iDEN (Integrated Digital Enhanced Network) - definition
A TDMA based digital mobile network system. It was developed by Motorola, which remains the main manufacturer for iDEN devices. The main advantage of iDEN is the Push-To-Talk system, which enables mobile phones to be used as walkie-talkies.
Newer iDEN phones use a SIM card that is compatible with GSM phones for international roaming, but only a few phones support both standards.