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Television In The United States
Television is one of the major mass media outlets in the United States. , household ownership of television sets in the country is 96.7%, with approximately 114,200,000 American households owning at least one television set as of August 2013. The majority of households have more than one set. The peak ownership percentage of households with at least one television set occurred during the 1996–97 season, with 98.4% ownership. In 1948, 1 percent of U.S. households owned at least one television while 75 percent did by 1955, and by 1992, 60 percent of all U.S. households received cable television subscriptions. As a whole, the television networks that broadcast in the United States are the largest and most distributed in the world, and programs produced specifically for US-based networks are the most widely syndicated internationally. Due to a recent surge in the number and popularity of critically acclaimed television series during the 2000s and the 2010s to date, many critics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Media In The United States
Mass media in the United States consist of several types of media: television, radio, cinema, newspapers, magazines, and web sites. The U.S. also has a strong music industry. New York City, Manhattan in particular, and to a lesser extent Los Angeles, are considered the epicenters of U.S. media. Many media entities are controlled by large for-profit corporations who reap revenue from advertising, subscriptions, and sale of copyrighted material. American media conglomerates tend to be leading global players, generating large revenues as well as large opposition in many parts of the world. With the passage of the Telecommunications Act of 1996, further deregulation and convergence are under way, leading to mega-mergers, further concentration of media ownership, and the emergence of multinational media conglomerates. These mergers enable tighter control of information. Currently, five corporations control roughly 90% of the media. Critics allege that localism, local news ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultra High Frequency
Ultra high frequency (UHF) is the ITU designation for radio frequency, radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (one decimeter). Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range. Lower frequency signals fall into the VHF (very high frequency) or lower bands. UHF radio waves propagate mainly by Line-of-sight propagation, line of sight; they are blocked by hills and large buildings although the transmission through building walls is strong enough for indoor reception. They are used for UHF television broadcasting, television broadcasting, cell phones, satellite communication including GPS, personal radio services including Wi-Fi and Bluetooth, walkie-talkies, cordless phones, satellite phones, and numerous other applications. The Institute of Electrical and Electronics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Affairs (broadcasting)
In broadcasting, public affairs radio or television programs focus on matters of politics and public policy. Among commercial broadcasters, such programs are often only to satisfy Federal Communications Commission (FCC) regulatory expectations and are not scheduled in prime time. Public affairs television programs are often broadcast at times when few listeners or viewers are tuned in (or even awake) in the U.S., in time slots known as graveyard slots; such programs can be frequently encountered at times such as 5-6 a.m. on a Sunday. Sunday morning talk shows are a notable exception to this obscure scheduling. Harvard University claims that the public affairs genre has been losing popularity since the beginning of the digital era. References See also *Public service announcement (PSA) *Sunday morning talk show A Sunday morning talk show is a television program with a news/ talk/ public affairs–hybrid format that is broadcast on Sunday mornings. This type of program o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcast License
A broadcast license is a type of spectrum license granting the licensee permission to use a portion of the radio frequency spectrum in a given geographical area for broadcasting purposes. The licenses generally include restrictions, which vary from band to band. Spectrum may be divided according to use. As indicated in a graph from the National Telecommunications and Information Administration (NTIA), frequency allocations may be represented by different types of services which vary in size. Many options exist when applying for a broadcast license; the FCC determines how much spectrum to allot to licensees in a given band, according to what is needed for the service in question. The determination of frequencies used by licensees is done through frequency allocation, which in the United States is specified by the FCC in a table of allotments. The FCC is authorized to regulate spectrum access for private and government uses; however, the National Telecommunications and Informatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television Transition
The digital television transition, also called the digital switchover (DSO), the analogue switch/sign-off (ASO), the digital migration, or the analogue shutdown, is the process in which older analogue television broadcasting technology is converted to and replaced by digital television. Conducted by individual nations on different schedules, this primarily involves the conversion of analogue terrestrial television broadcasting infrastructure to digital terrestrial (DTT), a major benefit being extra frequencies on the radio spectrum and lower broadcasting costs, as well as improved viewing qualities for consumers. The transition may also involve analogue cable conversion to digital cable or Internet Protocol television, as well as analog to digital satellite television. Transition of land based broadcasting was begun by some countries around 2000. By contrast, transition of satellite television systems was well underway or completed in many countries by this time. It is an inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virtual Channel
