Editing Virtual channel (section)

{{short description|Method of remapping a digital program stream to a channel number}}
{{About||the SDRAM technology|VC-RAM|the computer networking term|virtual circuit}}
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{{too technical|date=March 2015}}
{{original research|date=May 2024}}
{{More citations needed|date=September 2024}}
{{Expert needed|telecommunications|date=May 2025}}}}

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 as digits on a receiver's [[remote control]].

Often, virtual channels are implemented in [[digital television]] to help users select channels easily and in general to ease the transition from analogue to [[digital broadcasting]]. Assigning virtual channels is most common where TV stations were colloquially named after the [[Radio frequency|RF]] channel they were transmitting on ("Channel 6 Springfield"), as 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, because 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 called a '''logical channel number''' ('''LCN''') and used for private European [[Digital Video Broadcasting]] extensions widely used by the [[NDS Group]] and by NorDig in other markets.

[[Pay television]] operators were the first to use these systems for channel reassignment and rearrangement to allow them to group channels by content or origin and, to a lesser extent, to localize advertising.

Free-to-air stations using [[Advanced Television Systems Committee standards]] (ATSC) used the same [[North American television frequencies|television frequency channel]] allocation that the [[NTSC]] channel used when both were [[simulcasting]]. They achieved this by the DigiCipher 2 method. Viewers could then use one number to bring up either service.

Free-to-air [[Digital Video Broadcasting|DVB]] network operators, such as [[Freeview (UK)|DTV Services Ltd. (d.b.a. Freeview)]] and [[Freeview (New Zealand)|Freeview New Zealand Ltd.]], use the NorDig method and follow the same practice as pay-TV operators. The exception is [[Freeview (Australia)|Freeview Australia Ltd.]]<!--All three "Freeview" companies only share the name. They are otherwise unrelated.-->, which also use the NorDig method and partly follow the ATSC practice of using the same [[VHF]] radio-frequency channel allocation that the [[PAL]] channel is simulcasting on from the metropolitan station's main transmission point (ie. 2, 7, 9, and 10) with the major and minor format emulated by multiplying by ten.