PBS Satellite Service

Starting in 1971, PBS began distributing programs via telephone lines leased from AT&T.[7][8] 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.[9] The interconnection system consisted of nearly 20,000 miles of telephone lines spread across the country.[8] To send programming, PBS would feed these videotaped programs via their network of phone lines throughout the country.[8] 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.[10] 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).[10] 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."[8] 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.[8] 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.[8] 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.[11]

PBS began to inquire about the use of satellite for program distribution dating back to 1971.[12] PBS quickly discovered the benefits satellite distribution would have on their operations. A satellite-based interconnection system would allow improved video and audio quality.[8] 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.[8] A satellite-based system would also allow for more than one program feed.[8]

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".[13]  Decoders for the DATE system cost up to $11,000 in the mid-1980s.[14] PBS recommended that a station purchase at least two decoders, one of these acting as a backup unit.[14] 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.[14]

In 1976, PBS, as well as NPR, received approval from the FCC regarding their plans to create a satellite-based interconnection network.[10] Implementation of this project began in mid-1977.^[1] PBS launched their satellite interconnection system on March 1, 1978.[15] This was their second-generation interconnection system.[9] At the time, only 24 stations, all located in the southeastern portion of the U.S., were able to receive the satellite feeds.[15] Throughout 1978, satellite dishes were installed at each public television station in the country.[15] At the end of 1978, all public television stations were now receiving programs via satellite, which ended PBS’s terrestrial-based interconnection system.[15] The interconnection system cost $39.5 million to implement and develop.[16] 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.[16] Westar 2, a satellite at orbital position 123.5°W, would be designated as a backup in case of a failure of Westar 1.[8] In 1982, Westar 4 replaced Westar 1 in the same orbital position; PBS transferred their feeds to this new satellite.[17] One primary advantage of Westar 4 was that it contained 24 transponders, compared to Westar 1’s 12 transponders.[18][19]

To communicate with stations, PBS launched a service called the Dial Access Communications System (DACS).[20] DACS, considered a form of "electronic mail," allowed PBS and its stations to communicate with each other about private matters.[21] On July 21, 1995, a new communications system, known as PBS Express, launched.[22] PBS Express launched alongside DACS, which would be discontinued in 1996.[22]

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.[14] 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.[14] 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."[14] PBS had "serious reservations" about this and requested that this section be removed from the proposal.[14] 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.[14] 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.[14] 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.[14] "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.[14] 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?"[14]

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.[13][14] 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."[14] 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.[14] 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."[14] 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."[14] In April 1988, PBS began encoding programs with VideoCipher II.[13] 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.[23] 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.[13]

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.'"[23] 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.[23]

In 1987, PBS, along with the Corporation for Public Broadcasting (CPB), approached Congress with a request upgrade the interconnection system.[24] 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.[13] "The satellite currently used by public television (Westar 4) will run out of fuel by mid-1991, which means that public television must find new satellite capacity," he said in a statement.[13] "Faced with a failing satellite and deteriorating ground facilities, public television must acquire a new satellite distribution system if it is to continue its present services, let alone provide new opportunities for all Americans, in the future."[13] The proposal, "authorizes an additional $200 million to be used over a three year period to replace the satellite interconnection system."[13]

The Public Telecommunications Act of 1988 became law on November 7, 1988, guarantee funding for the upgrade of PBS’s interconnection system.[25] 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.[26] 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.[24] The committee was made up of "designated representatives of the public stations".[24] This committee approved a satellite replacement plan in December 1981, with PBS's board endorsing the plan.[24] In this plan, PBS would continue to lease four C-band transponders starting in 1991, with the goal being to convert their satellite operations to Ku-band sometime in 1993 or 1994.[24] In 1991, PBS purchased C-band transponder space on the Spacenet 1 satellite, owned by GTE, at orbital position 120°W.[9] This move occurred on January 3, 1991.[1][17] This began the third generation of PBS’s interconnection system. The system was guaranteed to last at least 15 years, until 2006.[9] PBS later moved their feeds to a new satellite, Spacenet 4, at orbital position 101°W, on July 18, 1992.[1][17]

