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North American Broadcast Television Frequencies
The Pan-American television frequencies are different for terrestrial and cable television systems. Terrestrial television channels are divided into two bands: the VHF band which comprises channels 2 through 13 and occupies frequencies between 54 and 216 MHz, and the UHF band, which comprises channels 14 through 36 and occupies frequencies between 470 and 700 MHz. These bands are different enough in frequency that they often require separate antennas to receive (although many antennas cover both VHF and UHF), and separate tuning controls on the television set. The VHF band is further divided into two frequency ranges: VHF low band (Band I) between 54 and 88 MHz, containing channels 2 through 6, and VHF high band (Band III) between 174 and 216 MHz, containing channels 7 through 13. The wide spacing between these frequency bands is responsible for the complicated design of rooftop TV antennas. The UHF band has higher noise and greater attenuation, so higher gain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Television
Terrestrial television or over-the-air television (OTA) is a type of television broadcasting in which the signal transmission occurs via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an antenna. The term ''terrestrial'' is more common in Europe and Latin America, while in Canada and the United States it is called ''over-the-air'' or simply ''broadcast''. This type of TV broadcast is distinguished from newer technologies, such as satellite television (direct broadcast satellite or DBS television), in which the signal is transmitted to the receiver from an overhead satellite; cable television, in which the signal is carried to the receiver through a cable; and Internet Protocol television, in which the signal is received over an Internet stream or on a network utilizing the Internet Protocol. Terrestrial television stations broadcast on television channels with frequencies between about 52 and 600 MHz in the VHF and U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Band III
Band III is the name of the range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum from 174 to 240 megahertz (MHz). It is primarily used for radio and television broadcasting. It is also called high-band VHF, in contrast to Bands I and II. Broadcast Television North America The band is subdivided into seven channels for television broadcasting, each occupying 6 MHz. Europe European Band III allocations vary from country to country, with channel widths of 7 or 8 MHz. The standard channel allocations for European countries that use System B with 7 MHz channel spacing are as follows: The Irish (8 MHz) system is shown below. Oceania Australia has allocated 8 channels in Band III for digital television, each with 7 MHz bandwidth. Russia and other former members of OIRT Russian analog television is transmitted using System D with 8 MHz channel bandwidth. Radio The band came into use for radio broa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunked Radio System
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users (a ''talkgroup'') with mobile and portable two-way radios communicate over a single shared radio channel, with one user at a time talking. These systems typically have access to multiple channels, up to 40-60, so multiple groups in the same area can communicate simultaneously. In a conventional (non-trunked) system, channel selection is done manually; before use the group must decide which channel to use, and manually switch all the radios to that channel. This is an inefficient use of scarce radio channel resources because the user group must have exclusive use of their channel regardless of how much or how little they are transmitting. There is also nothing to prevent multiple groups in the same area from choosing the same channel, causing conflicts and 'cross-talk'. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Safety
Public security or public safety is the prevention of and protection from events that could endanger the safety and security of the public from significant danger, injury, or property damage. It is often conducted by a state government to ensure the protection of citizens, persons in their territory, organizations, and institutions against threats to their well-being, survival, and prosperity. The public safety issues that a municipality, county, regional, or federal jurisdiction may handle include crimes (ranging from misdemeanors to felonies), structure fires, conflagrations, medical emergencies, mass-casualty incidents, disasters, terrorism, and other concerns. Public safety organizations are organizations that conduct public safety. They generally consist of emergency services and first responders such as law enforcement, fire services, emergency medical services, security forces, and military forces. They are often operated by a government, though some private public safe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Allocation
Frequency allocation (or spectrum allocation or spectrum management) is the allocation and regulation of the electromagnetic spectrum into radio frequency bands, normally done by governments in most countries. Because radio propagation does not stop at national boundaries, governments have sought to harmonise the allocation of RF bands and their standardization. ITU definition The International Telecommunication Union defines frequency allocation as being of "a given frequency band for the purpose of its use by one or more terrestrial or space radiocommunication services or the radio astronomy service under specified conditions".ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.16, definition: allocation (of a frequency band). ''Frequency allocation'' is also a special term, used in national frequency administration. Other terms are: Bodies Several bodies set standards for frequency allocation, including: * International Telecommunication Union (IT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Radio-Telecommunications Commission
