Senin, 14 November 2011

Wireless broadband

Wireless broadband

The term broadband

Originally broadband had a technical meaning, but became a marketing term for any kind of relatively high-speed computer network or Internet access technology. According to the 802.16-2004 standard, broadband means "having instantaneous bandwidths greater than 1 MHz and supporting data rates greater than about 1.5 Mbit/s."[1] Wireless networks can feature data rates roughly equivalent to wired networks, such as that of Asymmetric Digital Subscriber Line (ADSL) or a cable modem. Wireless networks can also be symmetrical, meaning the same rate in both directions (downstream and upstream), which is most commonly associated with fixed wireless networks. A fixed wireless network link is a stationary terrestrial wireless connection, which can support higher data rates for the same power as mobile or satellite systems.

 Technology and speeds


A typical WISP Customer Premises Equipment (CPE) installed on a residence
Few Wireless Internet Service Providers (WISPs) provide download speeds of over 100 Mbit/s; most broadband wireless access services are estimated to have a range of 50 km (31 mi) from a tower.[2] Technologies used include LMDS and MMDS, as well as heavy use of the ISM bands and one particular access technology was standardized by IEEE 802.16, with products known as WiMAX. WiMAX is highly popular in Europe but has not met full acceptance in the United States because cost of deployment does not meet return on investment figures. In 2005 the Federal Communications Commission adopted a Report and Order that revised the FCC’s rules to open the 3650 MHz band for terrestrial wireless broadband operations.[3] On November 14, 2007 the Commission released Public Notice DA 07-4605 in which the Wireless Telecommunications Bureau announced the start date for licensing and registration process for the 3650–3700 MHz band.[4] In 2010 the FCC adopted the TV White Space Rules (TVWS) and allowed some of the better none line of sight frequency (700 MHz) into the FCC Part-15 Rules.[5] The Wireless Internet Service Providers Association, a National association of WISPs, petitioned the FCC and won.[citation needed]
Initially, WISPs were only found in rural areas not covered by cable or DSL.[6] These early WISPs would employ a high-capacity T-carrier, such as a T1 or DS3 connection, and then broadcast the signal from a high elevation, such as at the top of a water tower. To receive this type of Internet connection, consumers mount a small dish to the roof of their home or office and point it to the transmitter. Line of sight is usually necessary for WISPs operating in the 2.4 and 5 GHz bands with 900 MHz offering better NLOS (non-line-of-sight) performance.

 Mobile wireless broadband

Called mobile broadband, wireless broadband technologies include services from mobile phone service providers such as Verizon, Sprint, and AT&T Mobility, which allow a more mobile version of Internet access. Consumers can purchase a PC card, laptop card, or USB equipment to connect their PC or laptop to the Internet via cell phone towers. This type of connection would be stable in almost any area that could also receive a strong cell phone connection. These connections can cost more for portable convenience as well as having speed limitations in all but urban environments.[citation needed]
On June 2, 2010, after months of discussion, AT&T became the first wireless Internet provider to announce plans to charge according to usage. As the only iPhone service in the United States, AT&T experienced the problem of excess Internet use more than other providers. About 3 percent of AT&T smart phone customers account for 40 percent of the technology's use. 98 percent of the company's customers use less than 2 gigabytes (4000 page views, 10,000 emails or 200 minutes of streaming video), the limit under the $25 monthly plan, and 65 percent use less than 200 megabytes, the limit for the $15 plan. For each gigabyte in excess of the limit, customers would be charged $10 a month starting June 7, 2010, though existing customers would not be required to change from the $30 a month unlimited service plan. The new plan would become a requirement for those upgrading to the new iPhone technology later in the summer.[7]

Licensing

A wireless connection can be either licensed or unlicensed. In the US, licensed connections use a private spectrum the user has secured rights to from the Federal Communications Commission (FCC). In other countries, spectrum is licensed from the country's national radio communications authority (such as the ACMA in Australia or Nigerian Communications Commission in Nigeria (NCC)). Licensing is usually expensive and often reserved for large companies who wish to guarantee private access to spectrum for use in point to point communication. Because of this, most wireless ISP's use unlicensed spectrum which is publicly shared.

