Mobile Device Security Mode Command Failure Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In cellular communication networks, security mode command failures can lead to prolonged service disruptions due to the E-UTRAN's failure to release RRC connections, causing User Equipment (UE) to wait for guard timers to expire before retrying procedures, resulting in extended downtime for users.
Innovation Solution
A mobile communication device and method that determine whether a SECURITY MODE COMMAND message fails integrity protection checks and, if so, locally release connections without waiting for timers to expire, allowing immediate retry of NAS procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the E-UTRAN fails to release the RRC connection after security activation failure, then the UE must wait for guard timer expiry before retrying, but this causes extended service downtime for users
Solution Approach 1:
The UE proactively detects security mode command failures through integrity protection checks before the network can initiate timer-based recovery procedures. By performing preliminary detection and locally releasing the RRC connection immediately upon failure detection, the UE eliminates the need to wait for guard timer expiry, thus resolving the contradiction between maintaining security reliability and minimizing service downtime
Solution Approach 2:
The UE continuously monitors the integrity protection status of SECURITY MODE COMMAND messages and provides immediate feedback when failures are detected. This feedback mechanism enables the UE to trigger local RRC connection release without waiting for network-initiated timer expiry, thereby reducing service downtime while maintaining security activation reliability
2Ease of operation
If the UE waits for guard timer expiry before retrying NAS procedures, then the protocol specification is followed, but user service is blocked for extended periods
Solution Approach 1:
The UE performs preliminary integrity protection checks on SECURITY MODE COMMAND messages and proactively detects failures before the guard timer expires. By taking preliminary action to detect and respond to failures, the UE can locally release the RRC connection and retry NAS procedures immediately, thus improving service recovery speed while still following the spirit of the protocol specification
Solution Approach 2:
The UE dynamically adjusts its behavior based on the detected failure condition. When integrity protection failure is detected, the UE transitions from passive timer-waiting mode to active local release mode, enabling immediate retry of NAS procedures. This dynamic adaptation resolves the contradiction between protocol compliance and service recovery speed
3Extent of automation
If the E-UTRAN does not release the RRC connection upon security activation failure, then network control is maintained, but the UE remains in a stuck state unable to perform any operations
Solution Approach 1:
The UE autonomously detects security mode command failures through integrity protection checks and self-resolves the stuck state by locally releasing the RRC connection without requiring network intervention. This self-service capability enables the UE to recover from failure states independently, improving operational capability while the network maintains overall control through the integrity protection mechanism
Data Source
AI summary
A mobile communication device including a wireless transceiver and a controller is provided. The wireless transceiver performs wireless transmission and reception to and from a service network. The controller determines, during an ongoing Non-Access Stratum (NAS) procedure, whether a SECURITY MODE COMMAND message received from the service network via the wireless transceiver fails an integrity protection check and no RRC CONNECTION RELEASE message has been received from the service network via the wireless transceiver, or whether transmission of a SECURITY MODE COMPLETE message to the service network via the wireless transceiver has failed. Also, the controller locally releases a connection to the service network when the SECURITY MODE COMMAND message fails the integrity protection check and no RRC CONNECTION RELEASE message has been received, or when the transmission of the SECURITY MODE COMPLETE message has failed.