Later, many AMPS networks were partially converted to D-AMPS, often referred to as TDMA ( though TDMA is a generic term that applies to many cellular systems ).

AMPS is a first-generation cellular technology that uses separate frequencies, or " channels ", for each conversation ( see FDMA ).

AMPS cellular service operated in the 800 MHz Cellular FM band.

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.

After that point, however, most cellular companies were eager to shut down AMPS and use the remaining channels for digital services.

It also operates a cellular telephone service on the AMPS and GSM platforms.

This frequency band was designated by the United States FCC and Industry Canada to be used for new wireless services to alleviate capacity caps inherent in the original AMPS and D-AMPS cellular networks in the 800-894 MHz frequency band ( commonly referred to as the " 850 MHz band ").

Developed by Bell Labs in the 1970s and first used commercially in the United States in 1983, AMPS operates in the 800 MHz band in the United States and is the most widely distributed analog cellular standard.

IS-54 was, in fact, backward compatible with analog cellular and indeed co-exists on the same radio channels as AMPS.

To maintain compatibility with the existing AMPS cellular telephone system, the primary forward and reverse control channels in IS-54 cellular systems use the same signaling techniques and modulation scheme ( binary FSK ) as AMPS.

* 1978: Bell Labs launched a trial of the first commercial cellular network in Chicago using Advanced Mobile Phone System ( AMPS ).

typically used the Mobile Telephone Service ( MTS ), which was first used in St. Louis, or Improved Mobile Telephone Service ( IMTS ) before giving way to analog cellular service ( AMPS ) in 1984.

These cellular systems were based on US Advanced Mobile Phone Service ( AMPS ) technology, the modified technology being named Total Access Communication System ( TACS ).

Parallel to Improved Mobile Telephone Service ( IMTS ) in the US until the rollout of cellular AMPS systems, a competing mobile telephone technology was called Radio Common Carrier or RCC.

The service was provided from the 1960s until the 1980s when cellular AMPS systems made RCC equipment obsolete.

RCC based services were provided until the 1980s when cellular AMPS systems made RCC equipment obsolete.

While Motorola was developing the cellular phone itself, during 1968-1983, Bell Labs worked on the system called AMPS, which became the first cellular network in the U. S. Motorola and others designed cell phones for that and other cellular systems.

), except the voice channel was analog ( as was the original NMT and AMPS cellular systems ).

The Oki 900 was the ultimate tool of cell phone hackers because it could listen in to AMPS phone calls right out of the box with no hardware modifications.

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.

The station moved from channel 79 to channel 57 on July 1, 1983, because of complaints that it was interfering with mobile radio in the Toronto area, and so that the frequencies used by channels 70 to 83 could be reclaimed for use by new AMPS mobile phones as a result of a CCIR international convention in 1982.

* Telecom New Zealand — Operated an AMPS / TDMA network in New Zealand from 1987 until 2007 throughout the whole country and the network was renowned for its superb coverage, In 2000 Telecom announced that they would discontinue the AMPS network within 5 years ( 2005 ) to give customers an opportunity to transition to the CDMA2000 and later 1XRTT technologies that replaced it.

It was the third largest AMPS network, by subscribers, in the world at the time of its turndown.

Ananda Marga counts hundreds of missions around the world through which its members carry out various forms of selfless service on Relief ( The social welfare and development organization under AMPS is Ananda Marga Universal Relief Team, or AMURT., Education and women's welfare ( The service activities of this section founded in 1963 are focused on: 1-Education: creating and managing primary, post primary and higher schools, research institutes etc., 2-Relief: creating and managing children's and students ' homes for destitute children and for poor students, cheap hostels, retiring homes, academies of light for deaf dumb and crippled, invalid homes, refuge reabilitation etc., 3-Tribal: tribal welfare units, medical camps etc., 4-Women's welfare: women welfare units, women's homes, nursing homes etc.

Telecom originally operated a TDMA ( AMPS, Digital D-AMPS / TDMA ) mobile network ; this was superseded by its CDMA network.

Rogers deactivated its IS-136 network ( along with AMPS ) on May 31, 2007.

Alltel, who primarily uses CDMA2000 technology but acquired a TDMA network from Western Wireless, shut down its TDMA and AMPS networks in September 2008.

Most of its network was initially IS-95 / cdmaOne based, although there were parts of it that were still analog AMPS and parts ( resulting from acquisition of other companies ) using TDMA ( IS-136 ).

The company operates AMPS and IS-136 networks on the 800 / 850 MHz band and a GSM network on the 1800 MHz ( DCS ) band in its licensed coverage area, the state of Minas Gerais.

It has now phased out the older 025 prefix since the prefix was only used by its now redundant AMPS and TDMA networks.

Telus Mobility discontinued its AMPS analog network in February 2008, and launched its HSPA + network in November 2009.

Due to the age and security problems of this technology, Telus Mobility discontinued its AMPS analog mobile network in 2008.

Cellular South, Inc. began its wireless service on the Mississippi Gulf Coast on February 4, 1988, using AMPS technology.

At the time of the Bell System divestiture in 1984, each Regional Bell Operating Company ( Baby Bell ) was given a portion of the Advanced Mobile Phone System ( AMPS ) network corresponding to its service area.

An AMPS / IS-54 infrastructure can support use of either analog AMPS phones or D-AMPS phones.

They are externally similar to the 3310 and 3390, but use Digital AMPS (" TDMA ")/ AMPS technology rather than GSM.

This trial system was licensed by the FCC to ATT for commercial use in 1982 and, as part of the divestiture arrangements for the breakup of ATT, the AMPS technology was distributed to local telcos.

A GAIT-compliant mobile phone typically accepts a SIM card, similar to a standard GSM phone ; however, depending on the wireless provider, the SIM card enables access not only to that wireless provider's GSM network, but also enables use of the telephone on any TDMA or AMPS networks run by the wireless provider.

However, reducing interference is a significant component in how GSM and other TDMA based mobile phone systems make better use of the available spectrum compared to older analog systems such as AMPS and NMT.

Because of the wide base of older technologies like TDMA and AMPS they are still in use.

With the removal of analog network cells nearly all over the world, the DynaTAC models running on AMPS or other analog networks are mostly obsolete.