Unlicensed Band SI Window Scheduling for Wireless Access
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Solution Overview
Problem
In unlicensed spectrum wireless communication systems, determining whether a channel is free for DL-SCH transmission is challenging, leading to potential delays in initial access, and multiple operators' networks can cause UE to search for system information across multiple cells, increasing complexity and battery life impact.
Innovation Solution
A method where UE receives SI scheduling information to identify primary and secondary SI windows, monitoring these windows to ensure successful SI message transmission, and uses CORESET or BWP information to distinguish between SI messages, while also determining PLMN ID to optimize cell selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the network determines channel availability for DL-SCH transmission in unlicensed spectrum, then transmission reliability is improved, but transmission delay increases due to channel access procedures
Solution Approach 1:
The network performs channel availability determination and SI message preparation in advance before the actual transmission window. By pre-checking channel conditions and preparing SI messages beforehand, the system reduces the time required during the actual transmission window, thereby decreasing transmission delay while maintaining reliable transmission through prior validation of channel suitability
2Adaptability or versatility
If multiple operators deploy networks in unlicensed band, then network capacity and coverage are improved, but UE complexity and battery consumption increase due to searching system information across multiple cells
Solution Approach 1:
The patent combines system information from multiple operators' cells into a unified SI message structure that can be transmitted through a single primary cell. Instead of requiring the UE to separately search and process SI messages from multiple cells, the network consolidates this information, reducing UE complexity and battery consumption while maintaining the ability to support multiple operators' networks
3Device complexity
If the UE monitors only primary SI windows, then monitoring complexity is reduced, but SI message acquisition reliability decreases when primary windows are unavailable
Solution Approach 1:
The network pre-configures both primary and secondary SI window opportunities for SI message transmission. By preparing alternative transmission windows in advance, the system ensures that if primary windows are unavailable due to channel conditions, the UE has pre-known alternative windows to monitor, thereby maintaining acquisition reliability without significantly increasing monitoring complexity
Solution Approach 2:
The secondary SI windows act as intermediary transmission opportunities between the primary windows and the UE. When primary windows cannot be used, the secondary windows serve as intermediate alternatives that maintain the communication link, ensuring reliable SI message acquisition while keeping the monitoring structure organized and manageable
Data Source
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AI summary
Methods and apparatuses for performing communication on an unlicensed band. A method, performed by a UE, of performing the communication on the unlicensed band, according to an embodiment, includes receiving SI (system information) scheduling information from a base station, identifying at least one of a primary SI window number or a secondary SI window number for a SI message based on the SI scheduling information, monitoring at least one window corresponding to the primary SI window number, and in response to the SI message being not received, monitoring at least one window corresponding to the secondary SI window number.