Digital Cable
Digital cable is the distribution of cable television using digital data and video compression. 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 HDTV standard, which was incompatible with existing analog cable systems. In addition to providing high-definition video, digital cable systems provide more services such as pay-per-view programming, cable internet access and cable telephone services. Most digital cable signals are encrypted, which reduced the incidence of cable television piracy which occurred in analog systems. History In 1990, General Instrument (acquired by Motorola and now owned by ARRIS Group) 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 G ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Distribution (business)
Distribution is the process of making a product or service available for the consumer or business user who needs it, and a distributor is a business involved in the distribution stage of the value chain. Distribution can be done directly by the producer or service provider or by using indirect channels with distributors or intermediaries. Distribution (or place) is one of the four elements of the marketing mix: the other three elements being product, pricing, and promotion. Decisions about distribution need to be taken in line with a company's overall strategic vision and mission. Developing a coherent distribution plan is a central component of strategic planning. At the strategic level, as well as deciding whether to distribute directly or via a distribution network, there are three broad approaches to distribution, namely mass, selective and exclusive distribution. The number and type of intermediaries selected largely depends on the strategic approach. The overall distr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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PrimeStar
PrimeStar was an American direct broadcast satellite broadcasting company formed in November 1990 by seven cable television companies including Comcast Corp. and TCI Communications Corp. PrimeStar was the first medium-powered DBS system in the United States but slowly declined in popularity with the arrival of DirecTV in 1994 and Dish Network in 1996. Technology PrimeStar was a medium-powered DBS-style system utilizing FSS technology that used a larger 3-foot (91 cm) satellite dish to receive signals. Broadcast originally in analog, they later converted to digital technology. The system used the DigiCipher 1 system for conditional access control and video compression. The video format was MPEG-2. Primestar's satellite receivers were made by General Instrument. PrimeStar was owned by a consortium of cable television companies who leased equipment to subscribers through the local cable company. The company was in the process of converting to a high-powered DBS ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Virtual Channel
In most telecommunications organizations, a virtual channel is a method of remapping the ''program number'' as used in H.222 Program Association Tables and Program Mapping Tables to a channel number that can be entered as digits on a receiver's remote control. Often, virtual channels are implemented in digital television to help users select channels easily and in general to ease the transition from analogue to digital broadcasting. Assigning virtual channels is most common where TV stations were colloquially named after the RF channel they were transmitting on ("Channel 6 Springfield"), as was common in North America during the analogue TV era. In other parts of the world, such as Europe, virtual channels are rarely used or needed, because TV stations there identify themselves by name, not by RF channel or callsign. A "virtual channel" was first used for DigiCipher 2 in North America. It was later called a logical channel number (LCN) and used for private European Digital V ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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PSIP
The Program and System Information Protocol (PSIP) is the MPEG (Moving Picture Experts Group, a video and audio industry group) and privately defined program-specific information originally defined by General Instrument for the DigiCipher 2 system and later extended for the ATSC standards, ATSC digital television system for carrying metadata about each communication channel, channel in the Broadcasting, broadcast MPEG transport stream of a television station and for publishing information about television programs so that viewers can select what to watch by title and description. Its FM radio equivalent is Radio Data System (RDS). Function PSIP defines virtual channels and Television content rating systems, content ratings, as well as electronic program guides with titles and (optionally) descriptions to be decoded and displayed by the ATSC tuner. PSIP can also send: * the exact time referenced to UTC and GPS time; * the nickname, short name, which some stations use to publish th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Subchannel
In broadcasting, digital subchannels are a method of transmitting more than one independent program stream simultaneously from the same digital radio or television station on the same radio frequency channel. This is done by using data compression techniques to reduce the size of each individual program stream, and multiplexing to combine them into a single signal. The practice is sometimes called " multicasting". ATSC television United States The ATSC digital television standard used in the United States supports multiple program streams over-the-air, allowing television stations to transmit one or more subchannels over a single digital signal. A virtual channel numbering scheme distinguishes broadcast subchannels by appending the television channel number with a period digit (".xx"). Simultaneously, the suffix indicates that a television station offers additional programming streams. By convention, the suffix position ".1" is normally used to refer to the station's main digi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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North American Cable Television Frequencies
