Uplink Grant Reallocation for Cellular Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In cellular networks, dynamic scheduling for uplink data transmission leads to latency issues, particularly in scenarios like online gaming and HTTP/TCP-based Internet traffic, due to the need for scheduling requests, and Semi-Persistent Scheduling (SPS) can result in inefficient radio resource utilization with over-allocation of resources when no data is available for transmission.
Innovation Solution
The method involves sending a UL grant for recurring time intervals and monitoring for an indication of intention to transmit uplink data; if no indication is detected, the access node reallocates the resources to another device, allowing for conditional utilization of UL radio resources, thereby reducing latency and improving resource efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If Semi-Persistent Scheduling (SPS) is used to allocate UL radio resources in reoccurring time intervals, then latency is reduced by avoiding scheduling requests, but radio resource utilization efficiency deteriorates due to over-allocation when no data is available
Solution Approach 1:
The patent implements dynamic resource allocation by introducing an intention indication mechanism that allows the network to adaptively adjust resource allocation based on actual transmission needs. The access node dynamically reallocates resources from devices with no transmission intention to devices with transmission needs, transforming the static SPS allocation into a dynamic system that balances low latency with resource efficiency.
Solution Approach 2:
The patent employs feedback through intention indication signals (such as PUCCH transmissions or DTX detection) that inform the network about the UE's actual transmission intentions. This feedback loop enables the access node to make informed reallocation decisions, preventing waste of allocated resources while maintaining the low-latency benefits of SPS for devices that do have data to transmit.
2Productivity
If long lasting grants are used to cover multiple TTIs, then the need to send scheduling requests is reduced, but over-allocation occurs when the UE has no UL data to transmit
Solution Approach 1:
The patent applies partial action by allocating resources for multiple TTIs (excessive allocation) but only activating them when needed (partial utilization). The intention indication mechanism allows the UE to signal whether it will actually use the allocated resources, enabling the network to partially reallocate unused resources to other UEs, thus preventing complete waste while maintaining the capability for fast transmission when data arrives.
Solution Approach 2:
The patent changes the parameter of resource allocation from fixed (standard SPS) to variable through reallocation based on intention indications. The access node modifies the allocation parameters dynamically by taking resources from UEs with no transmission intention and reallocating them to UEs with transmission needs, thus adapting the quantity of allocated resources to actual demand while maintaining the multi-TTI grant structure.
3Reliability
If UL radio resources are allocated to a UE, but the UE has no UL data to transmit, then the allocated resources are wasted and not available for other purposes
Solution Approach 1:
The patent uses feedback through the absence of PUCCH transmissions or DTX (Discontinuous Transmission) detection to identify when a UE has no data to transmit. This feedback mechanism allows the access node to detect unused resources reliably and reallocate them to other UEs that have transmission needs, thus eliminating waste while maintaining reliable allocation for UEs that do have data.
Solution Approach 2:
The patent implements discarding and recovering by identifying unused allocated resources (discarding the original allocation) and reallocating them to UEs with transmission needs (recovering the resources for productive use). This process ensures that radio resources are continuously utilized efficiently while maintaining the ability to provide reliable allocation when data is present.
Data Source
AI summary
An access node (100) of a cellular network sends an uplink grant to a communication device (10-A, 10-B, 10-C). The uplink grant indicates uplink radio resources allocated to the communication device (10-A, 10-B, 10-C) in reoccurring time intervals. The access node (100) monitors a uplink radio resource, configured before each of the reoccurring time intervals, for an indication of intention to transmit uplink data by an uplink transmission on the indicated uplink radio resources in the corresponding reoccurring time interval. In response to not detecting the indication and determining a need for an uplink transmission in the corresponding reoccurring time interval by a further communication device (10-A, 10-B, 10-C), the access node (100) reallocates the indicated uplink radio resources in the corresponding time interval to the further communication device.