Broadband Internet access: Difference between revisions
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<!--(Dial up is not the opposite of broadband, and is used here for practical understanding purposes only.)--> |
<!--(Dial up is not the opposite of broadband, and is used here for practical understanding purposes only.)--> |
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Although various minimum bandwidths have been used in definitions of broadband, ranging from 64 kbit/s up to 4.0 Mbit/s,<ref name="Birth">{{cite web |url=http://www.itu.int/osg/spu/publications/birthofbroadband/faq.html |title=Birth of Broadband |publisher=ITU |date= September 2003 |accessdate= July 12, 2011 }}</ref> the 2006 [[OECD]] report<ref name="OECD">{{cite web |url=http://www.fcc.gov/cgb/broadband.html |title=2006 OECD Broadband Statistics to December 2006 |publisher=OECD |accessdate=June 6, 2009}}</ref> defined broadband as having download [[data transfer rates]] equal to or |
Although various minimum bandwidths have been used in definitions of broadband, ranging from 64 kbit/s up to 4.0 Mbit/s,<ref name="Birth">{{cite web |url=http://www.itu.int/osg/spu/publications/birthofbroadband/faq.html |title=Birth of Broadband |publisher=ITU |date= September 2003 |accessdate= July 12, 2011 }}</ref> the 2006 [[OECD]] report<ref name="OECD">{{cite web |url=http://www.fcc.gov/cgb/broadband.html |title=2006 OECD Broadband Statistics to December 2006 |publisher=OECD |accessdate=June 6, 2009}}</ref> defined broadband as having download [[data transfer rates]] equal to or quicker than 256 kbit/s, The trend is to raise the threshold of the broadband definition as the marketplace rolls out quicker services.<ref name="engadget08">{{cite web |first=Nilay |last=Patel |url=http://www.engadget.com/2008/03/19/fcc-redefines-broadband-to-mean-768kbps-fast-to-mean-kinda/ |title=FCC redefines "broadband" to mean 768 kbit/s, "fast" to mean "kinda slow" |publisher=Engadget |date=March 19, 2008 |accessdate=June 6, 2009}}</ref> |
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Data rates are defined in terms of ''maximum download'' because network and server conditions significantly affect the maximum speeds that can be achieved and because common consumer broadband technologies such as [[ADSL]] are "asymmetric"—supporting much lower maximum upload data rate than download. |
Data rates are defined in terms of ''maximum download'' because network and server conditions significantly affect the maximum speeds that can be achieved and because common consumer broadband technologies such as [[ADSL]] are "asymmetric"—supporting much lower maximum upload data rate than download. |
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==Overview== |
==Overview== |
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Broadband is often called "'''high-speed'''" access to the Internet, because it usually has a high rate of data transmission. In general, any connection to the customer of 256 kbit/s or greater is more concisely considered '''broadband Internet access'''. The [[International Telecommunication Union]] Standardization Sector ([[ITU-T]]) recommendation I.113 has defined broadband as a transmission capacity that is |
Broadband is often called "'''high-speed'''" access to the Internet, because it usually has a high rate of data transmission. In general, any connection to the customer of 256 kbit/s or greater is more concisely considered '''broadband Internet access'''. The [[International Telecommunication Union]] Standardization Sector ([[ITU-T]]) recommendation I.113 has defined broadband as a transmission capacity that is quicker than [[Primary rate interface|primary rate]] [[ISDN]], at 1.5 to 2 Mbit/s.<ref name="Birth"/> The US Federal Communications Commission definition of broadband is 4.0 Mbit/s. The [[Organization for Economic Co-operation and Development]] (OECD) has defined broadband as 256 kbit/s in at least one direction and this bit rate is the most common baseline that is marketed as "broadband" around the world. There is no specific bitrate defined by the industry, however, and "[[broadband]]" can mean lower-bitrate transmission methods. Some [[Internet service provider|Internet Service Provider]]s (ISPs) use this to their advantage in marketing lower-bitrate connections as broadband. |
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In practice, the advertised maximum [[Bandwidth (computing)|bandwidth]] is not always reliably available to the customer; physical link quality can vary, and ISPs usually allow a greater number of subscribers than their [[Internet backbone|backbone connection]] or neighbourhood [[access network]] can handle, under the assumption that most users will not be using their full connection capacity very frequently. This aggregation strategy (known as a [[contended service]]) works more often than not, so users can typically burst to their full bandwidth most of the time; however, [[peer-to-peer]] (P2P) [[file sharing]] systems, often requiring extended durations of high bandwidth usage, violate these assumptions, and can cause major problems for ISPs. In some cases the contention ratio, or a download cap, is agreed in the contract, and businesses and other customers, who need a lower contention ratio or even an uncontended service, are typically charged more. |
In practice, the advertised maximum [[Bandwidth (computing)|bandwidth]] is not always reliably available to the customer; physical link quality can vary, and ISPs usually allow a greater number of subscribers than their [[Internet backbone|backbone connection]] or neighbourhood [[access network]] can handle, under the assumption that most users will not be using their full connection capacity very frequently. This aggregation strategy (known as a [[contended service]]) works more often than not, so users can typically burst to their full bandwidth most of the time; however, [[peer-to-peer]] (P2P) [[file sharing]] systems, often requiring extended durations of high bandwidth usage, violate these assumptions, and can cause major problems for ISPs. In some cases the contention ratio, or a download cap, is agreed in the contract, and businesses and other customers, who need a lower contention ratio or even an uncontended service, are typically charged more. |
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Roughly double the dial-up rate can be achieved with multilinking technology. What is required are two modems, two phone lines, two dial-up accounts, and ISP support for multilinking, or special software at the user end. This [[inverse multiplexing]] option was popular with some high-end users before ISDN, DSL and other technologies became available. |
Roughly double the dial-up rate can be achieved with multilinking technology. What is required are two modems, two phone lines, two dial-up accounts, and ISP support for multilinking, or special software at the user end. This [[inverse multiplexing]] option was popular with some high-end users before ISDN, DSL and other technologies became available. |
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Diamond and other vendors had created dual phone line modems with bonding capability. The data rate of dual line modems is |
