LBT Procedure Coordination in Licensed-Unlicensed Spectrum
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Solution Overview
Problem
In wireless communication networks, especially in LTE and 5G technologies, devices face challenges with power efficiency and interference when performing Listen-Before-Talk (LBT) procedures on multiple carriers, particularly in unlicensed spectra, which affects battery life and communication reliability.
Innovation Solution
A method where a terminal or network node receives information about carrier load conditions from a network node to determine whether to perform D2D or V2X operations, optimizing LBT procedures by reducing unnecessary channel sensing and coordinating transmissions using licensed carriers to minimize interference and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a terminal performs LBT procedures on multiple carriers in unlicensed spectrum, then communication reliability is improved, but power consumption increases
Solution Approach 1:
The patent segments the LBT procedure into two distinct parts: a simplified LBT on licensed carriers and a full LBT on unlicensed carriers. This segmentation allows the terminal to perform channel access more efficiently by leveraging the licensed carrier's reliability while reducing the burden of repeated full LBT procedures on unlicensed carriers, thereby improving communication reliability without proportionally increasing power consumption.
Solution Approach 2:
The patent implements preliminary action by performing LBT on the licensed carrier first before attempting LBT on unlicensed carriers. The result from the licensed carrier LBT is used to inform and potentially skip the unlicensed carrier LBT procedure. This preliminary check on the more reliable licensed carrier prevents unnecessary power consumption on unlicensed carriers when the licensed carrier already indicates channel availability.
2Reliability
If a terminal performs LBT procedures on multiple carriers in unlicensed spectrum, then channel access reliability is improved, but processing complexity increases
Solution Approach 1:
The patent segments the multi-carrier LBT process into distinct stages: licensed carrier LBT execution, result evaluation, and conditional unlicensed carrier LBT execution. This segmentation simplifies the overall processing complexity by breaking down the complex multi-carrier problem into manageable, sequential steps with clear decision points, making the system easier to implement and manage while maintaining high channel access reliability.
Solution Approach 2:
The patent uses the licensed carrier LBT result as a preliminary indicator that guides subsequent unlicensed carrier LBT decisions. This preliminary information reduces processing complexity by avoiding redundant full LBT procedures on unlicensed carriers when the licensed carrier already provides sufficient channel availability information, thereby simplifying the overall processing while maintaining reliability.
3Measurement precision
If a terminal performs full LBT procedures on all carriers, then interference detection accuracy is improved, but time consumption increases
Solution Approach 1:
The patent segments interference detection into two phases: initial detection on licensed carriers and conditional detection on unlicensed carriers. This segmentation maintains measurement precision by ensuring that licensed carriers undergo full interference detection while unlicensed carriers receive detection only when necessary, thereby reducing overall time consumption without sacrificing detection accuracy on critical licensed carriers.
Solution Approach 2:
The patent performs preliminary interference detection on licensed carriers first, using these results to determine whether full interference detection is needed on unlicensed carriers. This preliminary action reduces time consumption by avoiding redundant detection on unlicensed carriers when licensed carrier detection already provides sufficient interference information, while maintaining accuracy through selective full detection when needed.
Data Source
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AI summary
This disclosure pertains to a method for operating a terminal (10) in a wireless communication network. The method comprises performing a Listen-Before-Talk, LBT, procedure on at least one LBT communication link of a set of LBT communication links, wherein performing the LBT procedure is based on 475 information received by the terminal (10), the received information pertaining to operational conditions of the LBT communication links of the set of LBT communications links. The disclosure also pertains to related devices and methods.