It has been more than 4 years when Sony Ericsson released its last models for T-Mobile network in US. FCC approval documents have revealed an upcoming Sony Ericsson clamshell phone with T-Mobile logo on it. The new Sony Ericsson TM506 is similar to the Z780 HSDPA phone, it supports GSM Triband (850/1800/1900 MHz) and T-Mobile's 3G network. continued »