Radio access nodes and terminal devices in a communication network

Abstract

According to an exemplary embodiment, there is provided a method of operating a terminal device. The method includes operating the terminal device in a connected state with respect to the communication network. The method further includes receiving a first signal from a first radio access node in the communication network indicating that the connected state is to be suspended, the first signal having information for use in determining a first key for encrypting data to be sent between the terminal device and the first radio access node or another radio access node in the communication network if the connected state is resumed.

1 . A method of operating a terminal device in a communication network, the device configured to communicate with at least one radio access node in the communication network, the method comprising:
 operating the terminal device in a connected state with respect to the communication network;   receiving a first signal from a first radio access node indicating that the connected state is to be suspended, the first signal indicating a first security algorithm configuration;   switching the terminal device to a suspended state with respect to the communication network responsive to receiving the first signal;   sending a second signal a second radio access node, the second signal requesting resumption of the connected state;   receiving a third signal from the second radio access node indicating one of:
 that the connected state has been successfully resumed; and 
 that an error occurred in resuming the connected state; and 
   when the third signal indicates that an error occurred, the third signal indicates a second security algorithm configuration for encrypting data to be sent between the terminal device and the second radio access node on resumption of the connected state.   
     
     
         2 . The method of  claim 1 , wherein the method further comprises:
 transmitting encrypted data to the second radio access node, the data being encrypted using the second security algorithm configuration indicated in the third signal.   
     
     
         3 . The method of  claim 1 , wherein the second signal includes an authorization token. 
     
     
         4 . The method of  claim 3 , wherein the error indicated in the third signal is associated with a failure to match the authorization token of the second signal with a reference authorization token received at the second radio access node from the first radio access node. 
     
     
         5 . The method of  claim 4 , wherein the error indicated in the third signal is associated with the second radio access node failing to support the first security algorithm configuration indicated in the first signal. 
     
     
         6 . A terminal device configured to operate in a communication network, the terminal device configured to communicate with at least one radio access node in the communication network, the terminal device comprising processing circuitry configured to:
 operate the terminal device in a connected state with respect to the communication network;   receive a first signal from a first radio access node indicating that the connected state is to be suspended, the first signal indicating a first security algorithm configuration;   switch the terminal device to a suspended state with respect to the communication network responsive to receiving the first signal;   cause transmission of a second signal a second radio access node, the second signal requesting resumption of the connected state;   receive a third signal from the second radio access node indicating one of:
 that the connected state has been successfully resumed; and 
 that an error occurred in resuming the connected state; and 
   when the third signal indicates that an error occurred, the third signal indicates a second security algorithm configuration for encrypting data to be sent between the terminal device and the second radio access node on resumption of the connected state.   
     
     
         7 . The terminal device of  claim 6 , wherein the processing circuitry is further configured to:
 transmit encrypted data to the second radio access node, the data being encrypted using the second security algorithm configuration indicated in the third signal.   
     
     
         8 . The terminal device of  claim 6 , wherein the second signal includes an authorization token. 
     
     
         9 . The terminal device of  claim 8 , wherein the error indicated in the third signal is associated with a failure to match the authorization token of the second signal with a reference authorization token received at the second radio access node from the first radio access node. 
     
     
         10 . The terminal device of  claim 9 , wherein the error indicated in the third signal is associated with the second radio access node failing to support the first security algorithm configuration indicated in the first signal.