Wireless Node Synchronization for Shared Spectrum Efficiency
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Solution Overview
Problem
Current wireless communication systems using shared radio frequency spectrum face inefficiencies due to unsynchronized listen-before-talk (LBT) procedures among base stations, leading to suboptimal channel access and reduced frequency reuse, which affects network performance and fairness in coexistence with other users.
Innovation Solution
Implementing synchronization techniques that allow wireless nodes to perform fast synchronization with detected LBT frame transmissions from other nodes of the same operator, enabling concurrent auxiliary and primary transmissions, and adjusting transmission rates based on feedback to optimize channel utilization and interference management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If base stations perform independent LBT procedures without synchronization, then each base station can autonomously access the shared spectrum, but frequency reuse is suboptimal and channel access fairness is reduced
Solution Approach 1:
The patent combines independent LBT procedures with synchronization mechanisms. Base stations continue to autonomously perform LBT but coordinate their frame structures and synchronization signals to align their channel access patterns. This merging of autonomous operation with coordinated timing enables both ease of operation and improved frequency reuse efficiency.
Solution Approach 2:
The patent implements dynamic synchronization where base stations continuously adjust their frame timing based on detected synchronization signals from other base stations. This dynamic adaptation allows the system to maintain autonomous LBT operations while dynamically optimizing frequency reuse through synchronized channel access patterns.
2Productivity
If base stations transmit simultaneously on the same frequency, then frequency reuse is enhanced and network efficiency improves, but interference management becomes more challenging
Solution Approach 1:
The patent employs feedback mechanisms where base stations monitor the shared spectrum for transmissions from other base stations and adjust their own transmissions accordingly. By detecting synchronization signals and data transmissions from other base stations, each base station can adapt its transmission timing and power to maintain frequency reuse while managing interference through continuous feedback-based adjustments.
3Reliability
If a base station wins contention for channel access, then it can transmit data, but other base stations must wait, reducing overall channel utilization
Solution Approach 1:
The patent implements periodic synchronization signals transmitted by base stations at regular intervals. This periodic action creates predictable channel access patterns where base stations can anticipate when other base stations will transmit, allowing them to coordinate their access attempts. This periodic structure maintains reliable channel access while improving overall utilization by reducing idle waiting periods.
4Ease of manufacture
If base stations use unsynchronized LBT frames, then implementation is simpler, but coexistence with other spectrum users is less fair
Solution Approach 1:
The patent implements preliminary synchronization actions where base stations transmit synchronization signals before data transmissions. This preliminary action allows other base stations and spectrum users to detect and coordinate their access patterns in advance, establishing fair coexistence rules before actual data transmission begins. This preliminary coordination maintains implementation simplicity while significantly improving coexistence fairness.
Data Source
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AI summary
Techniques for synchronization across transmitting nodes of a same public land mobile network (PLMN) operator using a shared radio frequency spectrum band may include initiating, at a first wireless node, a listen-before-talk (LBT) procedure for access to the shared radio frequency spectrum band, and identifying that a second wireless node associated with a same PLMN operator as the first wireless node has won contention for the shared radio frequency spectrum band. The first wireless node may discontinue the LBT procedure and initiate an auxiliary transmission using the shared radio frequency spectrum band concurrently with a primary transmission of the second wireless node.