The move to Spacenet 1 and, later, Spacenet 4 was only a temporary solution. In 1989, an agreement was reached with AT&T for PBS to purchase transponder space on a new satellite named Telstar 401, which wouldn’t launch until 1993.[9] Six Ku-band transponders were purchased, but one C-band transponder was purchased; this C-band transponder was purchased to fulfill the "clear feed" requirement in the Public Telecommunication Act of 1988.[9] This C-band feed was the "PBS-X" service. PBS’s primary reason for converting to a Ku-band system was to take advantage of "more advanced technical capabilities available on Ku-band transponders," such as increased transponder bandwidth and an increase in the number of services that could be provided.[9] PBS also wanted to create an “educational neighborhood” on Telstar 401 where other public educational services, including PBS’s services, would be on the same satellite.[9] PBS said that as many as 80 educational services would be provided via Telstar 401, allowing libraries, schools, and universities to access a multitude of programming on the same satellite.[27] Telstar 401 launched on December 16, 1993.[28] PBS moved to Telstar 401, at orbital position 97°W, on February 5, 1994, ending primary program distribution to affiliates via C-band.[1][17] Telstar 402R, a satellite that launched to orbital position 89°W on September 24, 1995, would serve as a backup.[28]

In 1994, with the launch of the Ku-Band feeds, PBS began testing DigiCipher I, the digital equivalent to VideoCipher.[27] Initial tests proved to be successful, leading PBS to adopt DigiCipher I for all their services in August 1994.[27] PBS had wanted to use the newest version of DigiCipher, known as DigiCipher II, but due to "delays in the adoption of MPEG-2," PBS said that they wouldn’t be able to utilize DigiCipher II until  "late 1995".[27] Sometime in early 1996, PBS made the switch to DigiCipher II and, in the process, converted their services from analog to digital.[17]

On January 11, 1997, at 6:15 a.m., Telstar 401 suffered a failure due to a coronal mass ejection.[29] AT&T tried to re-establish contact with the satellite, but all attempts failed.[30] To restore service, PBS temporarily moved their feeds to Telstar 402R (later Telstar 4).[31] To prevent noticeable interruption to their service, PBS carried out a Satellite Service Recovery Plan.[9] It took “less than 25 minutes” for PBS to switch service to Telstar 402R, preventing a severe disruption to their services.[9]

The fourth generation of the interconnection system launched in 1997.[9] In April, an agreement was made with GE Americom for PBS to purchase transponder space on GE-3, a satellite at orbital position 87W that launched on August 9, 1996.[32][9] PBS moved to GE-3 in October 1997. The use of this satellite caused some trouble for areas outside too contiguous U.S., such as Alaska and the Caribbean islands, because these areas were outside the satellite’s footprint.[9] To remedy this, PBS purchase one C-band transponder on another GE satellite, GE-1, which was at orbital position 131°W.[9] There were not many major changes between the third and fourth generation interconnection systems.

In 2004, PBS published a proposal for the fifth generation of their interconnection system, known as the Next Generation Interconnection System (NGIS).[9] PBS and the CPB expected the upgrade to cost $177 million. PBS had three reasons for upgrading the interconnection system, one of these being that their satellite contracts were scheduled to end on October 4, 2006. The current fourth generation interconnection system would be 15 years old in 2006; PBS said that this system "has run its course" and needed to be upgraded.[9] Adding on to this, PBS wanted a new system that could fully support digital television. One other reason for the upgrade involved "[leveraging] new technologies to enhance efficiency and service to stations."[9] PBS warned that the NGIS must be operational by October 4, 2016, otherwise, "PTV will be unable to function in its current form."[9] One important aspect of the NGIS was that it would allow PBS to distribute programs in non-real time (NRT) by sending programs as digital video files to public television station by using a terrestrial Internet-based network. PBS said that the "vast majority" of programming would be sent via NRT distribution, a move away from the tape-based interconnection system currently in use.[9] Files would be stored on "cache servers" at each public television station.[9] Even with NRT program distribution, PBS was still committed to satellite distribution, but mainly reserved satellite distribution for live or near-live programs with a "short turnaround," such as A Capitol Fourth, Charlie Rose, and The NewsHour with Jim Lehrer; other programs besides these, such as children’s programming and other general prerecorded programs, would still be fed via satellite.[9] The NGIS would also revolve heavily revolve around the Internet, allowing public television stations and PBS to contact each other more easily.[9]

