Cellular Uplink Transmission on Unlicensed Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cellular communication networks face challenges in efficiently operating on unlicensed frequency bands due to limited resources and interference issues, leading to LBT blocking and reduced link throughput.
Innovation Solution
The method involves a cellular wireless device obtaining an initial opportunity for uplink data transmission on an unlicensed frequency band, and if the frequency channel is occupied, determining a second opportunistic resource for the uplink or downlink transmission, with a sufficient time gap between the first and second opportunities to minimize interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the first transmission opportunity is used on an unlicensed frequency band, then the uplink data transmission can proceed, but the transmission is blocked if the frequency channel is occupied by other signals
Solution Approach 1:
The patent performs a listen-before-talk (LBT) check before the first transmission opportunity to detect if the frequency channel is occupied. If occupied, the system prepares alternative second transmission opportunities in advance, ensuring that transmission can proceed without excessive delay when the channel becomes available.
Solution Approach 2:
The patent dynamically selects between first and second transmission opportunities based on real-time channel conditions. The system transitions from a static scheduled transmission approach to a dynamic selection mechanism that adapts to LBT outcomes, choosing the appropriate transmission opportunity based on channel availability.
2Reliability
If a second opportunistic resource is determined when the first opportunity is blocked, then transmission reliability improves, but the complexity of resource management increases
Solution Approach 1:
The patent segments the transmission opportunities into first opportunities (initial scheduled slots) and second opportunities (alternative slots activated when LBT fails). This segmentation allows the system to maintain simple scheduled transmission as the default while introducing alternative resources only when needed, reducing overall management complexity.
Solution Approach 2:
The patent introduces an intermediary mechanism (the second transmission opportunity as a fallback) that mediates between the blocked first opportunity and the actual transmission need. This intermediary resource absorbs the impact of LBT blocking without requiring complex reconfiguration of the entire transmission system.
3Object-affected harmful factors
If the time gap between first and second opportunities is increased to minimize interference, then interference reduction improves, but the time loss increases
Solution Approach 1:
The patent adjusts the time gap parameter between first and second transmission opportunities based on interference conditions and transmission urgency. The system can configure different time gaps dynamically, balancing interference mitigation against transmission delay requirements for different service types and channel conditions.
Data Source
AI summary
According to an example aspect of the present invention, there is provided a method for a cellular wireless device, including, obtaining, from a cellular base station, a first opportunity for an uplink data transmission on an unlicensed frequency band, wherein the first opportunity is within a first period reserved for first transmission opportunities on a frequency channel, upon detecting that the frequency channel is occupied at a beginning of the first opportunity, determining a second opportunistic resource for the uplink data transmission or a downlink transmission and receiving or transmitting using the second opportunistic resource.