Radio Equipment Controller Synchronization via Dedicated Link
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Solution Overview
Problem
Current distributed radio base station technologies face challenges in synchronizing multiple radio equipment controllers (RECs) without increasing costs or decreasing reliability, particularly when they support different wireless communication standards and lack standardized synchronization methods, leading to issues like bit slips and distortion in the air interface.
Innovation Solution
The solution involves providing synchronization reference information between REC nodes and the radio equipment (RE) node, using a transmission link to adjust timing units and ensure synchronization, which can include GPS timing information or transport network references, and allows for configurations such as cascade or parallel connections of REC nodes to achieve timing and frequency synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple RECs are connected to one RE to support different wireless communication standards, then the capacity and performance of the radio base station are increased, but synchronization problems occur leading to bit slips and distortion in the air interface
Solution Approach 1:
The patent introduces an extra dedicated cable as an intermediary synchronization link between multiple RECs. This dedicated cable carries synchronization signals directly between RECs, acting as a mediator to coordinate their operations and maintain synchronization accuracy despite handling different wireless communication standards.
Solution Approach 2:
The patent creates a universal synchronization mechanism that works across multiple RECs supporting different wireless communication standards (WCDMA, LTE, etc.). The synchronization system is designed to be multi-functional, accommodating various standards simultaneously while maintaining a common time and frequency reference through the dedicated cable connection.
2Measurement precision
If an extra dedicated cable is added to connect RECs for synchronization, then synchronization accuracy is improved, but the reliability decreases due to increased probability of fatal fault
Solution Approach 1:
The patent implements beforehand cushioning by creating redundant synchronization paths. The system is designed so that if the extra dedicated cable fails, the RECs can still maintain synchronization through alternative paths via the existing transmission links to the RE and back, preventing complete system failure.
Solution Approach 2:
The patent changes the synchronization parameter transmission path by utilizing the existing transmission link parameters (already present cables and interfaces) to carry synchronization information indirectly between RECs, rather than relying solely on the extra dedicated cable, thus reducing the criticality of any single cable.
3Shape
If GPS receiver is mounted on the base station tower near the RE, then aesthetic appearance is improved, but cable run length increases and lightning protection becomes more difficult
Solution Approach 1:
The patent makes the existing transmission link multi-functional by using it for both data transmission and synchronization signal transmission. This eliminates the need for separate cable runs from the GPS receiver to each REC, as the same cable infrastructure already connecting the RE to RECs can carry synchronization information.
Solution Approach 2:
The patent merges the synchronization signal transmission function with the existing data transmission function of the transmission link. By combining these functions into a single cable infrastructure, the system reduces the total cable run length and eliminates the need for separate lightning protection systems for synchronization cables.
4Device complexity
If standardized synchronization solution is implemented for multiple RECs in CPRI, then device complexity is reduced, but current CPRI standard does not support multiple RECs
Solution Approach 1:
The patent introduces dynamic adaptability to the CPRI interface by enabling it to function in multiple modes: traditional single-REC mode and new multi-REC mode. The system can dynamically adjust its operation to support different numbers of RECs and different wireless communication standards while maintaining a standardized interface, thus increasing versatility without proportionally increasing complexity.
Data Source
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AI summary
A distributed radio base station includes a first radio equipment controller (REC) node (12), a second radio equipment controller (REC) node (14), and a radio equipment (RE) node (16) for transceiving information over a radio interface with one or more radio terminals. The first REC node and the second REC node are physically separate from the RE node. The first REC node and/or the second REC node are/is connected to the RE node by a transmission link. Synchronization reference information is provided to one of the REC and RE nodes. The synchronization reference information in the one node is compared with timing information received from another of the REC nodes to generate a timing difference. The timing difference is used to adjust a timing unit at the another node in order to achieve timing synchronization between the RE node, the first REC node, and the second REC node.