Diamond and other vendors had created dual phone line modems with bonding capability. The data rate of dual line modems is quicker than 90 kbit/s. The Internet and phone charge will be twice the ordinary dial-up charge. |
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[[Load balancing (computing)|Load balancing]] takes two Internet connections and feeds them into your network as one double data rate, more resilient Internet connection. By choosing two independent Internet providers the load balancing hardware will automatically use the line with least load which means should one line fail, the second one automatically takes up the slack. |
[[Load balancing (computing)|Load balancing]] takes two Internet connections and feeds them into your network as one double data rate, more resilient Internet connection. By choosing two independent Internet providers the load balancing hardware will automatically use the line with least load which means should one line fail, the second one automatically takes up the slack. |
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===ISDN=== |
===ISDN=== |
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[[Integrated Services Digital Network]] (ISDN) was one of the oldest digital access methods for consumers and businesses to connect to the Internet. It is a telephone data service standard. |
[[Integrated Services Digital Network]] (ISDN) was one of the oldest digital access methods for consumers and businesses to connect to the Internet. It is a telephone data service standard. |
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A basic rate ISDN line (known as ISDN-BRI) is an ISDN line with 2 data "bearer" channels (DS0 - 64 kbit/s each). Using ISDN terminal adapters (erroneously called modems), it is possible to bond together 2 or more separate ISDN-BRI lines to reach bandwidths of 256 kbit/s or more. The ISDN channel bonding technology has been used for video conference applications and broadband data transmission. Its use in the United States peaked in the late 1990s prior to the availability of [[DSL]] and cable modem technologies. Broadband service is usually compared to ISDN-BRI because this was the standard broadband access technology that formed a baseline for the challenges faced by the early broadband providers. These providers sought to compete against ISDN by offering |
A basic rate ISDN line (known as ISDN-BRI) is an ISDN line with 2 data "bearer" channels (DS0 - 64 kbit/s each). Using ISDN terminal adapters (erroneously called modems), it is possible to bond together 2 or more separate ISDN-BRI lines to reach bandwidths of 256 kbit/s or more. The ISDN channel bonding technology has been used for video conference applications and broadband data transmission. Its use in the United States peaked in the late 1990s prior to the availability of [[DSL]] and cable modem technologies. Broadband service is usually compared to ISDN-BRI because this was the standard broadband access technology that formed a baseline for the challenges faced by the early broadband providers. These providers sought to compete against ISDN by offering quicker and cheaper services to consumers. |
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Primary rate ISDN, known as ISDN-PRI, is an ISDN line with 23 DS0 channels and total bandwidth of 1,544 kbit/s (US standard). ISDN E1 (European standard) line is an ISDN lines with 30 DS0 channels and total bandwidth of 2,048 kbit/s. Because ISDN is a telephone-based product, a lot of the terminology and physical aspects of the line are shared by the ISDN-PRI used for voice services. An ISDN line can therefore be "[[Provisioning|provisioned]]" for voice or data and many different options, depending on the equipment being used at any particular installation, and depending on the offerings of the telephone company's [[central office]] switch. Most ISDN-PRI's are used for telephone voice communication using large [[Private branch exchange|PBX]] systems, rather than for data. One obvious exception is that ISPs usually have ISDN-PRI's for handling ISDN data and modem calls. |
Primary rate ISDN, known as ISDN-PRI, is an ISDN line with 23 DS0 channels and total bandwidth of 1,544 kbit/s (US standard). ISDN E1 (European standard) line is an ISDN lines with 30 DS0 channels and total bandwidth of 2,048 kbit/s. Because ISDN is a telephone-based product, a lot of the terminology and physical aspects of the line are shared by the ISDN-PRI used for voice services. An ISDN line can therefore be "[[Provisioning|provisioned]]" for voice or data and many different options, depending on the equipment being used at any particular installation, and depending on the offerings of the telephone company's [[central office]] switch. Most ISDN-PRI's are used for telephone voice communication using large [[Private branch exchange|PBX]] systems, rather than for data. One obvious exception is that ISPs usually have ISDN-PRI's for handling ISDN data and modem calls. |
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Disadvantages: |
Disadvantages: |
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# ISDN offerings are dwindling in the marketplace due to the widespread use of |
# ISDN offerings are dwindling in the marketplace due to the widespread use of quicker and cheaper alternatives. |
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# ISDN routers, terminal adapters ("modems"), and telephones are more expensive than ordinary [[Plain old telephone service|POTS]] equipment, like dial-up modems. |
# ISDN routers, terminal adapters ("modems"), and telephones are more expensive than ordinary [[Plain old telephone service|POTS]] equipment, like dial-up modems. |
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# ISDN [[provisioning]] can be complicated due to the great number of options available. |
# ISDN [[provisioning]] can be complicated due to the great number of options available. |
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Most [[DSL modem]]s and cable modems are connected to local computers by Ethernet or Wi-Fi. The speed of the [[Local Area Network]] is sometimes mistaken for the speed of Internet access, but the LAN must be connected to the Internet by some means which in most cases is slower than the 10, 100, or 1000 Mbit/s connection of the LAN. In a business or college campus, for example, the 100 Mbit/s Ethernet rate might be fully available to on-campus networks, but the Internet access line might provide a [[T-carrier#Higher T|4xT-1]] (6 Mbit/s) or [[Digital Signal 3|T3]] (44 Mbit/s) rate. This is typically shared with other local users and the access bandwidth of this leased line governs the end-user's data rate. |
Most [[DSL modem]]s and cable modems are connected to local computers by Ethernet or Wi-Fi. The speed of the [[Local Area Network]] is sometimes mistaken for the speed of Internet access, but the LAN must be connected to the Internet by some means which in most cases is slower than the 10, 100, or 1000 Mbit/s connection of the LAN. In a business or college campus, for example, the 100 Mbit/s Ethernet rate might be fully available to on-campus networks, but the Internet access line might provide a [[T-carrier#Higher T|4xT-1]] (6 Mbit/s) or [[Digital Signal 3|T3]] (44 Mbit/s) rate. This is typically shared with other local users and the access bandwidth of this leased line governs the end-user's data rate. |
