in radio-. It is also used to describe the speeds at which computers, the hertz is equivalent to cycles per second, i. e. 1/second or s −1. In English, hertz is also used as the plural form, as an SI unit, Hz can be prefixed, commonly used multiples are kHz, MHz, GHz and THz. One hertz simply means one cycle per second,100 Hz means one hundred cycles per second, and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, the rate of aperiodic or stochastic events occur is expressed in reciprocal second or inverse second in general or, the specific case of radioactive decay, becquerels. Whereas 1 Hz is 1 cycle per second,1 Bq is 1 aperiodic radionuclide event per second, the conversion between a frequency f measured in hertz and an angular velocity ω measured in radians per second is ω =2 π f and f = ω2 π. This SI unit is named after Heinrich Hertz, as with every International System of Units unit named for a person, the first letter of its symbol is upper case. Note that degree Celsius conforms to this rule because the d is lowercase. — Based on The International System of Units, the hertz is named after the German physicist Heinrich Hertz, who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission in 1930, the term cycles per second was largely replaced by hertz by the 1970s. One hobby magazine, Electronics Illustrated, declared their intention to stick with the traditional kc. Mc. etc. units, sound is a traveling longitudinal wave which is an oscillation of pressure. Humans perceive frequency of waves as pitch. Each musical note corresponds to a frequency which can be measured in hertz. An infants ear is able to perceive frequencies ranging from 20 Hz to 20,000 Hz, the range of ultrasound, infrasound and other physical vibrations such as molecular and atomic vibrations extends from a few femtoHz into the terahertz range and beyond. Electromagnetic radiation is described by its frequency—the number of oscillations of the perpendicular electric and magnetic fields per second—expressed in hertz. Radio frequency radiation is measured in kilohertz, megahertz, or gigahertz
33.
BBC Radio 4
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BBC Radio 4 is a radio station owned and operated by the British Broadcasting Corporation that broadcasts a wide variety of spoken-word programmes including news, drama, comedy, science and history. It replaced the BBC Home Service in 1967, the station controller is Gwyneth Williams, and the station is part of BBC Radio and the BBC Radio department. The station is broadcast from the BBCs headquarters at Broadcasting House and it is also available through Freeview, Sky, Virgin Media and on the Internet. It is notable for its news bulletins and programmes such as Today and The World at One, BBC Radio 4 is the second most popular British domestic radio station by total hours, after Radio 2 – and the most popular in London and the South of England. It recorded its highest audience, of 11 million listeners, in May 2011 and was UK Radio Station of the Year at the 2003,2004 and 2008 Sony Radio Academy Awards and it also won a Peabody Award in 2002 for File On 4, Export Controls. Costing £71.4 million, it is the BBCs most expensive national radio network and is considered by many to be its flagship. There is no comparable British commercial network, Channel 4 abandoned plans to launch its own speech-based digital radio station in October 2008 as part of a £100m cost cutting review, in 2010 Gwyneth Williams replaced Mark Damazer as Radio 4 controller. Damazer became Master of St Peters College, Oxford, music and sport are the only fields that largely fall outside the stations remit. It broadcasts occasional concerts, and documentaries related to forms of both popular and classical music, and the long-running music-based Desert Island Discs. As a result, for around 70 days a year listeners have to rely on FM broadcasts or increasingly DAB for mainstream Radio 4 broadcasts – the number relying solely on long wave is now a small minority. The cricket broadcasts take precedence over on-the-hour news bulletins, but not the Shipping Forecast, as well as news and drama, the station has a strong reputation for comedy, including experimental and alternative comedy, many successful comedians and comedy shows first appearing on the station. The BBC Home Service was the predecessor of Radio 4 and broadcast between 1939 and 1967 and it had regional variations and was broadcast on medium wave with a network of VHF FM transmitters being added from 1955. Radio 4 replaced it on 30 September 1967, when the BBC renamed many of its radio stations. For a time during the 1970s Radio 4 carried regional news bulletins Monday to Saturday and these were broadcast twice at breakfast, at lunchtime and an evening bulletin was aired at 5. 55pm. There were also programme variations for the parts of England not served by BBC Local Radio stations and these included Roundabout East Anglia, a VHF opt-out of the Today programme broadcast from BBC Easts studios in Norwich each weekday from 6.45 am to 8.45 am. Roundabout East Anglia came to an end in 1980, when local services were introduced to East Anglia with the launch of BBC Radio Norfolk. All regional news bulletins broadcast from BBC regional news bases around England ended in August 1980 apart from in the south west, in September 1991 it was decided that the main Radio 4 service would be on FM as coverage had extended to cover almost all of the UK. Opt-outs were transferred to long wave, currently Test Match Special, extra shipping forecasts, The Daily Service, long wave very occasionally opts out at other times, such as to broadcast special services, the most recent being when Pope Benedict XVI visited Britain in 2010
34.
