PBS Satellite Service

The PBS Satellite Service (also known as the PBS National Program Service, with the primary C-band feed being formerly known as PBS Schedule X in Eastern Time, with the West Coast delay signal designated PBS-XP) consists of feeds relayed from PBS by satellite to public television stations throughout the United States. The service launched on March 1, 1978, with wider adoption beginning in September 1978 as more satellite downlinks were installed at each PBS stations. The service provides a mixed variety of programming selected from PBS's regular network services. In the X/XP years a satellite feed was multicast by some PBS member stations on an over-the-air DTV subchannel along with their regular programming, or during overnight hours on their main channel to provide a second opportunity for viewers to watch or record primetime programming.

PBS currently utilizes one transponder on the Galaxy 16 satellite, transponder 22. This is a MCPC (multiple channel per carrier) which currently has seven channels uplinked from the PBS NOC (Network Operations Center) in Alexandria, Virginia. However, in the event of approaching weather or technical difficulties at the NOC in Virginia, PBS will switch to a backup uplink location in Lincoln, Nebraska.

Currently, select stations broadcast the feed, usually overnight, like KGTF (PBS Guam, broadcasts most of the channel as a localised feed). The primary feed, known as HD01, is also available over satellite providers like DirecTV (Channel 389), though this feed is down-converted to SD. PBS provides all of their channels free to TV providers who do not receive local member stations.

As of 2026, PBS's satellite feeds, as well as a few other PBS stations, can be received unscrambled using a free-to-air satellite receiver set to these coordinates:

• PBS National Program Service at 99°W (on the Galaxy 16 satellite), K_u-band, unencrypted.
• Montana PBS at 99°W (on the Galaxy 16 satellite), K_u-band, unencrypted. Their removal from satellite coincided with the completion of their transition to fiber distribution. In March 2026, LPB begain simulasting on the SES-1 satellite. Later in the month, LPB shut down their transponder on SES-2 at 87ºW (where the station has been uplinking to since 2003 when it was originally known as AMC-3) competing the transition to SES-1.

PBS transitioned to a fiber-based interconnection system known as sIX, otherwise known as the sixth generation of PBS's interconnection system, in July 2021. The original end date for linear program feeds via satellite was slated for 2016, but was later pushed to 2018, and was then pushed again to the beginning of 2021; none of these deadlines were met. PBS's main network feeds are still active as of March 2026; however, only one NPS soft-feed service remains, namely HD03. The only programs airing on this feed are news and public affairs programming; all other linear program feeds have moved to sIX; however, there may occasionally be an unannounced feed of program unrelated to news or public affairs, such as re-feeds of certain live events, such as certain episodes of Great Performances.

History

1971–1978: The First-Generation Interconnection System

Starting in 1971, PBS began distributing programs via microwave relay circuits leased from AT&T Long Lines. This was the first generation of PBS's interconnection system. Prior to this, PBS would distribute programs to stations via "bicycling tapes," meaning that tapes would be shipped between stations through the mail. The interconnection system consisted of nearly 20,000 miles of microwave paths spread across the country. Examples of these regional networks included the Southern Educational Communications Association (SECA), which is now known as the National Educational Telecommunications Association (NETA); the Central Educational Network (CEN); the Eastern Educational Television Network (EEN), which is now known as American Public Television (APT); and Midwestern Educational Television (MET). Another issue was that this system was single channel only, meaning that PBS could not feed multiple programs at the same time, giving stations less programming options.

PBS began to inquire about the use of satellite for program distribution dating back to 1971. PBS quickly discovered the benefits satellite distribution would have on their operations. A satellite-based interconnection system would allow improved video and audio quality. This system consisted of four 15-KHz audio channels that would be "multiplexed" and transmitted via a "5.5-KHz subcarrier located above the video."  Decoders for the DATE system cost up to $11,000 in the mid-1980s. PBS recommended that a station purchase at least two decoders, one of these acting as a backup unit. ($226,854,261.86 adjusted for inflation as of March 2026). The details of the contract with Western Union follow: Western Union split the country into various segments during the implementation phase. One primary advantage of Westar 4 was that it contained 24 transponders, compared to Westar 1's 12 transponders.

