The following lines were added (+) and removed (-):
== GSM ==The original cellular technology was based on an analog signal. During the 1990s the new PCS digital mobile phone technology was introduced. PCS stood for Personal Communication System, and Sprint being one of the first companies to adopt this started their digital phone division, called Sprint PCS. 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. == [[AMPS]] == {{:AMPS}} == [[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. Phones using GSM can do both voice and data at the same time, which cannot be done with CDMA.== 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 See [http://support.verizonwireless.com/information/4gsim.html 4G SIM Information].== TDMA ==This is an outdated technology.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).== U.S. Providers and Technologies ==* Verizon - CDMA, UMTS* AT&T Mobility - GSM, UMTS, HSDPA* Sprint - CDMA, UMTS:* Nextel - iDEN* US Cellular - CDMA* T-Mobile - GSM, UMTS, GAN* Cricket Communications - CDMA* Virgin Mobile - CSMAA Mobile Virtual Network Operator (MVNO) is a cell phone company that doesn't own any wireless spectrum, but instead buys it from a network operator such as Sprint. Essentially, an MVNO is a marketing company that believes it can build a profitable business targeting niche markets such as Hispanics or teenagers. Prior to 2006, most MVNOs offered prepaid service, with TracFone and Virgin Mobile among the notable-name providers. == Roaming ==A CDMA-only phone from Verizon, Sprint, or US Cellular is only able to roam on other CDMA networks. This is fine in North America, but CDMA networks are rare in Europe and other countries. These three carriers offer phones with built-in GSM support for International traveling, but this feature is missing from their most popular handsets. 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}} == Mobile Broadband Data == 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 CDMA-based mobile broadband technology is called EV-DO. The GSM mobile broadband technology is called HSDPA. === 1xEVDO === == Other Technologies and Related Termonology == === WiMax ===CDMA phones do not use sim cards, while GSM phones do.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)CDMA and GSM are different technologies that are incompatible with each other.=== 4G LTE ===The term "unlocking" referring to an unlocked phone is used when discussing GSM and iDEN phones.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.There are other CDMA providers besides Verizon, which include Sprint and US Cellular.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.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.=== 3G EV-DO ===In North America, Verizon and Sprint have large network coverage for 3G EV-DO data technology. [[Category:Telephone]]