View source for Program and System Information Protocol

{{short description|Video and audio industry protocol}}
[[Image:MPEG Transport Stream HL.svg|thumb|right|400px|Multiple MPEG programs are combined then sent to a transmitting antenna. An [[ATSC tuner|ATSC receiver]] then decodes the TS and displays it.]]
The '''Program and System Information Protocol''' ('''PSIP''') is the [[MPEG]] (Moving Picture Experts Group, a video and audio industry group) and privately defined [[program-specific information]] originally defined by [[General Instrument]] for the [[DigiCipher 2]] system and later extended for the [[ATSC standards|ATSC]] digital television system for carrying [[metadata]] about each [[communication channel|channel]] in the [[Broadcasting|broadcast]] [[MPEG transport stream]] of a [[television station]] and for publishing information about television programs so that viewers can select what to watch by title and description. Its FM radio equivalent is [[Radio Data System]] (RDS).

==Function==
{{Anchor|What PSIP does}}
PSIP defines [[virtual channel]]s and [[Television content rating systems|content rating]]s, as well as [[electronic program guide]]s with [[title]]s and (optionally) descriptions to be decoded and displayed by the [[ATSC tuner]].<!-- Why is this needed? See Discussion page for full question. -->

PSIP can also send:
* the exact [[time]] referenced to [[UTC]] and [[GPS time]];
* the [[nickname|short name]], which some stations use to publish their callsign. A maximum of seven characters can be used in a short name.

PSIP is defined in ATSC standard '''A/65''', the most recent revision of which is '''A/65:2013''', published in 2013.<ref name=A_65_2013>{{cite tech report |date=7 August 2013 |number=A/65:2013 |title=Program And System Information Protocol For Terrestrial Broadcast And Cable |type=ASTC standard |institution=Advanced Television Systems Committee |url=https://www.atsc.org/standard/a652013-program-and-system-information-protocol-for-terrestrial-broadcast-and-cable/ }}</ref> '''A/69''' is a recommended practice for implementing PSIP in a television station.<ref name=A_69>{{cite tech report |date=25 December 2009 |number=A/69 |title=Program and System Information Protocol Implementation Guidelines for Broadcasters |type=ATSC recommended practice |institution=Advanced Television Systems Committee |url=https://www.atsc.org/recommended-practice/a69-program-and-system-information-protocol-implementation-guidelines-for-broadcasters/ }}</ref>

PSIP also supersedes the '''A/55''' and '''A/56''' protocol methods of delivering program guide information (which the ATSC has deleted). [[TV Guide On Screen]] is a different, proprietary system provided by [[datacasting]] on a single station, while PSIP is required, at least in the United States, to be sent by every digital television station.

PSIP information may be passed through the [[airchain]] using proprietary protocols or through use of the ''Programming Metadata Communication Protocol'' metadata scheme.

===Programming Metadata Communication Protocol===

PMCP, defined in the Advanced Television Systems Committee's A/76B,<ref name=A_76B>{{cite tech report |date=14 January 2008 |number=A/76B |title=Programming Metadata Communication Protocol Standard, Revision B |type=ASTC standard |institution=Advanced Television Systems Committee |url=https://www.atsc.org/standard/a76b-programming-metadata-communication-protocol-standard-revision-b/ }}</ref> provides ATSC broadcasters with a standardized means to exchange system information (SI) among systems that create and manage these data elements. These systems can be outside Program listing services, program management systems, traffic (commercial and program scheduling) and [[broadcast automation]] systems, which all contribute a portion of the PSIP data to a PSIP Generator.