Direct/Dial Access Communication System (DACS)

To communicate with stations, PBS launched a service called the Dial (later Direct) Access Communications System (DACS). DACS launched in 1981. DACS was transmitted in Line 13 of the VBI of their satellite feeds. On July 21, 1995, a new communications system, known as PBS Express, launched. PBS Express launched alongside DACS, which would be discontinued in 1996. It is unknown what – if any – meaning the abbreviation "NOLA" has. A simple NOLA code is formatted as such: [NOLA 000000]. These codes are assigned to every public television program distributed by APT, NETA, and PBS. For example, the Masterpiece series is assigned the NOLA code "MAST". Further, the complete NOLA code for episode one of the Downton Abbey series (broadcast as season 41, episode 01 of the Masterpiece franchise) would be: [MAST 004101]. Additional NOLA codes include "FRON" for Frontline, "GPER" for Great Performances, and "MLNH" for PBS News Hour.

1987: Controversy Surrounding Potential Use of VideoCipher II

During this time, PBS did not utilize any type of encryption on their feeds. However, beginning in mid-1987, PBS began to explore the possibility of encoding their feeds with VideoCipher II. PBS, however, would encrypt the feeds anytime they aired what they referred to as "private communications," which include teleconferences and previews of programs that they haven't yet received broadcast rights for; all other programs remained unencrypted. On March 15, 1988, Bruce L. Christensen, the President of PBS at the time, appeared before a Senate committee to discuss the proposed Public Telecommunications Act of 1988. This act included a provision stating that PBS must provide a "clear" feed of its programming to home-dish viewers who do not have a decoder. This act also created a committee to research and propose new plans regarding replacement of the satellite used for the interconnection system, known as the Public Television Interconnection Committee. Telstar 401 launched on December 16, 1993. PBS moved to Telstar 401, at orbital position 97°W, on February 5, 1994, ending primary program distribution to affiliates via C-band. AT&T tried to re-establish contact with the satellite, but all attempts failed. To restore service, PBS temporarily moved their feeds to Telstar 402R (later Telstar 4). To prevent noticeable interruption to their service, PBS carried out a Satellite Service Recovery Plan. During time on Telstar 402R, PBS began researching options to restore full service. Two proposals from Loral Space Systems and GE American were submitted to PBS for consideration. These proposals are listed below: On October 6, leased analog and digital services on TX #9 and TX #18, respectively, were added. On October 15, PBS's MCPC feeds, now encoded in DigiCipher II, would be added to TX #24 (same schedules as the DigiCipher I transponder with the addition of Schedule 8). The DigiCipher I MCPC transponder would be removed on November 2 and new DTV test feeds would be added to TX #7. TX #9 would also become the home of The Business Channel, in addition to other analog services. In mid-November, services on three transponders were moved to other transponders: services on TX 9 move to TX 19, the DTV feed moved from TX 7 to TX 21, and services on TX 3 move to TX 23. Once the move was completed in the beginning of 1998, PBS would own TX 18-24 on GE-3. In October 2012, PBS began encoding their feeds in the DVB-S2 MPEG-4 codec, which they currently use. To help consider their options, they commissioned the help of Cognizant Technology Solutions to come up with a new cost-effective solution to improve the Public Television Interconnection System. A report discussing the proposed model for the sixth generation of the interconnection system was published in November 2015. The CPB tasked Vigor Systems, Inc. with developing and deploying the new interconnection system. Other codecs that are approved for use when delivering in HD are three versions of the DNxHD codec: DNx145, DNx220, and DNx220x.

Transition away from satellite

With initial tests of sIX throughout 2018 proving successful, PBS discontinued their NRT (non-real-time) file-based services on AMC-21, NR01 and NR02, created as part of the NGIS interconnection system, on January 2, 2019; with the closure of the NGIS NRT service, this marked the official launch of the sIX system. The goal was to move all linear-fed content to sIX in the near future. PBS has expressed that they will continue to lease transponder space for live and near-live programs, such as the PBS NewsHour; PBS will also continue to lease transponder space in the event their sIX system suddenly fails or experiences an outage.

As the transition to sIX has progressed, PBS began to shut down some of their NPS satellite distribution feeds. The first feed to shut down was PBS's SD01 service, shutting down on September 5, 2016; this occurred before the transition to sIX. Two years later, as previously mentioned, the NRT file-based service was shut down sometime near the end of 2018. On November 13, 2019, PBS discontinued their SD07 Ku-band service on AMC-21, which was uplinked from SCETV in Columbia, South Carolina. All programming on SD07 could be found on HD04, albeit in HD.

