Advanced Mobile Phone System: Difference between revisions

'''Advanced Mobile Phone System''' ('''AMPS''') was an [[analog mobile phone]] system standard originally developed by [[Bell Labs]] and later modified in a cooperative effort between Bell Labs and Motorola. It was officially introduced in the Americas on October 13, 1983,<ref name="Testing the First Cell Phone Network">{{cite web|author=AT&T Tech Channel |url=http://techchannel.att.com/play-video.cfm/2011/6/13/AT&T-Archives-AMPS:-coming-of-age |title=AT&T Archives : Testing the First Public Cell Phone Network |publisher=Techchannel.att.com |date=June 13, 2011 |access-date=September 28, 2013 |url-status=dead |archive-url=https://web.archive.org/web/20131029194138/http://techchannel.att.com/play-video.cfm/2011/6/13/AT%26T-Archives-AMPS%3A-coming-of-age |archive-date=October 29, 2013 }}</ref><ref name="PrivateLine">[http://www.privateline.com/dailynotes/index13.html Private Line] {{webarchive|url=https://web.archive.org/web/20120610001231/http://www.privateline.com/dailynotes/index13.html |date=June 10, 2012 }}</ref><ref name = "MilestonesPast">[http://www.milestonespast.com/exbringing.htm MilestonesPast] {{Webarchive|url=https://web.archive.org/web/20111006011650/http://www.milestonespast.com/exbringing.htm |date=October 6, 2011 }}</ref> and was deployed in many other countries too, including Israel in 1986, Australia in 1987, Singapore in 1988, and Pakistan in 1990.<ref name="Australian Mobile Telecommunications Association">{{cite web|url=http://www.amta.org.au/default.asp?Page=142 |title=Ten years of GSM in Australia |access-date=August 16, 2008 |work=AMTA |publisher=Australian Mobile Telecommunications Association |year=2003 |archive-url=https://web.archive.org/web/20080720110058/http://www.amta.org.au/default.asp?Page=142 |archive-date=July 20, 2008 |url-status=dead }}</ref> It was the primary analog mobile phone system in North America (and other locales) through the 1980s and into the 2000s. As of February 18, 2008, carriers in the United States were no longer required to support AMPS and companies such as [[AT&T]] and [[Verizon Communications]] have discontinued this service permanently. AMPS was discontinued in Australia in September 2000, in India by October 2004,<ref name="Australian Mobile Telecommunications Association"/><ref>{{cite web|url=https://www.pta.gov.pk/index.php/en?Itemid=1&cur_t=vtext&id=237&option=com_content&scid=146|title=Home &#124; PTA|website=pta.gov.pk}}</ref> in Israel by January 2010, and Brazil by 2010.<ref>{{cite web|url=http://g1.globo.com/tecnologia/noticia/2010/07/celulares-analogicos-estao-extintos-no-brasil-diz-anatel.html|title=Celulares analógicos estão extintos no Brasil, diz Anatel|first=Agencia|last=Estado|date=July 16, 2010|website=Tecnologia e Games}}</ref>

In 1960, [[John Francis Mitchell|John F. Mitchell]]<ref>{{cite web|url=http://www.brophy.net/PivotX/?p=john-francis-mitchell-biography |title=John F. Mitchell Biography |publisher=Brophy.net |date=August 7, 2012 |access-date=September 28, 2013}}</ref><ref>{{cite web|url=http://www.historyofthecellphone.com/people/john-mitchell.php |archive-url=https://web.archive.org/web/20130117052435/http://www.historyofthecellphone.com/people/john-mitchell.php |url-status=dead |archive-date=January 17, 2013 |title=The Top Giants in Telephony |publisher=Historyofthecellphone.com |date=June 11, 2009 |access-date=September 28, 2013 }}</ref><ref>{{cite web|url=http://www.brophy.net/PivotX/?p=john-francis-mitchell-biography#CELLPHONEINVENTOR |title=Who invented the cell phone? |publisher=Brophy.net |date=August 7, 2012 |access-date=September 28, 2013}}</ref>

