Patent ID: 8374604
Filing Date: 2013-02-12
Classification: H04W

Abstract:
1. A method for performing multiple registrations across different radio access technologies (RATs) by a multimode mobile device, the method comprising: registering the mobile device with a primary RAT; and pre-registering the mobile device with at least one non-primary RAT different from the primary RAT, wherein the pre-registration includes: determining whether a full PDN context or partial PDN context is preset on the non-primary RAT; when a full PDN context is preset on the non-primary RAT, performing handoff from primary RAT to non-primary RAT using preset PDN context; and when a partial PDN context is preset on the non-primary RAT, (i) completing the PDN context with the missing parameters obtained from the mobile device, primary RAT or external PDN gateway, and (ii) performing handoff from primary RAT to non-primary RAT using the completed PDN context.