GSM is an abbreviation of 'Global System for mobile communications'. GSM was seen as a significant improvement over pre-existing mobile network systems as both speech and signalling channels are digital and came to be known as a 2G (Second Generation) system. Using digital modulation for both voice and signal enabled much easier integration of data communications. More.
GSM uses a network of base stations to cover an area allowing mobile phones (cell phones in USA) to connect to and route the call. The base stations can be located in a number of areas depending on the type. There are five types and generally located in the following places as depicted in the table below.
In the USA, Canada and some South America countries GSM-850 and GSM-1900 are used
RF & Noise Components have a number of circulator products that have been designed for use in GSM communication systems. This includes a range of coaxial, drop in and surface mount solutions with various other options including power monitors, heat-sinks and cable assemblies