Motorola had long produced [[Radiotelephone|mobile telephone]]s for automobiles, but these large and heavy models consumed too much power to allow their use without the automobile's engine running. Mitchell's team, which included [[Martin Cooper (inventor)|Dr. Martin Cooper]], developed portable cellular telephony. Cooper and Mitchell were among the Motorola employees granted a patent for this work in 1973. The first call on the prototype connected, reportedly, to a wrong number.<ref>

While Motorola was developing a cellular phone, from 1968 to 1983 Bell Labs worked out a system called Advanced Mobile Phone System (AMPS), which became the first cellular network standard in the United States. The Bell system deployed ASTM in Chicago, Illinois, first as an equipment test serving approximately 100 units in 1978, and subsequently as a service test planned for 2,000 billed units.<ref>{{ Citation | last = Huff | first = D. L. | date = January 1979 | title = Advanced Mobile Phone Service: The Developmental System | journal = Bell System Technical Journal | volume = 58 | issue = 1  | pages = 249-269 | url = https://onlinelibrary.wiley.com/doi/abs/10.1002/j.1538-7305.1979.tb02218.x | accessdate = 13 Nov 2024 }} </ref> Motorola and others designed and built the cellular phones for this and other cellular systems. Louis M. Weinberg, a marketing director at AT&T, was named the first president of the AMPS corporation. He served in this position during the startup of the AMPS subsidiary of AT&T.

[[Martin Cooper (inventor)|Martin Cooper]], a former general manager for the systems division at Motorola, led a team that produced the first cellular handset in 1973 and made the first phone call from it. In 1983 Motorola introduced the [[Motorola DynaTAC|DynaTAC 8000x]], the first commercially available cellular phone small enough to be easily carried. He later introduced the so-called [[Motorola Bag Phone|Bag Phone]].

In 1992, the first [[smartphone]], called [[IBM Simon]], used AMPS. [[Frank J. Canova|Frank Canova]] led its design at [[IBM]] and it was demonstrated that year at the [[COMDEX]] computer-industry trade-show. A refined version of the product was marketed to consumers in 1994 by [[BellSouth]] under the name [[IBM Simon|Simon Personal Communicator]]. The Simon was the first device that can be properly referred to as a "smartphone", even though that term was not yet coined.<ref name=bus_week_2012>{{cite web |url=http://www.businessweek.com/articles/2012-06-29/before-iphone-and-android-came-simon-the-first-smartphone |archive-url=https://web.archive.org/web/20120701034025/http://www.businessweek.com/articles/2012-06-29/before-iphone-and-android-came-simon-the-first-smartphone |url-status=dead |archive-date=July 1, 2012 |title=Before IPhone and Android Came Simon, the First Smartphone |last=Sager |first=Ira |date=June 29, 2012 |work=Bloomberg Businessweek |publisher=Bloomberg L.P |access-date=June 30, 2012 |quote=Simon was the first smartphone. Twenty years ago, it envisioned our app-happy mobile lives, squeezing the features of a cell phone, pager, fax machine, and computer into an 18-ounce black brick.}}</ref><ref name=schneidawind>{{cite news |last=Schneidawind |first=John |title=Poindexter putting finger on PC bugs; Big Blue unveiling |date=November 23, 1992 |newspaper=USA Today |page=2B}}</ref>