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In certain locations, however, the Internet access rate might be as |
In certain locations, however, the Internet access rate might be as quick as the LAN. This would most commonly be the case at a POP or a data center, and not at a typical residence or business. When Ethernet Internet access is offered, it could be [[fiber-optic]] or copper [[twisted pair]], and the bandwidth will conform to standard Ethernet data rates of up to 10 Gbit/s. Most 21st century computers have Ethernet hardware built in, and laptops have Wi-Fi while high speed Internet access hardware is usually external and not bundled with the computer. |
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=== Satellite broadband === |
=== Satellite broadband === |
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===Cellular broadband=== |
===Cellular broadband=== |
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{{Main|Cellular broadband}} |
{{Main|Cellular broadband}} |
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[[Cellular phone]] towers are very widespread, and as cellular networks move to third generation ([[3G]]) networks they can support |
[[Cellular phone]] towers are very widespread, and as cellular networks move to third generation ([[3G]]) networks they can support quick data; using technologies such as [[EVDO]], HSDPA and [[Universal Mobile Telecommunications System|UMTS]]. |
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These can give broadband access to the Internet, with a cell phone, with [[Cardbus]], [[ExpressCard]], or [[Universal Serial Bus|USB]] cellular modems, or with cellular [[broadband router]]s, which allow more than one computer to be connected to the Internet using one cellular connection. |
These can give broadband access to the Internet, with a cell phone, with [[Cardbus]], [[ExpressCard]], or [[Universal Serial Bus|USB]] cellular modems, or with cellular [[broadband router]]s, which allow more than one computer to be connected to the Internet using one cellular connection. |
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This is a new service still in its infancy that may eventually permit broadband Internet data to travel down standard high-voltage [[electric power transmission|power line]]s. However, the system has a number of complex issues, the primary one being that power lines are inherently a very noisy environment. Every time a device turns on or off, it introduces a pop or click into the line. Energy-saving devices often introduce noisy [[harmonics]] into the line. The system must be designed to deal with these natural signaling disruptions and work around them. |
This is a new service still in its infancy that may eventually permit broadband Internet data to travel down standard high-voltage [[electric power transmission|power line]]s. However, the system has a number of complex issues, the primary one being that power lines are inherently a very noisy environment. Every time a device turns on or off, it introduces a pop or click into the line. Energy-saving devices often introduce noisy [[harmonics]] into the line. The system must be designed to deal with these natural signaling disruptions and work around them. |
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Broadband over power lines (BPL), also known as [[Power line communication]], has developed |
Broadband over power lines (BPL), also known as [[Power line communication]], has developed quicker in Europe than in the US due to a historical difference in power system design philosophies. Nearly all large power grids transmit power at high voltages in order to reduce transmission losses, then near the customer use step-down transformers to reduce the voltage. Since BPL signals cannot readily pass through transformers, repeaters must be attached to the transformers. In the US, it is common for a small transformer hung from a utility pole to service a single house. In Europe, it is more common for a somewhat larger transformer to service 10 or 100 houses. For delivering power to customers, this difference in design makes little difference, but it means delivering BPL over the power grid of a typical US city will require an order of magnitude more repeaters than would be required in a comparable European city. |
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The second major issue is [[signal strength]] and operating [[frequency]]. The system is expected to use frequencies in the 10 to 30 [[Megahertz|MHz]] range, which has been used for decades by licensed [[amateur radio operator]]s, as well as international [[shortwave]] broadcasters and a variety of communications systems (military, aeronautical, etc.). Power lines are unshielded and will act as transmitters for the signals they carry, and have the potential to completely wipe out the usefulness of the 10 to 30 MHz range for shortwave communications purposes, as well as compromising the security of its users. |
The second major issue is [[signal strength]] and operating [[frequency]]. The system is expected to use frequencies in the 10 to 30 [[Megahertz|MHz]] range, which has been used for decades by licensed [[amateur radio operator]]s, as well as international [[shortwave]] broadcasters and a variety of communications systems (military, aeronautical, etc.). Power lines are unshielded and will act as transmitters for the signals they carry, and have the potential to completely wipe out the usefulness of the 10 to 30 MHz range for shortwave communications purposes, as well as compromising the security of its users. |
Revision as of 12:36, 21 October 2011
![]() | The examples and perspective in this article may not represent a worldwide view of the subject. (October 2010) |
![]() | It has been suggested that this article be merged into Internet access. (Discuss) Proposed since November 2010. |
Broadband Internet access, often shortened to just "broadband", is a high data rate connection to the Internet— typically contrasted with dial-up access using a 56 kbit/s modem.
Dial-up modems are limited to a bitrate of about 60 kbit/s and require the dedicated use of a telephone line — whereas broadband technologies supply more than this rate and generally without disrupting telephone use.
Although various minimum bandwidths have been used in definitions of broadband, ranging from 64 kbit/s up to 4.0 Mbit/s,[1] the 2006 OECD report[2] defined broadband as having download data transfer rates equal to or quicker than 256 kbit/s, The trend is to raise the threshold of the broadband definition as the marketplace rolls out quicker services.[3]
Data rates are defined in terms of maximum download because network and server conditions significantly affect the maximum speeds that can be achieved and because common consumer broadband technologies such as ADSL are "asymmetric"—supporting much lower maximum upload data rate than download.
