Satellite feeds of national PBS programming
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.
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 2023, 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 affiliate KETA, part of the Oklahoma Educational Television Authority (OETA), was also available on AMC-21 until June 2016. Their removal from satellite coincided with the completion of their transition to fiber distribution.
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 June 2023; however, only one NPS feed 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 "Great Performances".
History.
1971–1978: The First-Generation Interconnection System.
Starting in 1971, PBS began distributing programs via microwave relay circuits leased from AT&amp;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. To send programming, PBS would feed these videotaped programs via the AT&amp;T network of microwave relay circuits throughout the country. Instead of each program being received by each individual public television station, these programs were fed to "regional networks," which would then redirect these feeds to stations within their network. 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). This system made use of a "round-robin" method when distributing programming; this meant that, "a number of stations on the loop can originate to all other stations in the system." The system, however, had its limits. One problem was that video and audio quality would be lessened the farther away a receiving station was due to the distance the program had to travel via the interconnection system. Furthermore, areas outside the contiguous U.S., such as Hawaii, was not "economically feasible," all stations received the same feed, and there was no ability for a second or alternate program feed. In addition, according to PBS, the use of telephone lines to deliver programming was "incapable of producing high-fidelity sound," so they started to look for an alternate method of distributing programming.
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. Unlike the terrestrial-based system, where quality degrades the farther the signal travels, programs fed via satellite would suffer no loss in quality; each station would receive the same copy of the program. A satellite-based system would also allow for more than one program feed.
Before the transition to satellite, PBS utilized what was known as DATE (Digital Audio for TElevision) to transmit stereo audio; however, according to PBS, it was never widely adopted due to "high cost".  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. By 1987, "less than half of PBS’s member stations" could adequately decode and broadcast DATE audio signals due to these high costs and the lack of available parts.
1978: The Launch of the Second-Generation, Satellite-Based Interconnection System.
In 1976, PBS, as well as NPR, received approval from the FCC regarding their plans to create a satellite-based interconnection network. Implementation of this project began in mid-1977.[1] PBS launched their satellite interconnection system on March 1, 1978. This was their second-generation interconnection system. At the time, only 24 stations, all located in the southeastern portion of the U.S., were able to receive the satellite feeds. Throughout 1978, satellite dishes were installed at each public television station in the country. At the end of 1978, all public television stations were now receiving programs via satellite, which ended PBS’s terrestrial-based interconnection system. The interconnection system cost $39.5 million to implement and develop. PBS originally utilized three full-time C-band transponders on the Westar 1 satellite, at orbital position 99°W, to deliver programing, but they also leased a fourth "occasional" transponder beginning sometime in 1980. Westar 2, a satellite at orbital position 123.5°W, would be designated as a backup in case of a failure of Westar 1. In 1982, Westar 4 replaced Westar 1 in the same orbital position; PBS transferred their feeds to this new satellite. One primary advantage of Westar 4 was that it contained 24 transponders, compared to Westar 1’s 12 transponders.
To communicate with stations, PBS launched a service called the Dial Access Communications System (DACS). DACS, considered a form of "electronic mail," allowed PBS and its stations to communicate with each other about private matters. On July 21, 1995, a new communications system, known as PBS Express, launched. PBS Express launched alongside DACS, which would be discontinued in 1996. Stations now communicate private matters via myPBS, launched in 2013, which is where stations are alerted to new program offers from PBS and other distributors, any schedule changes, or program availability changes. Other station matters are also communicated via The Hub.
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. With PBS planning to encode their feeds with VideoCipher II, home-dish viewers of PBS’s feeds began to voice concerns that PBS was preparing to encrypt their feeds. One of these viewers was named Diane Friedel Davis, who lived in St. Joe, Arkansas, a rural part of the state; she appeared before a congressional hearing on July 31, 1987, to discuss the recently proposed Satellite TV Fair Marketing Act. This act, as it relates to public broadcasting, stipulated, "No person shall encrypt or continue to encrypt satellite delivered Public Broadcasting Service programming intended for public viewing by retransmission by public broadcast stations." PBS had "serious reservations" about this and requested that this section be removed from the proposal. Michael E. Hobbs, the former Vice President of Policy and Planning for PBS, urged congress to remove this section. "We urge you to delete the section that prohibits PBS from scrambling: not because we want to scramble, but because the practical effect of that section would be to freeze public television in the backwater of an obsolescent technology, and deny real benefits to home dish owners and broadcast viewers alike," he said in a statement. In Diane’s statement, she echoed the sentiment felt by home-dish viewers at the time by expressing her worry about PBS potentially encrypting their signals. "PBS… [does] not have a right to scramble our public airwaves," she said in her statement. In a written statement, she said that using a satellite dish was the only way for her to receive television broadcasts because not only would a television antenna not receive a signal, but the local cable company was not willing to travel such a long distance to establish service. "If a satellite dish is the only way a person can receive that signal, then he/she should be allowed access," she said in her written statement. She continued, "There are the farmers, the elderly, the physically challenged, and millions of rural Americans who, for one reason or another, live in remote and isolated areas of this vast country. For them, television is their window. Should these people be denied their First Amendment rights just because they do not live in urban or suburban areas where a television signal is received over a standard VHF antenna?"
According to PBS during the July 1987 hearing, VideoCipher II would not be used for general encryption purposes, but rather more efficient stereo audio and the opportunity to add other audio services, such as Descriptive Video Service or a Secondary Audio Program. David Hobbs later explained more concerning the reasoning for using VideoCipher II. "We are planning to use that technology to install stereo audio capability system-wide, a dream that we have had in public television for 20 years. We are also working on the development of Descriptive Video Services for the blind, and multi-lingual audio tracks for the non-English-speakers in our audience." Utilizing VideoCipher II would also be cheaper for PBS and its stations; VideoCipher II decoders cost an average of $500 and could be easily found on the market. He also made clear that PBS’s proposal to use VideoCipher II did not mean eventual encryption. "We at PBS are proud to have worked vigorously since our earliest days to extend public television service to as many Americans as possible. …In keeping with that commitment, PBS has never scrambled any satellite transmission of our program service. We have not done so, and we have no plan to do so." In a later statement, he reaffirmed this point again by saying, "At the outset, I would like to say once again that PBS has no plans to encrypt its regular program transmissions." In April 1988, PBS began encoding programs with VideoCipher II. The feeds were usually broadcast in a "fixed key" mode (usually 0000), which allowed anyone with a VideoCipher II receiver to be able to receive these feeds. 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.
The use of VideoCipher II also created confusion among home-dish users who did not have a way to view content encoded with VideoCipher II since, "they have not been able to get reliable information as to the schedule for PBS's 'clear feeds.'" To combat this, PBS took several steps to accommodate these viewers: publishing schedules in satellite magazines, broadcasting nearly every "clear" program transmission on one transponder, broadcasting a slate showing a program schedule, creating an office to answer viewer questions, broadcasting an audio barker message to explain how to obtain a schedule, and sending viewers a monthly schedule of programs upon request.
1991–1997: The Third-Generation Interconnection System.
In 1987, PBS, along with the Corporation for Public Broadcasting (CPB), approached Congress with a request upgrade the interconnection system. On March 15, 1988, Bruce L. Christensen, the President of PBS at the time, appeared before a Senate committee to discuss the