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193:) demonstrated that it was possible to use digital compression to deliver high quality HDTV in a standard 6 MHz television channel. Using the same technology General Instrument (GI) demonstrated the digital transmission of multiple high quality standard definition programs in a 6 MHz cable channel.
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numbers to underlying physical and sub-channels. For example, a cable company might call channel 5-1 "channel 732" and channel 5-2 "channel 733". This also allows the cable company to change the frequency of a channel without changing what the customer sees as a channel number. In such arrangements,
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Digital cable technology can allow many TV channels to occupy the frequency space that would normally be occupied by a single analog cable TV channel. The number of channels placed on a single analog frequency depends on the compression used. Many cable providers are able to fit about 10 digital SD
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In theory, a set-top box can decode the PSIP information from every channel it receives and use that information to build the mapping between QAM channel and virtual channel. However, cable companies do not always reliably transmit PSIP information. Alternatively, CableCards receive the channel
142:. The technology was first developed by General Instrument. By 2000, most cable companies offered digital features, eventually replacing their previous analog-based cable by the mid 2010s. During the late 2000s, broadcast television converted to the digital
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channels or 2 digital HD channels on a single analog channel frequency. Some providers are able to squeeze more channels onto a single frequency with higher compression, but often this can cause the video quality of the channel to degrade.
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is a logical channel of data within the physical channel. Technically there can be up to 1024 subchannels in a physical channel, though in practice only a few are used (as the bandwidth must be divided among all the subchannels).
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In the 1990s, cable providers began to invest heavily in this new multi-channel digital TV technology to expand the number of channels and services available to subscribers. Increased competition and programming choices from
418:.) Between 552 and 750 MHz, there is space for 33 6-MHz channels (231–396 SDTV channels); when going all the way to 864 MHz, there is space for 52 6-MHz channels (364–624 SDTV channels).
297:, is where program and channel information is broadcast along with the video, allowing the consumer's decoder (set-top box or display) to automatically identify the many channels and subchannels.
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the physical/sub-channel numbers are called the "QAM channel", and the alternative channel designation is called the "mapped channel", "virtual channel", or simply "channel".
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programming, digital music services, and high speed internet services. By 2000, most cable providers in the US were offering some form of digital cable TV to their customers.
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to ensure the integrity of the received signal and uses a secure digital distribution system (i.e. a secure encrypted signal to prevent eavesdropping and theft of service.)
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Digital cable channels typically are allocated above 552 MHz, the upper frequency of cable channel 78. (Cable channels above channel 13 are at lower frequencies than
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376:(480p) as well as HDTV (720p, 1080i, and 1080p). By contrast, analog cable transmits programs solely in the 480i format (the lowest television definition in use today).
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In the U.S., digital cable systems with 750 MHz or greater activated channel capacity are required to comply with a set of SCTE and CEA standards, and to provide
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caused cable providers to seek new ways to provide more programming. Customers were increasingly interested in more channels,
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The addition of this capability complicates the notion of a "channel" in digital cable (as well as in over-the-air
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transmission over cable at 38.4 Mbit/s, but the encoding has not yet gained wide acceptance. Some
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channel, which can carry nearly two full ATSC 19.39 Mbit/s transport streams. Each 6-MHz
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The physical channel is a number corresponding to a specific 6 MHz frequency range. See:
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standards for data services. Some providers have also begun to roll out video services using
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that delivers digital channels by satellite to small cable systems).
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526:"History of General Instrument Corporation – FundingUniverse"
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MP/ML streams of 3–5 Mbit/s). On many boxes with
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US CATV Channels and
Frequencies table (up to channel 78)
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153:, digital cable systems provide more services such as
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mapping and can communicate that to the set-top box.
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broadcast channels with the same number, as seen in
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49:. Unsourced material may be challenged and removed.
552:"Your Guide to Free Broadcast Digital Television"
381:Advanced Television Systems Committee standards
353:is typically used to carry 7–12 digital
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416:North American cable television frequencies
280:North American cable television frequencies
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372:Digital cable allows for the broadcast of
109:Learn how and when to remove this message
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232:services that don't require a separate
1108:Downloadable Conditional Access System
967:Template:American broadcast television
972:Template:Canadian television networks
440:Cable television in the United States
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961:Digital multicast television network
47:adding citations to reliable sources
1063:Interactive-digital-cable-ready TV
173:which occurred in analog systems.
