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Digital cable is a generic term for any type of cable television distribution using digital video compression or distribution. The technology was originally developed by Motorola.^[1]

Background[link]

In 1989, General Instrument (which was later acquired by Motorola) demonstrated that it was possible to convert an analog cable signal to digital and transmit it in a standard 6-MHz television channel. In the 1990s cable providers began to invest heavily in new digital based distribution systems. Increased competition and programming choices from Direct-broadcast satellite services such as DirecTV, Dish Network, and PrimeStar caused cable providers to seek new ways to provide more programming. Customers were increasingly interested in more channels, pay-per-view programming, digital music services, and high speed internet services. By 2000, most cable providers in the US were offering some form of digital services to their customers.

Digital cable technology has allowed cable providers to compress video channels so that they take up less frequency space and to offer various two-way communication capabilities. This has enabled digital cable providers to offer more channels, video on demand services (without use of a telephone line), telephone services, high speed internet services, and interactive television services. In addition, digital cable technology allows for error correction to ensure the quality of the received signal and uses a secure digital distribution system (i.e. a secure encrypted signal to prevent eavesdropping and theft of service.)

Most digital cable providers use QAM for video services and DOCSIS standards for data services. Some providers have also begun to roll out video services using IPTV or Switched video.

Channels[link]

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 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.

The addition of this capability complicates the notion of a "channel" in digital cable (as well as in over-the-air ATSC digital broadcasts). The formal names for the two numbers that now identify a channel are the physical channel and the subchannel.

The physical channel is a number corresponding to a specific 6 MHz frequency range. See: North American cable television frequencies.

The subchannel 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).

There are two ways providers try to make this easier for consumers. The first, accomplished through PSIP, 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.

The second (also accomplished through PSIP) is where, in an effort to hide subchannels entirely, many cable companies map virtual channel 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, 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".

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 mapping and can communicate that to the set-top box.

Preserving bandwidth[link]

Digital cable has allowed out of market television stations to be removed from the basic cable lineup from Channels 2 through 13. They would be moved over to digital cable channels 100 and above for bandwidth preservation. Currently, Comcast Cable outlets in New Jersey and Virginia are adapting this in significantly viewed counties that are bordering nearby television markets.

Technical information[link]

This unreferenced section requires citations to ensure verifiability.

The standard for signal transmission over digital cable television systems in the United States is now fixed as both 64-QAM and 256-QAM (Quadrature Amplitude Modulation), which is specified in SCTE 07, and is part of the DVB standard (but not ATSC). This method carries 38.47 Mbit/s using 256-QAM on a 6 MHz channel, which can carry nearly two full ATSC 19.39 Mbit/s transport streams. Each 6-MHz channel is typically used to carry 7–12 digital SDTV channels (256-QAM, MPEG2 MP/ML streams of 3–5 Mbit/s). On many boxes with QAM tuners (most notably the DVR boxes), High Definition versions of local channels and some cable channels are available.

Digital Cable allows for the broadcast of EDTV (480p) as well as HDTV (720p, 1080i, and eventually 1080p). By contrast, analog cable transmits programs solely in the 480i format (the lowest television definition in use today).

The ATSC standards include a provision for 16-VSB transmission over cable at 38.4 Mbit/s, but the encoding has not yet gained wide acceptance. Some MATV systems may carry 8-VSB and QAM signals, mostly in apartment buildings and similar facilities that use a combination of terrestrial antennas and cable distribution sources (such as HITS or "Headend in the Sky", a unit of Comcast that delivers digital channels by satellite to small cable systems).

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 UHF broadcast channels with the same number, as seen in North American cable television frequencies.) 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).

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 CableCARDs to customers that request them.

See also[link]

• Digital television
• QAM Tuner
• CableCARD
• Tru2way
• Cable television in the United States
• Direct-broadcast satellite
• Significantly viewed

References[link]

External links[link]

• National Cable and Telecommunications Association - Digital Cable
• Digital cable & Digital house
• US CATV Channels and Frequencies table (up to channel 78)
• US CATV Channels and Frequencies table (comprehensive)

Han Hyo-joo (Korean: 한효주, born February 22, 1987 in Cheongju, North Chungcheong) is a South Korean actress and model.

Career[link]

Han was first discovered in a teenage beauty pageant in 2003. She began her acting career in the sitcom Nonstop 5^[2] and the gangster comedy My Boss, My Teacher. Han raised her profile by being cast in Spring Waltz, the fourth and final installment of TV director Yoon Suk-ho's Season Dramas series, following Autumn in My Heart, Winter Sonata and Summer Scent. Though it received low ratings in Korea, Spring Waltz was exported to and aired in other Asian countries, including Indonesia, China, Taiwan, Hong Kong, Thailand, Singapore and the Philippines.

