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Small-scale DAB
In the United Kingdom, the roll-out of digital radio has been proceeding since engineering test transmissions were started by the BBC in 1990 followed by a public launch in September 1995. The UK currently has one of the world's biggest digital radio networks, with about 500 transmitters, three national DAB ensembles, one regional DAB ensemble, 48 local DAB ensembles and an increasing number of small-scale DAB ensembles broadcasting over 250 commercial and 34 BBC radio stations across the UK. In London there are already more than 100 different digital stations available. In addition to DAB and DAB+, radio stations are also broadcast on digital television platform as well as internet radio in the UK. Digital radio ensemble operators and stations need a broadcasting licence from the UK's media regulator Ofcom to broadcast. In the long term there will be a switchover from analogue to digital radio when the AM and FM services will cease. The government has set crit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DAB Digital Radio
Digital radio is the use of digital technology to transmit or receive across the radio spectrum. Digital transmission by radio waves includes digital broadcasting, and especially digital audio radio services. Types In digital broadcasting systems, the analog audio signal is digitized, compressed using an audio coding format such as AAC+ (MDCT) or MP2, and transmitted using a digital modulation scheme. The aim is to increase the number of radio programs in a given spectrum, to improve the audio quality, to eliminate fading problems in mobile environments, to allow additional datacasting services, and to decrease the transmission power or the number of transmitters required to cover a region. However, analog radio (AM and FM) is still more popular and listening to radio over IP (Internet Protocol) is growing in popularity. In 2012 four digital wireless radio systems are recognized by the International Telecommunication Union: the two European systems Digital Audio Broadcasting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital One
Digital One is a national commercial digital radio multiplex in the United Kingdom, owned by Arqiva. , the multiplex covered more than 90% of the population from 137 transmitters. Coverage was extended to Northern Ireland in July 2013. It contains a list of DAB and DAB+ radio stations operated by Bauer Media Audio UK, Global and Wireless Group. Stations carried DAB DAB+ History On 24 March 1998, the Radio Authority advertised for the first national ensemble to be broadcast on DAB, with the three national commercial services on FM and medium wave required to be included in the ensemble. This included Classic FM, Talk Radio UK (now Talksport) and Virgin Radio (now Absolute Radio). The licence was awarded to the sole applicant, GWR Group and NTL Broadcast to form Digital One. The original licence application included the following stations: Digital One was due to launch on 1 October 1999, but this was postponed until 15 November 1999. The "Classic Gold Rock" service ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Which?
''Which?'' is a United Kingdom brand name that promotes informed consumer choice in the purchase of goods and services by testing products, highlighting inferior products or services, raising awareness of consumer rights and offering independent advice. The brand name is used by the Consumers' Association, a registered charity and company limited by guarantee that owns several businesses, including ''Which? Financial Services Limited'' (''Which? Mortgage Advisers''), ''Which? Legal Limited'' and ''Which? Limited'', which publishes the ''Which?'' Papers. The vast majority of the association's income comes from the profit it makes on its trading businesses, for instance subscriptions to ''Which?'' magazine, which are donated to the campaigning part of the organisation to fund advocacy activity and inform the public about consumer issues. ''Which?'' magazine maintains its independence by not accepting advertising, and the organisation receives no government funding. The Consumers' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Radio Mondiale
Digital Radio Mondiale (DRM; ''mondiale'' being Italian and French for "worldwide") is a set of digital audio broadcasting technologies designed to work over the bands currently used for analogue radio broadcasting including AM broadcasting—particularly shortwave—and FM broadcasting. DRM is more spectrally efficient than AM and FM, allowing more stations, at higher quality, into a given amount of bandwidth, using xHE-AAC audio coding format. Various other MPEG-4 and Opus codecs are also compatible, but the standard now specifies xHE-AAC. Digital Radio Mondiale is also the name of the international non-profit consortium that has designed the platform and is now promoting its introduction. Radio France Internationale, TéléDiffusion de France, BBC World Service, Deutsche Welle, Voice of America, Telefunken (now Transradio) and Thomcast (now Ampegon) took part at the formation of the DRM consortium. The principle of DRM is that bandwidth is the limiting factor, and comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors in visible light after passing through a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum. It thereby became a mapping of a range of magnitudes (wavelengths) to a range of qualities, which are the perceived "colors of the rainbow" and other properties which correspond to wavelengths that lie outside of the visible light spectrum. Spectrum has since been applied by analogy to topics outside optics. Thus, one might talk about the " spectrum of political opinion", or the "spectrum of activity" of a drug, or the "autism spectrum". In these uses, values within a spectrum may not be associated with precisely quantifiable numbers or definitions. Such uses imply a broad range of condition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bit Rate