PBS stated within their report that the NGIS would lead to "increased efficiency" of the distribution or programs.[9] According to PBS, "smaller, financially strained, rural market" stations would air a program as it was being fed via satellite; this was done to save costs.[9] This method led to many "redundant national program feeds," with PBS saying that one program would be fed "as many as five times or more" in a single day.[9] Some of these refeeds would also occur due to weather interfering with satellite reception or due to problems recording the program to tape. In 2001, PBS distributed nearly 120,000 hours of programming through their interconnection system; according to PBS, "all but 7,000 hours were repeated programming" feeds.[9] By using NRT distribution, these redundant feeds would be greatly reduced. The NGIS would also save be cheaper to operate, with station expected to save between $50,000 and $250,000 ever year.[9] PBS expected this system to last about 10 years. The NGIS would launch in October 2006. When the new system launched, PBS launched a transponder that would carry IP data via satellite; this would be the feed used for NRT program distribution.[9] PBS also made the switch to DVB-S MPEG-2 when the new system was launched.

During planning for the NGIS, PBS considered seven different models for this interconnection system.[9]

• The first model would’ve continued the current operations of the fourth generation interconnection system, with all programming being fed via satellite. The number of transponders would decrease from seven to six. PBS eliminated this model from consideration because they claimed that this was no longer an adequate option due to advancements in digital television; NRT distribution was also not possible.[9]

• The second model was like the first model but would make use of a local "cache server" at the public television station.[9] This model would have considerably decreased the number of transponders, going from seven to three. This model was eliminated for the same reasons as the first model.[9]

• The third model incorporated both satellite and terrestrial distribution, in addition to "terrestrial transaction management".[9] PBS selected this model due to its "reasonable cost and low risk".[9]

• The fourth model would’ve reserved satellite distribution solely for real-time programming and terrestrial distribution solely for non-real time programming.[9] This model was eliminated due to "high operational and implementation costs," with PBS saying the cost of this model would have been "double" that of the model selected for the NGIS.[9]

• The fifth model was like the first model, an all-satellite distribution system, but would’ve incorporated both Ku-band and Ka-band satellite.[9] PBS said that there was "significant risk" with this model because, at the time, Ka-band technology was "untested," meaning they had no "proven business model" of a Ka-band system operating without trouble.[9] At that time, Ka-band satellites for commercial use did not exist, not to mention that investment costs that covered the satellite’s lifespan could total up to $2 billion.[9] PBS also didn’t think "any satellite communications company will base their operation on public broadcasting's business".[9]

• The sixth model would’ve created a terrestrial interconnection system that would’ve distributed all programs, both real-time and NRT.[9] Satellite would continue to be used for "a small percentage of live and near-live programs," but terrestrial distribution would be the primary method of distribution.[9] This model was eliminated due to "extremely high capital and operating costs," with this model expected to cost nearly three times the operating price of the current NGIS model.[9] PBS noted that terrestrial distribution at this scale wasn’t yet possible, but said, "In the future, this model may provide significant opportunities."[9]

• The seventh model, the last to be considered, would use satellite to distribute live and near-live programs, but all other programs would be distributed to stations via "fixed media," such as DVDs.[9] This method has similarities to the "bicycling tapes" system used by PBS before 1971 in that stations would receive a physical copy of programs, being DVDs in this case, through the mail, but these DVDs would not be sent to other stations after one station was finished broadcasting the program. This model was eliminated because it would have created "significant operational complexity" for the public television stations, in addition to there being an "extremely high operational cost and complexity and high risk."[9]

