Air Interface Key Update During SRNC Relocation

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Solution Overview

Problem

In the HSPA+ network, static SRNC relocation triggered by cell updates or URA updates can lead to prolonged relocation times and increased UE disconnection risks due to fast user equipment movement.

Innovation Solution

The method involves performing the relocation from the source RNC to the target RNC first, followed by intra-relocation of the target RNC, where the enhanced air interface key is updated during the intra-relocation process, thereby avoiding prolonged relocation times and disconnection risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If enhanced air interface key update is performed during static SRNC relocation, then security is improved, but relocation time increases

Engineering Contradiction:
ImprovesecurityVSAvoidrelocation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The source RNC performs key update in advance before handing over the UE to the target RNC. The source RNC updates the enhanced air interface key using the deformation intermediate key, and stores the updated key for subsequent use during the relocation process, thereby avoiding time-consuming key updates at the target RNC

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The key update process is separated from the relocation execution process. The key update is performed as a preliminary action by the source RNC, while the target RNC directly uses the transferred key information, dividing the overall process into independent stages that can be executed efficiently

Inventive Principle:
Principle #1Segmentation

2Speed

If static SRNC relocation is performed for fast moving UE, then mobility support is improved, but UE disconnection risk increases

Engineering Contradiction:
ImproveUE movement speedVSAvoidUE connection stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The source RNC completes key update and prepares all necessary security parameters before initiating the handover to target RNC. This preliminary preparation ensures that the target RNC receives complete key information in advance, enabling seamless continuation of secure communication without interruption

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The target RNC receives the deformation intermediate key and updated enhanced air interface key from the source RNC through standardized interface signaling. This feedback mechanism ensures that the target RNC has the correct key material to maintain security while supporting fast UE movement

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2579633B1Method for updating and generating air interface key, and wireless access system
Publication Date: 2017.04.19 ZTE CORP
  • EP2579633B1 patent drawingFigure 1~2
  • EP2579633B1 patent drawingFigure 3~4
  • EP2579633B1 patent drawingFigure 5~6

AI summary

The disclosure discloses a method for updating and generating an air interface key and a radio access system. The updating method comprises: a source Radio Network Controller (RNC) completes the static relocation towards a target RNC; the target RNC performs intra-Serving-RNC (SRNC) relocation; during the intra-SRNC relocation, the target RNC updates enhanced key of itself according to a key received from the source RNC or a core network node. With the disclosure, the enhanced air interface key can be updated during the SRNC static relocation process without increasing the time delay of the SRNC relocation, and security and efficiency of the system are improved.