Editing Television channel

{{short description|Frequency/channel over which a television station is distributed}}
{{about|television broadcast frequencies|the infrastructure and issues relating to transmission|Television station|the concept of a specific television service (known as a channel or station in some areas around the world)|Television network}}<!-- Please see [[Talk:Television_channel#Hatnote_restored]] for why this hatnote is necessary -->
{{Use American English|date=August 2023}}
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[[File:Mythbuntu Program Guide.png|thumb|upright=1.4|An [[electronic program guide]] showing television listings in [[New Orleans]] for broadcast and cable channels.]]

A '''television channel''', or '''TV channel''', is a [[Channel (broadcasting)|terrestrial frequency or allocated 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 wave|carrier]] [[Frequency|frequencies]] of 55.25&nbsp;MHz for [[NTSC]] analog video ([[Vestigial sideband|VSB]]) and 59.75&nbsp;MHz for analog audio ([[Frequency modulation|FM]]), or 55.31&nbsp;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 region, [[analog television]] channels are typically 6, 7, or 8&nbsp;MHz in [[Bandwidth (signal processing)|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 technology|legacy]] reasons, however through [[multiplexing]], each physical [[radio frequency]] (RF) channel can carry several [[digital subchannel]]s. On [[communications satellite|satellite]]s, each [[transponder]] normally carries one channel, however multiple [[single channel per carrier|small, independent channels]] can be on one transponder, with some loss of [[Bandwidth (signal processing)|bandwidth]] due to the need for [[guard band]]s between unrelated [[radio transmission|transmission]]s. [[ISDB]], used in [[Japan]] and [[Brazil]], has a similar segmented mode.

Preventing interference between terrestrial channels in the same area is accomplished by skipping at least one channel between two analog stations' [[frequency allocation]]s. Where channel numbers are sequential, frequencies are not [[wikt:contiguity|contiguous]], such as channel 6 to 7 skip from [[VHF]] low to high band, and channel 13 to 14 jump to [[UHF]]. On cable TV, it is possible to use [[adjacent channel]]s only because they are all at the same power, something which could only be done terrestrially if the two stations were transmitted at the same [[effective radiated power|power]] and [[HAAT|height]] from the same [[broadcast tower|location]]. For DTT, [[selectivity (radio)|selectivity]] is inherently better, therefore channels adjacent (either to analog or digital stations) can be used even in the same [[media market|area]].

==Other meanings==
Commonly, the term ''television channel'' is used to mean a [[television station]] or its [[pay television]] counterpart (both outlined below). Sometimes, especially outside the U.S. and in the context of pay television, it is used instead of the term [[television network]], which otherwise (in its technical use above) describes a group of geographically-distributed television stations that share [[network affiliate|affiliation]]/[[Owned-and-operated station|ownership]] and some or all of their programming with one another.
This terminology may be muddled somewhat in other [[jurisdiction]]s, for instance [[Europe]], where terrestrial channels are commonly mapped from physical channels to common numerical positions (i.e. [[BBC One]] does not broadcast on any particular ''channel 1'' but is nonetheless [[Analogue terrestrial television in the United Kingdom#625 lined system|mapped to the ''1'' input]] on most British television sets). On digital platforms, such (location) channels are usually arbitrary and changeable, due to [[virtual channel]]s.

===Television station===
{{Main|Television station|Digital television transition}}
A television station is a type of terrestrial station that [[Broadcasting|broadcast]]s both [[Soundframe|audio]] ''and'' [[video]] to [[television]] [[receiver (radio)|receiver]]s in a particular area. Traditionally, TV stations made their broadcasts by sending specially-encoded [[radio]] signals over the air, called [[terrestrial television]]. Individual television stations are usually granted [[license]]s by a [[government agency]] to use a particular section of the [[radio spectrum]] (a [[Communication channel|channel]]) through which they send their signals. Some stations use [[LPTV]] [[broadcast translator]]s to [[repeater|retransmit]] to further areas.

Many television stations are now in the process of converting from analog terrestrial ([[NTSC]], [[PAL]] or [[SECAM]]) broadcast, to [[digital terrestrial television|digital terrestrial]] ([[ATSC broadcast]], [[Digital Video Broadcasting|DVB]] or [[Integrated Services Digital Broadcasting|ISDB]]).

===Non-terrestrial television channels===
Because some regions have had difficulty picking up [[terrestrial television]] signals (particularly in [[mountain]]ous areas), alternative means of distribution such as direct-to-home satellite and cable television have been introduced. Television channels specifically built to run on cable or satellite blur the line between TV station and TV network. That fact led some early cable channels to call themselves [[superstation]]s.

Satellite and cable have created changes. [[Local programming]] TV stations in an area can [[retransmission consent|sign-up]] or even [[must-carry|be required]] to be carried on cable, but content providers like [[TLC (TV channel)|TLC]] cannot. They are not licensed to run broadcast equipment like a station, and they do not regularly provide content to licensed broadcasters either. Furthermore, a distributor like [[Turner Network Television|TNT]] may start producing its own programming, and shows presented exclusively on pay-TV by one distributor may be [[television syndication|syndicated]] to terrestrial stations. The cost of creating a nationwide channel has been reduced and there has been a huge increase in the number of such channels, with most catering to a small group.

From the definitions above, use of the terms ''network'' or ''station'' in reference to nationwide cable or satellite channels is technically inaccurate. However, this is an arbitrary, inconsequential distinction, and varies from company to company. Indeed, the term ''[[cable network]]'' has entered into common usage in the United States in reference to such channels, even with the existence of [[Satellite television#Direct broadcast via satellite|direct broadcast satellite]]. There is even some geographical separation among ''national'' pay television channels in the U.S., be it programming (e.g., the [[Bally Sports]] group of regional sports channels, which share several programs), or simply regionalized advertising inserted by the local cable company.

Should a legal distinction be necessary between a (location) channel as defined above and a television channel in this sense, the terms ''programming service'' (e.g.<ref>{{cite web|url=http://arbiter.wipo.int/domains/decisions/html/2001/d2001-1440.html|title=WIPO Domain Name Decision: D2001-1440|first=Arbitration and Mediation|last=Center|website=arbiter.wipo.int|url-status=live|archive-url=http://archive.wikiwix.com/cache/20060416121854/http://arbiter.wipo.int/domains/decisions/html/2001/d2001-1440.html|archive-date=2006-04-16}}</ref>) or ''programming undertaking'' (for instance,<ref>{{cite web |url=http://www.crtc.gc.ca/Eng/forms/efiles/f109.htm |title=Application to renew a broadcasting licence for a specialty programming undertaking |access-date=2006-03-31 |url-status=dead |archive-url=https://web.archive.org/web/20060614071402/http://www.crtc.gc.ca/Eng/forms/efiles/f109.htm |archive-date=2006-06-14 }}</ref>) may be used instead of the latter definition.

==See also==
{{Wiktionary}}
*[[Barker channel]]
*[[Free-to-air]]
*[[Lists of television channels]]
*[[Pay television]]
*[[Streaming television]]
*[[Television channel frequencies]]

==References==
{{Reflist}}

==External links==
*{{Commonscatinline|Television channels}}
*[http://www.tech-notes.tv/History&Trivia/Channel%20One/Channel_1.htm What ever happened to Channel 1?]

{{Telecommunications}}
{{Authority control}}
[[Category:Television terminology|Channel]]
[[Category:Broadcast engineering]]
[[Category:Telecommunication theory]]
[[Category:Television stations|*]]