In 2008, PBS switched to a new satellite, AMC-21, which would be in orbital position 125W.[33] In October 2012, PBS began encoding their feeds in the DVB-S2 MPEG-4 codec, which they cuirrently use.[34][2]

In June 2015, the CPB began to consider options for the sixth generation of PBS’s interconnection system, known at the time as "v6".[35] 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.[35] Included in this report were the results of interviews with twelve public television stations, who were chosen as a representative sample of all public television stations; these stations were asked about their satisfaction with the fifth generation interconnection system, the NGIS (referenced in the report, and hereafter, as "v5").[35] Two-thirds of interviewed stations, eight out the chosen twelve, expressed dissatisfaction with the current version of the interconnection system.[35] Overall, according to these stations, the v5 system was able to "effectively" distribute live and near-live content, but as for NRT content, this was where the v5 system failed.[35] NRT program feeds were not "reliable" nor were they "consistent," and because of this, there were "many" stations, according to the report, that did not "fully adopted v5"; two stations that were interviewed "did not use the v5 system at all".[35] Indeed, the delivery of NRT content was the biggest problem with the v5 system, with 90% of stations (based on the representative sample size described earlier) agreeing that receiving NRT content was problematic. With that, Cognizant's recommendation was "that the system adopt a single interconnection system that is cloud-based, using mainly the public internet and an ecosystem of centralized master control service providers".[35] The selected model would primarily utilize "a terrestrial fiber-based network," with satellite being used as a back-up.[35] This system would decrease the number of transponders used by PBS from three to one. As part of this plan, PBS would switch their primary feeds back to the C-band spectrum beginning in March 2016; however, this transition never occurred. The primary plan was to transition linear program feeds via satellite, as well as programs fed via the NRT transponder, to the terrestrial-based system.[35] One of the key benefits of the v6 system was that it would allow stations to send content to each other via FTP (File Transfer Protocol), allowing for P2P (peer-to-peer) sharing.[35] By using an FTP client, all stations could send easily send content to each other. However, stations could still receive physical media, such as tapes (usually HDCAM) and disks (usually XDCAM discs) “via courier service”.[35] The v6 system also allowed for cloud-based storage of content instead of local storage, which allowed for a more efficient approach to storing and managing content, as well as the possibility for a "joint master control" operations.[35] CPB expected this system to be completed and operational by May 2018.[35] The CPB tasked Vigor Systems, Inc. with developing and deploying the new interconnection system.[35] According to Vigor, this interconnection system is known as sIX ("six"), the official meaning being "Service Interconnection."[35]

Testing of sIX commenced in March 2018.[35] With initial tests proving successful, PBS discontinued their NRT (non-real-time) file-based transponder on AMC-21, created as part of the NGIS interconnection system, sometime in Q4 2018.[36] The goal was to move all linear-fed content to sIX in the near future. The rollout of sIX is occurring in several phases.[35] Phase 1 involved phasing out the NRT file-based Ku-band transponder. Phase 2 began in 2020 and is currently ongoing, which according to a May 2021 report from the CPB, "considers future options for the delivery of linear and live content."[37] The report says that later stages will be "defined as business and technology needs evolve."[37] 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.[35] According to KNME (New Mexico PBS), "99% of Public Television Stations have successfully implemented sIX functionality".[38]

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 feed, shutting down on September 5, 2016.[39] Two years later, as previously mentioned, the NRT file-based transponder was shut down sometime near the end of 2018.[36] On March 4, 2019, PBS's C-Band feed on SES-3 (103°W) was discontinued, leaving PBS with no active C-band transponders for the first time.[40] On November 13, 2019, PBS discontinued their SD07 Ku-band feed on AMC-21, which was uplinked from SCETV in Columbia, South Carolina.[41]

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.[42] Program uplinks from KNME, with the exception of Democracy Now!, also migrated to sIX. However, select programs from APT, such as Consuelo Mack Wealthtrack and GZERO World with Ian Bremmer continue to be fed via satellite on HD03. 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 feeds 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). 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.