Kismat Radio
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Kismat Radio is a radio station broadcasting from the Crystal Palace Transmitter in south-east London. The target audience is British Asians and South Asian expats aged 30+, with programme formats comprising Asian Talk, the station can be heard on 1035 AM in London, DAB Digital Radio across Bradford and Huddersfield, it also broadcasts a live web stream from its website. The station was available on Sky channel 0173 until 20 March 2013. Kismat Radio is a part of the Sunrise Radio Group
35.
BBC
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The British Broadcasting Corporation is a British public service broadcaster. It is headquartered at Broadcasting House in London, the BBC is the worlds 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. The BBC is established under a Royal Charter and operates under its Agreement with the Secretary of State for Culture, Media and Sport. The fee is set by the British Government, agreed by Parliament, and used to fund the BBCs radio, TV, britains first live public broadcast from the Marconi factory in Chelmsford took place in June 1920. It was sponsored by the Daily Mails Lord Northcliffe and featured the famous Australian Soprano Dame Nellie Melba, the Melba broadcast caught the peoples imagination and marked a turning point in the British publics attitude to radio. However, this public enthusiasm was not shared in official circles where such broadcasts were held to interfere with important military and civil communications. By late 1920, pressure from these quarters and uneasiness among the staff of the licensing authority, the General Post Office, was sufficient to lead to a ban on further Chelmsford broadcasts. But by 1922, the GPO had received nearly 100 broadcast licence requests, John Reith, a Scottish Calvinist, was appointed its General Manager in December 1922 a few weeks after the company made its first official broadcast. The company was to be financed by a royalty on the sale of BBC wireless receiving sets from approved manufacturers, to this day, the BBC aims to follow the Reithian directive to inform, educate and entertain. The financial arrangements soon proved inadequate, set sales were disappointing as amateurs made their own receivers and listeners bought rival unlicensed sets. By mid-1923, discussions between the GPO and the BBC had become deadlocked and the Postmaster-General commissioned a review of broadcasting by the Sykes Committee and this was to be followed by a simple 10 shillings licence fee with no royalty once the wireless manufactures protection expired. The BBCs broadcasting monopoly was made explicit for the duration of its current broadcast licence, the BBC was also banned from presenting news bulletins before 19.00, and required to source all news from external wire services. Mid-1925 found the future of broadcasting under further consideration, this time by the Crawford committee, by now the BBC under Reiths leadership had forged a consensus favouring a continuation of the unified broadcasting service, but more money was still required to finance rapid expansion. Wireless manufacturers were anxious to exit the loss making consortium with Reith keen that the BBC be seen as a service rather than a commercial enterprise. The recommendations of the Crawford Committee were published in March the following year and were still under consideration by the GPO when the 1926 general strike broke out in May. The strike temporarily interrupted newspaper production and with restrictions on news bulletins waived the BBC suddenly became the source of news for the duration of the crisis. The crisis placed the BBC in a delicate position, the Government was divided on how to handle the BBC but ended up trusting Reith, whose opposition to the strike mirrored the PMs own
36.
