Cable Internet access: Difference between revisions
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{{short description|Form of broadband Internet access}} |
{{short description|Form of broadband Internet access}} |
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In [[telecommunication]]s, '''cable Internet access''', shortened to '''cable Internet''', is a form of [[broadband |
In [[telecommunication]]s, '''cable Internet access''', shortened to '''cable Internet''', is a form of [[Internet access#Hardwired_broadband|broadband internet access]] which uses the same infrastructure as [[Cable modem|cable television]]. Like [[digital subscriber line]] and [[fiber to the premises]] [[Network service|services]], cable [[Internet]] [[Access control|access]] provides [[Computer network|network]] edge [[Connectivity Technologies|connectivity]] ([[Last mile (telecommunications)|last mile]] access) from the [[Internet service provider]] to an end [[Android root|user]]. It is integrated into the [[cable television]] infrastructure analogously to DSL which uses the existing [[telephone]] network. Cable TV [[Networks and States|networks]] and [[telecommunications]] networks are the two [[Prevailing winds|predominant]] forms of [[Residential area|residential]] [[Global Internet usage|Internet access]]. Recently, both have seen increased competition from [[Fiber-optic communication cable|fiber deployments]], [[Wireless network|wireless]], [[Mobile Broadband Network Limited|mobile]] [[Computer network|networks]] and [[satellite internet access]]. |
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==Hardware and bit rates== |
==Hardware and bit rates== |
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{{Main|Cable modem}} |
{{Main|Cable modem}} |
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Broadband cable Internet access requires a cable modem at the customer's premises and a [[cable modem termination system]] (CMTS) at a [[Multi system operator|cable operator]] facility, typically a [[cable television headend]]. The two are connected via [[coaxial cable]] to a [[hybrid fibre-coaxial]] (HFC) network. While [[access network]]s are referred to as ''[[Last mile (telecommunications)|last-mile]]'' technologies, cable Internet systems can typically operate where the distance between the modem and the termination system is up to {{convert|160|km|mi}}. If the HFC network is large, the cable modem termination system can be grouped into hubs for efficient management. |
Broadband cable Internet access requires a cable modem at the customer's premises and a [[cable modem termination system]] (CMTS) at a [[Multi system operator|cable operator]] facility, typically a [[cable television headend]]. The two are connected via [[coaxial cable]] to a [[hybrid fibre-coaxial]] (HFC) network. While [[access network]]s are referred to as ''[[Last mile (telecommunications)|last-mile]]'' technologies, cable Internet systems can typically operate where the distance between the modem and the termination system is up to {{convert|160|km|mi}}. If the HFC network is large, the cable modem termination system can be grouped into hubs for efficient management. Several standards have been used for cable internet, but the most common is DOCSIS.<ref>{{cite book | url=https://books.google.com/books?id=-QELAAAAQBAJ&dq=docsis&pg=PA214 | title=Hands-On Networking Fundamentals | isbn=978-1285402758 | last1=Palmer | first1=Michael | date=21 June 2012 }}</ref> |
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A cable modem at the customer |
A cable modem at the customer is connected via coaxial cable to an optical node, and thus into an HFC network. An optical node serves many modems as the modems are connected with coaxial cable to a coaxial cable "trunk" via distribution "taps" on the trunk, which then connects to the node, possibly using amplifiers along the trunk. The optical node converts the Radiofrequency (RF) signal in the coaxial cable trunk into light pulses to be sent through optical fibers in the HFC network. At the other end of the network, an optics platform or headend platform converts the light pulses into RF signals in coaxial cables again using transmitter and receiver modules,<ref>[http://ecet.ecs.uni-ruse.bg/cst06/Docs/cp/SIII/IIIA.6.pdf On The Design of Hybrid Fiber-Coax Networks ]</ref><ref name="CCAP™ Operations Support System Interface">Data-Over-Cable Service Interface Specifications |
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DOCSIS® 3.1 |
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CCAP™ Operations Support System Interface |
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Specification |
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CM-SP-CCAP-OSSIv3.1-I25-220819. Cable labs.</ref> and the cable modem termination system (CMTS) connects to these coaxial cables. An example of an optics platform is the Arris CH3000. |
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There are two coaxial cables at the CMTS for each node: one for the downstream (download speed signal), and the other for the upstream (upload speed signal).<ref name="CCAP™ Operations Support System Interface"/> The CMTS then connects to the ISP's IP (Internet Protocol) network.<ref>Data-Over-Cable Service Interface Specifications |
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DOCSIS® 4.0 |
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Physical Layer Specification |
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CM-SP-PHYv4.0-I06-221019. Cablelabs.</ref> |
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[[Downstream (computer science)|Downstream]], the direction toward the user, bit rates can be as high as 1 [[Gbit/s]].<ref>{{cite web | url = https://www.thestar.com/business/2015/10/05/rogers-bell-and-telus-hike-internet-speeds-prices-with-gigabit-service.html | title = Rogers, Bell and Telus hike Internet speeds, prices with 'gigabit' service | date = October 5, 2015 | first = David | last = Friend | publisher = The Canadian Press | website = [[Toronto Star]] | access-date = May 12, 2016}}</ref> Upstream traffic, originating at the user, ranges from 384 [[kbit/s]] to more than 50 |
