Wireless communications

Abstract

Integrity protection is activated for user plane data transferred between a network node and a terminal device of the cellular communications network. The activation can be initiated by the terminal device sending a request message to a second network node. Thus, a UE, such as a Cellular IoT UE, and a network node such as a SGSN are able to use LLC layer integrity protection for both control plane and user plane data.

1 - 26 . (canceled) 
     
     
         27 . A method of operation of a terminal device in a cellular communications network, the method comprising:
 transmitting a request message to a network node;   receiving from the network node a response message responsive to the request message, the response message comprising information indicating that integrity protection is to be used for user plane data transferred between the network node and the terminal device and information indicating a selected integrity algorithm; and   activating integrity protection for user plane data transferred between the terminal device and the network node of the cellular communications network using the selected integrity algorithm.   
     
     
         28 . The method of  claim 27 , wherein the request message indicates the ability of the terminal device to use integrity protection for user plane data. 
     
     
         29 . The method of  claim 28 , wherein the request message also specifies at least one algorithm that the terminal device is capable of using for integrity protection of user plane data. 
     
     
         30 . The method of  claim 28 , wherein the terminal device perform the activating step in response to receiving the response message. 
     
     
         31 . The method of  claim 27 , further comprising
 activating integrity protection for the user plane data in a Logical Link Control layer in response to an activation message from a GPRS Mobility Management layer; and   deriving an integrity key to be used by running UMTS AKA on the USIM.   
     
     
         32 . The method of  claim 27 , further comprising using null encryption for the user plane data. 
     
     
         33 . A computer program product comprising a non-transitory computer readable storage medium storing a computer program, wherein the computer program is configured, when run on a computer, to cause the computer to carry out the method of  claim 27 . 
     
     
         34 . A method of operation of a network node in a cellular communications network, the method comprising:
 receiving a request message from a terminal device;   in response to receiving the request message, determining whether to use integrity protection for user plane data transferred between the network node and the terminal device;   selecting an integrity algorithm;   informing the terminal device that integrity protection is used for user plane data and of the selected integrity algorithm; and   activating integrity protection for user plane data transferred between the network node and the terminal device.   
     
     
         35 . The method of  claim 34 , wherein the request message indicates the ability of the terminal device to use integrity protection for user plane data. 
     
     
         36 . The method of  claim 35 , wherein the request message also specifies at least one algorithm that the terminal device is capable of using for integrity protection of user plane data. 
     
     
         37 . The method of  claim 35 , further comprising activating integrity protection for the user plane data after sending a return message to the terminal device, the return message specifying that integrity protection is to be used for the user plane data. 
     
     
         38 . The method of  claim 34 , further comprising deriving an integrity key to be used. 
     
     
         39 . A computer program product comprising a non-transitory computer readable storage medium storing a computer program, wherein the computer program is configured, when run on a computer, to cause the computer to carry out the method of  claim 34 . 
     
     
         40 . A terminal device, the terminal device comprising:
 a receiver for receiving from a network node a response to a request, the response comprising information indicating that integrity protection is to be used for user plane data transferred between the network node and the terminal device and information indicating a selected integrity algorithm; and   a processor configured to derive an integrity key, wherein   the terminal device is configured to activate integrity protection for user plane data transferred between the terminal device and the network node using the selected integrity algorithm.   
     
     
         41 . The terminal device of  claim 40 , wherein the request message indicates the ability of the terminal device to use integrity protection for user plane data. 
     
     
         42 . The method of  claim 41 , wherein the request message also specifies at least one algorithm that the terminal device is capable of using for integrity protection of user plane data. 
     
     
         43 . A network node for use in a cellular communications network, the network node comprising:
 a receiver for receiving a request message transmitted by a terminal device; and   a processor for determining whether to use integrity protection for user plane data transferred between the network node and the terminal device, wherein   the network node is configured such that, if it is determined that integrity protection is to be used for user plane data transferred between the network node and the terminal device, the network node:   selects an integrity algorithm;   informs the terminal device that integrity protection is used for user plane data and of the selected integrity algorithm; and   activates integrity protection for user plane data transferred between the network node and the terminal device.   
     
     
         44 . The terminal device of  claim 43 , wherein the request message indicates the ability of the terminal device to use integrity protection for user plane data. 
     
     
         45 . The method of  claim 44 , wherein the request message also specifies at least one algorithm that the terminal device is capable of using for integrity protection of user plane data.