Random Access Method for Unlicensed Band Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional random access methods in licensed bands are inefficient in unlicensed bands due to interference from various communication nodes, leading to unreliable quality of service and mobility issues in wireless communication systems.
Innovation Solution
A random access method for unlicensed bands that involves transmitting a random access preamble in a first cell and receiving a random access response in a second cell, which can be either in the unlicensed or licensed band, to adjust uplink transmission timing and power, considering interference from multiple communication nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional random access procedure is used in unlicensed band, then device complexity is reduced, but reliability deteriorates due to interference between communication nodes
Solution Approach 1:
The patent divides the random access procedure into distinct phases: preamble transmission in the first cell, response reception in the second cell, and scheduled message transmission in the third cell. This segmentation allows each phase to be optimized for its specific function, improving overall reliability while maintaining manageable complexity through structured process division.
Solution Approach 2:
The patent introduces a licensed band cell as an intermediary element in the random access procedure. The licensed band cell provides a reliable control channel for transmitting random access responses and scheduled messages, mediating between the unlicensed band cells to ensure reliable communication despite interference in the unlicensed spectrum.
2Productivity
If unlicensed band is used for data distribution, then productivity is improved through higher throughput, but reliability deteriorates due to interference from various communication nodes
Solution Approach 1:
The patent segments the spectrum usage by separating unlicensed band cells for high-throughput data transmission from licensed band cells for reliable control signaling. This allows the system to achieve high productivity in the unlicensed band while maintaining reliability through the licensed band's interference-free environment.
Solution Approach 2:
The licensed band cell acts as an intermediary that provides reliable control channels for random access responses and scheduled messages, enabling the unlicensed band to achieve high throughput while maintaining quality of service through the stable licensed band infrastructure.
3Productivity
If LTE service in unlicensed band is implemented, then productivity is improved through higher frequency efficiency, but device complexity increases due to carrier aggregation configuration
Solution Approach 1:
The patent segments the carrier aggregation configuration into manageable components by defining specific cell roles (first cell for preamble, second cell for response, third cell for scheduled messages) within the carrier aggregation framework. This segmentation simplifies the configuration process while maintaining the frequency efficiency benefits of LTE in unlicensed band.
Data Source
AI summary
A disclosure of the present specification provides a random access method for an unlicensed band. The method comprises the steps of: transmitting, by a user equipment (UE), a random access preamble in a first cell of the unlicensed band; and receiving, by the UE, a random access response in a second cell, wherein the second cell may be a first cell, a cell of the unlicensed band, included in a cell group to which the first cell belongs, or a cell of the unlicensed band, included in a timing advance group (TAG) within the cell group, to which the first cell belongs.