Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)


cable TV

The transmission of TV programs into the home and office via coaxial cable. The first cable TV dates back to the late 1940s, when antennas were located at the highest point in a community to deliver TV to areas that had difficulty receiving over-the-air broadcasts (see CATV).

From TV to Internet to Telephony
Since the cable companies were already wired into millions of homes, they had great success selling Internet access to its subscribers, starting in the late 1990s. Unlike the telephone company's DSL service, Internet access via the cable infrastructure does not have distance limitations. Cable TV companies later added telephone service to offer the "triple play" (data, voice and video service). See cable Internet.

Many Analog and Digital Channels
Cable TV typically transmits 125 6 MHz channels using frequency division multiplexing (FDM) to its subscribers. Each channel can hold one analog TV program, three high-definition (HD) digital programs or 10 standard definition (SD) digital programs. The digital channels provide 40 Mbps of digital bandwidth, 38 of which is the actual payload.

The channels are also used for video-on-demand, Internet access and voice over IP (VoIP) telephone service. Upstream channels use from 0 to 50 MHz, while downstream channels use 50 MHz to 750 MHz. See FDM, CMTS and digital TV transition.

Personal Use Only

Before/After Your Search Term
cable Internetcable TV box
cable matchercable TV killer
cable modemcable types
cable modem/routercable VoIP modem
cable modem termination systemCableCARD
cable plantCablegate
cable routercabletext
Cable SelectCabletron
cable telephonecache
cable telephonycache coherency

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
ProgrammingHealthcare IT
System design