LTE Radio Link Failure Test Method Using Timer-Based Synchronization Detection
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Solution Overview
Problem
The existing test method for confirming downlink synchronization state in mobile communication systems, particularly in the WCDMA scheme, cannot be applied to LTE systems where the mobile station stops the uplink signal at a time point detecting a radio link failure in the RRC layer, leading to incorrect synchronization state detection.
Innovation Solution
A test method and device that determine whether a mobile station correctly detects a synchronization state by changing the radio quality from a higher to a lower threshold value and vice versa, using a timer to assess the mobile station's operation, allowing for correct synchronization state confirmation even during re-establishment of a connection state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing test method for confirming downlink synchronization state in WCDMA scheme is applied, then the test can confirm synchronization state based on DPCCH radio quality, but it cannot be applied to LTE systems where the mobile station stops uplink signal at RRC layer failure detection time point
Solution Approach 1:
The patent changes the test parameters by introducing a timer mechanism and modifying the judgment criteria. Instead of directly judging synchronization state based on uplink signal presence, the system now uses a timer to track the duration since uplink signal cessation and compares it against a threshold value, adapting the test method to LTE's RRC layer failure detection mechanism while maintaining test validity
Solution Approach 2:
The patent applies preliminary action by setting a timer before the actual judgment occurs. When the mobile station stops the uplink signal, the timer starts counting. This preliminary timing action allows the system to account for the delay between physical layer synchronization detection and RRC layer failure declaration, ensuring accurate test results in LTE systems
2Speed
If the mobile station stops uplink signal immediately upon detecting radio link failure in RRC layer, then the connection re-establishment process can start promptly, but the existing test method cannot correctly determine the synchronization state detection timing
Solution Approach 1:
The patent implements feedback by using the timer to provide timing information back to the test system. The timer measures the actual duration from uplink signal cessation to the point when synchronization state should be confirmed, and this feedback allows the test system to accurately verify whether the mobile station detected the synchronization state at the correct time, even during rapid connection re-establishment
Solution Approach 2:
The patent applies dynamics by making the judgment timing adaptive rather than fixed. The system dynamically adjusts the expected judgment time based on the timer measurement, allowing the test method to accommodate varying processing speeds and correctly identify synchronization state detection timing even when connection re-establishment occurs rapidly
Data Source
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AI summary
A test method according to the present invention includes: a first step of determining whether or not the mobile station detects the problem in a radio link state, when a radio quality is changed from a first state where the radio quality is equal to or more than a first threshold value to a second state where the radio quality is equal to or less than the first threshold value; and a second step of determining whether or not the mobile station does not detect the problem in a radio link state, when the radio quality is changed to a third state where the radio quality is equal to more than a second threshold value, after a lapse of a first time interval from a time point at which the radio quality is changed from the first state to the second state.