The disclosure is directed to a mobile communication device that is capable of accessing different types of networks at the same time. The mobile device registers a public ID with a first IP address over a first access network and also registers the same public ID with a different IP address over a second access network. Additional registrations and IP addresses may occur as well. Of particular benefit is that the different registrations are active during at least some concurrent period of time. This allows a user of the mobile device to have improved continuity of service, select preferred access methods, and receive different data services simultaneously.