Digital audio broadcasting
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Digital audio broadcasting is a digital radio standard for broadcasting digital audio radio services, used in several countries across Europe and Asia Pacific. The DAB standard was initiated as a European research project in the 1980s, the Norwegian Broadcasting Corporation launched the first DAB channel in the world on 1 June 1995, and the BBC and Swedish Radio launched their first DAB digital radio broadcasts in September 1995. DAB receivers have been available in many countries since the end of the 1990s, DAB may offer more radio programmes over a specific spectrum than analogue FM radio. Audio quality varies depending on the used and audio material. Most stations use a bit rate of 128 kbit/s or less with the MP2 audio codec, which requires 160 kbit/s to achieve perceived FM quality. 128 kbit/s gives better dynamic range or signal-to-noise ratio than FM radio, but a more smeared stereo image, however, CD quality sound with MP2 is possible with 256…192 kbps. An upgraded version of the system was released in February 2007, DAB is not forward compatible with DAB+, which means that DAB-only receivers are not able to receive DAB+ broadcasts. However, broadcasters can mix DAB and DAB+ programs inside the same transmission, DAB+ is approximately twice as efficient as DAB, and more robust. In spectrum management, the bands that are allocated for public DAB services, are abbreviated with T-DAB, where the T stands for terrestrial. More than 30 countries provide DAB transmissions, and several countries, such as Norway, UK, Australia, Italy, Malta, Switzerland, The Netherlands, in many countries it is expected that DAB will gradually replace FM radio. Norway was the first country to announce national FM radio analog switchoff starting from 2017, DAB has been under development since 1981 at the Institut für Rundfunktechnik. In 1985 the first DAB demonstrations were held at the WARC-ORB in Geneva, later DAB was developed as a research project for the European Union, which started in 1987 on initiative by a consortium formed in 1986. The MPEG-1 Audio Layer II codec was created as part of the EU147 project, a choice of audio codec, modulation and error-correction coding schemes and first trial broadcasts were made in 1990. Public demonstrations were made in 1993 in the United Kingdom, the protocol specification was finalized in 1993 and adopted by the ITU-R standardization body in 1994, the European community in 1995 and by ETSI in 1997. Pilot broadcasts were launched in countries in 1995. The UK was the first country to receive a range of radio stations via DAB. Commercial DAB receivers began to be sold in 1999 and over 50 commercial, the standard was coordinated by the European DAB forum, formed in 1995 and reconstituted to the World DAB Forum in 1997, which represents more than 30 countries. In 2006 the World DAB Forum became the World DMB Forum which now presides over both the DAB and DMB standard, in October 2005, the World DMB Forum instructed its Technical Committee to carry out the work needed to adopt the AAC+ audio codec and stronger error correction coding
37.
