Patent ID: 9185584
Filing Date: 2015-11-10
Classification: H04L,H04W

Abstract:
1. A method comprising: a first radio access network (RAN) serving a user equipment device (UE), wherein the first RAN includes a primary controller and a secondary controller, wherein the primary controller manages bearer connectivity and tracking area updates for the UE in the first RAN and the primary controller has a primary signaling interface with a second RAN, and wherein the secondary controller has a secondary signaling interface with the second RAN, wherein in a first mode of operation, inter-RAN signaling to facilitate transition of the UE from being served by the first RAN to being served by the second RAN passes over the primary signaling interface between the primary controller and the second RAN; detecting failure of the primary signaling interface; and responsive to detecting the failure, transitioning from the first mode of operation to a second mode of operation in which the inter-RAN signaling to facilitate transition of the UE from being served by the first RAN to being served by the second RAN instead passes over the secondary signaling interface between the secondary controller and the second RAN, and in which the primary controller still manages bearer connectivity and tracking area updates for the UE in the first RAN.