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780:U.S. Converter Box Coupon Program
611:Digital cable & Digital house
243:Most digital cable providers use
169:, which reduced the incidence of
165:. Most digital cable signals are
732:Metropolitan Television Alliance
425:to customers that request them.
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705:Distributed transmission system
331:quadrature amplitude modulation
34:needs additional citations for
1068:OpenCable Application Platform
577:"How Digital Television Works"
502:. motorola.com. Archived from
500:"Decades of proven experience"
1:
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775:Digital television adapter
621:February 24, 2020, at the
455:Direct-broadcast satellite
199:direct-broadcast satellite
1285:Channel protection ratios
1275:Active Format Description
1196:Digital Satellite Service
1018:wireless spectrum auction
333:), which is specified in
149:In addition to providing
933:Serial digital interface
921:Ultra high-definition TV
765:Digital channel election
755:All-Channel Receiver Act
383:include a provision for
163:cable telephone services
1295:Hierarchical modulation
802:Digital video recorders
530:www.fundinguniverse.com
337:07, and is part of the
273:ATSC digital broadcasts
247:for video services and
171:cable television piracy
1336:Television terminology
1051:Digital-cable-ready TV
882:Enhanced-definition TV
865:Standard-definition TV
435:Cable Internet access
321:is now fixed as both
313:Technical information
226:two-way communication
159:cable internet access
151:high-definition video
1305:Standards conversion
682:Digital broadcasting
475:Significantly viewed
43:improve this article
981:National deployment
695:Digital subchannels
357:channels (256-QAM,
1162:Telus Satellite TV
1145:GlobeCast World TV
899:High-definition TV
792:Analog passthrough
747:Digital switchover
664:Digital television
583:. January 10, 2001
450:Digital television
401:Headend in the Sky
391:systems may carry
365:(most notably the
341:standard (but not
183:General Instrument
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1300:Pirate decryption
1270:14:9 aspect ratio
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720:National Datacast
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99:November 2019
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60: –
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54:Find sources:
48:
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38:
37:
32:This article
30:
26:
21:
20:
1244:Bell Fibe TV
1174:DigiCipher 2
1140:Dish Network
1127:Satellite TV
1042:
585:. Retrieved
580:
571:
559:. Retrieved
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533:. Retrieved
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508:. Retrieved
504:the original
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465:DigiCipher 2
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207:Dish Network
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136:digital data
128:distribution
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41:Please help
36:verification
33:
1184:Shaw Direct
1167:Dish México
1150:Free-to-air
785:legislation
725:UpdateLogic
710:Datacasting
690:ATSC tuners
673:Terrestrial
587:December 3,
561:December 3,
535:December 3,
191:ARRIS Group
1325:Categories
1239:U-verse TV
1219:Sky Mexico
1214:Sky Brazil
1080:Must-carry
1075:Encryption
1056:QAM tuners
1013:transition
715:Guide Plus
486:References
423:CableCARDs
363:QAM tuners
287:subchannel
69:newspapers
1290:HDTV blur
1103:CableCARD
858:full list
760:SAFER Act
470:QAM Tuner
445:CableCARD
222:bandwidth
211:PrimeStar
181:In 1990,
167:encrypted
1153:receiver
828:ATSC-M/H
619:Archived
510:March 5,
429:See also
263:Channels
187:Motorola
1249:FibreOP
1205:DirecTV
1113:Tru2way
943:CEA-909
480:Tru2way
405:Comcast
351:channel
327:256-QAM
203:DirecTV
177:History
126:is the
83:scholar
1200:DVB-S2
1098:AllVid
998:Mexico
993:Canada
385:16-VSB
323:64-QAM
249:DOCSIS
209:, and
134:using
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64:
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1135:DVB-S
1034:Cable
926:2160p
914:1080p
909:1080i
843:E-VSB
838:A-VSB
460:DVB-C
393:8-VSB
389:SMATV
359:MPEG2
90:JSTOR
76:books
1231:IPTV
1210:Vrio
1179:4DTV
1008:HDTV
965:see
904:720p
892:576p
887:480p
875:576i
870:480i
853:PMCP
848:PSIP
833:8VSB
823:ATSC
589:2020
563:2020
556:AARP
537:2020
512:2008
399:or "
397:HITS
379:The
374:EDTV
355:SDTV
343:ATSC
335:SCTE
325:and
295:PSIP
285:The
253:IPTV
161:and
144:HDTV
138:and
62:news
412:UHF
367:DVR
347:MHz
339:DVB
255:or
245:QAM
130:of
45:by
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329:(
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97:(
87:·
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