Inter-RAT Measurement Using C-DRX Dormant Periods
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Solution Overview
Problem
Current inter-RAT measurement methods in communications networks, particularly in LTE networks, result in excessively long call handover preparation times due to the need for multiple cycles of 40 ms/80 ms measurements, leading to voice session interruptions during CSFB or VoLTE services when transitioning between LTE and 2G/3G networks.
Innovation Solution
An inter-RAT measurement method that utilizes a measurement control message with a C-DRX parameter and measurement configuration parameter to instruct user equipment to continuously measure signal quality in the dormant period of a C-DRX cycle, allowing for accelerated measurement by extending the dormant period and reducing the activation period, thereby shortening the overall measurement time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If inter-RAT measurement is performed in GAP mode with multiple 2G/3G neighboring cells, then measurement coverage is improved, but measurement time becomes excessively long
Solution Approach 1:
The patent utilizes C-DRX (Connected-Discontinuous Reception) periodic cycles to perform inter-RAT measurements. Instead of continuous GAP mode measurements, the UE performs measurements periodically during dormant periods of C-DRX cycles, which reduces overall measurement time while maintaining adequate measurement coverage through multiple measurement opportunities across successive C-DRX cycles.
Solution Approach 2:
The network configures C-DRX parameters and measurement configurations in advance before handover occurs. The UE is pre-configured with measurement objects, reporting configurations, and C-DRX parameters, allowing measurements to begin immediately when entering dormant periods without waiting for gap allocation, thus reducing measurement time.
2Productivity
If measurement cycle is extended to 40 ms/80 ms with 6 ms measurement duration, then service impact is reduced, but handover preparation time becomes excessively long
Solution Approach 1:
The patent enables continuous measurement opportunities by utilizing every dormant period of C-DRX cycles for inter-RAT measurements. This continuous measurement approach during dormant periods eliminates the need for lengthy periodic gap modes, reducing handover preparation time while maintaining service continuity through proper C-DRX cycle management.
3Measurement precision
If multiple C-DRX cycles are used for measurement, then measurement accuracy is improved, but measurement time increases
Solution Approach 1:
The patent leverages the periodic nature of C-DRX cycles to perform measurements across multiple cycles. By configuring appropriate C-DRX cycle lengths and utilizing dormant periods efficiently, the system achieves adequate measurement accuracy through multiple sampling opportunities while minimizing total measurement time compared to traditional GAP mode.
Solution Approach 2:
The network can dynamically adjust C-DRX parameters (cycle length, dormant period duration, activation period duration) to optimize the balance between measurement accuracy and measurement time. By changing these parameters based on service requirements and signal conditions, the system achieves accurate measurements without excessive time delays.
Data Source
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AI summary
Embodiments of the present invention provide an inter-RAT measurement method, and a related apparatus and system. An evolved NodeB eNodeB may send a measurement control message to UE when determining that the UE supports a handover from an LTE network to a CS domain of a 2G or 3G network, where the measurement control message carries a first C-DRX parameter and a measurement control parameter, and the first C-DRX parameter and the measurement control parameter are used to instruct the UE to measure signal quality of the 2G or 3G network in a dormant period of a first C-DRX cycle. In this way, the UE can continually measure the signal quality of the 2G or 3G network in the dormant period of the first C-DRX cycle, so as to avoid performing measurement in a GAP mode, accelerate a measurement process, and shorten a measurement time, thereby effectively reducing a call handover preparation time and avoiding voice session interruption.