"Broadband penetration" is now treated as a key economic indicator.[2][4]
Overview
Broadband is often called "high-speed" access to the Internet, because it usually has a high rate of data transmission. In general, any connection to the customer of 256 kbit/s or greater is more concisely considered broadband Internet access. The International Telecommunication Union Standardization Sector (ITU-T) recommendation I.113 has defined broadband as a transmission capacity that is quicker than primary rate ISDN, at 1.5 to 2 Mbit/s.[1] The US Federal Communications Commission definition of broadband is 4.0 Mbit/s. The Organization for Economic Co-operation and Development (OECD) has defined broadband as 256 kbit/s in at least one direction and this bit rate is the most common baseline that is marketed as "broadband" around the world. There is no specific bitrate defined by the industry, however, and "broadband" can mean lower-bitrate transmission methods. Some Internet Service Providers (ISPs) use this to their advantage in marketing lower-bitrate connections as broadband.
In practice, the advertised maximum bandwidth is not always reliably available to the customer; physical link quality can vary, and ISPs usually allow a greater number of subscribers than their backbone connection or neighbourhood access network can handle, under the assumption that most users will not be using their full connection capacity very frequently. This aggregation strategy (known as a contended service) works more often than not, so users can typically burst to their full bandwidth most of the time; however, peer-to-peer (P2P) file sharing systems, often requiring extended durations of high bandwidth usage, violate these assumptions, and can cause major problems for ISPs. In some cases the contention ratio, or a download cap, is agreed in the contract, and businesses and other customers, who need a lower contention ratio or even an uncontended service, are typically charged more.
When traffic is particularly heavy, the ISP can deliberately throttle back users traffic, or just some kinds of traffic. This is known as traffic shaping. Careful use of traffic shaping by the network provider can ensure quality of service for time critical services even on extremely busy networks, but overuse can lead to concerns about network neutrality if certain types of traffic are severely or completely blocked.
As takeup for these introductory products increases, telcos are starting to offer higher bit rate services. For existing connections, this most of the time simply involves reconfiguring the existing equipment at each end of the connection.
As the bandwidth delivered to end users increases, the market expects that video on demand services streamed over the Internet will become more popular, though at the present time such services generally require specialized networks[citation needed]. The data rates on most[citation needed] broadband services still do not suffice to provide good quality video, as MPEG-2 video requires about 6 Mbit/s for good results. Adequate video for some purposes becomes possible at lower data rates, with rates of 768 kbit/s and 384 kbit/s used for some video conferencing applications, and rates as low as 100 kbit/s used for videophones using H.264/MPEG-4 AVC. The MPEG-4 format delivers high-quality video at 2 Mbit/s, at the low end of cable modem and ADSL performance.
At the turn of the century most residential access was by dial-up, while access from businesses was usually by broadband Internet access connections. In subsequent years, dial-up has declined. In rural areas where DSL and cable are not available, satellite Internet is a good solution.
Technology
The standard broadband technologies in most areas are ADSL and cable Internet. Newer technologies in use include VDSL and pushing optical fibre connections closer to the subscriber in both telephone and cable plants. Fibre-optic communication, while only recently being used in fibre to the premises and fibre to the curb schemes, has played a crucial role in enabling Broadband Internet access by making transmission of information over larger distances much more cost-effective than copper wire technology.
In a few areas not served by cable or ADSL, community organizations have begun to install Wi-Fi networks, and in some cities and towns local governments are installing municipal Wi-Fi networks. As of 2006, broadband mobile Internet access has become available at the consumer level in some countries, using the HSDPA and EV-DO technologies. The newest technology being deployed for mobile and stationary broadband access is WiMAX and LTE.
DSL (ADSL/SDSL)
DSL is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. In telecommunications marketing, the term Digital Subscriber Line is widely understood to mean Asymmetric Digital Subscriber Line (ADSL), the most commonly installed technical variety of DSL. DSL service is delivered simultaneously with regular telephone on the same telephone line. This is possible because DSL uses a higher frequency. These frequency bands are subsequently separated by filtering.
The data throughput of consumer DSL services typically ranges from 256 kbit/s to 20 Mbit/s in the direction to the customer (downstream), depending on DSL technology, line conditions, and service-level implementation. In ADSL, the data throughput in the upstream direction, (i.e. in the direction to the service provider) is lower, hence the designation of asymmetric service. In Symmetric Digital Subscriber Line (SDSL) service, the downstream and upstream data rates are equal.
Multilinking Modems
Roughly double the dial-up rate can be achieved with multilinking technology. What is required are two modems, two phone lines, two dial-up accounts, and ISP support for multilinking, or special software at the user end. This inverse multiplexing option was popular with some high-end users before ISDN, DSL and other technologies became available.
Diamond and other vendors had created dual phone line modems with bonding capability. The data rate of dual line modems is quicker than 90 kbit/s. The Internet and phone charge will be twice the ordinary dial-up charge.
Load balancing takes two Internet connections and feeds them into your network as one double data rate, more resilient Internet connection. By choosing two independent Internet providers the load balancing hardware will automatically use the line with least load which means should one line fail, the second one automatically takes up the slack.
ISDN
Integrated Services Digital Network (ISDN) was one of the oldest digital access methods for consumers and businesses to connect to the Internet. It is a telephone data service standard. A basic rate ISDN line (known as ISDN-BRI) is an ISDN line with 2 data "bearer" channels (DS0 - 64 kbit/s each). Using ISDN terminal adapters (erroneously called modems), it is possible to bond together 2 or more separate ISDN-BRI lines to reach bandwidths of 256 kbit/s or more. The ISDN channel bonding technology has been used for video conference applications and broadband data transmission. Its use in the United States peaked in the late 1990s prior to the availability of DSL and cable modem technologies. Broadband service is usually compared to ISDN-BRI because this was the standard broadband access technology that formed a baseline for the challenges faced by the early broadband providers. These providers sought to compete against ISDN by offering quicker and cheaper services to consumers.
