More than 6 billion people worldwide use the Global System for Mobile Communications (GSM) family of technologies. GSM is the most widely used wireless technology in the world, available in more than 219 countries and territories worldwide, with a market share of more than 90 percent.
GSM market share has grown exponentially over recent years. Although it took 12 years for GSM to achieve 1 billion customers (February 2004), it was only another 2.5 years before GSM subscribers passed the 2 billion mark (June 2006), less than two years to exceed 3 billion customers (April 2008) and reached more than 6 billion in 2012.
GSM has quickly become the fastest-growing wireless technology in North America and Latin America and the Caribbean. GSM’s share of market in the Western Hemisphere is 79 percent with more than 830 million customer connections.
GSM is the legacy network of the evolution to the third generation (3G) technologies Universal Mobile Telecommunication System (UMTS), also known as WCDMA, and High Speed Packet Access (HSPA). Commonly referred to as the GSM family of technologies, the following diagram represents the evolution from second generation (2G) GSM and General Packet Radio System (GPRS) to 3G Enhanced Data for GSM Evolution (EDGE), UMTS and HSPA.
The oldest member of the GSM family of technologies is GSM itself; a digital or Personal Communications System (PCS), 2G technology that provides voice and circuit-switched data services.
There are several reasons why GSM is so popular among operators and their customers:
GSM has a straightforward, cost-effective migration path to 3G through GPRS, EDGE and UMTS-HSPA, as well as beyond 3G via the HSPA Evolution (HSPA+), LTE and System Architecture Evolution (SAE) initiatives. Each step in the GSM-based migration path leverages the network infrastructure deployed for the previous steps and is backwards compatible. For example, a UMTS phone can provide voice and data service when connected to a GSM network. This family of technologies also provides a viable, flexible 3G migration path for Code Division Multiple Access (CDMA) and Time Division Multiple Access (TDMA) operators. In fact, the majority of TDMA operators have already migrated to GSM and many CDMA operators have likewise migrated.