Secondary Node Scanning Unlicensed Bands for LTE Coexistence
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Solution Overview
Problem
Current technologies fail to provide efficient channel allocation in unlicensed frequency bands for LTE cellular communications, leading to interference with other radio transmitters like Wi-Fi, which degrades their performance.
Innovation Solution
A method and system for a secondary cellular network node to scan unlicensed frequency bands, identify interference-free intervals, and configure LTE secondary serving cells to minimize interference by adjusting bandwidth and frequency allocation, ensuring coexistence with other radio access technologies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LTE is deployed in unlicensed frequency bands using carrier aggregation, then network capacity and throughput are improved, but interference with other radio transmitters (e.g., Wi-Fi) occurs and their performance degrades
Solution Approach 1:
The system performs preliminary scanning of the unlicensed frequency band to detect transmitting interferers before LTE transmission begins. This advance detection allows the network to identify occupied frequency intervals and select alternative intervals that avoid interference with Wi-Fi and other radio transmitters, thereby improving network capacity without degrading other systems' performance
Solution Approach 2:
The patent applies local quality by determining specific frequency intervals within the unlicensed band that are free from interferers. Instead of treating the entire unlicensed band uniformly, the system identifies and utilizes only the portions (local intervals) that are currently available and interference-free, allowing LTE to operate in specific frequency ranges while leaving other ranges available for Wi-Fi and other transmitters
2Productivity
If LTE transmits continuously in unlicensed bands, then network throughput is maintained, but Wi-Fi transmitters are forced to defer transmission and their performance severely degrades
Solution Approach 1:
The system implements dynamic frequency selection by continuously monitoring the unlicensed band and adapting the frequency intervals used by LTE based on detected interferer activity. When Wi-Fi or other transmitters are detected, the LTE network dynamically switches to different frequency intervals that are currently free, allowing both systems to operate simultaneously without one forcing the other to defer
Solution Approach 2:
The patent introduces an intermediary scanning and detection mechanism that acts as a mediator between LTE and other radio transmitters. This intermediary function identifies which frequency intervals are occupied and communicates this information to the LTE network, enabling coordinated usage where LTE operates in intervals free from other transmitters, thus improving ease of coexistence while maintaining throughput
Data Source
Figure 1(a)~1(b)
Figure 2a~4
Figure 5a~6b
AI summary
There is provided configuration of a secondary cellular network node for a secondary serving cell associated with a primary serving cell in a carrier aggregation enabled communications network. The secondary cellular network node receives an indication from a primary cellular network node associated with the primary serving cell to start scanning an unlicensed frequency band for deployment of the secondary serving cell. The secondary cellular network node scans at least one unlicensed frequency band to determine whether or not interference from transmitting interferers is present in the at least one unlicensed frequency band. The secondary cellular network node determines, based on the scanning, at least one frequency interval of the at least one unlicensed frequency band substantially free from the transmitting interferers. The secondary cellular network node transmits first configuration information of the at least one frequency interval to the primary cellular network node. The secondary cellular network node deploys the secondary serving cell by configuring the secondary cellular network node for transmission in one of the at least one frequency interval according to second configuration information being based on the first configuration information.