Unlicensed Spectrum Channel Occupancy Time Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication networks using unlicensed spectrum, network devices face challenges in preempting downlink channels due to high demand from terminal devices, leading to data transmission delays and low frequency band utilization.
Innovation Solution
A method where a network device sends signaling to a terminal device to perform a listen before talk (LBT) procedure on an unlicensed frequency band for a specified uplink time length, allowing the network device to schedule downlink data transmission using the remaining time, thereby reducing delays and improving frequency band utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If terminal devices frequently preempt the unlicensed frequency band to perform uplink transmission, then uplink transmission opportunities increase, but downlink transmission delays increase and frequency band utilization decreases
Solution Approach 1:
The patent segments the channel occupancy time (MCOT) into multiple parts: the first part is allocated for uplink transmission after terminal LBT, and the second part is reserved for downlink transmission. This segmentation allows both uplink and downlink transmissions to occur within the same MCOT, reducing downlink transmission delays while maintaining uplink opportunities.
Solution Approach 2:
The network device performs downlink LBT in advance to determine whether the channel is available for downlink transmission. Based on this preliminary action, the network device can allocate the second part of MCOT for downlink transmission, ensuring that downlink transmissions are scheduled efficiently without excessive delays.
2Ease of operation
If terminal devices preempt the unlicensed frequency band for uplink transmission, then uplink access is enabled, but network device downlink transmission opportunities decrease
Solution Approach 1:
The patent merges uplink and downlink transmissions within a single MCOT by allocating the first part for uplink (after terminal LBT) and the second part for downlink (after network LBT). This combining approach allows both directions to share the same channel occupancy period, increasing overall transmission opportunities for the network device.
Solution Approach 2:
The patent introduces dynamic allocation of MCOT parts based on channel conditions and traffic requirements. The network device can flexibly adjust the proportion of first and second parts of MCOT, enabling adaptive optimization of uplink and downlink transmission opportunities according to real-time network conditions.
3Ease of operation
If terminal devices with small uplink data volumes preempt the frequency band, then they can transmit data, but frequency band utilization becomes low
Solution Approach 1:
The patent ensures continuous utilization of the frequency band by filling the second part of MCOT with downlink transmissions after terminal uplink transmission. This continuous action eliminates idle time in the frequency band, maximizing utilization while allowing terminals with small data volumes to transmit their data.
Solution Approach 2:
The patent recovers the remaining time in MCOT after terminal uplink transmission by allocating it for downlink transmission. Instead of discarding the remaining channel occupancy time, the network device utilizes it for downlink data transmission, thereby improving overall frequency band utilization.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Embodiments of the present invention describe a communications method and apparatus, to resolve a problem of a large delay of downlink data caused by difficulties in preempting a downlink channel by a network device. In the method and apparatus, the network device sends first signaling to a first terminal device, the first signaling is used to instruct the first terminal device to perform, on an unlicensed spectrum, a listen before talk LBT procedure used for occupying an unlicensed frequency band, and send uplink information within a first time length on the unlicensed frequency band; the network device receives, on the unlicensed spectrum, the uplink information from the first terminal device within the first time length, where the first time length is a part of maximum channel occupancy time obtained by the first terminal device on the unlicensed spectrum, and the first time length is less than the maximum channel occupancy time.