Cable Internet access

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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.

Contents

Hardware and bit rates

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

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

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 attached to the television; or satellite television, in which the television signal is transmitted over-the-air by radio waves from a communications satellite orbiting the Earth, and received by a satellite dish antenna 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.

Digital subscriber line is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric digital subscriber line (ADSL), the most commonly installed DSL technology, for Internet access.

<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 fibre-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 terminology

In telecommunications, broadband 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 connections. The medium can be coaxial cable, optical fiber, wireless Internet (radio), twisted pair, or satellite.

<span class="mw-page-title-main">DSLAM</span> Network device that connects DSL interfaces to a digital communications channel

A digital subscriber line access multiplexer is a network device, often located in telephone exchanges, that connects multiple customer digital subscriber line (DSL) interfaces to a high-speed digital communications channel using multiplexing techniques. Its cable internet (DOCSIS) counterpart is the cable modem termination system.

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">Internet access</span> Individual connection to the Internet

Internet access is a facility or service that provides connectivity for a computer, a computer network, or other network device to the Internet, and for individuals or organizations to access or use applications such as email and the World Wide Web. Internet access is offered for sale by an international hierarchy of Internet service providers (ISPs) using various networking technologies. At the retail level, many organizations, including municipal entities, also provide cost-free access to the general public.

<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.

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.

<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 high speed data services, such as cable Internet or Voice over Internet Protocol, to cable subscribers. A CMTS provides many of the same functions provided by the DSLAM in a DSL system.

<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 technology for delivering broadband network access to end-customers. Its architecture implements a point-to-multipoint topology in which a single optical fiber serves multiple endpoints by using unpowered (passive) fiber optic splitters to divide the fiber bandwidth among the endpoints. Passive optical networks are often referred to as the last mile between an Internet service provider (ISP) and its customers. Many fiber ISPs prefer this technology.

<span class="mw-page-title-main">Triple play (telecommunications)</span>

In telecommunications, triple play service is a marketing term for the provisioning, over a single broadband connection, of two bandwidth-intensive services, broadband Internet access and television, and the latency-sensitive telephone. Triple play focuses on a supplier convergence rather than solving technical issues or a common standard. However, standards like G.hn might deliver all these services on a common technology.

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.

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.

Com21 was an early pioneer in developing cable modem networks in the era before the standard DOCSIS was introduced for Internet access via cable television networks. The company filed for bankruptcy in 2003.

10G-PON is a 2010 computer networking standard for data links, capable of delivering shared Internet access rates up to 10 Gbit/s over existing dark fiber. This is the ITU-T's next generation standard following on from GPON or Gigabit-capable PON. Optical fibre is shared by many subscribers in a network known as FTTx in a way that centralises most of the telecommunications equipment, often displacing copper phone lines that connect premises to the phone exchange. Passive optical network (PON) architecture has become a cost-effective way to meet performance demands in access networks, and sometimes also in large optical local networks for "Fibre-to-the-desk".

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 & fiber internet and Digital TV services through a hybrid fiber-coaxial (HFCC) network. The Internet and 280+ TV channels that it offers provides support to Nepal's educational, entertainment, professional and other sectors. It is the first and the only cable internet service provider in Nepal.

<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. ↑ Palmer, Michael (21 June 2012). Hands-On Networking Fundamentals. ISBN   978-1285402758.
  2. ↑ On The Design of Hybrid Fiber-Coax Networks
  3. 1 2 Data-Over-Cable Service Interface Specifications DOCSIS® 3.1 CCAP™ Operations Support System Interface Specification CM-SP-CCAP-OSSIv3.1-I25-220819. Cable labs.
  4. ↑ Data-Over-Cable Service Interface Specifications DOCSIS® 4.0 Physical Layer Specification CM-SP-PHYv4.0-I06-221019. Cablelabs.
  5. ↑ 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.
  6. ↑ 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.
  7. ↑ Aughton, Simon (May 8, 2007). "Virgin Media cuts broadband speeds for heavy downloaders". PC Pro. Retrieved May 12, 2016.[ better source needed ]
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