In telecommunications , the term outside plant has the following meanings:
71-462: The CATV industry divides its fixed assets between head end or inside plant , and outside plant. The electrical power industry also uses the term outside plant to refer to electric power distribution systems. Network connections between devices such as computers, printers, and phones require a physical infrastructure to carry and process signals. Typically, this infrastructure will consist of: The portion of this infrastructure contained within
142-524: A cable network ) is a television network available via cable television. Many of the same channels are distributed through satellite television . Alternative terms include non-broadcast channel or programming service , the latter being mainly used in legal contexts. The abbreviation CATV is used in the US for cable television and originally stood for community antenna television , from cable television's origins in 1948; in areas where over-the-air TV reception
213-731: A $ 200 million investment in iconectiv and received a 16.7 percent ownership stake in the company. In 2015, iconectiv won a contract procured by the Federal Communications Commission (FCC) to operate the Number Portability Administration Center (NPAC). The service had been operated by Neustar Inc. for 18 years. iconectiv completed the transition from Neustar on May 29, 2018 becoming the Local Number Portability Administrator (LNPA) for
284-442: A building is the inside plant , and the portion of this infrastructure connecting buildings or facilities is the outside plant. Where these two plants meet in a given structure is the demarcation point . Outside plant cabling, whether copper or fiber, is generally installed as aerial cable between poles, in an underground conduit system, or by direct burial. Hardware associated with the outside plant must be either protected from
355-467: A decade later. Bellcore also operated the former Bell System Center for Technical Education in Lisle, Illinois . In 1996, the company was provisionally acquired by Science Applications International Corporation (SAIC). The sale was closed one year later, following a regulatory approval process that covered every U.S. state individually. Since the divested company no longer had any ownership connection with
426-405: A dedicated analog circuit-switched service. Other advantages include better voice quality and integration to a Voice over Internet Protocol (VoIP) network providing cheap or unlimited nationwide and international calling. In many cases, digital cable telephone service is separate from cable modem service being offered by many cable companies and does not rely on Internet Protocol (IP) traffic or
497-543: A high elevation. At the outset, cable systems only served smaller communities without television stations of their own, and which could not easily receive signals from stations in cities because of distance or hilly terrain. In Canada, however, communities with their own signals were fertile cable markets, as viewers wanted to receive American signals. Rarely, as in the college town of Alfred, New York , U.S. cable systems retransmitted Canadian channels. Although early ( VHF ) television receivers could receive 12 channels (2–13),
568-466: A higher rate. At the local headend, the feed signals from the individual television channels are received by dish antennas from communication satellites . Additional local channels, such as local broadcast television stations, educational channels from local colleges, and community access channels devoted to local governments ( PEG channels) are usually included on the cable service. Commercial advertisements for local business are also inserted in
639-405: A local VHF television station broadcast. Local broadcast channels were not usable for signals deemed to be a priority, but technology allowed low-priority signals to be placed on such channels by synchronizing their blanking intervals . TVs were unable to reconcile these blanking intervals and the slight changes due to travel through a medium, causing ghosting . The bandwidth of the amplifiers also
710-463: A microwave-based system, may be used instead. Coaxial cables are capable of bi-directional carriage of signals as well as the transmission of large amounts of data . Cable television signals use only a portion of the bandwidth available over coaxial lines. This leaves plenty of space available for other digital services such as cable internet , cable telephony and wireless services, using both unlicensed and licensed spectra. Broadband internet access
781-564: A rarity, found in an ever-dwindling number of markets. Analog television sets are accommodated, their tuners mostly obsolete and dependent entirely on the set-top box. Cable television is mostly available in North America , Europe , Australia , Asia and South America . Cable television has had little success in Africa , as it is not cost-effective to lay cables in sparsely populated areas. Multichannel multipoint distribution service ,
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#1732780266455852-455: A receiver box. The cable company will provide set-top boxes based on the level of service a customer purchases, from basic set-top boxes with a standard-definition picture connected through the standard coaxial connection on the TV, to high-definition wireless digital video recorder (DVR) receivers connected via HDMI or component . Older analog television sets are cable ready and can receive
923-766: A series of signal amplifiers and line extenders. These devices carry the signal to customers via passive RF devices called taps. The very first cable networks were operated locally, notably in 1936 by Rediffusion in London in the United Kingdom and the same year in Berlin in Germany, notably for the Olympic Games , and from 1948 onwards in the United States and Switzerland. This type of local cable network
