Low Latency Wireless Resource Allocation via Mini-TTI Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems, such as LTE, face challenges in achieving low latency due to the limitations of traditional transmission time intervals (TTIs), which hinder efficient resource allocation and increase communication latency as demand for mobile broadband access grows.
Innovation Solution
The implementation of ultra-low latency (ULL) communication technology, which utilizes shorter TTIs, such as one or two symbols, within the legacy LTE framework, allowing for a physical downlink control channel within each TTI and separate search spaces for ULL and legacy control information, enabling more frequent and efficient resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional LTE TTI (1ms subframe) is used, then system compatibility and stability are maintained, but communication latency increases and resource allocation efficiency decreases
Solution Approach 1:
The patent segments the traditional 1ms TTI into shorter intervals by introducing symbol-based scheduling (1-2 symbols = 0.5-1ms) and mini-TTI structures. This segmentation allows more frequent scheduling opportunities, reducing latency while maintaining LTE compatibility through the eNodeB scheduler that manages both legacy and enhanced TTI formats.
Solution Approach 2:
The system dynamically switches between different TTI lengths (normal TTI, short TTI, mini-TTI) based on traffic type and latency requirements. The eNodeB scheduler adapts the TTI duration dynamically, using shorter TTIs for latency-sensitive traffic and longer TTIs for bulk data transmission, optimizing the trade-off between latency and resource allocation efficiency.
2Productivity
If shorter TTI (1-2 symbols) is introduced for low latency, then communication latency decreases and bandwidth utilization improves, but system complexity increases due to multiple search spaces and control information handling
Solution Approach 1:
The control channel structure is segmented into separate search spaces: a first search space for legacy LTE control information and a second search space for enhanced low-latency control information. This segmentation allows independent optimization of each control channel type while maintaining overall system manageability, reducing the complexity burden on any single control mechanism.
Solution Approach 2:
The eNodeB scheduler serves multiple functions: it schedules both legacy and enhanced TTIs, manages both search spaces, and handles diverse traffic types through a unified control structure. This multi-functionality reduces overall system complexity by consolidating control logic rather than requiring separate independent control mechanisms for each TTI type.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Various aspects described herein relate to defining, by a base station, resources associated with a search space for control information transmitted in the wireless communications, encoding, by the base station, low latency control information associated with a low latency communication technology for transmission in a control channel region in the search space, wherein the control channel region is associated with a second communication technology, wherein the low latency communication technology uses one of multiple possible transmission time interval (TTI) having a duration that is less than a subframe of the second communication technology, and wherein encoding the low latency control information comprises selecting, based on the duration of the TTI, a size of the low latency control information, as number of resource element groups (REGs) within a control channel element (CCE), from multiple sizes defined for the duration of the TTI, and transmitting, by the base station, the low latency control information in the control channel region that is associated with the second communication technology.