[[Downstream (computer science)|Downstream]], the direction toward the user, bit rates can be as high as 1 [[Gbit/s]].<ref>{{cite web | url = https://www.thestar.com/business/2015/10/05/rogers-bell-and-telus-hike-internet-speeds-prices-with-gigabit-service.html | title = Rogers, Bell and Telus hike Internet speeds, prices with 'gigabit' service | date = October 5, 2015 | first = David | last = Friend | publisher = The Canadian Press | website = [[Toronto Star]] | access-date = May 12, 2016}}</ref> Upstream traffic, originating at the user, ranges from 384 [[kbit/s]] to more than 50 Mbit/s, although maximum effective range seems to be unknown. One downstream channel can handle hundreds of cable modems. As the system grows, the CMTS can be upgraded with more downstream and upstream ports, and grouped into hub CMTSs for efficient management. |
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Most ''Data Over Cable Service Interface Specification'' ([[DOCSIS]]) cable modems restrict upload and download rates, with customizable limits. These limits are set in configuration files which are downloaded to the modem using the [[Trivial File Transfer Protocol]], when the modem first establishes a connection to the provider's equipment.<ref>{{cite web | last= Ferri | first=Vic | url = http://pubs.logicalexpressions.com/Pub0009/LPMArticle.asp?ID=102 | title = Cable Internet-Are You Being Capped? | series = Using the Internet | publisher = MouseTrax Computing Solutions | website = TechTrax | access-date = May 12, 2016 | archive-url = https://web.archive.org/web/20120224120506/http://pubs.logicalexpressions.com/Pub0009/LPMArticle.asp?ID=102 | archive-date = February 24, 2012}}</ref> Some users {{specify|date=September 2014}} have attempted to override the bandwidth cap and gain access to the full bandwidth of the system |
Most ''Data Over Cable Service Interface Specification'' ([[DOCSIS]]) cable modems restrict upload and download rates, with customizable limits. These limits are set in configuration files which are downloaded to the modem using the [[Trivial File Transfer Protocol]], when the modem first establishes a connection to the provider's equipment.<ref>{{cite web | last= Ferri | first=Vic | url = http://pubs.logicalexpressions.com/Pub0009/LPMArticle.asp?ID=102 | title = Cable Internet-Are You Being Capped? | series = Using the Internet | publisher = MouseTrax Computing Solutions | website = TechTrax | access-date = May 12, 2016 | archive-url = https://web.archive.org/web/20120224120506/http://pubs.logicalexpressions.com/Pub0009/LPMArticle.asp?ID=102 | archive-date = February 24, 2012}}</ref> Some users {{specify|date=September 2014}} have attempted to override the bandwidth cap and gain access to the full bandwidth of the system by uploading their own configuration file to the cable modem - a process called [[uncapping]]. |
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==Shared bandwidth== |
==Shared bandwidth== |
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In most residential broadband technologies, such as cable Internet, [[DSL]], [[satellite internet]], or [[wireless broadband]], a population of users share the available [[Bandwidth (computing)|bandwidth]]. Some technologies share only their [[core network]], while some including cable internet and [[passive optical network]] (PON) also share the [[access network]]. This arrangement allows the network operator to take advantage of [[statistical multiplexing]], a [[Bandwidth (computing)|bandwidth]] sharing technique which is employed to distribute bandwidth fairly, in order to provide an adequate level of service at an acceptable price. However, the operator has to monitor usage patterns and scale the network appropriately, to ensure that customers receive adequate service even during peak-usage times. |
In most residential broadband technologies, such as cable Internet, [[DSL]], [[satellite internet]], or [[wireless broadband]], a population of users share the available [[Bandwidth (computing)|bandwidth]]. Some technologies share only their [[core network]], while some including cable internet and [[passive optical network]] (PON) also share the [[access network]]. This arrangement allows the network operator to take advantage of [[statistical multiplexing]], a [[Bandwidth (computing)|bandwidth]] sharing technique which is employed to distribute bandwidth fairly, in order to provide an adequate level of service at an acceptable price. However, the operator has to monitor usage patterns and scale the network appropriately, to ensure that customers receive adequate service even during peak-usage times. If the network operator does not provide enough bandwidth for a particular neighborhood, the connection would become saturated and speeds would drop if many people are using the service at the same time, or drop out completely. Operators have been known to use a [[bandwidth cap]], or other [[bandwidth throttling]] technique; users' download speed is limited during peak times, if they have downloaded a large amount of data that day.<ref name="WHO">{{cite web | website = PC Pro | title = Virgin Media cuts broadband speeds for heavy downloaders | date = May 8, 2007 | url = http://www.alphr.com/news/home-and-leisure/112273/virgin-media-cuts-broadband-speeds-for-heavy-downloaders | access-date = May 12, 2016 | last = Aughton | first = Simon}}{{better source|date=September 2014}}</ref> |
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==See also== |
==See also== |
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Latest revision as of 21:25, 25 April 2024
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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 and fiber to the premises services, cable Internet access provides network edge connectivity (last mile access) 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 predominant forms of residential Internet access. Recently, both have seen increased competition from fiber deployments, wireless, mobile networks and satellite internet access.
