Asynchronous Spatial LBT with Beamforming for Shared Spectrum Access
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Solution Overview
Problem
Existing wireless communication networks face inefficiencies and increased latency due to multiple network operating entities contending for shared radio frequency spectrum, leading to interference and signaling overhead, particularly in unlicensed frequency bands.
Innovation Solution
Implementing an asynchronous spatial listen before talk (LBT) procedure that allows network operating entities to utilize reserved and prioritized time resources, reducing the need for medium-sensing procedures and minimizing interference by allocating exclusive and prioritized communication intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple network operating entities contend for shared radio frequency spectrum using traditional medium-sensing procedures, then spectrum sharing is enabled, but interference increases and communication efficiency decreases
Solution Approach 1:
The patent segments the shared spectrum access process by introducing dedicated reservation signals (RTS/CTS) that divide channel access into reserved and non-reserved periods. This segmentation allows certain network operating entities to have protected time intervals free from contention, reducing interference while maintaining spectrum sharing capabilities.
Solution Approach 2:
The patent implements preliminary action through the reservation signal exchange mechanism where network operating entities send reservation signals before actual data transmission. This preliminary reservation establishes protected time intervals in advance, allowing subsequent transmissions to occur without medium-sensing procedures, thereby reducing interference and improving efficiency.
2Loss of time
If traditional listen before talk procedures are used in unlicensed frequency bands, then channel access coordination is achieved, but signaling overhead increases and latency increases
Solution Approach 1:
The patent uses preliminary reservation signal exchanges to establish future transmission rights before actual data transmission occurs. This preliminary action reduces latency by pre-coordinating access rights, eliminating the need for repeated listen-before-talk procedures during the reserved time intervals.
Solution Approach 2:
The patent enables continuous useful action by creating protected time intervals where predetermined network operating entities can transmit without performing medium-sensing procedures. This continuity eliminates repeated sensing overhead and reduces latency by maintaining uninterrupted transmission during reserved periods.
3Object-affected harmful factors
If medium-sensing procedures are performed frequently to coordinate channel access, then interference avoidance is improved, but communication efficiency decreases and latency increases
Solution Approach 1:
The patent segments channel access into reserved and non-reserved periods, where reserved periods are protected from medium-sensing procedures. This segmentation maintains interference avoidance during critical transmission intervals while improving overall communication efficiency by eliminating repeated sensing overhead.
Solution Approach 2:
The patent ensures continuous useful action during reserved time intervals by eliminating the need for frequent medium-sensing procedures. Network operating entities with reserved rights can transmit continuously without interruption from sensing operations, thereby improving communication efficiency while maintaining interference avoidance.
Data Source
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AI summary
Improvements to asynchronous spatial listen before talk (LBT) procedures are disclosed. In a shared spectrum network spatial LBT procedures are used for directionally targeting the channel reservation process. Prior to transmitting channel reservation signaling, the transmitter and receiver determine an effective interference considering available multiple input, multiple output (MDVIO) configuration information. When the effective interference exceeds a predefined threshold, the node may without transmission of its channel reservation signal. Otherwise, when the effective interference remains within the threshold, each node's transmitted channel reservation signal may also identify at least a beamforming matrix either as payload or used to precode the node's channel reservation signal.