In 2006 director Lee Yoon-ki cast the newbie in the starring role in his low-budget indie Ad-lib Night, which follows a young woman who rediscovers herself through an eerie overnight encounter with strangers. Han followed that with two highly successful TV projects - KBS daily drama Like Land and Sky in 2007 and SBS masked-adventurer series Iljimae in 2008.^[3] She made another independent film, Ride Away, which debuted at the 2008 Jeonju International Film Festival.

Han filmed the collaborative Korean-Japanese telecinema production Heaven's Postman in 2008, which also featured popstar Kim Jaejoong from TVXQ.^[4][5] After several postponements, the telecinema was released in late 2009.

In 2009 her Cinderella drama Brilliant Legacy (co-starring Lee Seung Gi) became a massive hit, reaching a peak viewership rating of 47.1%.^[6] Since the drama's conclusion, Han has experienced a sharp rise in endorsement deals and media requests for interviews.

Following her success on Brilliant Legacy, Han was slated to assume the lead female role in the drama Chuno. However, she withdrew from the drama prior to production allegedly due to issues relating to her management and salary.^[7]

In September 2009 Han wrapped up her starring role in the musical drama Soul Special, which also stars K.Will in his acting debut. The drama aired in twelve five-minute segments on various online portals, with KBS airing the entire drama in four parts.^[8]

As the titular character in MBC's 49th Anniversary Project Dong Yi,^[9] Han won several acting awards for her portrayal of Choi Suk Bin.

In the melodrama Always,^[10] So Ji-sub plays an ex-boxer with a rough past that delivers water during the day and works as a parking lot attendant at night, while Han is a telemarketer who despite going blind is strong in spirit. Helmed by critically acclaimed director Song Il-gon, it premiered as the opening film of the 2011 Busan International Film Festival.^{[11][12][13][14][15][16]}

She plays the queen opposite A-list actor Lee Byung-hun in historical film I am the King of Joseon.^[17][18]

She and Go Soo have been cast in Love 911, an unlikely romance between a firefighter and a doctor, which starts principal photography in April 2012.^[19]

Personal life[link]

Han's mother worked as an elementary school teacher before becoming an inspector for public schools and her father worked in the military. As a child, she was good in sports and enjoyed track & field. In her sophomore year of high school, she moved to Seoul and attended Bulgok High School. Although her father, conservative and strict, opposed her move to Seoul she was able to go forth with her wishes. After high school she attended Dongguk University, where she joined the theatre and film department. Her hobbies include singing and writing and her talents are playing the piano, telling fairy tales, writing, running and fencing. Han has a younger brother and is currently single.

Filmography[link]

MC[link]

• 2005 - 2006: 인기가요 Popular Song (SBS) MC

Soundtracks[link]

• 2005: 저음이 웃어요 "It's the First Time" (Nonstop 5 OST)
• 2008: 달려라 자전거 "Ride Away" (Ride Away OST)
• 2009: 왈칵눈물이 Sudden Burst of Tears feat. Gan-D (Soul Special OST)
• 2009: 헤어져 Break up by As One (narr. Han Hyo Joo)
• 2010: Don't You Know feat. No Reply (Grand Mint Festival 2010)
• 2011: 아침 8시 "8 am" feat. My-Q
• 2011: 오 서울 "Oh Seoul " feat. My-Q
• 2011: 그대 "You" by Brown Eyed Soul feat. Han Hyo Joo
• 2011: Love Time by Lee Seung Gi (narr. Han Hyo Joo)

Music Videos[link]

• 2004: 사랑해요 I Love You by Simply Sunday
• 2005: 그대가 세상에 있는 것 만으로 by Position
• 2005: Paris by Epik High
• 2006: 이별은 Farewell is... by U
• 2006: Tree by Kwon Jin Won
• 2009: 남잔 다 그래 by Lee Woo Sang
• 2009: 사랑한단 말을 못해서 Because I Couldn't Say that I Love You by K.Will
• 2009: 너 정말이니 Are You Serious? by Rumble Fish

Variety Show Appearance[link]

• 2005: X-Man
• 2006: Love Letter
• 2006: Come To Play
• 2007: Are You Ready
• 2007: Ya Shim Man Man
• 2008: Park Kyung Lim's Wonderful Outing
• 2009: Ya Shim Man Man (Brilliant Legacy Special)
• 2010: 100% Entertainment (Taiwan)

Endorsement[link]

Awards[link]

References[link]

External links[link]

• Han Hyo-Joo's Official Homepage in BH Entertainment (Korean)
• Han Hyo Joo Cyworld (Korean)
• Han Hyo Joo Official me2day (Korean)
• daum Official fan cafe 〈T.E.A〉- The bEst Actress Han Hyo Joo♡ (Korean)
• DCinside Han Hyo-Joo Gallery (Korean)

• Han Hyo-joo at HanCinema (English)
• Han Hyo-joo at the Internet Movie Database (English)
• 韓孝珠中文網Han hyo joo (Chinese)

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