Periodic Uplink Grant Alignment for Cellular Network Latency
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Solution Overview
Problem
In cellular networks, the latency associated with sending scheduling requests for uplink data transmissions is significant, leading to delays that are undesirable for applications like online gaming, and existing solutions like periodic pre-scheduling increase resource consumption by allocating unnecessary resources.
Innovation Solution
A method and node configuration that aligns the sending of periodic UL grants with the opportunities for scheduling requests, optimizing latency by using two types of grants: dynamic grants sent in response to requests and periodic grants sent according to a configured periodicity, with the alignment controlled based on the periodicities of both.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If periodic pre-scheduling is used to reduce latency, then scheduling delay is reduced, but resource consumption increases due to allocation of unnecessary resources
Solution Approach 1:
The patent implements dynamic adjustment of periodic UL grant periodicity based on UE activity status. When the UE is inactive, the periodicity is extended or grants are suspended, reducing resource consumption. When the UE becomes active, the original periodicity is restored to maintain low latency. This dynamic adaptation resolves the contradiction by making the scheduling mechanism flexible rather than static.
Solution Approach 2:
The patent changes the periodicity parameter of periodic UL grants based on UE activity detection. By adjusting this key parameter dynamically - extending periodicity during inactivity and maintaining original periodicity during activity - the system optimizes both resource efficiency and latency performance according to actual traffic conditions.
2Stability of the object's composition
If dedicated resources are provided for scheduling requests with 10ms periodicity, then scheduling opportunities are regular, but latency increases when data arrives just after an opportunity
Solution Approach 1:
The patent sends periodic UL grants to the UE in advance without requiring the UE to wait for scheduling request opportunities. By proactively providing uplink resources beforehand, the system eliminates the waiting time associated with periodic scheduling requests, thereby reducing latency while maintaining regular grant intervals.
Solution Approach 2:
The patent extracts the scheduling request step from the traditional scheduling process by providing periodic UL grants directly. This removes the dependency on periodic SR opportunities and their associated latency, allowing the UE to transmit uplink data immediately when resources are available without needing to wait for or request scheduling opportunities.
Data Source
AI summary
A node (100, 200) of a cellular network controls sending of first uplink grants to a communication device (10). The first uplink grants indicate first uplink radio resources allocated to the communication device (10) and are sent in response to receiving scheduling requests from the communication device (10). Further, the node (100, 200) controls sending of second uplink grants to the communication device (10). The second uplink grants indicate second uplink radio resources allocated to the communication device (10) and are sent according to a configured periodicity. Depending on a periodicity of opportunities for transmission of the scheduling requests by the communication device (10) and the configured periodicity of sending the second uplink grants, the node (100, 200) controls an alignment of the sending of the second uplink grants with respect to the opportunities for transmission of the scheduling requests.