Primary rate ISDN, known as ISDN-PRI, is an ISDN line with 23 DS0 channels and total bandwidth of 1,544 kbit/s (US standard). ISDN E1 (European standard) line is an ISDN lines with 30 DS0 channels and total bandwidth of 2,048 kbit/s. Because ISDN is a telephone-based product, a lot of the terminology and physical aspects of the line are shared by the ISDN-PRI used for voice services. An ISDN line can therefore be "provisioned" for voice or data and many different options, depending on the equipment being used at any particular installation, and depending on the offerings of the telephone company's central office switch. Most ISDN-PRI's are used for telephone voice communication using large PBX systems, rather than for data. One obvious exception is that ISPs usually have ISDN-PRI's for handling ISDN data and modem calls.
Many of the earlier ISDN data lines used 56 kbit/s rather than 64 kbit/s "B" channels of data. This caused ISDN-BRI to be offered at both 128 kbit/s and 112 kbit/s rates, depending on the central office's switching equipment.
Advantages:
- Constant data rate at 64 kbit/s for each DS0 channel.
- Two way broadband symmetric data transmission, unlike ADSL.
- One of the data channels can be used for phone conversation without disturbing the data transmission through the other data channel. When a phone call is ended, the bearer channel can immediately dial and re-connect itself to the data call.
- Call setup is very quick.
- Low latency
- ISDN Voice clarity is unmatched by other phone services.
- Caller ID is almost always available for no additional fee.
- Maximum distance from the central office is much greater than it is for DSL.
- When using ISDN-BRI, there is the possibility of using the low-bandwidth 16 kbit/s "D" channel for packet data and for always on capabilities.
Disadvantages:
- ISDN offerings are dwindling in the marketplace due to the widespread use of quicker and cheaper alternatives.
- ISDN routers, terminal adapters ("modems"), and telephones are more expensive than ordinary POTS equipment, like dial-up modems.
- ISDN provisioning can be complicated due to the great number of options available.
- ISDN users must dial in to a provider that offers ISDN Internet service, which means that the call could be disconnected.
- ISDN is billed as a phone line, to which is added the bill for Internet ISDN access.
- "Always on" data connections are not available in all locations.
- Some telephone companies charge unusual fees for ISDN, including call setup fees, per minute fees, and higher rates than normal for other services.
Leased Lines
Leased lines are highly-regulated services traditionally intended for businesses, that are managed through Public Service Commissions (PSCs) in each state, must be fully defined in PSC tariff documents, and have management rules dating back to the early 1980s which still refer to teleprinters as potential connection devices. As such, T-1 services have very strict and rigid service requirements which drive up the provider's maintenance costs and may require them to have a technician on standby 24 hours a day to repair the line if it malfunctions. (In comparison, ISDN and DSL are not regulated by the PSCs at all.) Due to the expensive and regulated nature of T-1 lines, they are normally installed under the provisions of a written agreement, the contract term being typically one to three years. However, there are usually few restrictions to an end-user's use of a T-1, uptime and bandwidth data rates may be guaranteed, quality of service may be supported, and blocks of static IP addresses are commonly included.
Since a T-1 was originally conceived for voice transmission, and voice T-1's are still widely used in businesses, it can be confusing to the uninitiated subscriber. It is often best to refer to the type of T-1 being considered, using the appropriate "data" or "voice" prefix to differentiate between the two. A voice T-1 would terminate at a phone company's central office (CO) for connection to the PSTN; a data T-1 terminates at a point of presence (POP) or data center. The T-1 line which is between a customer's premises and the POP or CO is called the local loop. The owner of the local loop need not be the owner of the network at the POP where your T-1 connects to the Internet, and so a T-1 subscriber may have contracts with these two organizations separately.
The nomenclature for a T-1 varies widely, cited in some circles a DS-1, a T1.5, a T1, or a DS1. Some of these try to distinguish amongst the different aspects of the line, considering the data standard a DS-1, and the physical structure of the trunk line a T-1 or T-1.5. They are also called leased lines, but that terminology is usually for data rates under 1.5 Mbit/s. At times, a T-1 can be included in the term "leased line" or excluded from it. Whatever it is called, it is inherently related to other broadband access methods, which include T-3, SONET OC-3, and other T-carrier and Optical Carriers. Additionally, a T-1 might be aggregated with more than one T-1, producing an nxT-1, such as 4xT-1 which has exactly 4 times the bandwidth of a T-1.
When a T-1 is installed, there are a number of choices to be made: in the carrier chosen, the location of the demarcation point, the type of channel service unit (CSU) or data service unit (DSU) used, the WAN IP router used, the types of bandwidths chosen, etc. Specialized WAN routers are used with T-1 lines that route Internet or VPN data onto the T-1 line from the subscriber's packet-based (TCP/IP) network using customer premises equipment (CPE). The CPE typical consists of a CSU/DSU that converts the DS-1 data stream of the T-1 to a TCP/IP packet data stream for use in the customer's Ethernet LAN. It is noteworthy that many T-1 providers optionally maintain and/or sell the CPE as part of the service contract, which can affect the demarcation point and the ownership of the router, CSU, or DSU.
Although a T-1 has a maximum of 1.544 Mbit/s, a fractional T-1 might be offered which only uses an integer multiple of 128 kbit/s for bandwidth. In this manner, a customer might only purchase 1/12 or 1/3 of a T-1, which would be 128 kbit/s and 512 kbit/s, respectively.
T-1 and fractional T-1 data lines are symmetric, meaning that their upload and download data rates are the same.
Local Area Network
Most DSL modems and cable modems are connected to local computers by Ethernet or Wi-Fi. The speed of the Local Area Network is sometimes mistaken for the speed of Internet access, but the LAN must be connected to the Internet by some means which in most cases is slower than the 10, 100, or 1000 Mbit/s connection of the LAN. In a business or college campus, for example, the 100 Mbit/s Ethernet rate might be fully available to on-campus networks, but the Internet access line might provide a 4xT-1 (6 Mbit/s) or T3 (44 Mbit/s) rate. This is typically shared with other local users and the access bandwidth of this leased line governs the end-user's data rate.
