Editing 8VSB (section)

==Disputes over ATSC's use==
For some period of time, there had been a continuing lobby for changing the [[modulation]] for ATSC to [[COFDM]], the way [[DVB-T]] is transmitted in [[Europe]], and [[Integrated Services Digital Broadcasting#ISDB-T|ISDB-T]] in [[Japan]]. However, the [[Federal Communications Commission|FCC]] has always held that 8VSB is the better modulation for use in U.S. digital television broadcasting. In a 1999 report, the Commission found that 8VSB has better threshold or carrier-to-noise (C/N) performance, has a higher data rate capability, requires less transmitter power for equivalent coverage, and is more robust to impulse and phase noise.<ref>{{Citation
  | title = DTV REPORT ON COFDM AND 8-VSB PERFORMANCE
  | url = http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/reports/dtvreprt.pdf
  | publisher = FCC Office of Engineering and Technology
  | access-date = 2007-03-04
  | archive-url= https://web.archive.org/web/20070414182411/http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/reports/dtvreprt.pdf| archive-date= 14 April 2007 | url-status= live}}, September 30, 1999.
</ref> As a result, it denied in 2000 a petition for rulemaking from [[Sinclair Broadcast Group]] requesting that broadcasters be allowed to choose between 8VSB or COFDM as is most appropriate for their area of coverage.<ref>{{Citation
 |title=Sinclair Claims Wide Support For Dtv Petition 
 |url=http://findarticles.com/p/articles/mi_m3169/is_41_19/ai_56290133
 |archive-url=https://web.archive.org/web/20040902074405/http://www.findarticles.com/p/articles/mi_m3169/is_41_19/ai_56290133
 |url-status=dead
 |archive-date=2004-09-02
 |publisher=Television Digest with Consumer Electronics 
 |access-date=2008-06-06 
 |year=1999 
}}, Oct 11, 1999.
</ref>
The FCC report also acknowledged that COFDM would "generally be expected to perform better in situations where there is dynamic multipath," such as mobile operation or in the presence of trees that are moving in high winds. However, with the introduction of 5th Generation demodulators in 2005 and subsequent improvements in generations 6 and 7, the equalization span is now about −60 to +75 microseconds (a 135 microsecond spread) and has virtually eliminated multipath, both static and dynamic, in 8VSB reception. In comparison, the equalization span in COFDM is −100 to +100 microseconds (200 microsecond spread), but the application of this much guard band space for COFDM substantially reduces its useful payload. In fact, much of Europe has adopted 1280×720p as its HD standard for DVB-T1 because of its reduced payload capacity{{citation needed|date=August 2014}}. The introduction of DVB-T2 is meant to increase the ability of terrestrial transmissions to carry 1920×1080p content. 1920×1080i has always been part of the 8VSB scheme from its inception, and its improved demodulators have had no effect on its innate payload capacity{{citation needed|date=August 2014}}.

Because of continued adoption of the 8VSB-based ATSC standard in the U.S., and a large growing ATSC receiver population, a switch to COFDM will be challenging. Most analog terrestrial transmissions in the US were turned off in June 2009, and 8VSB tuners are common to all new TVs, further complicating a future transition to COFDM.

However, with the development of [[ATSC 3.0]], an updated version of the American digital television standard designed for mobile reception and better single frequency network performance, [[Advanced Television Systems Committee|the ATSC]] has decided to make the switch to OFDM with [[Low-density parity-check code|LDPC]] error correction (essentially COFDM).<ref>{{cite web|date=8 March 2021|title=ATSC 3.0 Technical overview|url=https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/ATSC_3_po_folded_en_3607-4093-82__v0100.pdf|url-status=live|archive-url=https://web.archive.org/web/20210308155634/https://cdn.rohde-schwarz.com/pws/dl_downloads/dl_common_library/dl_brochures_and_datasheets/pdf_1/ATSC_3_po_folded_en_3607-4093-82__v0100.pdf|archive-date=8 March 2021|access-date=8 March 2021|website=Rohde & Schwarz}}</ref> As a result, ATSC 3.0 will be incompatible with all current ATSC 1.0 receivers, and viewers will need a new TV with a compatible tuner or a converter box.<ref>{{cite web |last1=Cohen |first1=Simon |title=ATSC 3.0: Everything you need to know about broadcast TV's next big thing |url=https://www.digitaltrends.com/home-theater/atsc-3-0-ota-broadcast-standard-4k-dolby-atmos/ |website=Digital Trends |publisher=Designtechnica Corporation |access-date=8 March 2021 |archive-url=https://web.archive.org/web/20201129055050/https://www.digitaltrends.com/home-theater/atsc-3-0-ota-broadcast-standard-4k-dolby-atmos/ |archive-date=29 November 2020}}</ref> Unlike the previous digital TV transition which was mandated by the FCC, the "transition" to ATSC 3.0 will be completely voluntary. Additionally, the FCC has required that broadcasters who decided to make the switch to ATSC 3.0 continue to make their main channel available through a simulcast agreement with another in-market station (with a similar coverage area) through at least 2022.<ref>{{cite web |title=Report and Order and Further Notice of Proposed Rulemaking |url=https://docs.fcc.gov/public/attachments/FCC-17-158A1.docx |website=Federal Communications Commission |access-date=8 March 2021 |archive-url=https://web.archive.org/web/20201018191123/https://docs.fcc.gov/public/attachments/FCC-17-158A1.docx |archive-date=18 October 2020 |date=20 November 2017}}</ref> Sinclair announced an intention to bring ATSC 3.0 to 40 cities by 2020.<ref>{{cite web |last1=Munson |first1=Ben |title=Sinclair announces 40 U.S. cities getting ATSC 3.0 by 2020 |url=https://www.fiercevideo.com/video/sinclair-announces-40-u-s-cities-getting-atsc-3-0-by-2020 |website=Fierce Video |access-date=8 March 2021 |archive-url=https://web.archive.org/web/20210308162446/https://www.fiercevideo.com/video/sinclair-announces-40-u-s-cities-getting-atsc-3-0-by-2020 |archive-date=8 March 2021 |date=8 April 2019}}</ref>