Apparatus and method for determining uplink ciphering activation time in universal mobile telecommunications system user equipment

• US 20050036619A1
• Filed: 08/12/2004
• Published: 02/17/2005
• Est. Priority Date: 08/15/2003
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: M-Stack Limited (Blackberry Limited)
• Inventors: Funnell, Nicola M., Farnsworth, Andrew, Harrison, Robert J.
• Granted Patent: US 7,826,617 B2
• Time in Patent Office: Days
• US Class Current: 380/256
• CPC Class Codes: H04L 47/34 ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04W 12/037 of the control plane, e.g. signalling traffic
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 84/04 Large scale networks; Deep hierarchical networks
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

The details of an apparatus and method for determining uplink ciphering activation time in universal mobile telecommunications system user equipment are disclosed herein. The ciphering activation time is determined for radio bearers other than RB2 by measuring the data rate on each target radio bearer during the time that it takes for a polling or RRC message sent from the user equipment UE to be acknowledged by the network UTRAN. For RB2, the uplink ciphering activation time is determined by taking into account the size of the RRC response message and the data already queued on RB2 for transmission.

Claims

1. A method of determining uplink ciphering activation time for a communications channel between a user equipment and a telecommunications network, the uplink ciphering activation time for determining the time at which a new ciphering configuration is to be implemented between the user equipment and the network, the method comprising the steps of selecting an uplink activation time so as to minimise delay in the change to the new ciphering configuration.

2. The method of claim 1, wherein the step of selecting the activation time comprises selecting an arbitrary value.

3. The method of claim 2, further comprising choosing a smaller activation time if a delay in changing to the new ciphering configuration is excessive and choosing a larger activation time if data flow has been stopped.

4. The method of claim 1, further comprising the steps of:

sending a message from the user equipment to the network on a signalling channel;

determining a response time for said message, said response time being related to the time at which an acknowledgment of said message is received from the network at the user equipment; and

determining the uplink ciphering activation time for the communications channel in dependence on the response time.

5. The method of claim 4, further comprising determining a data rate for the communications channel during a time interval represented by the response time and determining the uplink ciphering activation time based on said data rate.

6. The method of claim 5, wherein the data rate is determined by a rate at which a logical sequence number for the communication channel is increasing.

7. The method of claim 6, wherein the step of determining the uplink activation time comprises setting the activation time to be a function of a current sequence number for the channel plus the measured increment.

8. The method of claim 7, wherein said function comprises the current sequence number plus the measured increment.

9. The method of claim 1, wherein the network comprises a UMTS Terrestrial Access Network (UTRAN).

10. User equipment for determining uplink ciphering activation time for a communications channel between the user equipment and a telecommunications network, the uplink ciphering activation time for determining the time at which a new ciphering configuration is to be implemented between the user equipment and the network, the equipment including:

a processor for calculating an uplink activation time so as to minimise delay in the change to the new ciphering configuration.