The Canadian Radio-television and Telecommunications Commission (CRTC; french: Conseil de la radiodiffusion et des télécommunications canadiennes, links=) is a public organization in Canada with mandate as a regulatory agency for broadcasting and telecommunications. It was created in 1976 when it took over responsibility for regulating telecommunication carriers. Prior to 1976, it was known as the Canadian Radio and Television Commission, which was established in 1968 by the Parliament of Canada to replace the Board of Broadcast Governors. Its headquarters is located in the Central Building (Édifice central) of Les Terrasses de la Chaudière in Gatineau, Quebec. History The CRTC was originally known as the Canadian Radio-Television Commission. In 1976, jurisdiction over telecommunications services, most of which were then delivered by monopoly common carriers (for example, telephone companies), was transferred to it from the Canadian Transport Commission although the abbr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industry Canada
Innovation, Science and Economic Development Canada (ISED; french: Innovation, Sciences et Développement économique Canada; french: ISDE, label=none)''Innovation, Science and Economic Development Canada'' is the applied title under the Federal Identity Program; the legal title is Department of Industry (). is a department of the Government of Canada. ISED is responsible for a number of the federal government's functions in regulating industry and commerce, promoting science and innovation, and supporting economic development. The department was known as Industry Canada (IC) prior to 2015. The department is led by the minister of innovation, science and industry (currently François-Philippe Champagne), who also serves as the registrar general of Canada and is responsible for the department to Parliament. Several other ministerial portfolios are associated with the department. While the minister is head of the department, and provides policy/political direction, the day-to-day ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adjacent-channel Interference
Adjacent-channel interference (ACI) is interference caused by extraneous power from a signal in an adjacent channel. ACI may be caused by inadequate filtering (such as incomplete filtering of unwanted modulation products in FM systems), improper tuning or poor frequency control (in the reference channel, the interfering channel or both). ACI is distinguished from crosstalk.Federal Standard 1037Accessed: 2011-10-19. (Archived by WebCite at http://webcitation.org/62Z8qe0pC)/ref> Origin The adjacent-channel interference which receiver A experiences from a transmitter B is the sum of the power that B emits into A's channel—known as the "unwanted emission", and represented by the ACLR (Adjacent Channel Leakage Ratio)—and the power that A picks up from B's channel, which is represented by the ACS (Adjacent Channel Selectivity). B emitting power into A's channel is called adjacent-channel leakage (unwanted emissions). It occurs for two reasons. First, because RF filters require a rol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrum Reallocation
The 2016 United States wireless spectrum auction, officially known as Auction 1001, allocated approximately 100 MHz of the United States Ultra High Frequency (UHF) spectrum formerly allocated to UHF television in the 600 MHz band. The spectrum auction and subsequent reallocations were authorized by Title VI (The Spectrum Act) of the payroll tax cut extension passed by the United States Congress on February 17, 2012. Background The 2008 United States wireless spectrum auction, dealing with allocations for UHF television in the 700 MHz band, generated $19.6 billion from companies such as AT&T and Verizon Communications. This auction re-allocated the UHF space formerly occupied by channels 52–69, after the completion of the primary digital television transition in the United States from NTSC to ATSC in 2009. In effect, the digital transition had eliminated 25% of the space allocated for UHF television in the United States. Wireless broadband internet access interest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WNWT-LD
WNWT-LD (channel 37) is a television station in New York City, airing programming from Story Television. It is owned by Weigel Broadcasting alongside Middletown Township, New Jersey-licensed MeTV station WJLP (channel 33) and Bridgeport, Connecticut-licensed Story Television outlet WZME (channel 43). WNWT-LD and WJLP share studios in Freehold Township, New Jersey, and transmitter facilities at 4 Times Square in midtown Manhattan. Despite WNWT-LD legally holding a low-power license, it transmits using WJLP's full-power spectrum through a channel sharing agreement. This ensures complete reception across the New York City television market. The station has used various virtual channels since its conversion to digital television in 2012, due to the lack of allocations in the New York and Philadelphia markets, starting on channel 3 (conflicting with KYW-TV), then 51 (averting a conflict with NJ PBS station WNJN on channel 50) from late 2013 until mid-2019, then 6 and 18 (conflictin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the List of United States cities by population density, most densely populated major city in the United States, and is more than twice as populous as second-place Los Angeles. New York City lies at the southern tip of New York (state), New York State, and constitutes the geographical and demographic center of both the Northeast megalopolis and the New York metropolitan area, the largest metropolitan area in the world by urban area, urban landmass. With over 20.1 million people in its metropolitan statistical area and 23.5 million in its combined statistical area as of 2020, New York is one of the world's most populous Megacity, megacities, and over 58 million people live within of the city. New York City is a global city, global Culture of New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
