Patent ID: 11882613
Assignee: SONY GROUP CORPORATION
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. A terminal device for use in a wireless telecommunication system comprising a first radio access node and a second radio access node, the terminal device comprising a controller and a transceiver configured to operate together such that the terminal device is operable
to establish a radio resource control, RRC, connection with the first radio access node and to enter an RRC connected mode for communicating the data between the terminal device and the first radio access node in accordance with one or more parameters configured by the first radio access node and associated with the terminal device,
to enter a dual connectivity mode of operation for the terminal device in which the first radio access node acts as a master radio access node and the second radio access node acts as a secondary radio access node,
to communicate the same first data between the terminal device and the first radio access node and between the terminal device and the second radio access node,
to determine that a radio link failure has been detected in respect of at least the first radio access node,
to transmit to the second radio access node a re-establishment request message,
to receive from the second radio access node a re-establishment response message, the re-establishment response message being transmitted by the second radio access node in response to the re-establishment request message and without the second radio access node requesting context information comprising the one or more parameters associated with the terminal device from the first radio access node after receiving the re-establishment request message,
to communicate second data between the terminal device and the second radio access node,
to, before determining that the radio link failure criteria are satisfied in respect of at least the first radio access node, receive a security key associated with the first radio access node, and
to calculate an authentication token based on the security key associated with the first radio access node,
wherein the re-establishment request message comprises the authentication token.