Multiplexing
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In telecommunications and computer networks, multiplexing is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share an expensive resource, for example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy in the 1870s, and is now applied in communications. In telephony, George Owen Squier is credited with the development of telephone carrier multiplexing in 1910, the multiplexed signal is transmitted over a communication channel such as a cable. The multiplexing divides the capacity of the channel into several logical channels. A reverse process, known as demultiplexing, extracts the original channels on the receiver end, a device that performs the multiplexing is called a multiplexer, and a device that performs the reverse process is called a demultiplexer. Multiple variable bit rate digital bit streams may be transferred efficiently over a fixed bandwidth channel by means of statistical multiplexing. This is an asynchronous mode time-domain multiplexing which is a form of time-division multiplexing, digital bit streams can be transferred over an analog channel by means of code-division multiplexing techniques such as frequency-hopping spread spectrum and direct-sequence spread spectrum. In wired communication, space-division multiplexing, also known as Space-division multiple access is the use of separate point-to-point electrical conductors for each transmitted channel, in wireless communication, space-division multiplexing is achieved with multiple antenna elements forming a phased array antenna. Examples are multiple-input and multiple-output, single-input and multiple-output and multiple-input and single-output multiplexing, different antennas would give different multi-path propagation signatures, making it possible for digital signal processing techniques to separate different signals from each other. These techniques may also be utilized for space diversity or beamforming rather than multiplexing Frequency-division multiplexing is inherently an analog technology, FDM achieves the combining of several signals into one medium by sending signals in several distinct frequency ranges over a single medium. In FDM the signals are electrical signals, one of the most common applications for FDM is traditional radio and television broadcasting from terrestrial, mobile or satellite stations, or cable television. Only one cable reaches a customers residential area, but the provider can send multiple television channels or signals simultaneously over that cable to all subscribers without interference. Receivers must tune to the frequency to access the desired signal. A variant technology, called wavelength-division multiplexing is used in optical communications, time-division multiplexing is a digital technology which uses time, instead of space or frequency, to separate the different data streams. TDM involves sequencing groups of a few bits or bytes from each individual input stream, one after the other, if done sufficiently quickly, the receiving devices will not detect that some of the circuit time was used to serve another logical communication path. Consider an application requiring four terminals at an airport to reach a central computer, each terminal communicated at 2400 baud, so rather than acquire four individual circuits to carry such a low-speed transmission, the airline has installed a pair of multiplexers. A pair of 9600 baud modems and one dedicated analog communications circuit from the ticket desk back to the airline data center are also installed
38.
DVB-T2
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DVB has been standardized by ETSI. This system transmits compressed digital audio, video, and other data in physical layer pipes, the higher offered bit rate, with respect to its predecessor DVB-T, makes it a system suited for carrying HDTV signals on the terrestrial TV channel. As of 2014, it was implemented in broadcasts in the United Kingdom, Italy, Finland, Germany, Sweden, Thailand Flanders, Serbia, Ukraine, Croatia, Denmark, Romania, in March 2006 DVB decided to study options for an upgraded DVB-T standard. The novel system should provide a minimum 30% increase in payload, the BBC, ITV, Channel 4 and Channel 5 agreed with the regulator Ofcom to convert one UK multiplex to DVB-T2 to increase capacity for HDTV via DTT. They expected the first TV region to use the new standard would be Granada in November 2009 and it was expected that over time there would be enough DVB-T2 receivers sold to switch all DTT transmissions to DVB-T2, and H.264. Ofcom published its decision on 3 April 2008, for HDTV using DVB-T2 and H.264. ITV and C4 had, as expected, applied to Ofcom for the 2 additional HD slots available from 2009 to 2012. Ofcom indicated that it found a channel covering 3.7 million households in London. Ofcom indicated that they would look for more unused UHF channels in other parts of the UK, the DVB-T2 draft standard was ratified by the DVB Steering Board on 26 June 2008, and published on the DVB homepage as DVB-T2 standard BlueBook. It was handed over to the European Telecommunications Standards Institute by DVB. ORG on 20 June 2008, the ETSI process resulted in the DVB-T2 standard being adopted on 9 September 2009. The ETSI process had several phases, but the changes were text clarifications. Since the DVB-T2 physical layer specification was complete, and there would be no further technical enhancements, a draft PSI/SI specification document was also agreed with the DVB-TM-GBS group. Prototype receivers were shown in September IBC2008 and more recent version at the IBC2009 in Amsterdam, as of 2012, Appear TV also produce DVB-T2 receivers, DVB-T2 modulators and DVB-T2 gateways. Other companies like ENKOM or IfN develop software based decoding, NORDIG published a DVB-T2 receiver specification and performance requirement on 1 July 2009. The DTGs test house, DTG Testing are testing Freeview HD products against this specification, many tests broadcast transmission using this standard are being in process in France, with local Gap filler near Rennes CCETT. DVB-T2 was tested in October 2010, in Geneva region, with Mont Salèves repeater, a mobile van was testing BER, strength, and quality reception, with special PCs used as spectrum analysers, constellation testers. The van was moving in Canton Geneva, and France, however, there were none demonstrated in TELECOM2011 at Palexpo. The following characteristics have been devised for the T2 standard, COFDM modulation with QPSK, 16-QAM, 64-QAM, OFDM modes are 1k, 2k, 4k, 8k, 16k, and 32k
39.
