Patent ID: 9706449
Date: 2017-07-11
CPC Classifications: H04L,H04W

Claim:
1. A method of triggering a change of a call state of a mobile device connectable to a telecommunications network by a first Radio Access Technology and a second Radio Access Technology, wherein the telecommunications network is configured to forward towards a callee an invitation for a call originating by the first Radio Access Technology from the mobile device and to forward a response of the callee by the first Radio Access Technology towards the mobile device, the response indicating a change of the call state from a first state to a second state, and wherein a first network component of the telecommunications network is configured to change by providing a message to the mobile device by the second Radio Access Technology the call state of the mobile device to the second state when receiving a second message indicative of the second state preceded by receiving a first message indicative of the first state, the method comprising the steps performed by a second network component of the telecommunications network: receiving from the first network component an invitation for a transfer of the call from the first Radio Access Technology to the second Radio Access Technology; and responsive to an acknowledgement for the response forwarded to the mobile device being absent, sending to the first network component the second message indicative of the second state preceded by sending to the first network component the first message indicative of the first state.