Downlink Grant Positioning in Short TTI Frequency Bands
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communications networks face challenges in achieving efficient data transmission and capacity due to fixed subframe lengths, which limit the ability to perform scheduling of uplink and downlink data in short subframes, leading to higher packet latency and reduced throughput.
Innovation Solution
The method involves transmitting a downlink grant and data in a short transmission time interval (sTTI) frequency band, where the position of the downlink grant identifies the position of the downlink data, allowing for flexible subframe durations and efficient scheduling of data, reducing overhead in control messages and enabling faster data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If fixed subframe length of 1ms is used for downlink control channel transmission, then device complexity and protocol compatibility are maintained, but packet latency increases and throughput decreases
Solution Approach 1:
The patent applies dynamics by making the subframe length variable rather than fixed. The downlink control channel can be transmitted in subframes of different lengths (e.g., 1ms, 0.5ms, or shorter), allowing the system to adapt the scheduling time interval based on traffic conditions and latency requirements, thereby reducing packet latency while maintaining protocol compatibility.
Solution Approach 2:
The patent changes the parameter of subframe length from a fixed value to a variable parameter. By allowing the subframe duration to be adjusted dynamically, the system can optimize packet latency and throughput by selecting appropriate subframe lengths for different scheduling scenarios, while the downlink control information structure remains compatible with existing protocols.
2Productivity
If subframe length is reduced to improve packet latency, then throughput increases, but control signaling complexity increases and existing DCI formats become incompatible
Solution Approach 1:
The patent applies universality by designing a downlink control information structure that can function across multiple subframe lengths. The same DCI format and resource allocation mechanisms are used whether the subframe is 1ms or shorter, allowing the control signaling to be universal and compatible with different TTI configurations without requiring separate signaling schemes.
Solution Approach 2:
The patent segments the downlink control information transmission from the data transmission in terms of timing flexibility. The control channel can be transmitted at the beginning of subframes of varying lengths, with the data portion following in the remaining subframe time. This segmentation allows independent optimization of control signaling and data transmission timing.
3Loss of time
If scheduling is performed only once per 1ms subframe, then device complexity is reduced and protocol simplicity is maintained, but packet latency increases and radio resource efficiency decreases
Solution Approach 1:
The patent applies periodic action by enabling multiple scheduling opportunities within a 1ms interval through shorter subframe lengths. Instead of a single scheduling decision per millisecond, the system can perform scheduling at each shorter subframe boundary (e.g., every 0.5ms or 0.25ms), increasing the frequency of scheduling actions and reducing scheduling delay while improving radio resource utilization.
Solution Approach 2:
The patent applies preliminary action by allowing scheduling decisions to be made earlier and more frequently. With shorter subframes, the network can allocate resources in advance for upcoming data transmissions, reducing the waiting time for scheduling decisions and enabling more proactive resource management, which improves both latency and resource efficiency.
Data Source
Figure 1~2b
Figure 3a~7
Figure 6~8
AI summary
There is provided mechanisms for transmitting a downlink (DL) grant and DL data to a wireless device. A method is performed by a network node. The method comprises obtaining an indication for providing the DL data to the wireless device. The method comprises transmitting, in a transmission time interval (sTTI) frequency band, the DL grant for the wireless device and the DL data for the wireless device. A position of the DL grant in the sTTI frequency band identifies a position of the DL data in the sTTI frequency band. There is also provided a network node configured to perform such a method. There is further provided mechanisms for receiving a DL grant and DL data from a network node, as performed by a wireless device.