In certain locations, however, the Internet access rate might be as quick as the LAN. This would most commonly be the case at a POP or a data center, and not at a typical residence or business. When Ethernet Internet access is offered, it could be fiber-optic or copper twisted pair, and the bandwidth will conform to standard Ethernet data rates of up to 10 Gbit/s. Most 21st century computers have Ethernet hardware built in, and laptops have Wi-Fi while high speed Internet access hardware is usually external and not bundled with the computer.
Satellite broadband
Satellites in geostationary orbits are able to relay broadband data from the satellite company to each customer. Satellite Internet is usually among the most expensive ways of gaining broadband Internet access, but in rural areas it may be the only choice other than cellular broadband. However, costs have been coming down in recent years to the point that it is becoming more competitive with other broadband options.
Broadband satellite Internet also has a high latency problem which is due to the signal having to travel to an altitude of 35,786 km (22,236 mi) above sea level (from the equator) out into space to a satellite in geostationary orbit and back to Earth again. The signal delay can be as much as 500 milliseconds to 900 milliseconds, which makes this service unsuitable for applications requiring real-time user input such as certain multiplayer Internet games and first-person shooters played over the connection. Despite this, it is still possible for many games to be played, but the scope is limited to real-time strategy or turn-based games. The functionality of live interactive access to a distant computer can also be subject to the problems caused by high latency. Additionally, some satellite Internet providers do not support VPN due to latency issues.[5] These problems are more than tolerable for just basic email access and web browsing and in most cases are barely noticeable.
For geostationary satellites there is no way to eliminate this problem. The delay is primarily due to the great distances travelled which, even at the speed of light (about 300,000 km/s (190,000 mi/s)), can be significant. Even if all other signalling delays could be eliminated it still takes electromagnetic radio waves about 500 milliseconds, or half a second, to travel from ground level to the satellite and back to the ground, a total of over 71,400 km (44,400 mi) to travel from the source to the destination, and over 143,000 km (89,000 mi) for a round trip (user to ISP, and then back to user—with zero network delays). Factoring in other normal delays from network sources gives a typical one-way connection latency of 500–700 ms from the user to the ISP, or about 1,000–1,400 milliseconds latency for the total Round Trip Time (RTT) back to the user. This is far worse than most dial-up modem users' experience, at typically only 150–200 ms total latency.
Medium Earth Orbit (MEO) and Low Earth Orbit (LEO) satellites however do not have such great delays. The current LEO constellations of Globalstar and Iridium satellites have delays of less than 40 ms round trip, but their throughput is less than broadband at 64 kbit/s per channel. The Globalstar constellation orbits 1,420 km above the earth and Iridium orbits at 670 km altitude. The proposed O3b Networks MEO constellation scheduled for deployment in 2012 would orbit at 8,062 km, with RTT latency of approximately 125 ms. The proposed new network is also designed for much higher throughput with links well in excess of 1 Gbit/s (Giga bits per second). The planned COMMStellation™, scheduled for launch in 2015, will orbit the earth at 1,000 km with a latency of approximately 7 ms. This polar orbiting constellation of 78 microsatellites will provide global backhaul with throughput in excess of 1.2 Gbit/s.
Most satellite Internet providers also have a FAP (Fair Access Policy). Perhaps one of the largest disadvantages of satellite Internet, these FAPs usually throttle a user's throughput to dial-up data rates after a certain "invisible wall" is hit (usually around 200 MB a day). This FAP usually lasts for 24 hours after the wall is hit, and a user's throughput is restored to whatever tier they paid for. This makes bandwidth-intensive activities nearly impossible to complete in a reasonable amount of time (examples include P2P and newsgroup binary downloading).
Some systems have a FAP based on a monthly limit of data downloaded, with download data rates reduced for the remainder of the month if the limit is exceeded. Other Satellite Internet offers have advanced FAP mechanisms based on sliding time windows. These services verify download quotas during the last hours, days and weeks. The purpose is to allow temporary excessive downloads when needed while saving volume for the end of the month.
Advantages
- True global broadband Internet access availability
- Mobile connection to the Internet (with some providers)
Disadvantages
- High latency compared to other broadband services, especially 2-way satellite service
- Unreliable: drop-outs are common during travel, inclement weather, and during sunspot activity
- The narrow-beam highly directional antenna must be accurately pointed to the satellite orbiting overhead
- The Fair Access Policy limits heavy usage, if applied by the service provider
- VPN use is discouraged, problematic, and/or restricted with satellite broadband, although available at a price
- One-way satellite service requires the use of a modem or other data uplink connection
- Satellite dishes are very large. Although most of them employ plastic to reduce weight, they are typically between 80 and 120 cm (30 to 48 inches) in diameter.
Cellular broadband
Cellular phone towers are very widespread, and as cellular networks move to third generation (3G) networks they can support quick data; using technologies such as EVDO, HSDPA and UMTS.
These can give broadband access to the Internet, with a cell phone, with Cardbus, ExpressCard, or USB cellular modems, or with cellular broadband routers, which allow more than one computer to be connected to the Internet using one cellular connection.
According to the international Organisation for Economic Co-operation and Development (OECD), "Wireless broadband subscriptions in OECD countries had exceeded half a billion by the end of 2010, an increase of more than 10 percent on June 2010, according to new OECD statistics." [6] In contrast, fixed broadband subscriptions reached 300 million in 2010.[7]
Power-line Internet
This is a new service still in its infancy that may eventually permit broadband Internet data to travel down standard high-voltage power lines. However, the system has a number of complex issues, the primary one being that power lines are inherently a very noisy environment. Every time a device turns on or off, it introduces a pop or click into the line. Energy-saving devices often introduce noisy harmonics into the line. The system must be designed to deal with these natural signaling disruptions and work around them.
