GSM Global System for Mobile communications.

   
 

The most important aspect of GSM is its standardisation. This allows some one with a SIM card, to insert the SIM into any SIM Free GSM phone (with compatible frequencies) and the phone would work. This standardisation also applies to anywhere one goes with a GSM network.

This is provided that the correct frequency of the card / network is available to that handset. GSM frequencies are:

GSM 900 (BT Cellnet, Vodafone and most networks around the world)

GSM 1800 (Orange, T-Mobile and some of the European networks)

GSM 1900 (Used in USA and Canada)

   
mPhone Motorola