Radio Interface Frame Timing Synchronization in REC Pools
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Solution Overview
Problem
In cellular communication networks, maintaining precise synchronization of downlink and uplink frame timing between base stations and mobile devices is challenging, especially with the increased complexity of radio equipment control and the need for synchronization across multiple Radio Equipment Controllers (RECs) and Radio Equipments (REs), leading to timing errors and costly recalibration processes.
Innovation Solution
The use of chirped sine waves for cross-correlation measurements to determine end-to-end path delays and synchronize radio interface frame timing references across multiple RECs and REs, even in asynchronous communication networks, allowing for precise alignment and compensation of delays due to frequency variations, temperature changes, and component aging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple RECs control multiple REs in a pool configuration, then system capacity and functionality are improved, but timing synchronization complexity and difficulty increase significantly
Solution Approach 1:
A master REC is designated as an intermediary to coordinate timing synchronization across the pool of RECs. The master REC collects timing offset measurements from all RECs and distributes correction values, simplifying the synchronization process compared to peer-to-peer coordination. This intermediary approach reduces the complexity of maintaining timing alignment in multi-REC configurations.
Solution Approach 2:
The system implements continuous feedback mechanisms where RECs measure their timing offsets relative to the master REC and report these measurements back. The master REC processes this feedback and generates correction values that are distributed to all RECs. This closed-loop feedback system enables automatic timing alignment without manual intervention, resolving the synchronization complexity issue.
2Reliability
If in-equipment delay calibration data is stored in non-volatile memory, then timing alignment is maintained, but the system becomes sensitive to frequency variations, temperature changes, and component aging
Solution Approach 1:
The system transitions from static timing calibration data stored in non-volatile memory to dynamic timing offset measurements that are continuously updated. RECs periodically measure their timing offsets relative to the master REC and apply real-time corrections, allowing the system to adapt to frequency variations, temperature changes, and component aging while maintaining timing alignment.
Solution Approach 2:
The system changes the timing offset parameter dynamically based on environmental conditions and component characteristics. Instead of using fixed calibration values, the system continuously measures and adjusts timing offsets to compensate for drift caused by temperature, frequency changes, and component aging, thereby maintaining reliability while improving environmental adaptability.
3Measurement precision
If field recalibration is performed to correct large timing variations, then timing precision is restored, but maintenance costs and downtime increase
Solution Approach 1:
The system implements self-service timing synchronization where RECs automatically measure their timing offsets and apply corrections without requiring field technician intervention. The master REC coordinates this self-calibration process, enabling the system to maintain timing precision continuously without scheduled maintenance downtime or expensive field recalibration operations.
Solution Approach 2:
The system maintains continuous timing synchronization through automatic measurements and corrections performed in real-time operation. This eliminates the need for periodic maintenance stoppages where timing would be disrupted, ensuring uninterrupted service while maintaining precision through ongoing self-adjustment rather than intermittent field recalibration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables precise synchronization of radio interface frame timing references, reducing timing errors and the need for frequent recalibration, while allowing for efficient operation of multiple RECs and REs, even in complex network configurations, thereby improving network reliability and reducing maintenance costs.
Implementation Method 1
The target REC correlates a reference synchronization signal and a received signal to thereby measure a delay between the two signals
Data Source
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AI summary
Systems and methods of aligning a radio interface frame timing reference in a pool of Radio Equipment Controllers (RECs) are provided. In some embodiments, a method of operation of an REC includes computing a radio interface frame timing offset for a target REC relative to a reference time and 5 sending the radio interface frame timing offset to the target REC via an asynchronous communication network. According to some embodiments, this provides a substantially aligned radio interface frame timing reference in a pool of RECs. In some embodiments, the method also includes, prior to computing the radio interface frame timing offset, determining that the REC is a master REC. In some embodiments, determining that the REC is the master REC includes exchanging information indicative of at least one capability of each of the RECs and determining that the REC is the master REC based on the at least one capability.