What is GSM System?

Global System for Mobile communications (GSM) is a2G standard

GSM stands for Global System for Mobile Communication and is an open, digital cellular technology used for transmitting mobile voice and data services. The GSM standard is the most widely accepted standard and is implemented globally.The GSM provides basic to advanced voice and data services including Roaming service.Using your own phone abroad ,understanding your phone's technology can help you determine whether to use it abroad.  Almost all phones use either GSM (Global System for Mobile Communications) or CDMA (Code Division Multiple Access) technology.If you have a GSM phone, you can convert it to a local phone abroad by buying a local SIM card for it . This is especially useful for making cheap, local calls.To use local sim card you may need to unlock from network lock .It is not a big issue to get it unlocked, you may be able to do it by finding the relevant software in the internet or by an online provider like Unlock-Zone.com

GSM system is like a radio can send voice via air & can also receive. It considered that it can have huge no. of transmitters & not one main station of radio and also considered the huge no. of receivers. It works like the landline phone in establishing a call but considered that the mobile owner is moving through different areas while the call is taking place. Threquencies used in GSM are850\\900 MHZ -1800\\1900 MHZ.