994-544: A service network and operations management and numbering solutions span trusted communications, digital identity management and fraud prevention. Known as Bellcore after its establishment in the United States in 1983 as part of the break-up of the Bell System , the company's name changed to Telcordia Technologies after a change of ownership in 1996. The business was acquired by Ericsson in 2012, then restructured and rebranded as iconectiv in 2013. A major architect of
1065-417: A special telephone interface at the customer's premises that converts the analog signals from the customer's in-home wiring into a digital signal, which is then sent on the local loop (replacing the analog last mile , or plain old telephone service (POTS) to the company's switching center, where it is connected to the public switched telephone network ( PSTN ). The biggest obstacle to cable telephone service
1136-607: A variety of environments. The major distinctions in these environments focus on the strength and frequency of vehicular and foot traffic loading. There are four basic application environments: Handhole-type products deployed in any environment are subjected to the following types of traffic loading: Vertical Cover Load, Vertical Sidewall Load, Lateral Sidewall Load, and Long-Term Lateral Sidewall Load. Telcordia GR-902, Generic Requirements for Handholes and Other Below-Ground Splice Vaults, contains detailed industry requirements for handholes, and includes specific loading requirements for
1207-538: A wholly owned subsidiary of Ericsson. On June 15, 2011, Ericsson announced the completion of the purchase from private-equity firms Providence Equity Partners and Warburg Pincus , with the goal to pursue industry trends that include mobile broadband , managed services / outsourcing and global OSS / BSS transformation. The acquisition, which officially closed on January 12, 2012, added about 2,600 employees to Ericsson's staff. On June 4, 2012, Telcordia and its products were officially rebranded as Ericsson. In
1278-404: Is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables , or in more recent systems, light pulses through fibre-optic cables . This contrasts with broadcast television , in which the television signal is transmitted over-the-air by radio waves and received by a television antenna , or satellite television , in which
1349-422: Is achieved over coaxial cable by using cable modems to convert the network data into a type of digital signal that can be transferred over coaxial cable. One problem with some cable systems is the older amplifiers placed along the cable routes are unidirectional thus in order to allow for uploading of data the customer would need to use an analog telephone modem to provide for the upstream connection. This limited
1420-641: Is dc stray current from electrified rail transportation systems, cathodic protection rectifiers, or welding and mining operations. Although such dc currents are mostly dealt with “after the fact” using protective systems (e.g., low resistance bonds, reverse current switches, cathodic protection), some of the protection has to be included at the manufacturing stage. This protection may include insulating covers on cable shields, or nonmetallic components or coatings for apparatus. Buried plant consists of telecommunications equipment such as cables, splice closures, lower parts of pedestals, and grounding systems directly buried in
1491-433: Is designed to withstand various environmental operating conditions resulting from climatic conditions that may include rain, snow, sleet, high winds, ice, salt spray, and sand storms. Since outside temperatures can possibly range from −40 °C (−40 °F) to 46 °C (115 °F), with varying degrees of solar loading, along with humidity levels ranging from below 10% up to 100%, significant environmental stresses within
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#17327802664551562-452: Is not a modern approach, the cost of replacement of the older cabling with sealed cabling is often prohibitively expensive. The cabling used in the outside plant must also be protected from electrical disturbances caused by lightning or voltage surges due to electrical shorts or induction. In civilian telecommunications, the copper access network (also known as the local loop ) providing basic telephone or DSL services typically consists of
1633-482: Is the need for nearly 100% reliable service for emergency calls. One of the standards available for digital cable telephony, PacketCable , seems to be the most promising and able to work with the quality of service (QOS) demands of traditional analog plain old telephone service (POTS) service. The biggest advantage to digital cable telephone service is similar to the advantage of digital cable, namely that data can be compressed, resulting in much less bandwidth used than
1704-492: The DVB-C , DVB-C2 stream to IP for distribution of TV over IP network in the home. Many cable companies offer internet access through DOCSIS . In the most common system, multiple television channels (as many as 500, although this varies depending on the provider's available channel capacity) are distributed to subscriber residences through a coaxial cable , which comes from a trunkline supported on utility poles originating at
1775-840: The Regional Bell Operating Companies ( Baby Bells ), the name was changed to Telcordia Technologies in 1999. The headquarters was moved to Piscataway , New Jersey. The former headquarters campus in Morristown and its offices and laboratories in Red Bank, New Jersey, are former Bell Labs locations that were transferred to Telcordia. Equal stakes in the company were sold in March 2005 to Providence Equity Partners and Warburg Pincus . On June 14, 2011, Ericsson announced an agreement to acquire Telcordia for $ 1.15 billion. On January 12, 2012, Telcordia became
1846-616: The high band 7–13 of North American television frequencies . Some operators as in Cornwall, Ontario , used a dual distribution network with Channels 2–13 on each of the two cables. During the 1980s, United States regulations not unlike public, educational, and government access (PEG) created the beginning of cable-originated live television programming. As cable penetration increased, numerous cable-only TV stations were launched, many with their own news bureaus that could provide more immediate and more localized content than that provided by
1917-580: The 1982 Modification of Final Judgment that broke up the Bell System . It later received the name Bell Communications Research. Nicknamed Bellcore , it was a consortium established by the Regional Holding Companies upon their separation from AT&T. Since AT&T retained Bell Laboratories , the operating companies desired a separate research and development facility. Bellcore, the tenth company to register an Internet domain name in comTLD , provided joint research and development,
1988-594: The Internet. Traditional cable television providers and traditional telecommunication companies increasingly compete in providing voice, video and data services to residences. The combination of television, telephone and Internet access is commonly called triple play , regardless of whether CATV or telcos offer it. More than 400,000 television service subscribers. Telcordia iconectiv supplies communications providers with network planning and management services. The company’s cloud-based information as
2059-485: The United States have switched to or are in the course of switching to digital cable television since it was first introduced in the late 1990s. Most cable companies require a set-top box ( cable converter box ) or a slot on one's TV set for conditional access module cards to view their cable channels, even on newer televisions with digital cable QAM tuners, because most digital cable channels are now encrypted, or scrambled , to reduce cable service theft . A cable from
2130-557: The United States telecommunications system, the company pioneered many services, including caller ID , call waiting , mobile number portability , and toll-free telephone (800) service. It also pioneered the prepaid charging system and the Intelligent Network . Headquartered in Bridgewater, New Jersey (U.S.), iconectiv provides network and operations management, numbering, registry and fraud prevention services for
2201-404: The basic selection. By subscribing to additional tiers, customers could get specialty channels, movie channels, and foreign channels. Large cable companies used addressable descramblers to limit access to premium channels for customers not subscribing to higher tiers, however the above magazines often published workarounds for that technology as well. During the 1990s, the pressure to accommodate
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2272-563: The cable box itself, these midband channels were used for early incarnations of pay TV , e.g. The Z Channel (Los Angeles) and HBO but transmitted in the clear i.e. not scrambled as standard TV sets of the period could not pick up the signal nor could the average consumer de-tune the normal stations to be able to receive it. Once tuners that could receive select mid-band and super-band channels began to be incorporated into standard television sets, broadcasters were forced to either install scrambling circuitry or move these signals further out of
2343-429: The cable company's local distribution facility, called the headend . Many channels can be transmitted through one coaxial cable by a technique called frequency division multiplexing . At the headend, each television channel is translated to a different frequency . By giving each channel a different frequency slot on the cable, the separate television signals do not interfere with each other. At an outdoor cable box on
2414-515: The cable to send data from the customer box to the cable headend, for advanced features such as requesting pay-per-view shows or movies, cable internet access , and cable telephone service . The downstream channels occupy a band of frequencies from approximately 50 MHz to 1 GHz, while the upstream channels occupy frequencies of 5 to 42 MHz. Subscribers pay with a monthly fee. Subscribers can choose from several levels of service, with premium packages including more channels but costing
2485-675: The case of no local CBS or ABC station being available – rebroadcast the programming from a nearby affiliate but fill in with its own news and other community programming to suit its own locale. Many live local programs with local interests were subsequently created all over the United States in most major television markets in the early 1980s. This evolved into today's many cable-only broadcasts of diverse programming, including cable-only produced television movies and miniseries . Cable specialty channels , starting with channels oriented to show movies and large sporting or performance events, diversified further, and narrowcasting became common. By
2556-508: The chosen channel into the TV set on Channel 2, 3 or 4. Initially, UHF broadcast stations were at a disadvantage because the standard TV sets in use at the time were unable to receive their channels. With the passage of the All-Channel Receiver Act in 1964, all new television sets were required to include a UHF tuner, nonetheless, it would still take a few years for UHF stations to become competitive. Before being added to
2627-645: The defined application environments. It provides explicit correlations to other standards such as ANSI/SCTE-77, AASHTO specifications, and ASTM C857. Corrosion in outside plant telecommunications network components is caused by exposure to the effects of temperature, humidity, electrical power, and contaminants. Corrosion resistance criteria for these network components are based on the environments to which they are exposed. Outside plant environments can be above-ground, underground, buried, or underwater. Industry requirements document Telcordia GR-2836 defines these environments and provides corrosion resistance criteria for
2698-441: The elements (for example, distribution frames are generally protected by a street side cabinet) or constructed with materials suitable for exposure to the elements. Installation of the outside plant elements often require construction of significant physical infrastructure, such as underground vaults. In older large installations, cabling is sometimes protected by air pressure systems designed to prevent water infiltration. While this
2769-677: The enclosure or facility can be produced. Telcordia GR-3108, Generic Requirements for Network Equipment in the Outside Plant (OSP) , contains the most recent industry data regarding each Class described above. It also discusses what is currently happening in ATIS and Underwriters Laboratories (UL) . The document also includes Handholes and other below-ground splice vaults house telecommunications components used in an Outside Plant (OSP) environment. Handholes are plastic or polymer concrete structures set below ground with their lids flush to
2840-415: The fact that the descrambling circuitry was for a time present in these tuners, depriving the cable operator of much of their revenue, such cable-ready tuners are rarely used now – requiring a return to the set-top boxes used from the 1970s onward. The digital television transition in the United States has put all signals, broadcast and cable, into digital form, rendering analog cable television service
2911-665: The following elements: Active equipment (such as a POTS or DSL line circuit) can then be connected to the line in order to provide service, but this is not considered part of outside plant. The environment can play a large role in the quality and lifespan of equipment used in the outside plant. It is critical that environmental testing criteria as well as design and performance requirements be defined for this type of equipment. There are generally four operating environments or classes covering all outside plant (OSP) applications, including wireless facilities. Electronic equipment located in one or more of these environmental class locations
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2982-610: The former headquarters of AT&T Wireless. In February 2013, Ericsson launched iconectiv for its interconnection business. During this time, Ericsson maintained its corporate presence in Plano, Texas and iconectiv's corporate presence in New Jersey. In July 2017, iconectiv moved its headquarters from Piscataway to Bridgewater , New Jersey . In August 2024, Ericson announced a sale of iconnectiv to Koch Equity for $ 1 billion. On August 10, 2017, Francisco Partners announced
3053-454: The global telecommunications industry. It provides numbering services in more than a dozen countries, including serving as the Local Number Portability Administrator (LNPA) for the United States. In that capacity, iconectiv manages the Number Portability Administration Center (NPAC), the system that supports the implementation of local number portability. iconectiv was established on October 20, 1983, as Central Services Organization as part of
3124-457: The growing array of offerings resulted in digital transmission that made more efficient use of the VHF signal capacity; fibre optics was common to carry signals into areas near the home, where coax could carry higher frequencies over the short remaining distance. Although for a time in the 1980s and 1990s, television receivers and VCRs were equipped to receive the mid-band and super-band channels. Due to
3195-450: The headend, the electrical signal is translated into an optical signal and sent through the fiber. The fiber trunkline goes to several distribution hubs , from which multiple fibers fan out to carry the signal to boxes called optical nodes in local communities. At the optical node, the optical signal is translated back into an electrical signal and carried by coaxial cable distribution lines on utility poles, from which cables branch out to
3266-460: The jack in the wall is attached to the input of the box, and an output cable from the box is attached to the television, usually the RF-IN or composite input on older TVs. Since the set-top box only decodes the single channel that is being watched, each television in the house requires a separate box. Some unencrypted channels, usually traditional over-the-air broadcast networks, can be displayed without
3337-490: The late 1980s, cable-only signals outnumbered broadcast signals on cable systems, some of which by this time had expanded beyond 35 channels. By the mid-1980s in Canada, cable operators were allowed by the regulators to enter into distribution contracts with cable networks on their own. By the 1990s, tiers became common, with customers able to subscribe to different tiers to obtain different selections of additional channels above
3408-425: The local utility poles or underground utility lines. Coaxial cable brings the signal to the customer's building through a service drop , an overhead or underground cable. If the subscriber's building does not have a cable service drop, the cable company will install one. The standard cable used in the U.S. is RG-6 , which has a 75 ohm impedance , and connects with a type F connector . The cable company's portion of
3479-423: The maximum number of channels that could be broadcast in one city was 7: channels 2, 4, either 5 or 6, 7, 9, 11 and 13, as receivers at the time were unable to receive strong (local) signals on adjacent channels without distortion. (There were frequency gaps between 4 and 5, and between 6 and 7, which allowed both to be used in the same city). As equipment improved, all twelve channels could be utilized, except where
3550-546: The native soil. Utility holes often show evidence of corrosion of support hardware and bonding ribbons that is caused by sulfate-reducing bacteria. The environment in utility holes and ducts can be made corrosive by man-made chemicals such as industrial effluent, fertilizers, and de-icing salts. Protective plastic coatings and cable jackets can rapidly deteriorate from leaking steam pipes present in many urban areas and from gasoline leaking from underground storage tanks. The most aggressive contributor to corrosion of underground plant
3621-451: The nearest network newscast. Such stations may use similar on-air branding as that used by the nearby broadcast network affiliate, but the fact that these stations do not broadcast over the air and are not regulated by the FCC, their call signs are meaningless. These stations evolved partially into today's over-the-air digital subchannels, where a main broadcast TV station e.g. NBC 37* would – in
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#17327802664553692-408: The old analog cable without a set-top box. To receive digital cable channels on an analog television set, even unencrypted ones, requires a different type of box, a digital television adapter supplied by the cable company or purchased by the subscriber. Another new distribution method that takes advantage of the low cost high quality DVB distribution to residential areas, uses TV gateways to convert
3763-531: The presence of dc voltages used to power the networks. Secretions from insects can also accelerate corrosion. Finally, chewing by rodents may expose metallic components, normally protected by a polymer or paint coating, to a corrosive environment. Underground plant includes all the telecommunications equipment installed in underground structures such as utility holes, Controlled Environment Vaults (CEVs), and ducts, along with associated hardware. Underground plant can be exposed to waters containing water-soluble salts of
3834-446: The process of integration, Telcordia's Advanced Technology Solutions business unit, the company's research arm, was rebranded as Applied Communication Sciences , and became a wholly owned subsidiary of Ericsson that operated independently on day-to-day operations pursuant to a proxy structure mandated by the U.S. government. In October 2012, Applied Communication Sciences relocated its headquarters to Basking Ridge , New Jersey, occupying
3905-504: The programming at the headend (the individual channels, which are distributed nationally, also have their own nationally oriented commercials). Modern cable systems are large, with a single network and headend often serving an entire metropolitan area . Most systems use hybrid fiber-coaxial (HFC) distribution; this means the trunklines that carry the signal from the headend to local neighborhoods are optical fiber to provide greater bandwidth and also extra capacity for future expansion. At
3976-454: The programming without cost. Later, the cable operators began to carry FM radio stations, and encouraged subscribers to connect their FM stereo sets to cable. Before stereo and bilingual TV sound became common, Pay-TV channel sound was added to the FM stereo cable line-ups. About this time, operators expanded beyond the 12-channel dial to use the midband and superband VHF channels adjacent to
4047-476: The range of reception for early cable-ready TVs and VCRs. However, once consumer sets had the ability to receive all 181 FCC allocated channels, premium broadcasters were left with no choice but to scramble. The descrambling circuitry was often published in electronics hobby magazines such as Popular Science and Popular Electronics allowing anybody with anything more than a rudimentary knowledge of broadcast electronics to be able to build their own and receive
4118-419: The seasons and with daily temperature changes. When humidity condenses on the surfaces of outdoor apparatus or equipment, the corrosivity of the moisture layer can be increased by industrial pollutants that render the condensate moisture corrosive. In sea coastal areas, wind-borne, salt-laden water droplets can deposit on exposed components. Near large cultivated areas, where fertilizers are applied by airplanes,
4189-418: The signals are typically encrypted on modern digital cable systems, and the set-top box must be activated by an activation code sent by the cable company before it will function, which is only sent after the subscriber signs up. If the subscriber fails to pay their bill, the cable company can send a signal to deactivate the subscriber's box, preventing reception. There are also usually upstream channels on
4260-465: The soil. Buried plant can be exposed to the same corrosive environment as underground plant. In addition, attack by gophers can expose underlying components to corrosion attack. Underwater plant includes all telecommunications equipment located beneath the surface of a body of water. This includes cables and repeaters. The water can range from relatively pure, to brackish, to badly contaminated with industrial effluent. Cable TV Cable television