Digital television transition
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This primarily involves the conversion of analog terrestrial television to digital terrestrial. However, it also involves analog cable conversion to digital cable, in many countries, a simulcast service is operated where a broadcast is made available to viewers in both analog and digital at the same time. As digital becomes more popular, it is likely that the analog services will be removed. In some cases this has happened, where a broadcaster has offered incentives to viewers to encourage them to switch to digital. In other cases government policies have been introduced to encourage or force the switchover process, Government intervention usually involves providing some funding for broadcasters and, in some cases monetary relief to viewers, to enable a switchover to happen by a given deadline. The switchover for individual countries varies, in countries it is being implemented in stages as in Australia, India and the United Kingdom. In others, the whole country switches on one date, such as the Netherlands, some countries have different switch off dates for each channel, such as China where CCTV channels 1-5+ were switched off first. This date was viewed as an internationally mandated analog switch-off date. The European Commission has recommended that digital switchover should be completed by 1 January 2012 - Commission Recommendation 2009/848/EC, Netherlands moved to digital-only broadcasting on Monday,11 December 2006, being the first country to do so. Like Germany and Sweden, the Netherlands still has a number of analog cable viewers. Finland ceased analog terrestrial transmissions nationwide at 04,00, Saturday,1 September 2007 and this was controversial, as the cost of a digital TV set in Finland at the time was heavily criticised and saw a substantial decrease in how much the television license cost. Cable TV viewers continued to receive analog broadcasts until the end of February 2008, andorra completed its switch-off on Tuesday 25 September 2007. Sweden, The switch-off of the terrestrial network progressed region–by–region. It started on the island of Gotland on Monday,19 September 2005, and was completed on Monday,15 October 2007, like the Netherlands, Germany and Japan, cable distributors continued broadcasting analog television. Cable broadcasters continue to broadcast in analog, so therefore a switchover is unlikely to happen in the near future. Switzerland began with the switch-off on Monday 24 July 2006 in Ticino, the switch-off was completed on Monday 26 November 2007. A very high percentage of Swiss viewers receive their signals via cable distributors, by 2012 40% of cable viewers have switched to digital. The government planned to shut off analog cable by 2015, Germany started the switch-off in the Berlin area, beginning on Friday,1 November 2002 and completing on Monday 4 August 2003
40.
ITV Granada
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ITV Granada is the Channel 3 regional service for North West England. The licence for the region has been held by ITV Broadcasting Limited since November 2008 and it is the largest independent television-franchise producing company in the UK, accounting for 25% of the total broadcasting output of the ITV network. It had been held by Granada Television, which was founded by Sidney Bernstein and this was the only surviving company of the original four Independent Television Authority franchisees from 1954, Granada Media Group merged with Carlton Communications to form ITV plc in 2004. It covers Cheshire, Greater Manchester, Lancashire, Merseyside, northwestern Derbyshire, part of Cumbria, on 15 July 2009, the Isle of Man was transferred to ITV Granada from ITV Border. Broadcasting by Granada Television began on 3 May 1956 under the North of England weekday franchise and it was marked by a distinctive northern identity, and used stylised letter G logo forming an arrow pointing north, often with the tagline Granada, from the north. Granada plc merged with Carlton Communications to form ITV plc in 2004 after a duopoly had developed over the previous decade, Granada Television Ltd still legally exists. Along with most other companies owned by ITV plc, it is listed on www. companieshouse. gov. uk as a Dormant company. Other companies listed are Granada Television International and Granada Television Overseas Ltd, the North West region is regarded as ITVs most successful franchise. The Financial Times and The Independent once described Granada Television, the franchise holder. Nine