GSM carriers are telecommunications companies that provide mobile phone services through GSM technology. GSM stands for Global System for Mobile Communications and it represents a standard in cellular communication as developed by the ETSI or the European Telecommunications Standards Institute. GSM technology is specifically developed for mobile phones that are created with 2G digital mobile phone technology. Upon its inception, GSM became the standard in mobile telecommunications after the previous 1G analog technology was being phased out. In much of the world today, GSM technology is still the biggest in terms of reach and subscribers for the various telecommunications carriers. This is despite the fact that many countries nowadays are slowly shifting to better network technologies with 3G and 4G technology.
GSM carriers became very popular at the advent of digital mobile phones. Through GSM technology, mobile phones were equipped with SIM cards that are tied to the carrier rather than on the phone. This simply meant that GSM technology allowed for easy swapping of phones using the same SIM card from one GSM carrier. The identity or profile of subscribers are not tied to the mobile phone or unit but are embedded and stored on a SIM card. This simply translates to no worries when changing to a new phone unit. Another great service provided by GSM carriers is international roaming. Being accepted as the defacto standard in the world for mobile communications, GSM carriers are able to allow subscribers to continue using their mobile phones even when subscribers travel to other countries. GSM technology basically allows switching of networks from one location to another making mobile communication easy and seamless. With most countries mobile networks running on GSM technology, subscribers of one GSM carrier need not worry about getting a signal when going to another country. Through GSM, various carriers have roaming contracts with other providers in other countries allowing for easy switching between the networks and carriers.