Hardware and bit rates
[edit]Broadband cable Internet access requires a cable modem at the customer's premises and a cable modem termination system (CMTS) at a cable operator facility, typically a cable television headend. The two are connected via coaxial cable to a hybrid fibre-coaxial (HFC) network. While access networks are referred to as last-mile technologies, cable Internet systems can typically operate where the distance between the modem and the termination system is up to 160 kilometres (99 mi). If the HFC network is large, the cable modem termination system can be grouped into hubs for efficient management. Several standards have been used for cable internet, but the most common is DOCSIS.[1]
A cable modem at the customer is connected via coaxial cable to an optical node, and thus into an HFC network. An optical node serves many modems as the modems are connected with coaxial cable to a coaxial cable "trunk" via distribution "taps" on the trunk, which then connects to the node, possibly using amplifiers along the trunk. The optical node converts the Radiofrequency (RF) signal in the coaxial cable trunk into light pulses to be sent through optical fibers in the HFC network. At the other end of the network, an optics platform or headend platform converts the light pulses into RF signals in coaxial cables again using transmitter and receiver modules,[2][3] and the cable modem termination system (CMTS) connects to these coaxial cables. An example of an optics platform is the Arris CH3000. There are two coaxial cables at the CMTS for each node: one for the downstream (download speed signal), and the other for the upstream (upload speed signal).[3] The CMTS then connects to the ISP's IP (Internet Protocol) network.[4]
Downstream, the direction toward the user, bit rates can be as high as 1 Gbit/s.[5] Upstream traffic, originating at the user, ranges from 384 kbit/s to more than 50 Mbit/s, although maximum effective range seems to be unknown. One downstream channel can handle hundreds of cable modems. As the system grows, the CMTS can be upgraded with more downstream and upstream ports, and grouped into hub CMTSs for efficient management.
Most Data Over Cable Service Interface Specification (DOCSIS) cable modems restrict upload and download rates, with customizable limits. These limits are set in configuration files which are downloaded to the modem using the Trivial File Transfer Protocol, when the modem first establishes a connection to the provider's equipment.[6] Some users [specify] have attempted to override the bandwidth cap and gain access to the full bandwidth of the system by uploading their own configuration file to the cable modem - a process called uncapping.
Shared bandwidth
[edit]In most residential broadband technologies, such as cable Internet, DSL, satellite internet, or wireless broadband, a population of users share the available bandwidth. Some technologies share only their core network, while some including cable internet and passive optical network (PON) also share the access network. This arrangement allows the network operator to take advantage of statistical multiplexing, a bandwidth sharing technique which is employed to distribute bandwidth fairly, in order to provide an adequate level of service at an acceptable price. However, the operator has to monitor usage patterns and scale the network appropriately, to ensure that customers receive adequate service even during peak-usage times. If the network operator does not provide enough bandwidth for a particular neighborhood, the connection would become saturated and speeds would drop if many people are using the service at the same time, or drop out completely. Operators have been known to use a bandwidth cap, or other bandwidth throttling technique; users' download speed is limited during peak times, if they have downloaded a large amount of data that day.[7]
See also
[edit]- Cable modem
- Digital cable
- Internet service provider
- Network service provider
- Internet access
- Triple play (telecommunications) - single coaxial cable connection for internet, TV and telephone service
References
[edit]- ^ Palmer, Michael (21 June 2012). Hands-On Networking Fundamentals. ISBN 978-1285402758.
- ^ On The Design of Hybrid Fiber-Coax Networks
- ^ a b Data-Over-Cable Service Interface Specifications DOCSIS® 3.1 CCAP™ Operations Support System Interface Specification CM-SP-CCAP-OSSIv3.1-I25-220819. Cable labs.
- ^ Data-Over-Cable Service Interface Specifications DOCSIS® 4.0 Physical Layer Specification CM-SP-PHYv4.0-I06-221019. Cablelabs.
- ^ Friend, David (October 5, 2015). "Rogers, Bell and Telus hike Internet speeds, prices with 'gigabit' service". Toronto Star. The Canadian Press. Retrieved May 12, 2016.
- ^ Ferri, Vic. "Cable Internet-Are You Being Capped?". TechTrax. Using the Internet. MouseTrax Computing Solutions. Archived from the original on February 24, 2012. Retrieved May 12, 2016.
- ^ Aughton, Simon (May 8, 2007). "Virgin Media cuts broadband speeds for heavy downloaders". PC Pro. Retrieved May 12, 2016.[better source needed]