The transition to sIX accelerated in March 2021 when APT began to transition select programs off satellite and into the sIX system. In July 2021, programming from the NETA and APT migrated fully to sIX, ending distribution via satellite. However, two programs from APT – Consuelo Mack WealthTrack and GZERO World with Ian Bremmer – continue to be fed via satellite on HD03 on Fridays. Program uplinks from KNME, with the exception of Democracy Now! until the closure of the HD05 service on May 31, 2023, also migrated to sIX. PBS themselves had also migrated many regular, non-news linear feeds to sIX, including feeds of pledge programs, which were last fed in May 2021. The only content left on their three (at the time) primary NPS HD distribution feeds, HD03, HD04, and HD05, was news and public affairs programming. On July 21, 2021, a few weeks after this transition, PBS decommissioned two more satellite feeds, SD05 and SD06, at 2:56 p.m. ET.

On January 20, 2023, PBS's main transponder on AMC-21 (which included HD01-HD03, HD06, SD02, SD04, and SD08) began simulcasting on Galaxy 16, a satellite at orbital position 99°W. On May 3, 2023, a ticker appeared on HD04 and HD05 alerting that both services would shut down on June 1, 2023, at 00:00 UTC (May 31, 2023, 8:00 p.m. ET); the ticker was later updated on May 25, 2023, with a new shutoff date of May 31, 2023, at 23:59:59 p.m. ET (11:59:59 p.m. ET). In the ticker, PBS said that program feeds on HD04 and HD05 would move to two new terrestrial-based services, HD64 and HD65. On May 31, 2023, at 11:58:52 p.m. ET, PBS completed the move to Galaxy 16. HD04 and HD05 were decommissioned at the same time.

In 2024, PBS started testing new terrestrial feeds as part of their sIX interconnection system. These services are the same as the current satellite feeds on Galaxy 16 (HD01, HD02, HD03, HD06, Create, and World). A terrestrial feed of HD03 launched on the sIX platform in December 2024. FNX will be added at a later date. This is part of a new phase on the sIX rollout known as Phase F2, which is currently ongoing. It is not known whether PBS will decommission the satellite feeds once Phase F2 is complete. For now, stations record programs from both the satellite and terrestrial feeds, with one or the other acting as a backup. The sIX file-based system also acts as a backup.

sIX Rollout Phases

The rollout of sIX is occurring in several phases: The report says that later stages will be "defined as business and technology needs evolve."

• Phase F1 (2022 - May 31, 2023) involved transitioning feeds from the HD04 and HD05 satellite services to the new HD64 and HD65 terrestrial services.
• Phase F2 (2023 - present) involves rolling out terrestrial services that mirror the services uplinked via satellite.

Overview of Past Services

Schedules A-E (1978 - August 15, 1994)

Throughout much of their history on satellite, PBS utilized four transponders corresponding to a different "Schedule," namely 'Schedule A,' 'Schedule B,' 'Schedule C,' and 'Schedule D'. Another feed, Schedule E, launched in 1988. Also starting around 1988, PBS would begin displaying an on-screen schedule on their feeds; this was in response to confusion and concerns from home dish users concerning schedule availability. to coincide with an ongoing transition to digital, PBS launched nine new services to replace the former A, B, C, D, and E feeds, namely: 5A0, 5A5, 5B0, 5B5, 5B6, 6, 7L, 7U, and 8. Some of these services, such as Schedule 5A0 and 5A5, shared the same MCPC transponder. this service originated from CPTV in Hartford, CT, most of the time. Schedule 512 was reserved for regional uplinks and other SD content. it is unknown when this service shut down or what content was fed. Schedule 505, based on available information, was decommissioned by PBS around April 2007 and was replaced with the Vme channel. Another new service, Schedule 515, launched in 2006; this would become the feed for the Create channel. Other full-time services were Schedules 500 (PBS-X) and later 540 (PBS-X West), 541 (PBS Kids channel until 2005), 542 (PBS You until 2005), and 543 (PBS-X East).

Adult Learning Service

During its operation, the PBS Adult Learning Service (ALS) fed programming via satellite, offering college telecourses and other adult education programs. When the service launched on August 29, 1981, feeds occurred on Schedule A during weekends. The ALS was most active during academic semesters, mainly during the Fall semester (August–December) and Spring semester (January–May), though there would be occasional "blockfeeds" (multiple episodes of one program, usually more than two episodes, fed in a row) during the months of June and July. In addition to PBS programs produced for the ALS, programs from Annenberg/CPB were also fed on this service. The ALS was discontinued in September 2005.