In most telecommunications organizations, a virtual channel is a method of remapping the ''program number'' as used in H.222 Program Association Tables and Program Mapping Tables to a channel number that can be entered via digits on a receiver's remote control. Often, "virtual channels" are implemented in digital television, helping users to find a desired channel easily, or easing the transition from analogue to digital broadcasting in general. The practice of assigning virtual channels is most common in those parts of the world where TV stations were colloquially named after the RF channel they were transmitting on ("Channel 6 Springfield"), as it was common in North America during the analogue TV era. In other parts of the world, such as Europe, virtual channels are rarely used or needed, as TV stations there identify themselves by name, not by RF channel or callsign. A "virtual channel" was first used for DigiCipher 2 in North America. It was later used and referred to as a l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies; these are the frequencies at which energy from an oscillating current can radiate off a conductor into space as radio waves. Different sources specify different upper and lower bounds for the frequency range. Electric current Electric currents that oscillate at radio frequencies (RF currents) have special properties not shared by direct current or lower audio frequency alternating current, such as the 50 or 60 Hz current used in electrical power distribution. * Energy from RF currents in conductors can radiate into space as electromagnetic waves ( radio waves). This is the basis of radio technology. * RF current does not penetrate deeply into electrical c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Terrestrial Television
Digital terrestrial television (DTTV or DTT, or DTTB with "broadcasting") is a technology for terrestrial television in which land-based (terrestrial) television stations broadcast television content by radio waves to televisions in consumers' residences in a digital format. DTTV is a major technological advance over the previous analog television, and has largely replaced analog which had been in common use since the middle of the 20th century. Test broadcasts began in 1998 with the changeover to DTTV (aka Analog Switchoff (ASO), or Digital Switchover (DSO)) beginning in 2006 and is now complete in many countries. The advantages of ''digital'' terrestrial television are similar to those obtained by digitising platforms such as cable TV, satellite, and telecommunications: more efficient use of limited radio spectrum bandwidth, provision of more television channels than analog, better quality images, and potentially lower operating costs for broadcasters (after the initial up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog Television
Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, instantaneous phase and frequency, phase and frequency of an analog signal. Analog signals vary over a continuous range of possible values which means that Noise (electronics), electronic noise and interference may be introduced. Thus with analog, a moderately weak signal becomes Noise (video), snowy and subject to interference. In contrast, picture quality from a digital television (DTV) signal remains good until the signal level drops below digital cliff, a threshold where reception is no longer possible or becomes intermittent. Analog television may be wireless (terrestrial television and satellite television) or can be distributed over a cable network as cable television. All broadcast television systems used analog signals before the arrival of DTV. Motivated by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, and optical networking technologies. The Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web (WWW), electronic mail, telephony, and file sharing. The origins of the Internet date back to the development of packet switching and research commissioned by the United States Department of Defense in the 1960s to enable time-sharing of computers. The primary precursor network, the ARPANET, initially served as a backbone for interconnection of regional academic and military networks in the 1970s to enable resource shari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IPTV
Internet Protocol television (IPTV) is the delivery of television content over Internet Protocol (IP) networks. This is in contrast to delivery through traditional terrestrial, satellite, and cable television formats. Unlike downloaded media, IPTV offers the ability to stream the source media continuously. As a result, a client media player can begin playing the content (such as a TV channel) almost immediately. This is known as streaming media. Although IPTV uses the Internet protocol it is not limited to television streamed from the Internet (Internet television). IPTV is widely deployed in subscriber-based telecommunications networks with high-speed access channels into end-user premises via set-top boxes or other customer-premises equipment. IPTV is also used for media delivery around corporate and private networks. IPTV in the telecommunications arena is notable for its ongoing standardisation process (e.g., European Telecommunications Standards Institute). IPTV service ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct-broadcast Satellite Television
Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location. The signals are received via an outdoor parabolic antenna commonly referred to as a satellite dish and a low-noise block downconverter. A satellite receiver then decodes the desired television program for viewing on a television set. Receivers can be external set-top boxes, or a built-in television tuner. Satellite television provides a wide range of channels and services. It is usually the only television available in many remote geographic areas without terrestrial television or cable television service. Modern systems signals are relayed from a communications satellite on the X band (8–12 GHz) or Ku band (12–18 GHz) frequencies requiring only a small dish less than a meter in diameter. The first satellite TV systems were an obsolete type now known as television receive-only. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