What really separated AMPS from older systems is the "back end" call setup functionality. In AMPS, the cell centers could flexibly assign channels to handsets based on signal strength, allowing the same frequency to be re-used, without interference, if locations were separated enough. The channels were grouped so a specific set was different of the one used on the cell nearby. This allowed a larger number of phones to be supported over a geographical area. AMPS pioneers coined the term "cellular" because of its use of small hexagonal "cells" within a system.<ref name="bell_young">{{ Citation | last = Young | first = W. Rae | date = January 1979 | title = Advanced Mobile Phone Service: Introduction, Background, and Objectives | journal = Bell System Technical Journal | volume = 58 | issue = 1  | pages = 1-14 | url = https://onlinelibrary.wiley.com/doi/abs/10.1002/j.1538-7305.1979.tb02208.x }} (Note: Young was the Bell Labs engineer who invented the hexagonal cell concept.)''</ref><ref name="fluhr_porter">{{ Citation | last = Fluhr | first = Z. C.  | last2 = Porter | first2 = P. T. | date = January 1979 | title = Advanced Mobile Phone Service: Introduction, Background, and Objectives | journal = Bell System Technical Journal | volume = 58 | issue = 1  | pages = 43-69 | url =https://onlinelibrary.wiley.com/doi/abs/10.1002/j.1538-7305.1979.tb02210.x }} ''(Note: Porter was the Bell Labs engineer who proposed that the cell towers be at the corners of the hexagons rather than the centers and have directional antennas that would transmit/receive in 3 directions into 3 adjacent hexagon cells.)''</ref>

AMPS suffered from many weaknesses compared to today's digital technologies. As an analog standard, it was susceptible to static and noise, and there was no protection from 'eavesdropping' using a [[Scanner (radio)|scanner]] or an older TV set that could tune into channels 70–83.<ref>{{cite web |title=Analog Cellphone Calls on UHF Channels of a TV | website=[[YouTube]] |url=https://www.youtube.com/watch?v=JsEgUA4z_SM}}</ref>

In the 1990s, an epidemic of "cloning" cost the cellular carriers millions of dollars.<ref>{{cite news |last1=O'Malley |first1=Kathy |title=COSTLY CELLULAR PHONE FRAUD RISES WITH NUMBER 'CLONING' |url=https://www.chicagotribune.com/news/ct-xpm-1995-03-19-9503190163-story.html |access-date=June 18, 2019 |work=Chicago Tribune |date=March 19, 1995}}</ref> An eavesdropper with specialized equipment could intercept a handset's [[Electronic Serial Number|ESN]] (Electronic Serial Number) and MDN or CTN (Mobile Directory Number or Cellular Telephone Number). The Electronic Serial Number, a 12-digit number sent by the handset to the cellular system for billing purposes, uniquely identified that phone on the network. The system then allowed or disallowed calls and/or features based on its customer file. A person intercepting an ESN/MDN pair could clone the combination onto a different phone and use it in other areas for making calls without paying.

Cellular [[phone cloning]] became possible with off-the-shelf technology in the 1990s. Would-be cloners required three key items :

The Oki 900 could listen in to AMPS phone-calls right out-of-the-box with no hardware modifications.<ref>Takedown, {{ISBN|0786862106}}, Tsutomu Shimomura John Markoff – Shimomura describes demonstrating a shrink-wrapped the Oki 900 during courtroom testimony</ref>

AMPS was originally standardized by [[American National Standards Institute]] (ANSI) as EIA/TIA/IS-3. EIA/TIA/IS-3 was superseded by EIA/TIA-553 and TIA interim standard with digital technologies, the cost of wireless service is so low that the problem of cloning <!-- in this what was meant, that cloning was the 'problem'? --> has virtually disappeared.

Laws were passed in the US which prohibited the FCC [[type acceptance]] and sale of any receiver which could tune the frequency ranges occupied by analog AMPS cellular services.{{why|date=August 2023}} Though the service is no longer offered, these laws remain in force (although they may no longer be enforced).<ref>{{cite web|url=http://www.arrl.org/forum/topics/view/112 |work=Forum-General discussion about technology and policy |title=Why are cellular bands blocked on receivers? |publisher=Arrl.org |access-date=September 28, 2013}}</ref><ref>47cfr15.121 http://edocket.access.gpo.gov/cfr_2010/octqtr/47cfr15.121.htm and http://wireless.fcc.gov/services/index.htm?job=service_home&id=cellular {{Webarchive|url=https://web.archive.org/web/20111026023132/http://wireless.fcc.gov/services/index.htm?job=service_home&id=cellular |date=October 26, 2011 }}</ref>