The Beginning of the HD Transition

DT1A, DT1B, DT1C, DT2A, and DT3A

DT1A-DT1C (Appx. Late 2005 - November 2006)

DT1A-DT1C were duplicates of the existing DigiCipher II PBS-X feeds: Schedules 500 (PBS-X), 540 (PBS-XP), and 543 (PBS-X). DT1A-DT1C, however, were DVB services. These services launched around late 2005 as PBS began to transition away from DigiCipher II. All programming that aired on 500, 540, and 543 aired at the same time on DT1A-DT1C. DT1A was a simulcast of 500, DT1B was a simulcast of 543, and DT1C was a simulcast of 540. DT1A-DT1C was on TX (transponder) #21, while the legacy DigiCipher II feeds (500, 540, and 543) were on TX #20. PBS shut down their DigiCipher II MCPC feeds around September 2006; the new DVB MCPC feeds launched on the same transponder. TX #20 shut down around November 2006., PBS launched a new HD service called DT2A, which would become the PBS HD Channel. This service broadcast a small variety of born HD and HD upconverted programs. As the years progressed, more HD programming was added to the service. With DT2A being the only national HD service PBS provided at the time, primetime programming from 8:00 p.m. ET to 11:00 p.m. ET would be repeated three hours later, from 11:00 p.m. ET to 2:00 a.m. ET, to benefit stations on the West coast.

DT3A (Early 2008 - December 21, 2008)

DT3A launched in early 2008. DT3A was the primary HD soft feed channel that was used to feed HD content to stations, such as HD broadcasts of the PBS NewsHour (then known as The NewsHour with Jim Lehrer).

December 2008: Full Transition (HD01-HD04 and SD01-SD07)

In December 2008, with the transition to HD, PBS launched new services that would phase out and consolidate some of their existing SD services. Schedule 540 feeds (PBS-XP) moved to HD02. HD03 would become the main service used by PBS to distribute HD content to stations. This service would carry content such as soft feeds, promo reels (from PBS and APT), pledge feeds, preview feeds, and other distributor content, such as content from APT. HD05, like HD04, was occasionally uplinked from various sites as well as the PBS NOC. Pledge feeds were likely to be uplinked on this feed as well during pledge seasons until February 2021, when nearly all pledge feeds moved to HD03. Daily feeds on HD05 included two feeds of Democracy Now! (originating from KNME) and two feeds from DW (DW News and The Day). Weekly feeds included a feed of DW's Euromaxx on Tuesdays and a feed of White House Chronicle on Fridays. Other weekly feeds included a feed of Florida Crossroads on Monday and Capitol Update on Fridays and Saturdays (originating from WFSU), as well as two back-to-back feeds of Market to Market (originating from Iowa PBS). HD05 did serve as the feed reserved for live political events covered by the PBS NewsHour. These broadcasts were originally fed on SD05 until the feed was shut down on July 21, 2021. This feed shut down on May 31, 2023. The final feed was a 4:30 p.m ET airing of DW's The Day.

October 2016: Launch of HD06

The newest feed to be launched by PBS was their HD06 feed in October 2016, initially airing only a test pattern. This feed was reserved for the new iteration of the PBS Kids channel, which launched in January 2017.

Current satellite services

PBS's National Program Service is freely and nationally available from the designated Ku-band broadcast satellites using free-to-air satellite dishes as small as 30 inches. Before PBS's transition to their new interconnection system in July 2021, the three (at the time) 'Schedule' feeds (HD03, HD04, HD05) used to broadcast different programs at various times throughout the day, with weekends and late night hours usually having no feeds. Some program feeds were only temporary and were usually not consistent. PBS would usually feed programs a few days to as long as a few weeks in advance. The former SD05 and SD06 services were rarely utilized, usually showing a test pattern for the whole day, though SD05 would occasionally show live feeds of major political events, such as confirmation hearings for new Supreme Court justices and, more recently, the entirety of the first and second impeachment trials of former President Donald Trump. SD05 (and sometimes SD06) was also used to host teleconferences from APT. The next few paragraphs will only discuss the HD services provided by PBS (HD01, HD02, HD03, and HD06). All services, including SD02, SD04, and SD08, are uplinked from the PBS NOC 24/7.

HD01 and HD02

HD01 and HD02 are the two primary services provided by PBS. Both services also feed PBS News Hour and Amanpour & Company on weekdays. Premieres of new programming feed during primetime on weekdays. and one feed of Amanpour & Company every weekday. Consuelo Mack WealthTrack, GZERO World with Ian Bremmer, MotorWeek, To the Contrary with Bonnie Erbé, and White House Chronicle continue to be fed on Fridays. On January 16, 2026, two new programs were added to the Friday schedule: Compass Points from PBS News and Horizons from PBS News, these programs replacing PBS News Weekend, which was canceled on January 11, 2026.