Guard Interval Clock Drift Management Coexistence
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Solution Overview
Problem
Wireless communication systems face challenges with clock drift between different radio access technologies (RATs), leading to inaccurate estimation of interference intervals and resulting in collisions or underutilization of medium time.
Innovation Solution
Implementing a guard interval that defines a non-transmission time interval relative to the scheduled interference interval, allowing for synchronization of clocks and preventing collisions or underutilization by ensuring no transmissions occur during this interval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If clock synchronization is performed frequently to maintain accurate timing, then timing accuracy is improved, but signaling overhead increases
Solution Approach 1:
The patent applies preliminary action by establishing a guard interval in advance before the scheduled interference interval begins. This guard interval is configured based on predetermined clock drift parameters, allowing the system to proactively accommodate timing variations without requiring frequent real-time synchronization signals. The guard interval is set up beforehand to absorb clock drift effects, eliminating the need for continuous timing correction exchanges between AP and STA.
2Reliability
If the guard interval is increased to accommodate clock drift, then collision avoidance is improved, but medium utilization decreases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the guard interval duration based on the specific clock drift characteristics of the coexisting radios. Rather than using a fixed conservative guard interval that would excessively reduce medium utilization, the system configures the guard interval length according to the actual clock drift parameters of the STA's multiple radios. This optimized parameter setting ensures sufficient protection against collisions while minimizing the impact on WLAN medium utilization.
3Measurement precision
If frequent clock resynchronization is implemented, then timing accuracy is improved, but communication efficiency deteriorates due to excessive signaling
Solution Approach 1:
The patent applies preliminary action by pre-configuring the guard interval based on known clock drift characteristics before communications begin. This preliminary configuration establishes a timing buffer that accommodates expected clock variations throughout the scheduled interference interval, eliminating the need for frequent mid-communication synchronization checks and maintaining high communication efficiency.
Solution Approach 2:
The patent applies self-service by designing the guard interval mechanism to autonomously handle clock drift compensation without requiring active intervention from either the AP or STA. The predetermined guard interval automatically absorbs timing variations, and the system self-corrects for clock drift effects through the built-in timing margin, reducing the need for synchronization protocol exchanges.
Data Source
AI summary
Methods, systems, and devices are described for dealing with mutual clock drifts for communications over multiple RATs by maintaining a guard interval. A guard interval is a time interval during which no transmissions should occur. For example, the guard interval may be set relative to a scheduled interference interval of a STA so that transmissions to the STA from an AP will not collide with different RAT (e.g., interference) transmissions/receptions even with clock drift (e.g., a guard interval at both sides of the scheduled interference interval). Such an approach may allow the clocks to be re-synchronized (e.g., by the STA notifying the AP of the schedule of interference interval) infrequently to avoid excessive signaling overhead, which would increase with an increase in the number of coexistence STAs being serviced by the AP.