The Global System for Mobile communications (GSM) is a second generation cellular telecommunication system which was first planned in the early 1980s. Unlike first generation systems operating at the time, GSM was digital and thus introduced greater enhancements such as security, capacity, quality and the ability to support integrated services. Initially, GSM was planned to be a European system allowing subscribers to roam between different networks however, GSM was quickly adopted by many other regions and is now a Global System. Many countries around the world have now met market saturation point, which means over 100% of the population of that country possess a GSM phone. The spectrum range for the GSM1800 operation is between 1710MHz and 1785MHz for uplink operation and 1805MHz and 1880MHz for downlink operation. GSM 1800 is also termed PCN (Personal Communication Network) and DCS (Digital Cellular System) 1800.