The Pan-American television frequencies are different for terrestrial and cable television systems. Terrestrial television channels are divided into two bands: the VHF band which comprises channels 2 through 13 and occupies frequencies between 54 and 216 MHz, and the UHF band, which comprises channels 14 through 36 and occupies frequencies between 470 and 608 MHz. These bands are different enough in frequency that they often require separate antennas to receive (although many antennas cover both VHF and UHF), and separate tuning controls on the television set. The VHF band is further divided into two frequency ranges: VHF low band ( Band I) between 54 and 88 MHz, containing channels 2 through 6, and VHF high band ( Band III) between 174 and 216 MHz, containing channels 7 through 13. The wide spacing between these frequency bands is responsible for the complicated design of rooftop TV antennas. The UHF band has higher noise and greater attenuation, so higher g ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Switched Video
Switched video or switched digital video (SDV), sometimes referred to as switched broadcast (SWB), is a telecommunications industry term for a network scheme for distributing digital video via a cable. Switched video sends the digital video more efficiently freeing bandwidth. The scheme applies to digital video distribution both on typical cable TV systems using QAM channels, or on IPTV systems. Description In hybrid fibre-coaxial systems, a fiber optic network extending from the operator's head end carries video channels out to a fiber optic node that services up to 2000 end points. Video is then sent via coaxial cable. Note that only a percentage of these homes are actively watching channels at a given time. Rarely are all channels being accessed by the homes in the service group. In a switched video system, the unwatched channels do not need to be sent. In US cable systems, equipment in the home sends a channel request signal back to the distribution hub. If a channel i ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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IPTV
Internet Protocol television (IPTV), also called TV over broadband, is the service delivery of television over Internet Protocol (IP) networks. Usually sold and run by a Telephone company, telecom provider, it consists of broadcast live television that is streamed over the Internet (multicast) — in contrast to delivery through traditional Terrestrial television, terrestrial, Satellite television, satellite, and Cable television, cable transmission formats — as well as video on demand services for watching or replaying content (unicast). IPTV broadcasts started gaining usage during the 2000s alongside the rising use of broadband-based internet connections. It is often provided bundled with internet access services by ISPs to subscribers and runs in a closed network. IPTV normally requires the use of a set-top box, which receives the encoded television content in the MPEG transport stream via IP multicast, and converts the Data packet, packets to be watched on a TV set or ot ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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DOCSIS
Data Over Cable Service Interface Specification (DOCSIS) is an international telecommunications standard that permits the addition of high-bandwidth data transfer to an existing cable television (CATV) system. It is used by many cable television operators to provide cable Internet access over their existing hybrid fiber-coaxial (HFC) infrastructure. DOCSIS was originally developed by CableLabs and contributing companies, including Broadcom, Xfinity, Comcast, Cox Communications, Cox, General Instrument, Motorola, Terayon, and Time Warner Cable. Versions ; : Released in March 1997, DOCSIS 1.0 included functional elements from preceding proprietary cable modems. ; : Released in April 1999, DOCSIS 1.1 standardized quality of service (QoS) mechanisms that were outlined in DOCSIS 1.0. ; (abbreviated D2) : Released in December 2001, DOCSIS 2.0 enhanced upstream data rates in response to increased demand for symmetric services such as IP telephony. ; (abbreviated D3) : Released in ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Error Correction
In information theory and coding theory with applications in computer science and telecommunications, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communication channels. Many communication channels are subject to channel noise, and thus errors may be introduced during transmission from the source to a receiver. Error detection techniques allow detecting such errors, while error correction enables reconstruction of the original data in many cases. Definitions ''Error detection'' is the detection of errors caused by noise or other impairments during transmission from the transmitter to the receiver. ''Error correction'' is the detection of errors and reconstruction of the original, error-free data. History In classical antiquity, copyists of the Hebrew Bible were paid for their work according to the number of stichs (lines of verse). As the prose books of the Bible were hardly ever w ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Telephone Line
A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. It is designed to reproduce speech of a quality that is understandable. It is the physical wire or other signaling medium connecting the user's telephone apparatus to the telecommunications network, and usually also implies a single telephone number for billing purposes reserved for that user. Telephone lines are used to deliver consistent landline telephone service and digital subscriber line (DSL) phone cable service to the premises. Telephone overhead lines are connected to the public switched telephone network. The voltage at a subscriber's network interface is typically 48 V between the ring and tip wires, with tip near ground and ring at –48 V. In the United States In 1878, the Bell Telephone Company began using two-wire circuits, called the local loop, from each user's telephone to end offices, which performed a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |