Hybrid fiber-coaxial

Last updated

Hybrid fiber-coaxial (HFC) is a broadband telecommunications network that combines optical fiber and coaxial cable. It has been commonly employed globally by cable television operators since the early 1990s. [1]

Contents

In a hybrid fiber-coaxial cable system, television channels are sent from the cable system's distribution facility, the headend, to local communities through optical fiber subscriber lines. At the local community, an optical node translates the signal from a light beam to radio frequency (RF), and sends it over coaxial cable lines for distribution to subscriber residences. [2] The fiber optic trunk lines provide enough bandwidth to allow additional bandwidth-intensive services such as cable internet access through DOCSIS. [3] Bandwidth is shared among users of an HFC. [4] Encryption is used to prevent eavesdropping. [5] Customers are grouped into service groups, which are groups of customers that share bandwidth among each other since they use the same RF channels to communicate with the company.

Description

A common HFC architecture HFC Network Diagram.svg
A common HFC architecture

The fiber optic network extends from the cable operators' master headend, sometimes to regional headends, and out to a neighborhood's hubsite, and finally to an optical to coaxial cable node which typically serves 25 to 2000 homes. A master headend will usually have satellite dishes for reception of distant video signals as well as IP aggregation routers. Some master headends also house telephony equipment (such as automatic telephone exchanges) for providing telecommunications services to the community. In an HFC network telephony is provided using PacketCable.

A regional or area headend/hub will receive the video signal from the master headend [6] and add to it the public, educational, and government access (PEG) cable TV channels as required by local franchising authorities or insert targeted advertising that would appeal to a local area, along with internet from a CMTS (an Integrated CMTS, which includes all parts required for operation), or a CCAP which provides both internet and video.

Separate Edge QAMs can be used to provide QAM modulated video suitable for transmission in a coaxial cable network, from digital video sources. [7] [8] Edge QAMs can also be connected to a CMTS to provide internet data instead of video, in a modular CMTS architecture. [9] [10] CCAPs aim to replace the conventional, integrated CMTS which only provides data and Edge QAMs used for video which are separate pieces of equipment. [11]

Video can be encoded according to standards such as NTSC, MPEG-2, DVB-C or the QAM standard and data according to DOCSIS, analog video can be scrambled, [12] signals can be modulated by analog or digital video modulators including QAM modulators [13] or edge QAMs for video and/or data depending on whether a modular CMTS is used, at the CMTS for data only, [14] [15] [16] or at the CCAP for video and data, and upconverted onto RF carriers in this equipment.

The various services from CMTSs, CCAPs, Edge QAMs and QAM modulators are combined onto a single RF electrical signal using headend RF management modules such as splitters and combiners [17] [18] [19] and the resulting signals are inserted into a broadband optical transmitter which in practice is a transmitter module in an "optics platform" or headend platform such as an Arris CH3000, Scientific Atlanta Prisma, or a Cisco Prisma II. [20] [21] These platforms host several transmitters and receivers the latter of which can be used for cable internet and can also host Erbium-Doped Fiber Amplifiers (EDFAs) to extend the reach of the optical signals in fiber optics. [22] [23] Each transmitter and receiver services one optical node. [24]

This optical transmitter converts the RF electrical signal to a downstream optically modulated signal that is sent to the nodes. Fiber optic cables connect the headend or hub to the optical nodes in a point-to-point or star topology, [25] or in some cases, in a protected ring topology. Each node can be connected via its own dedicated fiber, [26] so fiber optic cables laid outdoors in the outside plant can have several [27] dozen to several hundred or even thousands of fibers, an extreme example being 6912 fibers. [28]

Fiber optic node.jpg
An optical node with a fiber splice case (black)
HFC trunk amplifier.jpg
A trunk amplifier
HFC line extender.jpg
A distribution amplifier (line extender)
HFC taps.jpg
A series of taps (servicing multiple rooms in a hotel) from a distribution line or "trunk" with terminators on unused ports

Fiber optic nodes

A fiber optic node has a broadband optical receiver, which converts the downstream optically modulated signal coming from the headend or hub to an electrical signal going to the customers. As of 2015, the downstream signal is a RF modulated signal that typically begins at 50 MHz and ranges from 550 to 1000 MHz on the upper end. The fiber optic node also contains a reverse- or return-path transmitter that sends communication from customers back to the headend. In North America, this reverse signal is a modulated RF ranging from 5–42 MHz while in other parts of the world, the range is 5–65 MHz. This electrical signal is then outputted through coaxial cable to form a coaxial trunk.

The optical portion of the network provides a large amount of flexibility. If there are not many fiber-optic cables to the node, wavelength division multiplexing can be used to combine multiple optical signals onto the same fiber. Optical filters are used to combine and split optical wavelengths onto the single fiber. For example, the downstream signal could be on a wavelength at 1550 nm and the return signal could be on a wavelength at 1310 nm. [29] [30]

Final connection to customers

The coaxial trunk portion of the network connects 25–2000 homes (500 is typical) [31] in a tree-and-branch configuration off of the node. [32] [33]

Trunk coaxial cables are connected to the optical node [34] [35] and form a coaxial backbone to which smaller distribution cables connect. RF amplifiers called trunk amplifiers are used at intervals in the trunk to overcome cable attenuation and passive losses of the electrical signals caused by splitting or "tapping" the coaxial cable. Trunk cables also carry AC power which is added to the cable line at usually either 60 or 90 V by a power supply (with a lead acid backup battery inside) and a power inserter. The power is added to the cable line so that optical nodes, trunk and distribution amplifiers do not need an individual, external power source. [36] The power supply might have a power meter next to it depending on local power company regulations.

From the trunk cables, smaller distribution cables are connected to a port of one of the trunk amplifiers called a bridger to carry the RF signal and the AC power down individual streets. Usually trunk amplifiers have two output ports: one for the trunk, and another as a bridger. Distribution amplifiers (also called system amplifiers) can be connected from a bridger port to connect several distribution cables to the trunk if more capacity is needed as they have multiple output ports. Alternatively, line extenders, which are smaller distribution amplifiers with only one output port, can be connected to the distribution cable coming off the bridger port in the trunk and used to boost the signals in the distribution cables [37] to keep the power of the television signal at a level that the TV can accept. The distribution line is then "tapped" into and used to connect the individual drops to customer homes. [38]

These RF taps pass the RF signal and block the AC power unless there are telephony devices that need the back-up power reliability provided by the coax power system. [39] The tap terminates into a small coaxial drop using a standard screw type connector known as an F connector.

The drop is then connected to the house where a ground block protects the system from stray voltages. Depending on the design of the network, the signal can then be passed through a splitter to multiple TVs or to multiple set top boxes (cable boxes) which may then be connected to a TV. If too many splitters are used to connect multiple TVs, the signal levels will decrease, and picture quality on analog channels will decrease. The signal in TVs past those splitters will lose quality and require the use of a "drop" or "house" amplifier to restore the signal. [40]

Evolution of HFC networks

Historically the trend among cable operators has been to reduce the amount of coaxial cable used in their networks to improve signal quality, which initially led to the adoption of HFC. [41] HFC replaced coaxial cable networks which had coaxial trunk cables originating at the headend of the network, and HFC replaced part of these trunk cables with fiber optic cables and optical nodes. In these coaxial networks, trunk amplifiers were placed along the trunk cables to maintain adequate signal levels in the trunks, [42] [43] distribution feeder cables could be used to distribute signals from the trunks into individual streets, [44] [45] [46] directional couplers were used to improve signal quality, [47] trunk amplifiers could be equipped with automatic level control or automatic gain control, [48] hybrid amplifiers, which have a hybrid integrated circuit [49] [50] could also be used, [51] and separate bridgers were used to connect the trunk to distribution feeders. [52] [53] [54]

In 1953, C-COR was the first to introduce cable powering which transmits power through coaxial cables for powering cable amplifiers. In 1965, it introduced the use of integrated circuits in amplifiers used on utility poles and in 1969 was the first to use heat fins on amplifiers. [55] [56] The first amplifiers in outdoor housings with hinges and seals, for installation between utility poles hanging from messenger wires, were offered in 1965. [57] In around 1973, hubs began to be used in cable networks to increase signal quality as a result of network expansion, and cable operators made efforts to reduce the number of amplifiers in cascade on coaxial parts of the network from around 20 to 5. [58] [59] Supertrunks made of coaxial cable with FM modulated video signals, [60] [56] fiber optics or microwave links were used to connect headends to hubs. [61] [62] [63] [58] Fiber optics were first used as a supertrunk in 1976. [64] FM video could be also carried in fiber optics, [65] and fiber optics eventually replaced coaxial cables in supertrunks. [56] Bandwidth in cable networks increased from 216 MHz to 300 MHz in the 1970s, [49] to 400 MHz in the 1980s, [56] [66] [67] to 550 MHz, 600 MHz and 750 MHz in the 1990s, [66] [68] [69] and to 870 MHz in the year 2000. [70]

To cope with needs for increased digital bandwidth such as for DOCSIS internet, cable operators have implemented expansions in the RF spectrum in HFC networks beyond 1 GHz to 1.2 GHz, [71] [72] have transitioned to only handling IP traffic in the network thus eliminating dedicated video RF channels, used digital transport adapters (DTAs) for transmitting normally analog signals, or used Switched Digital Video (SDV) [73] [74] which allows the number of television channels in coaxial cables to be reduced without reducing the number of channels that are offered. [75] [76]

Towards the end of the 1990s GaAs (Gallium Arsenide) transistors were introduced in HFC nodes and amplifiers, replacing silicon transistors which allowed an expansion of the spectrum used in HFC from 870 MHz to 1 GHz by 2006. [70] GaN transistors, introduced in 2008 [49] and adopted in the 2010s allowed for another expansion to 1.2 GHz, or for expansion from 550 MHz to 750 MHz in older networks to 1 GHz without changing the spacing between amplifiers. [77] [78] [79]

Remote PHY is an evolution of the HFC network that aims to reduce the use of coaxial cable in the network and improve signal quality. In a conventional HFC network, headend equipment such as CMTSs and CCAPs are connected to the HFC network using RF interfaces which physically are coaxial cable connections [80] [81] [82] and optical signals in fiber optic cables in the network are analog. In Remote PHY, equipment such as CMTSs or CCAPs are connected directly to the HFC network using fiber optics carrying digital signals, eliminating the RF interface and coaxial cables at the CMTS/CCAP and RF modulation at the headend, [83] and replacing analog signals in fiber optic cables in the network, with digital signals such as 10 Gigabit Ethernet signals, [20] which eliminate the need for calibrating the HFC network bi-annually, extends the reach of the network, reduces the cost of equipment and maintenance, [84] and improves signal quality and allows for modulation such as 4096 QAM instead of 1024 QAM, allowing more information to be transmitted at a time, per bit. This requires more sophisticated optical nodes which can also convert signals from digital to analog performing modulation, unlike conventional optical nodes which only need to convert signals from optical to electrical. [83] These devices are known as Remote PHY devices (RPDs) or Remote MACPHY devices (RMDs). RPDs come in shelf variants which can be installed in apartment buildings (MDUs, multi dwelling units) and can also be installed in optical nodes or at a small hub which distributes signals similarly to a conventional HFC network. [20] [74] [85] [37] [86] Alternatively Remote PHY can allow for a CMTS/CCAP to be located in a remote data center away from customers. [87]

Remote MACPHY, besides achieving the same purpose as Remote PHY, also moves all DOCSIS protocol functionality to the optical node or the outside plant, which can reduce latency when compared to Remote PHY. [88] [89] Remote CMTS/Remote CCAP builds upon this by moving all CMTS/CCAP functionality to the outside plant. [85] [87] Distributed Access Architecture (DAA) covers Remote PHY and Remote MACPHY and has as the goal, moving functions closer to end customers, allowing for easier capacity expansions as centralized facilities for equipment are downsized or potentially eliminated, and newer DOCSIS versions beyond DOCSIS 3.1 with higher speeds. Remote PHY allows for some reuse of existing equipment such as CMTSs/CCAPs by replacing components. [88] [90]

Virtual CCAPs (vCCAPs) or virtual CMTSs (vCMTSs) are implemented on commercial off the shelf x86-based servers with specialized software, [91] are often implemented alongside DAA [92] and can be used to increase service capacity without purchasing new CMTS/CCAP chassis, or add features to the CMTS/CCAP more quickly. [74]

Improving internet speeds for customers can be carried out by reducing the number of service groups with subscribers from 500 subscribers to no more than 128, in what is known as a n+0 architecture, with a single node and no amplifiers. [93] [94] [83] HFC networks operating at 1.8 GHz [95] to 3 GHz have been explored with GaN transistors. [96] [97] Changes in the frequency range used for upstream signals have been proposed: a mid split which uses frequencies from 5 to 85 MHz for the upstream, a high split which uses a range from 5 to 205 MHz, and an ultra high split with several options that allow for ranges of up to 5 to 684 MHz. [98] Full duplex (FDX) DOCSIS allows upstream and downstream signals to simultaneously occupy a single frequency range without time division multiplexing. [99] Cable operators have been gradually shifting to FTTP networks using PON (Passive Optical Networks). [100] [101] [102]

Transport over HFC network

By using frequency-division multiplexing, a HFC network may carry a variety of services, including analog TV, digital TV (SDTV or HDTV), video on demand, telephony, and internet traffic. Services on these systems are carried on RF signals in the 5 MHz to 1000 MHz frequency band.

The HFC network is typically operated bi-directionally, meaning that signals are carried in both directions on the same network from the headend/hub office to the home, and from the home to the headend/hub office. The forward-path or downstream signals carry information from the headend/hub office to the home, such as video content, voice and Internet traffic. The very first HFC networks, and very old unupgraded HFC networks, are only one-way systems. Equipment for one-way systems may use POTS or radio networks to communicate to the headend. [103] HFC makes two-way communication over a cable network practical because it reduces the number of amplifiers in these networks. [1]

The return-path or upstream signals carry information from the home to the headend/hub office, such as control signals to order a movie or internet upstream traffic. The forward-path and the return-path are carried over the same coaxial cable in both directions between the optical node and the home.

To prevent interference of signals, the frequency band is divided into two sections. In countries that have traditionally used NTSC System M, the sections are 52–1000 MHz for forward-path signals, and 5–42 MHz for return-path signals. [98] Other countries use different band sizes, but are similar in that there is much more bandwidth for downstream communication than for upstream communication.

Traditionally, since video content was sent only to the home, the HFC network was structured to be asymmetrical: one direction has much more data-carrying capacity than the other direction. The return path was originally used for only some control signals to order movies, etc., which required very little bandwidth. As additional services have been added to the HFC network, such as Internet access and telephony, the return path is being utilised more.

Multiple-system operators

Multi-system operators (MSOs) developed methods of sending the various services over RF signals on the fiber optic and coaxial copper cables. The original method to transport video over the HFC network and, still the most widely used method, is by modulation of standard analog TV channels which is similar to the method used for transmission of over-the-air broadcast.

One analog TV channel occupies a 6-MHz-wide frequency band in NTSC-based systems, or an 8-MHz-wide frequency band in PAL or SECAM-based systems. Each channel is centred on a specific frequency carrier so that there is no interference with adjacent or harmonic channels. To be able to view a digitally modulated channel, home, or customer-premises equipment (CPE), e.g. digital televisions, computers, or set-top boxes, are required to convert the RF signals to signals that are compatible with display devices such as analog televisions or computer monitors. The US Federal Communications Commission (FCC) has ruled that consumers can obtain a cable card from their local MSO to authorize viewing digital channels.

By using digital video compression techniques, multiple standard and high-definition TV channels can be carried on one 6 or 8 MHz frequency carrier, thus increasing the channel carrying capacity of the HFC network by 10 times or more versus an all-analog network.

Comparison to competing network technologies

Digital subscriber line (DSL) is a technology used by traditional telephone companies to deliver advanced services (high-speed data and sometimes video) over twisted pair copper telephone wires. It typically has lower data carrying capacity than HFC networks and data speeds can be range-limited by line lengths and quality.

Satellite television competes very well with HFC networks in delivering broadcast video services. Interactive satellite systems are less competitive in urban environments because of their large round-trip delay times, but are attractive in rural areas and other environments with insufficient or no deployed terrestrial infrastructure.

Analogous to HFC, fiber in the loop (FITL) technology is used by telephone local exchange carriers to provide advanced services to telephone customers over the plain old telephone service (POTS) local loop.

In the 2000s, telecom companies started significant deployments of fiber to the x (FTTX) such as passive optical network solutions to deliver video, data and voice to compete with cable operators. These can be costly to deploy but they can provide large bandwidth capacity especially for data services.

See also

Related Research Articles

<span class="mw-page-title-main">Cable television</span> Television content transmitted via signals on coaxial cable

Cable television 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 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.

<span class="mw-page-title-main">Cable modem</span> Broadband Internet access device

A cable modem is a type of network bridge that provides bi-directional data communication via radio frequency channels on a hybrid fiber-coaxial (HFC), radio frequency over glass (RFoG) and coaxial cable infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high bandwidth of a HFC and RFoG network. They are commonly deployed in the Americas, Asia, Australia, and Europe.

<span class="mw-page-title-main">Broadband</span> Data transmission concept

In telecommunications, broadband or high speed is the wide-bandwidth data transmission that exploits signals at a wide spread of frequencies or several different simultaneous frequencies, and is used in fast Internet access. The transmission medium can be coaxial cable, optical fiber, wireless Internet (radio), twisted pair cable, or satellite.

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.

<span class="mw-page-title-main">Cable television headend</span> Facility for cable television system

A cable television headend is a master facility for receiving television signals for processing and distribution over a cable television system. A headend facility may be staffed or unstaffed and is typically surrounded by some type of security fencing. The building is typically sturdy and purpose-built to provide security, cooling, and easy access for the electronic equipment used to receive and re-transmit video over the local cable infrastructure. One can also find head ends in power-line communication (PLC) substations and Internet communications networks.

<span class="mw-page-title-main">Cable modem termination system</span> Equipment used to provide high speed data services

A cable modem termination system is a piece of equipment, typically located in a cable company's headend or hubsite, which is used to provide data services, such as cable Internet or Voice over IP, to cable subscribers.

<span class="mw-page-title-main">Passive optical network</span> Technology used to provide broadband to the end consumer via fiber

A passive optical network (PON) is a fiber-optic telecommunications network that uses only unpowered devices to carry signals, as opposed to electronic equipment. In practice, PONs are typically used for the last mile between Internet service providers (ISP) and their customers. In this use, a PON has a point-to-multipoint topology in which an ISP uses a single device to serve many end-user sites using a system such as 10G-PON or GPON. In this one-to-many topology, a single fiber serving many sites branches into multiple fibers through a passive splitter, and those fibers can each serve multiple sites through further splitters. The light from the ISP is divided through the splitters to reach all the customer sites, and light from the customer sites is combined into the single fiber. Many fiber ISPs prefer this system.

In telecommunications, cable Internet access, shortened to cable Internet, is a form of broadband internet access which uses the same infrastructure as cable television. Like digital subscriber line (DSL) and fiber to the premises, cable Internet access provides network edge connectivity from the Internet service provider to an end user. It is integrated into the cable television infrastructure analogously to DSL, which uses the existing telephone network. Cable TV networks and telecommunications networks are the two predominan forms of residential Internet access. Recently, both have seen increased competition from fiber deployments, wireless, and satellite internet access.

Fiber to the <i>x</i> Broadband network architecture term

Fiber to the x or fiber in the loop is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber optic cables are able to carry much more data than copper cables, especially over long distances, copper telephone networks built in the 20th century are being replaced by fiber.

<span class="mw-page-title-main">Multimedia over Coax Alliance</span> International standards consortium that publishes specifications for networking over coaxial cable

The Multimedia over Coax Alliance (MoCA) is an international standards consortium that publishes specifications for networking over coaxial cable. The technology was originally developed to distribute IP television in homes using existing cabling, but is now used as a general-purpose Ethernet link where it is inconvenient or undesirable to replace existing coaxial cable with optical fiber or twisted pair cabling.

<span class="mw-page-title-main">Fiber-optic communication</span> Transmitting information over optical fiber

Fiber-optic communication is a form of optical communication for transmitting information from one place to another by sending pulses of infrared or visible light through an optical fiber. The light is a form of carrier wave that is modulated to carry information. Fiber is preferred over electrical cabling when high bandwidth, long distance, or immunity to electromagnetic interference is required. This type of communication can transmit voice, video, and telemetry through local area networks or across long distances.

Radio over fiber (RoF) or RF over fiber (RFoF) refers to a technology whereby light is modulated by a radio frequency signal and transmitted over an optical fiber link. Main technical advantages of using fiber optical links are lower transmission losses and reduced sensitivity to noise and electromagnetic interference compared to all-electrical signal transmission.

Ethernet over Coax (EoC) is a family of technologies that supports the transmission of Ethernet frames over coaxial cable. The Institute of Electrical and Electronics Engineers (IEEE) maintains all official Ethernet standards in the IEEE 802 family.

Zenith Cable Modem was one of the first proprietary cable modems. The two basic models are one operating at 500 kilobits per second (Kbit/s), and the other at four megabits per second (Mbit/s) with BPSK and approximately a 25% alpha.

In telecommunications, radio frequency over glass (RFoG) is a deep-fiber network design in which the coax portion of the hybrid fiber coax (HFC) network is replaced by a single-fiber passive optical network (PON). Downstream and return-path transmission use different wavelengths to share the same fiber. The return-path wavelength standard is expected to be 1610 nm, but early deployments have used 1590 nm. Using 1590/1610 nm for the return path allows the fiber infrastructure to support both RFoG and a standards-based PON simultaneously, operating with 1490 nm downstream and 1310 nm return-path wavelengths.

<span class="mw-page-title-main">Remote radio head</span> Type of radio used in wireless telecommunications networks

A remote radio head (RRH), also called a remote radio unit (RRU) in wireless networks, is a remote radio transceiver that connects to an operator radio control panel via electrical or wireless interface. When used to describe aircraft radio cockpit radio systems, the control panel is often called the radio head.

Physical media refers to the physical materials that are used to store or transmit information in data communications. These physical media are generally physical objects made of materials such as copper or glass. They can be touched and felt, and have physical properties such as weight and color. For a number of years, copper and glass were the only media used in computer networking.

Subisu Cablenet Ltd. is a Nepalese Internet Service Provider company located in Kathmandu, Nepal, and was established in 2001. Subisu employs over 1500 full-time employees, of which around 900 are technical and around 700 are non-technical. As of 2023, the company has over 235,000 customers. It has coverage in all 77 districts of Nepal. Subisu primarily provides cable and fiber internet and digital TV services through a hybrid fiber-coaxial (HFCC) network.

<span class="mw-page-title-main">Ziggo</span> Dutch cable operator

Ziggo Holding B.V. is the largest cable operator in the Netherlands, providing digital cable television, Internet, and telephone service to both residential and commercial customers.

Inter is a Venezuelan television broadcaster and telecommunications provider headquartered in Barquisimeto, Lara, Venezuela. Inter was founded in 1996 as InterCable. Its fiscal name is Corporacion Telemic C.A, and its main shareholder is the investment fund HM Capital Partners.

References

  1. 1 2 Large, David; Farmer, James (November 25, 2008). Broadband Cable Access Networks: The HFC Plant. Morgan Kaufmann. ISBN   978-0-08-092214-0 – via Google Books.
  2. ↑ Kevin A. Noll. "Hybrid Fiber-Coaxial Networks: Technology and Challenges in Deploying Multi-Gigabit Access Services" (PDF). nanog.org. Retrieved March 30, 2023.
  3. ↑ Data-Over-Cable Service Interface Specifications DOCSIS® 3.1 CCAP™ Operations Support System Interface Specification CM-SP-CCAP-OSSIv3.1-I25-220819
  4. ↑ Achieving the Triple Play: Technologies and Business Models for Success: Comprehensive Report. Intl. Engineering Consortiu. March 15, 2024. ISBN   978-1-931695-37-4.
  5. ↑ Data-Over-Cable Service Interface Specifications DOCSIS® 3.0 MAC and Upper Layer Protocols Interface Specification CM-SP-MULPIv3.0-C01-171207
  6. ↑ Emil Stoilov (2006). "On The Design of Hybrid Fiber-Coax Networks" (PDF). International Conference on Computer Systems and Technologies. Retrieved May 16, 2023.
  7. ↑ CT's EDGE QAM Tech Guide. cablefax.com. Retrieved 18 October 2024
  8. ↑ QAM Resource Allocation in Mixed-Format VoD Systems. people.computing.clemson.edu. Retrieved 19 October 2024
  9. ↑ Chapman, John. "THE MODULAR CMTS ARCHITECTURE" . Retrieved March 2, 2024.
  10. ↑ "TRANSITIONING TO M-CMTS" . Retrieved March 2, 2024.
  11. ↑ "StackPath". www.lightwaveonline.com. September 13, 2013.
  12. ↑ Communications Technology 1984-09. worldradiohistory.com. Retrieved 18 October 2024
  13. ↑ Ciciora, Walter S. (March 7, 2004). Modern Cable Television Technology. Morgan Kaufmann. ISBN   978-1-55860-828-3 – via Google Books.
  14. ↑ Broadband Last Mile: Access Technologies for Multimedia Communications. CRC Press. October 3, 2018. ISBN   978-1-4200-3066-2.
  15. ↑ "Cisco CMTS Router Downstream and Upstream Features Configuration Guide - DOCSIS 2.0 A-TDMA Modulation Profiles for the Cisco CMTS Routers [Support]".
  16. ↑ "Configuring Cable Modulation Profiles on Cisco CMTSS".
  17. ↑ Swanson, Al; Mayer, Gary; Hartman, Bill. "Meeting the Needs of the Headend-of-the-Future Today--The Structured Headend". www.nctatechnicalpapers.com.
  18. ↑ "_6EzSt-xXJIC".
  19. ↑ Modern Cable Television Technology. Elsevier. January 13, 2004. ISBN   978-0-08-051193-1.
  20. 1 2 3 Downey, John J. "The Power of Distributed Access Architectures (DAA) Benefits of Digital Fiber Along with Remote-PHY". www.nctatechnicalpapers.com.
  21. ↑ "ARRIS CH3000" (PDF). www.normann-engineering.com.
  22. ↑ Pidgeon, Rezin E.; Frymyer, Don E. "Optical Amplifier Basic Properties And System Modeling: A Simple Tutorial". www.nctatechnicalpapers.com.
  23. ↑ "Prisma 1550 nm Strand Mounted Optical Amplifier" (PDF). www.cisco.com.
  24. ↑ Sniezko, Oleh J. "MULTI-LAYER HEAD END COMBINING NETWORK DESIGN FOR BROADCAST, LOCAL, AND TARGETED SERVICES". www.nctatechnicalpapers.com.
  25. ↑ Tunmann, Ernest (January 1, 1995). Hybrid Fiber-Optic Coaxial Networks: How to Design, Build, and Implement an Enterprise-Wide Broadband HFC Network. CRC Press. ISBN   978-1-4822-8107-1 – via Google Books.
  26. ↑ Ciciora, Walter S. (March 10, 2024). Modern Cable Television Technology. Morgan Kaufmann. ISBN   978-1-55860-828-3.
  27. ↑ Large, David; Farmer, James (January 13, 2004). Modern Cable Television Technology. Elsevier. ISBN   978-0-08-051193-1.
  28. ↑ "The FOA Reference for Fiber Optics - High Fiber Count Cables".
  29. ↑ "MODEL NC4000EG C4000EG OPTICAL NODE SERIES (NC), ESSENTIAL FEATURES FIBER DEEP NODE PLATFORM" (PDF). www.goamt.com. Archived from the original (PDF) on April 23, 2021.
  30. ↑ "Cable Technician Pocket Guide" (PDF). www.commscope.com.
  31. ↑ "Network World". IDG Network World Inc. August 5, 1996 – via Google Books.
  32. ↑ Tunmann, Ernest (January 1, 1995). Hybrid Fiber-Optic Coaxial Networks: How to Design, Build, and Implement an Enterprise-Wide Broadband HFC Network. CRC Press. ISBN   978-1-4822-8107-1 – via Google Books.
  33. ↑ France, Paul (January 30, 2004). Local Access Network Technologies. IET. ISBN   978-0-85296-176-6 – via Google Books.
  34. ↑ Schmitt, Matt. "Cable Network Overview" (PDF). www.ieee802.org.
  35. ↑ Large, David; Farmer, James (November 25, 2008). Broadband Cable Access Networks: The HFC Plant. Morgan Kaufmann. ISBN   978-0-08-092214-0 – via Google Books.
  36. ↑ Noll, Kevin A. "Hybrid Fiber-Coaxial Networks: Technology and Challenges in Deploying Multi-Gigabit Access Services" (PDF). archive.nanog.org.
  37. 1 2 Large, David; Farmer, James (November 25, 2008). Broadband Cable Access Networks: The HFC Plant. Morgan Kaufmann. ISBN   978-0-08-092214-0.
  38. ↑ "Taps: A Peek Under the Hood |". November 20, 2021.
  39. ↑ Large, David; Farmer, James (November 25, 2008). Broadband Cable Access Networks: The HFC Plant. Morgan Kaufmann. ISBN   978-0-08-092214-0 – via Google Books.
  40. ↑ Broadband Access and Network Management: NOC '98 - Networks and Optical Communication. IOS Press. March 2, 1998. ISBN   978-90-5199-400-1.
  41. ↑ Hardy, Daniel (March 2, 2024). Networks: Internet, Telephony, Multimedia : Convergences and Complementarities. Springer. ISBN   978-2-7445-0144-9.
  42. ↑ Laubach, Mark E.; Farber, David J.; Dukes, Stephen D. (February 28, 2002). Delivering Internet Connections over Cable: Breaking the Access Barrier. John Wiley & Sons. ISBN   978-0-471-43802-1 – via Google Books.
  43. ↑ "THE COMPLETE TECHNICAL PAPER PROCEEDINGS". www.nctatechnicalpapers.com.
  44. ↑ McGregor, Michael A.; Driscoll, Paul D.; McDowell, Walter (January 8, 2016). Head's Broadcasting in America: A Survey of Electronic Media (1-download). Routledge. ISBN   978-1-317-34793-4.
  45. ↑ Jackson, K. G.; Townsend, G. B. (May 15, 2014). TV & Video Engineer's Reference Book. Elsevier. ISBN   978-1-4831-9375-5.
  46. ↑ Communication Technology Update. Taylor & Francis. April 22, 1993. ISBN   978-0-240-80881-9.
  47. ↑ "TV & Communications - December 1964" (PDF). www.worldradiohistory.com.
  48. ↑ "Paper - Distribution Equipment for 400 MHZ Co-Axial Communications Systems - NCTA Technical Papers".
  49. 1 2 3 Young, Conrad. "RFMD.® CATV Hybrid Amplifier Modules: Past, Present, Future" (PDF). www.piedmontscte.org.
  50. ↑ Grant, Al; Eachus, Jim (1978). "Reliability Considerations in CATV Hybrids". IEEE Transactions on Cable Television. CATV-3 (1): 1–23. doi:10.1109/TCATV.1978.285736. S2CID   6899727.
  51. ↑ "Paper - the Design Approach to a New CATV Distribution Amplifier - NCTA Technical Papers".
  52. ↑ "Paper - Performance of a 400 MHZ, 54 Channel, Cable Television Distribution System - NCTA Technical Papers".
  53. ↑ "Paper - the Design, Construction, Cost and Performance the First 400 MHZ Cable Television System - NCTA Technical Papers".
  54. ↑ Hura, Gurdeep S.; Singhal, Mukesh (March 28, 2001). Data and Computer Communications: Networking and Internetworking. CRC Press. ISBN   978-1-4200-4131-6.
  55. ↑ "TV Communications". Communications Publishing Corporation. March 11, 1975 – via Google Books.
  56. 1 2 3 4 Taylor, Archer S. "HISTORY BETWEEN THEIR EARS" (PDF). syndeoinstitute.org.
  57. ↑ "TV & Communications - September 1965" (PDF). www.worldradiohistory.com.
  58. 1 2 "Communications Technology - December 1991" (PDF). www.worldradiohistory.com.
  59. ↑ Chadwick, Russell B. "A SURVEY OF TECHNICAL REQUIREMENTS FOR BROADBAND CABLE TELESERVICES VOLUME 3" (PDF). files.eric.ed.gov.
  60. ↑ "A Study of the Technical and Feasibility of Providing Narrowband and Broadband Communications Service in Rural Areas Volume 1".
  61. ↑ Borelli, Vincent R.; Gysel, Hermann (1990). "CATV fibre-optic supertrunking: A comparison of parameters and topologies using analog and/Or digital techniques". International Journal of Digital & Analog Communication Systems. 3 (4): 305–310. doi:10.1002/dac.4510030404.
  62. ↑ "Paper - Fiber Optic Technology for CATV Supertrunk Applications - NCTA Technical Papers".
  63. ↑ "Communications Engineering and Design - December 1987" (PDF). www.worldradiohistory.com.
  64. ↑ "The Cable History Timeline" (PDF). syndeoinstitute.org.
  65. ↑ "Broadband '89". March 12, 2024.
  66. 1 2 "THE COMPLETE TECHNICAL PAPER PROCEEDINGS 1991". www.nctatechnicalpapers.com.
  67. ↑ "Communications Engineering Digest - May 1981" (PDF). www.worldradiohistory.com.
  68. ↑ "Paper - Upgrade of 450/550 MHZ Cable Systems to 600 MHZ Using a Phase Area Approach - NCTA Technical Papers".
  69. ↑ McNamara, D.; Fukasawa, Y.; Wakabayashi, Y.; Shirakawa, Y.; Kakuta, Y. "750MHz Power Doubler and Push-Pull CATV Hybrid Modules Using Gallium Arsenide". www.nctatechnicalpapers.com.
  70. 1 2 Jones, Doug. "DOCSIS® 4.0 Technology Realizing Multigigabit Symmetric Services - Migration Scenarios for Multigigabit Return Services". www.nctatechnicalpapers.com.
  71. ↑ Ouyang, Tao. "Cable Lifespan Extension with FDX & ESD" (PDF). www.itu.int/. Retrieved March 2, 2024.
  72. ↑ "ATX looks to DOCSIS 4.0 and beyond". April 22, 2020.
  73. ↑ "The Switch to Switched Digital Video | NCTA — the Internet & Television Association".
  74. 1 2 3 "Lessons from Operating Tens of Thousands of Remote PHY Devices". SCTE. Retrieved March 2, 2024.
  75. ↑ Baumgartner, Jeff (June 1, 2008). "Who Makes What: Switched Digital Video". www.lightreading.com.
  76. ↑ "Switched IP Video Technology Frees up to 80% of Bandwidth for DOCSIS Expansion". June 30, 2017.
  77. ↑ Sniezko, Oleh; Combs, Doug; Brockett, Rei. "DISTRIBUTED DIGITAL HFC ARCHITECTURE EXPANDS BI-DIRECTIONAL CAPACITY". www.nctatechnicalpapers.com.
  78. ↑ Miguelez, Phil. "Hi Ho, Hi Ho, to a Gigabit We Go - Positioning the HFC Network for the New Gigabit Era". www.nctatechnicalpapers.com.
  79. ↑ Miguelez, Phil; Slowik, Fred; Eastman, Stuart. "REFUELING THE CABLE PLANT – A NEW ALTERNATIVE TO GAAS". www.nctatechnicalpapers.com.
  80. ↑ Large, David; Farmer, James (January 13, 2004). Modern Cable Television Technology. Elsevier. ISBN   978-0-08-051193-1.
  81. ↑ "E6000™ Converged Edge Router User Documentation" . Retrieved March 2, 2024.
  82. ↑ "Demystifying OOB and R-PHY |". November 24, 2018.
  83. 1 2 3 Jorge, Salinger. "Remote PHY: Why and How". SCTE. Retrieved March 2, 2024.
  84. ↑ "Paper - Evolution of CMTS/CCAP Architectures - NCTA Technical Papers".
  85. 1 2 Chapman, John. "DOCSIS Remote PHY Modular Headend Architecture (MHA v2)" (PDF). SCTE. Retrieved March 2, 2024.
  86. ↑ "Cisco Remote-PHY Compact Shelf Hardware Installation Guide" (PDF). Cisco Systems, Inc. Retrieved March 2, 2024.
  87. 1 2 "Impact of CCAP to CM Distance in a Remote PHY Architecture" (PDF). Retrieved March 2, 2024.
  88. 1 2 "Paper - Follow the Yellow Brick Road: From Integrated CCAP or CCAP + Remote PHY to FMA with Remote MACPHY - NCTA Technical Papers".
  89. ↑ Alharbi, Ziyad; Thyagaturu, Akhilesh S.; Reisslein, Martin; Elbakoury, Hesham; Zheng, Ruobin (2018). "Performance Comparison of R-PHY and R-MACPHY Modular Cable Access Network Architectures". IEEE Transactions on Broadcasting. 64: 128–145. doi:10.1109/TBC.2017.2711145. S2CID   3668345.
  90. ↑ "So, You Want to be a DOCSIS Engineer? You're Sure About This? |". February 17, 2023.
  91. ↑ "Harmonic's 'CableOS' now connected to 18.4M modems".
  92. ↑ "Practical Lessons of a DAA Deployment with a Virtualized CMTS". SCTE•ISBE. Retrieved March 2, 2024.
  93. ↑ "Distributed Access Architecture Is Now Widely Distributed – And Delivering On It's Promise". SCTE. Retrieved March 2, 2024.
  94. ↑ "Next-Generation HFC Part 1 – Upgrading the HFC Network". April 15, 2020.
  95. ↑ Foroughi, Nader. "Upgrading the Plant to Satisfy Traffic Demands - The One Touch Approach". www.nctatechnicalpapers.com.
  96. ↑ "2019 Blueprint for 3 ghz 25 gbps". SCTE•ISBE. Retrieved March 2, 2024.
  97. ↑ "Complexity is Complex |". November 18, 2019.
  98. 1 2 "Paper - Network Capacity Options on the Path to 10G - NCTA Technical Papers".
  99. ↑ "Paper - FDX & D3.1 Capacity Scenarios - NCTA Technical Papers".
  100. ↑ Baumgartner, Jeff (March 7, 2024). "The 'cable' fade-out continues". www.lightreading.com.
  101. ↑ Brown, Karen (June 18, 2021). "Cable players are taking many paths to PON". www.lightreading.com.
  102. ↑ "Omdia: Cable network operators deploy PONs – Technology Blog".
  103. ↑ Rahman, Syed, Mahbubur (July 1, 2001). Multimedia Networking: Technology, Management and Applications: Technology, Management and Applications. Idea Group Inc (IGI). ISBN   978-1-59140-005-9 – via Google Books.{{cite book}}: CS1 maint: multiple names: authors list (link)
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.