GAIT (an acronym for the GSM-ANSI Interoperability Team) is a wireless standard to allow cross-operation of mobile telephone technologies. In North America, which in addition to the contemporary GSM protocol also includes extensive legacy networks of TDMA and AMPS transceiver stations, phones compliant with the GAIT standard can operate on any of the GSM, TDMA or AMPS networks, while the majority of non-GAIT GSM mobile phones can only operate on GSM networks (which are not as widely deployed as the older TDMA and AMPS networks). Acronyms and initialisms are abbreviations formed from the initial letter or letters of words, such as NATO and XHTML, and are pronounced in a way that is distinct from the full pronunciation of what the letters stand for. ... Cellular redirects here. ... GSM (Global System for Mobile Communications) is the most popular standard for mobile phones in the world. ... Time Division Multiple Access (TDMA) is a technology for shared medium (usually radio) networks. ... Advanced Mobile Phone System or AMPS is the analog mobile phone system standard, introduced in the Americas during the early 1980s. ...

An advantage of the interoperability provided by GAIT is that a user can use a GAIT phone in a much larger area served by any of the three networks, rather than be constricted to only areas served by GSM networks.

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. In addition to the usual IMEI found on standard GSM mobile phones, a GAIT-complient mobile phone also includes an AMPS-style ESN unique to the mobile phone. SIM re-directs here; for alternate uses see Sim (disambiguation) A SIM card taken from a GSM mobile phone A subscriber identity module (SIM) is a smartcard securely storing the key identifying a mobile subscriber. ... The International Mobile Equipment Identity (or IMEI) is a unique number associated with every GSM and UMTS mobile phone. ... ESN or Electronic Serial Number refers to a 32-bit control number used for cell phone activation in wireless carrier networks. ...

In the United States, Cingular Wireless offered the Nokia 6340 to customers who wished to have a GAIT mobile phone (although this phone is no longer marketed through Cingular). Although Cingular is phasing out its legacy TDMA and AMPS networks in favor of GSM, nonetheless as of 2005 Cingular's legacy networks still have broader geographical coverage than its GSM network, making a GAIT phone attractive to customers who require the broadest coverage availability. Cingular Wireless LLC is the largest United States mobile phone company, with headquarters in Atlanta, Georgia, United States. ... 2005 is a common year starting on Saturday of the Gregorian calendar and is the current year. ...

In contrast to most North American CDMA networks (such as Verizon Wireless, for example), however, a GAIT phone cannot automatically switch over to AMPS after losing a GSM connection without interrupt a call in progress. General Information Generically (as a multiplexing scheme), code division multiple access (CDMA) is any use of any form of spread spectrum by multiple transmitters to send to the same receiver on the same frequency channel at the same time without harmful interference. ... Verizon Wireless, headquartered in Bedminster, N.J., owns and operates a national wireless network in the United States. ...