In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction with an SI prefix such as kilo (1 kbit/s = 1,000 bit/s), mega (1 Mbit/s = 1,000 kbit/s), giga (1 Gbit/s = 1,000 Mbit/s) or tera (1 Tbit/s = 1,000 Gbit/s). The non-standard abbreviation bps is often used to replace the standard symbol bit/s, so that, for example, 1 Mbps is used to mean one million bits per second. In most computing and digital communication environments, one byte per second (symbol: B/s) corresponds to 8 bit/s. Prefixes When quantifying large or small bit rates, SI prefixes (also known as metric prefixes or decimal prefixes) are used, thus: Binary prefixes are sometimes used for bit rates. The International Standard ( IEC 80000-13) specifies different a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-Efficiency Advanced Audio Coding
High-Efficiency Advanced Audio Coding (HE-AAC) is an audio coding format for lossy data compression of digital audio defined as an MPEG-4 Audio profile in ISO/IEC 14496–3. It is an extension of Low Complexity AAC (AAC-LC) optimized for low-bitrate applications such as streaming audio. The usage profile HE-AAC v1 uses spectral band replication (SBR) to enhance the modified discrete cosine transform (MDCT) compression efficiency in the frequency domain. The usage profile HE-AAC v2 couples SBR with Parametric Stereo (PS) to further enhance the compression efficiency of stereo signals. HE-AAC is used in digital radio standards like HD Radio, DAB+ and Digital Radio Mondiale. History The progenitor of HE-AAC was developed by Coding Technologies by combining MPEG-2 AAC-LC with a proprietary mechanism for spectral band replication (SBR), to be used by XM Radio for their satellite radio service. Subsequently, Coding Technologies submitted their SBR mechanism to MPEG as a basis of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiplexing
In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource - a physical transmission medium. For example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy in the 1870s, and is now widely 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 communication channel into several logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, extracts the original channels on the receiver end. A device that performs the multiplexing is called a multiplexer (MUX), and a dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-Efficiency Advanced Audio Coding
High-Efficiency Advanced Audio Coding (HE-AAC) is an audio coding format for lossy data compression of digital audio defined as an MPEG-4 Audio profile in ISO/IEC 14496–3. It is an extension of Low Complexity AAC (AAC-LC) optimized for low-bitrate applications such as streaming audio. The usage profile HE-AAC v1 uses spectral band replication (SBR) to enhance the modified discrete cosine transform (MDCT) compression efficiency in the frequency domain. The usage profile HE-AAC v2 couples SBR with Parametric Stereo (PS) to further enhance the compression efficiency of stereo signals. HE-AAC is used in digital radio standards like HD Radio, DAB+ and Digital Radio Mondiale. History The progenitor of HE-AAC was developed by Coding Technologies by combining MPEG-2 AAC-LC with a proprietary mechanism for spectral band replication (SBR), to be used by XM Radio for their satellite radio service. Subsequently, Coding Technologies submitted their SBR mechanism to MPEG as a basis of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Compression (data)
Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum *Digital audio, representation of sound in a form processed and/or stored by computers or digital electronics *Audio, audible content (media) in audio production and publishing *Semantic audio, extraction of symbols or meaning from audio * Stereophonic audio, method of sound reproduction that creates an illusion of multi-directional audible perspective * Audio equipment Entertainment *AUDIO (group), an American R&B band of 5 brothers formerly known as TNT Boyz and as B5 * ''Audio'' (album), an album by the Blue Man Group * ''Audio'' (magazine), a magazine published from 1947 to 2000 *Audio (musician), British drum and bass artist * "Audio" (song), a song by LSD Computing *, an HTML element, see HTML5 audio See also *Acoustic (other) *Audible (other) *Aud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-1 Audio Layer II
MPEG-1 Audio Layer II or MPEG-2 Audio Layer II (MP2, sometimes incorrectly called Musicam or MUSICAM) is a lossy audio compression format defined by ISO/IEC 11172-3 alongside MPEG-1 Audio Layer I and MPEG-1 Audio Layer III (MP3). While MP3 is much more popular for PC and Internet applications, MP2 remains a dominant standard for audio broadcasting. History of development from MP2 to MP3 MUSICAM MPEG-1 Audio Layer 2 encoding was derived from the MUSICAM (''Masking pattern adapted Universal Subband Integrated Coding And Multiplexing'') audio codec, developed by Centre commun d'études de télévision et télécommunications (CCETT), Philips, and the Institut für Rundfunktechnik (IRT) in 1989 as part of the EUREKA 147 pan-European inter-governmental research and development initiative for the development of a system for the broadcasting of audio and data to fixed, portable or mobile receivers (established in 1987). It began as the Digital Audio Broadcast (DAB) project manage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pure Digital
Pure International Ltd. is a British consumer electronics company, based in Kings Langley, Hertfordshire, founded in 2002. They are best known for designing and manufacturing digital audio broadcasting (DAB) and DAB+ radios. The imprint on the devices' casing states that they were designed in the UK and manufactured in China. Pure have sold over five million products worldwide. All products are digital tick approved, with three years' warranty as standard. Pure is also a member of World DAB Pure products are available in the United Kingdom, Australia, Denmark, France, Germany, Ireland, Italy, Netherlands, Norway and Switzerland, and via online suppliers. History 2002 Pure was formerly a division of another Hertfordshire-based company, Imagination Technologies, which primarily designs Central processing units and Graphics processing units. Imagination did not originally set out to sell consumer electronics and the first Pure radio was merely a demonstration platform for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
