(Wideband Code Division Multiple Access)
Wideband CDMA is a third-generation (3G) wireless standard which utilizes one 5 MHz channel for both voice and data, initially offering data speeds up to 384 Kbps. WCDMA is the 3G technology used in the US by AT&T and T-Mobile
I'm guessing there's no hardware in the phone to support this setting. Not sure why they would include this setting as well as the World setting on the phone. Someone should try throwing an AT&T or T-mobile SIM card and report back.