Granada programmes were listed in the BFI TV100 in 2000, some of its most notable programmes include Coronation Street, Seven Up. The Royle Family, The Jewel in the Crown, Brideshead Revisited, World in Action, University Challenge, notable employees have included Paul Greengrass, Michael Apted, Mike Newell, Jeremy Isaacs, Andy Harries, Russell T Davies and Leslie Woodhead. Granada Television, a subsidiary of Granada Ltd, originated in Granada Theatres Ltd and it was founded in Dover in 1930 by Sidney Bernstein and his brother Cecil. The company was incorporated as Granada Ltd in 1934 and listed on the London Stock Exchange in 1935 and it is named after the Spanish city of Granada. Channel 59 from Winter Hill and started broadcasting in colour in the Autumn of 1969, the Bernsteins became involved in commercial television, a competitor to the cinema chains. Bernstein bid for the North of England franchise, which he believed would not affect the companys largely southern-based cinema chain, in 1954, the Independent Television Authority awarded Granada the North of England contract for Monday to Friday, with ABC serving the same area on weekends. The North and London were the two biggest regions, Granada preferred the North because of its tradition of home-grown culture, and because it offered a chance to start a new creative industry away from the metropolitan atmosphere of London. Compare this with London and its suburbs—full of displaced persons, and, of course, if you look at a map of the concentration of population in the North and a rainfall map, you will see that the North is an ideal place for television. Bernstein selected a base from Leeds and Manchester, Granada executive Victor Peers believed Manchester was the preferred choice even before executives toured the region to find a suitable site
41.
Winter Hill (North West England)
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Winter Hill is a hill on the border of the boroughs of Chorley, Blackburn with Darwen and Bolton, in North West England. It is located on Rivington Moor, Chorley and is 1,496 feet high, part of the West Pennine Moors, it is a popular walking area, and has been the site of mining activity, aeroplane disasters and murders. Its prominent position made it the site for the Winter Hill TV Mast. There are also a number of other telecommunication masts and towers around the summit and side of the hill for mobile phones, Professional Mobile Radio users and emergency services. Lancashire Constabulary was the first to use the site for one of their stations in 1950, they had to build the road. Paths to the lead from Belmont & Rivington in Chorley Borough, as well as Horwich. The summit can be reached via a walk from the top of a road pass 1¼ miles west of Belmont. The hill is a feature on the skyline for most of the borough of Chorley. Winter Hills topographic prominence results in it being classified as a Marilyn and it offers views over the Greater Manchester Urban Area, including Manchester city centre, the Civic Centre in Oldham, Salford, Werneth Low, Wigan and Bolton. On a clear day the summit offers a view of four national parks - The Lake District, Yorkshire Dales, Peak District, the Rivington area contains remains of Lever Park and the private gardens constructed for William Lever, 1st Viscount Leverhulme in which several listed structures remain today. The bare hill top was covered by woodland that may have been destroyed by fire and it is thought that the hill was once inhabited. There is a Bronze Age round cairn dating from 1600–1400 BC on the hill, a stone axe dating from 2500 BC has also been found in the area in the River Douglas in Tigers Clough. A flint knife and two arrowheads were also discovered, Two burial mounds dating from the Bronze Age are located near the peak. On 24 March 1957, two men discovered curved lines of stones sticking out of the forming a two feet high wall which surrounded a raised area in the middle. In July 1958, a group from the University of Manchester excavated the central only to find it had been excavated 250 years earlier. The site was thought to have originated from 1500 BC in the Middle Bronze Age, the second mound was found higher up the hill on the southern edge of Noon Hill. The site was excavated in August 1958 by the Bolton & District Archaeological Society, Two memorial cairns on the hill are known as Wilder Lads or Two Lads. There are differing opinions on why they were erected, details of the site were recorded in 1776 and 1883
Television transmitter and major relay sites in the United Kingdom