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Radio Frequency Channel
In broadcasting, a channel or frequency channel is a designated radio frequency (or, equivalently, wavelength), assigned by a competent frequency assignment authority for the operation of a particular radio station, television station or television channel. See also *Frequency allocation, ITU RR, article 1.17 *Frequency assignment, ITU RR, article 1.18 *Broadcast law *Television channel frequencies The following tables show the frequencies assigned to broadcast television channels in various regions of the world, along with the ITU letter designator for the system used. The frequencies shown are for the analogue video and audio carriers. ... References International Telecommunication Union (ITU) Broadcasting {{Broadcast-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcasting
Broadcasting is the distribution (business), distribution of sound, audio or video content to a dispersed audience via any electronic medium (communication), mass communications medium, but typically one using the electromagnetic spectrum (radio waves), in a :wikt:one-to-many, one-to-many model. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and radio receiver, receivers. Before this, all forms of electronic communication (early radio, telephone, and telegraph) were wikt:one-to-one, one-to-one, with the message intended for a single recipient. The term ''broadcasting'' evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as ... [...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] |
Wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter ''lambda'' (λ). The term ''wavelength'' is also sometimes applied to modulated waves, and to the sinusoidal envelopes of modulated waves or waves formed by interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. Wavelength depends on the medium (for example, vacuum, air, or water) that a wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Assignment
Frequency assignment is the authorization of use of a particular radio frequency. In Article 1.18 of the International Telecommunication Union's (ITU) Radio Regulations (RR),ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.18, definition: ''assignment (of a radio frequency or radio frequency channel)'' the process is defined as "Authorization given by a frequency administration for a radio station to use a radio frequency or radio frequency channel under specified conditions". Daily impact Every day, users rely on assignment of frequencies for efficient use of such devices as: * cell phone * cordless phone * garage door opener * car key remote control * broadcast television and audio * Standard time broadcast * vehicle-speed radar, air traffic radar, weather radar * mobile radio * Global Positioning System (GPS) navigation * satellite TV broadcast reception; also backend signal dissemination * Microwave oven * Bluetooth * Wi-Fi * Zigbee * RFID device ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Assignment Authority
Spectrum management is the process of regulating the use of radio frequency, radio frequencies to promote efficient use and gain a net social benefit.Martin Cave, Chris Doyle, William Webb, ''Modern Spectrum Management'', Cambridge University Press, 2007 The term ''radio spectrum'' typically refers to the full frequency range from 1 hertz, Hz to 3000 hertz, GHz (3 hertz, THz) that may be used for wireless communication. Increasing demand for services such as mobile telephones and many others has required changes in the philosophy of spectrum management. Demand for wireless broadband has soared due to technological innovation, such as 3G and 4G mobile services, and the rapid expansion of wireless internet services. Since the 1930s, spectrum was assigned through administrative licensing. Limited by technology, signal interference was once considered as a major problem of spectrum use. Therefore, exclusive licensing was established to protect licensees' signals. This forme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Broadcasting
Radio broadcasting is transmission of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radio station, while in satellite radio the radio waves are broadcast by a satellite in Earth orbit. To receive the content the listener must have a broadcast radio receiver (''radio''). Stations are often affiliated with a radio network which provides content in a common radio format, either in broadcast syndication or simulcast or both. Radio stations broadcast with several different types of modulation: AM radio stations transmit in AM ( amplitude modulation), FM radio stations transmit in FM (frequency modulation), which are older analog audio standards, while newer digital radio stations transmit in several digital audio standards: DAB (digital audio broadcasting), HD radio, DRM ( Digital Radio Mondiale). Television broadcasting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Station
A television station is a set of equipment managed by a business, organisation or other entity, such as an amateur television (ATV) operator, that transmits video content and audio content via radio waves directly from a transmitter on the earth's surface to any number of tuned receivers simultaneously. Overview Most often the term "television station" refers to a station which broadcasts structured content to an audience or it refers to the organization that operates the station. A terrestrial television transmission can occur via analog television signals or, more recently, via digital television signals. Television stations are differentiated from cable television or other video providers in that their content is broadcast via terrestrial radio waves. A group of television stations with common ownership or affiliation are known as a TV network and an individual station within the network is referred to as O&O or affiliate, respectively. Because television station signals u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Channel
A television channel is a terrestrial frequency or virtual number over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the terrestrial or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video (VSB) and 59.75 MHz for analog audio ( FM), or 55.31 MHz for digital ATSC (8VSB). Channels may be shared by many different television stations or cable-distributed channels depending on the location and service provider Depending on the multinational bandplan for a given regional n, analog television channels are typically 6, 7, or 8 MHz in bandwidth, and therefore television channel frequencies vary as well. Channel numbering is also different. Digital terrestrial television channels are the same as their analog predecessors for legacy reasons, however through multiplexing, each physical radio frequency (RF) channel can carry several digital subchannels. On sat ... [...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] |
Frequency Assignment
Frequency assignment is the authorization of use of a particular radio frequency. In Article 1.18 of the International Telecommunication Union's (ITU) Radio Regulations (RR),ITU Radio Regulations, Section IV. Radio Stations and Systems – Article 1.18, definition: ''assignment (of a radio frequency or radio frequency channel)'' the process is defined as "Authorization given by a frequency administration for a radio station to use a radio frequency or radio frequency channel under specified conditions". Daily impact Every day, users rely on assignment of frequencies for efficient use of such devices as: * cell phone * cordless phone * garage door opener * car key remote control * broadcast television and audio * Standard time broadcast * vehicle-speed radar, air traffic radar, weather radar * mobile radio * Global Positioning System (GPS) navigation * satellite TV broadcast reception; also backend signal dissemination * Microwave oven * Bluetooth * Wi-Fi * Zigbee * RFID device ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcast Law
Broadcast law is the field of law that pertains to broadcasting. These laws and regulations pertain to radio stations and TV stations, and are also considered to include closely related services like cable TV and cable radio, as well as satellite TV and satellite radio. Likewise, it also extends to broadcast networks. Broadcast law includes technical parameters for these facilities, as well as content issues like copyright, profanity, and localism or regionalism. Philippines Under the Philippine law, broadcasting networks require a congressional franchise to operate television and radio stations. United States In the US, broadcasting falls under the jurisdiction of the Federal Communications Commission. Some of the more notable aspects of broadcast law involve: * frequency allocation: The division of the spectrum into unlicensed frequency bands -- ISM band and U-NII—and licensed frequency bands -- television channel frequencies, FM broadcast band, amateur radio frequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Channel Frequencies
The following tables show the frequencies assigned to broadcast television channels in various regions of the world, along with the ITU letter designator for the system used. The frequencies shown are for the analogue video and audio carriers. The channel itself occupies several megahertz of bandwidth. For example, North American channel 1 occupies the spectrum from 44 to 50 MHz. See Broadcast television systems for a table of signal characteristics, including bandwidth, by ITU letter designator. VHF Americas (most countries), South Korea, Taiwan, Burma (Myanmar) and the Philippines During World War II, the frequencies originally assigned as channels 13 to 18 were appropriated by the U.S. military, which still uses them to this day. It was also decided to move the allocation for FM radio from the 42-50 MHz band to a larger 88-106 MHz band (later extended to the current 88-108 MHz FM band). This required a reassignment of the VHF channels to the plan curre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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