T-Mobile International, a wholly-owned subsidiary of Deutsche Telekom was established in December 1999. Overtime, it has established itself as one of the largest international mobile communications carriers. It is first to operate a trans-atlantic mobile network based on GSM (Global System for Mobile Communications), the world's most successful digital wireless standard. T-Mobile was among the first operators worldwide to use future oriented technologies like GPRS, WLAN, 3G etc.