4331-403: The subscriber's residence, the company's service drop cable is connected to cables distributing the signal to different rooms in the building. At each television, the subscriber's television or a set-top box provided by the cable company translates the desired channel back to its original frequency ( baseband ), and it is displayed onscreen. Due to widespread cable theft in earlier analog systems,
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#17327802664554402-577: The surrounding soil, turf, footpath, or road surface. They can be used to house and protect copper, coaxial, and optical fiber telephone cable splices and distribution elements. They safeguard and provide convenient access to cable termination and branch points, provide flexibility and access for installation operations (e.g., pulling or blowing cables), provide mechanical and environmental protection for splices, allow access for craftsperson work activities, and discourage access by unauthorized persons. Handholes and other below-ground splice vaults are deployed in
4473-487: The telecommunications equipment in each. It also includes references to various associated ASTM Standards. Above-ground plant includes all the telecommunications equipment physically located on or above the ground. This includes enclosures such as huts, cabinets, and pedestals, and the equipment mounted therein. It also includes pole-mounted equipment and cases, and pole-line hardware. Above-ground plant can be exposed to extreme temperatures, and to humidity that varies with
4544-474: The television signal is transmitted over-the-air by radio waves from a communications satellite and received by a satellite dish on the roof. FM radio programming, high-speed Internet , telephone services , and similar non-television services may also be provided through these cables. Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation. A cable channel (sometimes known as
4615-532: The upstream speed to 31.2 Kbp/s and prevented the always-on convenience broadband internet typically provides. Many large cable systems have upgraded or are upgrading their equipment to allow for bi-directional signals, thus allowing for greater upload speed and always-on convenience, though these upgrades are expensive. In North America , Australia and Europe , many cable operators have already introduced cable telephone service, which operates just like existing fixed line operators. This service involves installing
4686-489: The wind may carry nitrates, phosphates, and ammonium compounds to settle on metallic components of the above-ground telephone plant. Similarly, in residential areas, lawn fertilizers and herbicides can cause corrosion. In regions with snow, the salts used to melt snow and ice on roadways can accelerate corrosion. Under extreme conditions, pedestals and cabinets may be flooded with water that contains mud and corrosive salts. Corrosion of these flooded components may be accelerated by
4757-552: The wiring usually ends at a distribution box on the building exterior, and built-in cable wiring in the walls usually distributes the signal to jacks in different rooms to which televisions are connected. Multiple cables to different rooms are split off the incoming cable with a small device called a splitter . There are two standards for cable television; older analog cable, and newer digital cable which can carry data signals used by digital television receivers such as high-definition television (HDTV) equipment. All cable companies in
4828-684: Was involved in standards setting, training, and centralized government point-of-contact functions for its co-owners, the seven Regional Holding Companies that were themselves divested from AT&T as holding companies for the 22 local Bell Operating Companies. Bellcore's initial staff and corporate culture were drawn from the nearby Bell Laboratories locations in northern New Jersey, plus additional staff from AT&T and regional operating companies. The company originally had its headquarters in Livingston with dedication by New Jersey Governor Thomas Kean in 1985, but moved its headquarters to Morristown
4899-444: Was limited by distance from transmitters or mountainous terrain, large community antennas were constructed, and cable was run from them to individual homes. In 1968, 6.4% of Americans had cable television. The number increased to 7.5% in 1978. By 1988, 52.8% of all households were using cable. The number further increased to 62.4% in 1994. To receive cable television at a given location, cable distribution lines must be available on
4970-427: Was limited, meaning frequencies over 250 MHz were difficult to transmit to distant portions of the coaxial network, and UHF channels could not be used at all. To expand beyond 12 channels, non-standard midband channels had to be used, located between the FM band and Channel 7, or superband beyond Channel 13 up to about 300 MHz; these channels initially were only accessible using separate tuner boxes that sent
5041-559: Was mainly used to relay terrestrial channels in geographical areas poorly served by terrestrial television signals. Cable television began in the United States as a commercial business in 1950s. The early systems simply received weak ( broadcast ) channels, amplified them, and sent them over unshielded wires to the subscribers, limited to a community or to adjacent communities. The receiving antenna would be taller than any individual subscriber could afford, thus bringing in stronger signals; in hilly or mountainous terrain it would be placed at
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