KT, a WiBro service provider in Korea, announced that it developed VCC (Voice Call Continuity) technology that seamlessly hands over WiBro calls to CDMA network when users are in areas outside WiBro coverage.

VCC technology offers service continuity between packet network and circuit network. Users are located by both the WiBro and CDMA network for seamless call handover, said KT. The technology makes it possible to receive all calls to WiBro network even when the phones are out of WiBro area. 
 
Call handover between landline phone and mobile phone is quite simple but handover between WiBro and CDMA network has been unprecedented around the world.
 
One precondition is that you have to have Dual Band Dual Mode (DBDM) phone to use the service. In other words, the phone should support both WiBro (mVoIP mobile Internet phone) and CDMA calls. KT said, "VCC enhanced technical support for WiBro voice service. It would be helpful to facilitate WiBro service in the future."
 
In the meantime, KT is set to make a decision on adding voice call function on WiBro devices after the government finalizes related policy.

Source:Telecoms Korea