Broadband over power lines (BPL), also known as Power line communication, has developed quicker in Europe than in the US due to a historical difference in power system design philosophies. Nearly all large power grids transmit power at high voltages in order to reduce transmission losses, then near the customer use step-down transformers to reduce the voltage. Since BPL signals cannot readily pass through transformers, repeaters must be attached to the transformers. In the US, it is common for a small transformer hung from a utility pole to service a single house. In Europe, it is more common for a somewhat larger transformer to service 10 or 100 houses. For delivering power to customers, this difference in design makes little difference, but it means delivering BPL over the power grid of a typical US city will require an order of magnitude more repeaters than would be required in a comparable European city.
The second major issue is signal strength and operating frequency. The system is expected to use frequencies in the 10 to 30 MHz range, which has been used for decades by licensed amateur radio operators, as well as international shortwave broadcasters and a variety of communications systems (military, aeronautical, etc.). Power lines are unshielded and will act as transmitters for the signals they carry, and have the potential to completely wipe out the usefulness of the 10 to 30 MHz range for shortwave communications purposes, as well as compromising the security of its users.
Wireless ISP
(See also Cellular Broadband, above)
This typically employs the current low-cost 802.11 Wi-Fi radio systems to link up remote locations over great distances, but can use other higher-power radio communications systems as well.
Traditional 802.11b was licensed for omnidirectional service spanning only 100–150 meters (300–500 ft). By focusing the signal down to a narrow beam with a Yagi antenna it can instead operate reliably over a distance of many kilometres (miles), although the technology's line-of-sight requirements hamper connectivity in areas with hilly and heavily foliated terrain. In addition, compared to hard-wired connectivity, there are security risks (unless robust security protocols are enabled); speeds are significantly slower (2 – 50 times slower); and the network can be less stable, due to interference from other wireless devices and networks, weather and line-of-sight problems.[6]
Rural Wireless-ISP installations are typically not commercial in nature and are instead a patchwork of systems built up by hobbyists mounting antennas on radio masts and towers, agricultural storage silos, very tall trees, or whatever other tall objects are available. There are currently a number of companies that provide this service.
Cable broadband
Fiber to the home
By fiber-optic cables connected directly to buildings will deliver broadband speeds up to 100 megabits per second. Australia has already begun rolling out the network over the country using fiber-optic cables to 90 percent of Australian homes, schools and business.[8]
Google has been working for a while on testing their own ultra high-speed fiber-optic system in an attempt to improve the way the average person's internet works. They have formed a google blog about this and asked communities across the country to nominate their towns to test the project. They currently have huge plans for the project. TechCrunch and FoxNews have posted announcements about this project hitting possibly as many as 50,000 people with 1 Gbit/s fiber-optic internet.
Available resources for broadband
It is estimated that 40 % of the world's population has less than US$ 20 per year available to spend on ICT (less than $2 per month)[9]. This is the budget people count with to buy all kinds of ICT, including hardware, software, etc. Any broadband viable solution must fit into this budget if this segment of the global population is to be reached. In Mexico, the poorest 20% of the society counts on an estimated US$ 35 per year (US$ 3 per month). In Brazil, the poorest 20% of the population counts with merely US$9 per year to spend on ICT (US$ 0.75 per month).
From Latin America it is known that the borderline between ICT as a necessity good and ICT as a luxury good is roughly around the “magical number” of US$10 per person per month, or US$120 per year.[9] This is the cost ICT people seem to strive for and therefore is generally accepted as a minimum.
Pricing
Traditionally, Internet service providers have used an "unlimited" or flat rate model, with pricing determined by the maximum bitrate chosen by the customer, rather than an hourly charge. With increased consumer demand for streaming content such as video on demand and peer-to-peer file sharing, the use of high bandwidth applications has increased rapidly.
For ISPs who are bandwidth limited, the flat rate pricing model may become unsustainable as demand for bandwidth increases. Fixed costs represent 80-90% of the cost of providing broadband service[citation needed], and although most ISPs keep their cost secret, the total cost (January 2008) is estimated to be about $0.10 per gigabyte[citation needed].
Currently some ISPs estimate that about 5% of users consume about 50% of the total bandwidth.[10]
To ensure these high-bandwidth users do not slow down the network, many ISPs have split their users’ bandwidth allocations into 'peak' and 'off peak', encouraging users to download large files late at night.[11]
In order to provide additional high bandwidth pay services[12] without incurring the additional costs of expanding current broadband infrastructure, ISPs are exploring new methods to cap current bandwidth usage by customers.[13]
Some ISPs have begun experimenting with usage-based pricing, notably a Time Warner test in Beaumont, Texas.[14] The effort to expand usage-based pricing into the Rochester, New York area met with public resistance, however, and was abandoned.[15] In Canada, Rogers Hi-Speed Internet and Bell Canada have imposed bandwidth caps on customers.
Worldwide
Approximately 500 million broadband subscribers were in service in 2010.[16]
To promote economic development and reduction of the digital divide, national broadband plans from around the world promote the universal availability of affordable broadband connectivity.
Rural broadband provision
One of the great challenges of broadband is to provide service to potential customers in areas of low population density, such as to farmers, ranchers, and small towns. In cities where the population density is high, it is easier for a service provider to recover equipment costs, but each rural customer may require expensive equipment to get connected. While 63% of Americans had an Internet connection in 2009, that figure was only 46% in rural areas, according to the Pew Internet & American Life Project.[17] Virgin Media advertised over 100 towns across the United Kingdom "from Cwmbran to Clydebank" that have access to their 100 Mbit/s service.[18]
Wireless Internet Service Provider (WISPs) are rapidly becoming a popular broadband option for rural areas.[19] The technology's line-of-sight requirements may hamper connectivity in some areas with hilly and heavily foliated terrain. However, the Tegola project, a successful pilot in remote Scotland, demonstrates that wireless can be a viable option.[20]
Government Broadband Index (gBBi)
The Government Broadband Index (gBBi) report released in January 2011 assesses countries on the basis of government planning, as opposed to current broadband capability. With ambitious targets for both the speed and coverage of next-generation broadband networks, the developed countries of Southeast Asia scored highest in this first government broadband index. Greece is the worst-performing country measured, owing to its relatively low coverage target and drawn-out deployment schedule. Greece also suffers due to the considerable size of its public-funding commitment as a percentage of overall government budget revenues, and because its plan does little to foment competition in the high-speed broadband market.
