Communications system

Abstract

A method performed by a mobile communications node at a setup or a reconfiguration of a radio link control unacknowledged mode (RLC-UM) radio bearer includes receiving a radio bearer setup message from a network communications node, the radio bearer setup message being applied in configuring an RLC-UM radio bearer within the mobile communications node to be able to communicate data with the network communications node, in response to receiving the radio bearer setup message, calculating new cipher data for determining values of a cipher input parameter used for ciphering and deciphering data communicated with the network communications node, and transmitting to the network communications node a radio bearer setup complete message confirming that the RLC-UM radio bearer has been setup and sending the new cipher data to the network communications node.

1 . A method performed by a mobile communications node at a setup or a reconfiguration of a radio link control unacknowledged mode (RLC-UM) radio bearer, the method comprising:
 receiving a radio bearer setup message from a network communications node, the radio bearer setup message being applied in configuring an RLC-UM radio bearer within the mobile communications node to be able to communicate data with the network communications node;   in response to receiving the radio bearer setup message, calculating new cipher data for determining values of a cipher input parameter used for ciphering and deciphering data communicated with the network communications node;   transmitting to the network communications node a radio bearer setup complete message confirming that the RLC-UM radio bearer has been setup and sending the new cipher data to the network communications node;   before said transmitting to the network communications node, ciphering data to be transmitted by the RLC-UM radio bearer or deciphering data received by the RLC-UM radio bearer using values of said cipher input parameter determined using existing cipher data; and   after said transmitting to the network communications node, ciphering data to be transmitted by the RLC-UM radio bearer or deciphering data received by the RLC-UM radio bearer using new values of said cipher input parameter determined using said new cipher data.   
     
     
         2 . A method according to  claim 1 , wherein said existing cipher data comprises previous cipher data previously sent from the mobile communications node to the network communications node. 
     
     
         3 . A method according to  claim 1 , wherein said new cipher data is included with said radio bearer setup complete message. 
     
     
         4 . A method according to  claim 1 , wherein said new cipher data includes a start value. 
     
     
         5 . A computer implementable instructions product comprising computer implementable instructions for causing a programmable computer device to perform the method of  claim 1 . 
     
     
         6 . A method performed by a network communications node at a setup or a reconfiguration of a radio link control unacknowledged mode (RLC-UM) radio bearer, the method comprising:
 transmitting a radio bearer setup message to a mobile communications node, the radio bearer setup message being applied in configuring an RLC-UM radio bearer within the mobile communications node to be able to communicate data with the network communications node;   receiving from the mobile communications node a radio bearer setup complete message confirming that the RLC-UM radio bearer has been setup and receiving new cipher data, calculated by the mobile communications node;   before said receiving from the mobile communications node, ciphering data to be transmitted by the RLC-UM radio bearer or deciphering data received by the RLC-UM radio bearer using values of said cipher input parameter determined using existing cipher data; and   after said receiving from the mobile communications node, ciphering data to be transmitted by the RLC-UM radio bearer or deciphering data received by the RLC-UM radio bearer using new values of said cipher input parameter determined using said new cipher data.   
     
     
         7 . A method according to  claim 6 , wherein said existing cipher data comprises previous cipher data previously sent from the mobile communications node to the network communications node. 
     
     
         8 . A method according to  claim 6 , wherein said new cipher data is included with said radio bearer setup complete message. 
     
     
         9 . A method according to  claim 6 , wherein said new cipher data includes a start value. 
     
     
         10 . A computer implementable instructions product comprising computer implementable instructions for causing a programmable computer device to perform the method of  claim 6 . 
     
     
         11 . A mobile communications node, comprising:
 means for receiving a radio bearer setup message from a network communications node, the radio bearer setup message being applied in configuring an RLC-UM radio bearer within the mobile communications node to be able to communicate data with the network communications node;   means responsive to receiving the radio bearer setup message, for calculating new cipher data in determining values of a cipher input parameter used for ciphering and deciphering data communicated with the network communications node;   means for transmitting to the network communications node a radio bearer setup complete message confirming that the RLC-UM radio bearer has been setup and sending the new cipher data to the network communications node; and   ciphering means operable:
 before the transmission of said radio bearer setup complete message, to cipher data to be transmitted by the RLC-UM radio bearer or to decipher data received by the RLC-UM radio bearer using values of said cipher input parameter determined using existing cipher data; and 
 after the transmission of said radio bearer setup complete message, to cipher data to be transmitted by the RLC-UM radio bearer or to decipher data received by the RLC-UM radio bearer using new values of said cipher input parameter determined using said new cipher data. 
   
     
     
         12 . A communications node according to  claim 11 , wherein said existing cipher data comprises previous cipher data previously sent from the mobile communications node to the network communications node. 
     
     
         13 . A communications node according to  claim 11 , wherein said new cipher data is included with said radio bearer setup complete message. 
     
     
         14 . A communications node according to  claim 11 , wherein said new cipher data includes a start value. 
     
     
         15 . A network communications node, comprising:
 means for transmitting a radio bearer setup message to a mobile communications node, the radio bearer setup message being applied in configuring an RLC-UM radio bearer within the mobile communications node to be able to communicate data with the network communications node;   means for receiving, from the mobile communications node, a radio bearer setup complete message confirming that the RLC-UM radio bearer has been setup and for receiving new cipher data, calculated by the mobile communications node; and   cipher means operable:
 before receiving the radio bearer setup complete message, to cipher data to be transmitted by the RLC-UM radio bearer or to decipher data received by the RLC-UM radio bearer using values of said cipher input parameter determined using existing cipher data; and 
 after receiving said radio bearer setup complete message, to cipher data to be transmitted by the RLC-UM radio bearer or to decipher data received by the RLC-UM radio bearer using new values of said cipher input parameter determined using said new cipher data. 
   
     
     
         16 . A network communications node according to  claim 15 , wherein said existing cipher data comprises previous cipher data previously sent from the mobile communications node to the network communications node. 
     
     
         17 . A network communications node according to  claim 15 , wherein said new cipher data is included with said radio bearer setup complete message. 
     
     
         18 . A network communications node according to  claim 15 , wherein said new cipher data includes a start value.