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== AMPS ==== [[AMPS]] ==This technology is mentioned for historical purposes. Although radio phones or a proto cell phone technology can be traced back to the 1950s, Advanced Mobile Phone System (AMPS) is considered the first true cell phone network commercially available to the United States, starting in 1978. {{:AMPS}}AMPS communication was unencrypted, so people to listen in on cell phone conversations with an ordinary police scanner. Phones were often cloned, causing issues of fraud and network abuse. AMPS was also a bandwidth hog, using a Frequency-division multiple access (FDMA) scheme that required significant amounts of wireless spectrum.== [[GSM]] ==AMPS started to get phased out beginning in the 1990s when PCS digital was introduced. [[GSM]] stands for Global System for Mobile Communications; it's the world's most prolific mobile standard. This is what you will find if you are, say for example, traveling in Europe. Verizon Wireless operated an AMPS network, and on February 18, 2008, Verizon discontinued all AMPS service. The last of the AT&T AMPS network was shut down February 18, 2008. == GSM == GSM stands for Global System for Mobile Communications; it's the world's most prolific mobile standard. This is what you will find if you are, say for example, traveling in Europe. == CDMA ==== [[CDMA]] ==CDMA stands for Code Division Multiple Access, including both CDMAOne or CDMA 2000. This is the most common standard in the United States of America throughout the 1990's and until present (2012).[[CDMA]] stands for Code Division Multiple Access, including both CDMAOne or CDMA 2000. This is the most common standard in the United States of America throughout the 1990's and until present (2012).3G Data phones do not use SIM cards.4G Data phones utilize a SIM card. Verizon, for example, states, "''All Verizon Wireless 4G Certified Devices will need a Verizon Wireless Subscriber Identity Module (SIM) Card. 4G SIM Cards are required for Verizon Wireless 4G LTE service.''" See [http://support.verizonwireless.com/information/4gsim.html 4G SIM Information].This is an outdated technology. The major TDMA carriers switched over to GSM. AT&T (including the former AT&T Wireless) and US Cellular were formerly on the TDMA standard. US Cellular actually went to CDMA. This is an outdated technology. The major TDMA carriers switched over to GSM. AT&T (including the former AT&T Wireless) and US Cellular were formerly on the TDMA standard. US Cellular actually went to CDMA. === iDEN === Sprint Nextel provided iDEN (Integrated Digital Enhanced Network) service across the United States, but its iDEN network was decommissioned on June 30, 2013. iDEN places more users in a given spectral space, compared to analog cellular and two-way radio systems, by using speech compression and time division multiple access (TDMA).The CDMA carriers offer a few models of "World Phones" which have SIM card slots for the installation of GSM SIM cards so these phones can operate on GSM networks. These phones require a second radio, so cost more to manufacturer. One example of such a World Phone is the [[BlackBerry Bold 9650]]. Currently (2012), there are no Verizon 4G LTE models that offer GSM support. The world phones are 3G phones when operated domestically. Verizon's phones and network are CDMA, which doesn't use sim cards. {{:CDMA vs GSM}}CDMA phones do not use sim cards, while GSM phones do.== Mobile Broadband Data ==CDMA and GSM are different technologies that are incompatible with each other.Mobile broadband is also known as 3G, or third-generation cell-phone technology. Both GSM and CDMA have developed their own 3G technology solutions for delivering high-speed Internet access to mobile devices.The term "unlocking" referring to an unlocked phone is used when discussing GSM and iDEN phones.The CDMA-based mobile broadband technology is called EV-DO.There are other CDMA providers besides Verizon, which include Sprint and US Cellular.The GSM mobile broadband technology is called HSDPA.Verizon will only activate another Verizon phone. A non-Verizon CDMA phone's ESN number will not be in Verizon's database of phones, and therefore, Verizon will not activate it.== Data ==== Other Technologies and Related Termonology ===== WiMax ===Sprint Nextel developed WiMax technology before Verizon's 4G LTE was available. WiMax is a high speed alternative to 4G LTE. However, Sprint Nextel has decided to abandoned WiMax and convert their networks to 4G LTE. (May 2012)=== 4G LTE ===CDMA 3G is being replaced / upgraded to 4G LTE, a faster data technology. Unlike CDMA 3G (called 3G EV-DO), 4G LTE is supposed to become a global standard, which includes Europe and regions previously not 3G EV-DO compatible. Even though 4G LTE will eventually be more universal, carriers such as Verizon are still using incompatible radio frequencies which Europe. As of 2012, Verizon 4G devices are not world roam compatible.AT&T and Verizon are each using 700 MHz to build their LTE networks. But they use different slivers of this frequency, and because the "bands" aren't harmonized, the specifications are different and devices built for AT&T won't work on Verizon's network and vice versa.=== 3G EV-DO ===In North America, Verizon and Sprint have large network coverage for 3G EV-DO data technology. [[Category:Telephone]]