At the heart of PMCP is an [[XML]] Schema (actually a collection of XML Schema Definition files), which provide a standardized structure into which PSI and PSIP-related data may be exchanged. PMCP does not dictate systems' internal database structures; it is simply a platform-independent protocol for the exchange of data.<ref>{{cite web|last=Whitaker|first=Jerry|date=10 March 2004|title=Making PSIP Work for Broadcasters|publisher=NewBay Media, LLC|url=http://www.tvtechnology.com/article/11784|work=TV Technology|access-date=24 March 2011|archive-date=11 January 2010|archive-url=https://web.archive.org/web/20100111051553/http://www.tvtechnology.com/article/11784|url-status=dead}}</ref>

PMCP was first published as A/76 in November 2004,<ref>{{cite press release |last=Hester |first=Lisa |date=18 November 2004 |title=New ATSC PMCP Standard Powers PSIP |location=Washington, DC |url=http://www.atsc.org/cms/index.php/communications/press-releases/122-new-atsc-pmcp-standard-powers-psip|publisher=Advanced Television Systems Committee|access-date=24 March 2011 |url-status=dead |archive-date=25 July 2011 |archive-url=https://web.archive.org/web/20110725022710/http://www.atsc.org/cms/index.php/communications/press-releases/122-new-atsc-pmcp-standard-powers-psip}}</ref>  and enjoys adoption from a variety of broadcast equipment and system vendors. Two revisions (largely backwards-compatible) with the standard have been made. ATSC A/76a extended PMCP to include metadata necessary for proper signaling of [[Advanced Common Application Platform |ACAP]] data broadcast elements, and A/76B, was released in 2007, fixed some errors and made the schema usable with the related SMPTE S2021 (BXF) schema.

==Included tables==
; System Time Table (STT){{efn|name=FCC_req|Indicates a [[Federal Communications Commission]] requirement}}
: Current time, transmitted at least once per [[second]], with an accuracy of new time values within 1 second or better.
; Master Guide Table (MGT){{efn|name=FCC_req}}
: [[Data pointer]]s to other PSIP tables.
; Terrestrial Virtual Channel Table (TVCT){{efn|name=FCC_req}}
: Defines each virtual channel and enables {{abbr|EITs|Event Information Table}} to be associated with the channel.
; Cable Virtual Channel Table (CVCT)
: Assigns numbers to each virtual channel and enables {{abbr|EITs|Event Information Tables}} to be associated with the channel.
; Rating Region Table (RRT)
: Content ratings for each country (region) covered by the station, save the U.S., as that region is loaded into television sets already.
; Event Information Table (EIT){{efn|name=FCC_req}}
: Titles and program guide data.
; Extended Text Table (ETT)
:; Channel Extended Text Table (CETT)
:: Detailed descriptions of channels.
:; Event Extended Text Table (EETT)
:: Detailed descriptions of aired events.
; Directed Channel Change Table ({{vanchor|DCCT}})
: The DCC function lets broadcasters tell a digital television receiver where to change, based upon the viewer's settings. This is most likely to be a [[ZIP Code|ZIP]] or other [[postal code]], which can select [[demographic]]ally-based programming to show, such as [[television commercial]]s or [[weather bulletin]]s, possibly taken from an accompanying [[datacasting]] channel.
: [[Implementation]] of the DCC feature is entirely optional, and depends on development of [[ATSC receiver|receiver]] and decoder technology. For example, a [[digital video recorder]] could record commercial broadcast at other times for later replay, so that many more different commercials could be shown in different parts of a large [[metro area]] than can actually be transmitted at once.
; Directed Channel Change Selection Code Table (DCCSCT)
: Provides for the ability to update states, counties and program genres used in {{abbr|DCCTs|Directed Channel Change Tables}}.

==See also==
* [[Electronic program guide]]

==Notes==
{{notelist}}

==References==
{{reflist}}

==External links==
* {{cite web |url=http://www.etherguidesystems.com/help/sdos/atsc/Syntax/TableSections/Default.aspx |title=Table Sections [ASTC Syntax] |website=EtherGuide Systems |url-status=dead |archive-date=30 December 2016 |archive-url=https://web.archive.org/web/20161230141240/http://www.etherguidesystems.com/help/sdos/atsc/Syntax/TableSections/Default.aspx }}

{{North American DTV}}
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{{Use dmy dates|date=December 2020}}


[[Category:ATSC]]
[[Category:Digital television]]