Australia, the country with the highest-profile and most controversial public-sector scheme, also falls in the bottom half of the index, mainly because it is spending a colossal 7.6% of annual government budget revenues on its National Broadband Network. In South Korea, by comparison, the government is spending less than 1% of annual budget revenues to realise its broadband goals, achieving targets by encouraging the private sector to invest in the country's broadband future.[21]
See also
Related technologies
- Back-channel, a low bandwidth, or less-than-optimal, transmission channel in the opposite direction to the main channel
- Baseband
- Fiber-optic communication
- List of device bandwidths
- Local loop
- Narrowband
- Public switched telephone network (PSTN)
- Residential gateway
- Mobile broadband
- Free-space optical communication
Broadband implementations and standards
- Digital Subscriber Line (DSL), digital data transmission over the wires used in the local loop of a telephone network
- Local Multipoint Distribution Service, broadband wireless access technology that uses microwave signals operating between the 26 GHz and 29 GHz bands
- WiMAX, a standards-based wireless technology that provides high-throughput broadband connections over long distances
- Other wireless technologies, including IEEE standards (802.11b, 802.11g, and 802.11a) and many proprietary wireless protocols. In 2008, with WiMAX still at the top of the learning curve in terms of price, these technologies dominate the market for fixed wireless broadband.
- Power line communication, wireline technology using the current electricity networks
- Satellite Internet access
- Cable modem, designed to modulate a data signal over cable television infrastructure
- Fiber to the premises, based on fiber-optic cables and associated optical electronics
- High-Speed Packet Access (HSPA), a new mobile telephony protocol, sometimes referred to as a 3.5G (or "3½G") technology
- Evolution-Data Optimized (EVDO), is a wireless radio broadband data standard adopted by many CDMA mobile phone service providers
- 802.20 MBWA (Mobile Broadband Wireless Access)
Future broadband implementations
- Bonded DSL Rings a ring topology at the remote end that enables 400 Mbit/s over existing DSL
- White Spaces Coalition a group of technology companies aiming to deliver broadband Internet access via unused analog television frequencies
- High-Speed Downlink Packet Access
Broadband applications
General
- Internet
- Telecommunications network
- World Wide Web
- Broadband mapping in the United States
- Global Internet usage
- List of countries by number of Internet users
- List of countries by number of broadband Internet users
- National broadband plans from around the world
References
- ^ a b "Birth of Broadband". ITU. September 2003. Retrieved July 12, 2011.
- ^ a b "2006 OECD Broadband Statistics to December 2006". OECD. Retrieved June 6, 2009.
- ^ Patel, Nilay (March 19, 2008). "FCC redefines "broadband" to mean 768 kbit/s, "fast" to mean "kinda slow"". Engadget. Retrieved June 6, 2009.
- ^ "OECD Broadband Report Questioned". Website Optimization. Retrieved June 6, 2009.
- ^ http://www.mybluedish.com/questions-and-answers/
- ^ http://www.oecd.org/document/4/0,3746,en_2649_34225_42800196_1_1_1_1,00.html
- ^ Id.
- ^ http://news.yahoo.com/s/ap/20110623/ap_on_hi_te/as_australia_broadband
- ^ a b Martin Hilbert "When is Cheap, Cheap Enough to Bridge the Digital Divide? Modeling Income Related Structural Challenges of Technology Diffusion in Latin America". World Development, Volume 38, issue 5, p. 756-770. free access to the study here: martinhilbert.net/CheapEnoughWD_Hilbert_pre-print.pdf
- ^ Hansell, Saul (January 17, 2008). "Time Warner: Download Too Much and You Might Pay $30 a Movie". The New York Times. Retrieved June 6, 2009.
- ^ http://www.comparebroadband.com.au/article_64_On--and-Off-Peak-Quotas.htm
- ^ Charny, Ben (January 10, 2005). "Comcast pushes VoIP to prime time". CNET News. Retrieved June 6, 2009.
- ^ Cauley, Leslie (April 20, 2008). "Comcast opens up about how it manages traffic". ABC News. Retrieved June 6, 2009.
- ^ Lowry, Tom (March 31, 2009). "Time Warner Cable Expands Internet Usage Pricing". BusinessWeek. Retrieved June 6, 2009.
- ^ Axelbank, Evan (April 16, 2009). "Time Warner Drops Internet Plan". Rochester Homepage. Retrieved December 6, 2010.
- ^ Giga.com Nearly Half a Billion Broadband Subscribers
- ^ Pew Internet & American Life Project Home Broadband Adoption 2009 June 2009
- ^ "Virgin Media's ultrafast 100Mb broadband now available to over four million UK homes". News release. Virgin Media. June 10, 2011. Retrieved August 18, 2011.
- ^ Wireless World: WiFi now in rural areas July 7, 2006
- ^ "Tegola project linking Skye, Knoydart and Loch Hourne". Retrieved 2010-03-16.
- ^ Full speed ahead: The government broadband index Q1 2011
"Rural Broadband Access Key Component in Community Success" Center for Rural Affairs, Brian Depew, refrieved 10/20/10 from http://www.cfra.org/weeklycolumn/2008/09/09/rural-broadband-access-key-component-community-success
External links
- Compare Australia Broadband Plans
- Broadband World Forum (International Engineering Consortium)
- Broadband gap
- European broadband portal
- UK broadband Providers
- Broadband for UK
- US broadband Providers
- Corporate vs. Community Internet, AlterNet, June 14, 2005, - on the clash between US cities' attempts to expand municipal broadband and corporate attempts to defend their markets
- Google - public data: Broadband penetration in Europe
- US National Broadband Map
- Broadbandlandia