More than 3.8 billion people worldwide used the Global System for Mobile Communications (GSM) family of technologies as of May 2009. GSM is the most widely usesd wireless technology in the world. GSM has strainghtforward, 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.