Demand for spectrum in the US

Main article: National Broadband Plan (United States)
In the United States, more of the broadcast spectrum was needed for wireless broadband Internet access, and in March 2009, Massachusetts Senator John Kerry introduced a bill requiring a study of efficient use of the spectrum.
Later in the year, the CTIA said 800 MHz needed to be added. David Donovan of The Association for Maximum Service Television said the 2 GHz band, allocated for mobile satellite service, was not even being used after ten years, and switching to this band would be better than asking broadcasters to give up even more. Because of the digital transition, television had lost 100 of its 400 MHz.[8] The National Association of Broadcasters and the AMST commented to the FCC that the government should make maximum use of this newly available spectrum and other spectrum already allocated for wireless before asking for more, while companies that would benefit asked the government to look everywhere possible.[9][10] Many broadcasters objected.[9]
Meredith Attwell Baker, the newest Republican FCC commissioner, agreed that properly using the existing spectrum was important, and part of doing this was using the latest technology. The wireless industry needed more spectrum, both licensed and unlicensed.[11]
FCC broadband advisor Blair Levin wanted a plan by February 2010.[10] Another proposal was "geo-filtered WiMAX", which would allow HDTV but only in a particular market, with the remainder of the spectrum sold for $60 billion. WiMax would replace the existing services but would make MVPD services cheaper, while still allowing broadcasters to make more money. The additional spectrum made available could then be sold to pay the industry's debt.[10]
An FCC workshop on November 23, 2009 produced several ideas. Virginia Tech professor Charles Bostian said sharing should be done, but not in the white spaces; WiFi spectrum should be used instead. Vint Cerf of Google said cable companies could share some spectrum, which the companies would like to do except they have "must-carry" rules that will not allow this. BBN Technologies chief engineer Chip Elliott called for government-funded broadband to be shared by researchers. Collaboration was the key to advancing the technology, and the word "collaboratories" referred to broadband as "not only the goal of the research, but the vehicle as well."[12]
Wi-Fi testing using white spaces took place in Virginia in Fall 2009 and in Wilmington, North Carolina in 2010.[13]
On December 14, 2009 at a hearing before the Communications Subcommittee of the House Energy & Commerce Committee, NAB president Gordon H. Smith recommended using white space in rural areas with fixed devices rather than mobile devices, and new types of broadband service such as those developed by Sezmi. CTIA president Steve Largent said that the industry needed spectrum, "wherever it comes from." He said government spectrum probably was not efficiently used and would "likely" be "repurposed", while other broadcast and satellite spectrum "may" be used better for wireless. Largent also said without more spectrum, companies might merge to better use what they had. Consultant Dave Hatfield, former FCC engineering and technology chief, said making maximum use of existing spectrum through compression and modulation would help, but it would not be enough.[14][15]
The February 17, 2010 deadline was extended by a month.[16] On March 16, at the FCC's monthly meeting, Connecting America: The National Broadband Plan was revealed, with a combination of mandatory and voluntary efforts expected to increase spectrum by 300 MHz; 120 MHz of that was expected to come from broadcasters, and 90 MHz from mobile satellite service.[17][18]
Mark Wigfield, broadband spokesman for the FCC, pointed out that even in the unlikely event all broadcasters in a market gave up their spectrum, the FCC would have to guarantee that some over-the-air service remained.[19]
In April 2011, FCC chairman Julius Genachowski said "realigning" would be necessary if broadcasters did not volunteer, while Intel's Peter Pitsch told Congress "the repacking process should not be made voluntary."[20] The NAB's Smith worried that the process could cause numerous problems for broadcasters and viewers.[20]

 See also

References

  1. ^ Coexistence of Fixed Broadband Wireless Access Systems
  2. ^ "WiMAX: Broadband Wireless Access". wi-fiplanet.com. Retrieved March 17, 2008.
  3. ^ "REPORT AND ORDER – Released: March 16, 2005" (PDF). Federal Communications Commission. Retrieved March 17, 2008.
  4. ^ "PUBLIC NOTICE – Released: November 14, 2007" (PDF). Federal Communications Commission. Retrieved March 17, 2008.
  5. ^ Alex Goldman. "The FCC Decision and the Use of White Spaces". Wireless Internet Service Providers Association. Retrieved July 16, 2011.
  6. ^ "A WISP with Vision". wi-fiplanet.com. Retrieved March 17, 2008.
  7. ^ Bartash, Jefffrey (June 3, 2010). "AT&T first carrier to end unlimited data plans". MarketWatch. Retrieved 2010-06=03.
  8. ^ Eggerton, John (October 5, 2009). "Broadcasters Tackle Spectrum-Sharing Debate". Broadcasting & Cable. Retrieved October 9, 2009.
  9. ^ a b Eggerton, John (October 26, 2009). "Broadcasters Defend Spectrum From Reclamation Proposals". Broadcasting & Cable. Retrieved October 30, 2009.
  10. ^ a b c Eggerton, John (November 2, 2009). "Broadcasters Defend Their Spectrum". Broadcasting & Cable. Retrieved November 5, 2009.
  11. ^ Eggerton, John (October 26, 2009). "Q&A: Baker Seeks Spectrum". Broadcasting & Cable. Retrieved October 30, 2009.
  12. ^ Eggerton, John (November 23, 2009). "Academics, Execs Signal Need For More Bandwidth, Money For Broadband Research". Broadcasting & Cable. Retrieved December 3, 2009.
  13. ^ Eggerton, John (February 24, 2010). "Wilmington Tests WiFi in White Spaces". Broadcasting & Cable. Retrieved February 25, 2010.
  14. ^ Eggerton, John (December 15, 2009). "Broadcast, Wireless Industries Keep Powder Dry". Broadcasting & Cable. Retrieved December 17, 2009.
  15. ^ Eggerton, John (December 14, 2009). "Smith: Broadcasters Must Be Part of Broadband Ecosystem". Broadcasting & Cable. Retrieved December 17, 2009.
  16. ^ Eggerton, John (January 18, 2010). "FCC's Bellaria Says Broadcasters Lobbying Against Scenario That's No Longer On Table". Broadcasting & Cable. Retrieved January 26, 2010.
  17. ^ Eggerton, John (March 15, 2010). "FCC Broadband Plan: Commission Sets 2015 Spectrum Deadline". Broadcasting & Cable. Retrieved March 23, 2010.
  18. ^ "The National Broadband Plan". Federal Communications Commission. Retrieved April 8, 2010.
  19. ^ Eggerton, John (March 8, 2010). "FCC Has Legal Obligation to Preserve Free TV". Broadcasting & Cable.
  20. ^ a b Eggerton, John (April 18, 2011). "FCC: Repacking Some Heat". Broadcasting & Cable.
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