Later, many AMPS networks were partially converted to [[D-AMPS]], often referred to as '''TDMA''' (though [[time-division multiple access|TDMA]] is a generic term that applies to many 2G cellular systems). D-AMPS, commercially deployed since 1993,<ref>Anton A. Huurdeman, [https://books.google.com/books?id=SnjGRDVIUL4C&dq=d-amps+tia+history&pg=PA533 The Worldwide History of Telecommunications], John Wiley & Sons, 31 juli 2003, page 533</ref> was a [[Digital data|digital]], [[2G]] standard used mainly by [[AT&T Mobility]] and [[U.S. Cellular]] in the United States, [[Rogers Wireless]] in Canada, [[Telcel]] in Mexico, [[Telecom Italia Mobile]] (TIM) in Brazil, [[VimpelCom]] in Russia, [[Movilnet]] in Venezuela, and [[Cellcom (Israel)|Cellcom]] in Israel. In most areas, D-AMPS is no longer offered and has been replaced by more advanced digital wireless networks.

AMPS and D-AMPS have now been phased out in favor of either [[CDMA2000]] or [[GSM]], which allow for higher capacity data transfers for services such as [[Wireless Application Protocol|WAP]], [[Multimedia Messaging System]] (MMS), and wireless Internet access. There are some phones capable of supporting AMPS, D-AMPS and GSM all in one phone (using the [[GAIT (wireless)|GAIT]] standard).

 

==Analog AMPS being replaced by digital==

In 2002, the FCC decided to no longer require A and B carriers to support AMPS service as of February 18, 2008. All AMPS carriers have converted to a digital standard such as CDMA2000 or GSM. Digital technologies such as GSM and CDMA2000 support multiple voice calls on the same channel and offer enhanced features such as two-way text messaging and data services.

[[OnStar]] relied heavily on North American AMPS service for its subscribers because, when the system was developed, AMPS offered the most comprehensive wireless coverage in the US. In 2006, [[ADT Security Services|ADT]] asked the FCC to extend the AMPS deadline due to many of their alarm systems still using analog technology to communicate with the control centers.<ref name="ITWorld">[http://wireless.itworld.com/4279/061004adt/page_1.html ITWorld] {{webarchive |url=https://web.archive.org/web/20061016114055/http://wireless.itworld.com/4279/061004adt/page_1.html |date=October 16, 2006 }}</ref> Cellular companies who own an A or B license (such as Verizon and Alltel) were required to provide analog service until February 18, 2008. After that point, however, most cellular companies were eager to shut down AMPS and use the remaining channels for digital services. [[OnStar]] transitioned to digital service with the help of data transport technology developed by Airbiquity, but warned customers who could not be upgraded to digital service that their service would permanently expire on January 1, 2008.<ref name="OnStar">{{Cite web |title=Helpful Info {{!}} Analog-to-Digital Transition |url=http://www.onstar.com/us_english/jsp/explore/onstar_basics/helpful_info.jsp?info-view=tech_equip |url-status=dead |archive-url=https://web.archive.org/web/20071011215630/http://www.onstar.com/us_english/jsp/explore/onstar_basics/helpful_info.jsp?info-view=tech_equip |archive-date=October 11, 2007 |website=OnStar}}</ref>

|2000 <ref>{{cite web |last1=Dickerson |first1=Mathew |title=Australia's mobile phone network has come a long way |url=https://www.canberratimes.com.au/story/6857507/cheers-to-more-than-30-years-for-our-mobile-phone-network/ |website=Canberra Times |access-date=2022-11-15}}</ref>

|<ref>{{Cite web |url=https://www.jetro.go.jp/ext_images/jfile/report/05001110/05001110_001_BUP_0.pdf |title=Cellular companies of Uzbekistan |date=January 25, 2006}}</ref>