Terminal COT Timing Control for Unlicensed D2D Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In newly-operated frequency bands with higher frequencies, device-to-device direct communication in an unlicensed band requires compliance with regulations such as LBT, necessitating COT sharing where terminals need to obtain information related to Channel Occupancy Time (COT) for transmission.
Innovation Solution
A terminal is equipped with a reception unit to obtain COT start and end timings and a control unit to determine operations based on these timings for device-to-device direct communication in an unlicensed band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If D2D communication is performed in unlicensed band with higher frequencies, then new frequency band utilization is achieved, but compliance with LBT regulations and COT sharing requirements increases complexity
Solution Approach 1:
The patent introduces COT (Channel Occupancy Time) information as an intermediary element that mediates between the terminal and the unlicensed band regulations. By obtaining and utilizing COT information from other terminals, the system enables compliant D2D communication without requiring complex real-time LBT decision-making at each terminal, thus resolving the contradiction between frequency band adaptability and operational complexity
Solution Approach 2:
The patent applies preliminary action by having terminals obtain COT information in advance before performing D2D communication. The reception unit acquires COT start timing and end timing information beforehand, allowing the control unit to pre-determine transmission operations within the COT period. This preliminary acquisition of channel access information simplifies subsequent communication operations while ensuring regulatory compliance
2Productivity
If COT sharing is implemented for D2D communication, then channel access efficiency is improved, but terminals must obtain and process COT information which increases signaling overhead
Solution Approach 1:
The patent extracts only the essential COT information (start timing and end timing) needed for D2D communication from the complete channel access protocol. By taking out only these critical parameters rather than processing entire LBT procedures or complete channel state information, the system achieves efficient channel access while minimizing signaling overhead and information processing requirements
3Reliability
If terminals perform LBT before transmission in unlicensed band, then regulatory compliance is achieved, but transmission delay increases
Solution Approach 1:
The patent applies preliminary action by having terminals obtain COT information in advance from other terminals before performing D2D transmission. This preliminary acquisition of channel access timing information eliminates the need for each terminal to perform time-consuming LBT procedures immediately before transmission, thereby maintaining regulatory compliance while significantly reducing transmission delay
Solution Approach 2:
The COT information acts as an intermediary that carries pre-acquired channel access authorization from one terminal to another. This intermediary mechanism allows terminals to bypass repeated LBT procedures while still ensuring regulatory compliance, thus resolving the contradiction between reliability (compliance) and time loss (delay)
Data Source
AI summary
A terminal includes: a reception unit configured to, when another terminal obtains a COT (Channel occupancy time) and transmits a signal related to device-to-device direct communication in an unlicensed band, obtain a start timing and an end timing of the COT; and a control unit configured to determine an operation related to transmission in the COT, based on the start timing and the end timing of the COT and a timing of transmission of the device-to-device direct communication by the terminal itself.