Radio Bearer Ciphering Initial Value Setup

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Solution Overview

Problem

In radio communication systems, reconfiguration of radio access bearers between DCH and E-DCH/HSDPA requires new ciphering configurations, but existing methods fail to properly set the initial value for ciphering, leading to incomplete encryption of circuit switched calls.

Innovation Solution

A radio communication apparatus with a control unit that sets and transmits a new initial value for ciphering configuration when reconfiguring radio access bearers between DCH and E-DCH/HSDPA, ensuring proper encryption by using either previously transmitted or recalculated START values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ciphering configuration is implemented during radio access bearer reconfiguration between DCH and E-DCH/HSDPA, then security of circuit switched calls is improved, but the process becomes more complex and may fail if initial value setting is not properly handled

Engineering Contradiction:
Improveciphering configuration reliabilityVSAvoidreconfiguration process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having the terminal device set the START value (initial value for ciphering) before the actual ciphering configuration takes effect. The terminal device calculates and determines the START value in advance during the reconfiguration process, ensures it is properly set in the ciphering configuration, and transmits it to the network side before ciphering operations begin. This preliminary setting prevents ciphering failures and ensures reliable security configuration when transitioning between DCH and E-DCH/HSDPA bearers.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a new initial value is set and transmitted during reconfiguration, then ciphering security is maintained, but additional signaling and processing steps are required

Engineering Contradiction:
Improveencryption securityVSAvoidreconfiguration time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies self-service by enabling the terminal device to autonomously calculate, set, and manage the START value without requiring extensive network-side intervention. The terminal device independently determines the initial value for ciphering configuration, transmits it to the network side, and ensures it is properly configured in the ciphering module. This self-service approach maintains encryption security while reducing signaling overhead and reconfiguration time compared to network-controlled methods.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2996431B1Radio communication system, radio communication apparatus, and ciphering method
Publication Date: 2019.03.06 NEC CORP
  • EP2996431B1 patent drawingFigure 1
  • EP2996431B1 patent drawingFigure 2
  • EP2996431B1 patent drawingFigure 3

AI summary

A radio communication apparatus comprising a control unit that, if a radio access bearer for a circuit switching domain is reconfigured between DCH and E-DCH/HSDPA, and a radio access bearer that matches RAB information exists as an established radio access bearer, and at least one RLC-AM or RLC-UM radio bearer is included in "RB information to setup", calculates a start value that is used on new radio access bearer.