Downlink Packet Timing Alignment for Scheduling Window Delays
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Solution Overview
Problem
In communication systems, scheduling delays at access network elements can introduce end-to-end delays in downlink service packets, failing to meet guaranteed delay requirements due to scheduling windows and processing constraints.
Innovation Solution
A downlink transmission method involving session management network elements adjusting time to align packet arrival with scheduling windows, using time adjustment information to ensure packets are sent at optimal moments, thereby reducing scheduling delays and ensuring end-to-end delay compliance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If downlink service packets are scheduled according to access network element scheduling windows, then scheduling is performed in an organized manner, but scheduling waiting delay increases causing end-to-end delay requirements to fail
Solution Approach 1:
The patent applies preliminary action by having the application server or user plane network element send the downlink service packet before the expected arrival time at the access network element. By calculating the first delay (difference between expected and estimated arrival moments) and adjusting the sending time accordingly, the packet arrives within the first scheduling window, allowing the access network element to schedule it in the next downlink scheduling window without excessive waiting delay, thus guaranteeing end-to-end delay requirements.
2Productivity
If downlink service packets arrive at access network element within processing window, then processing can be performed, but scheduling must wait for next downlink scheduling window increasing delay
Solution Approach 1:
The patent resolves this contradiction by performing preliminary action - adjusting the packet sending time upstream so that packets arrive at the access network element within the first scheduling window rather than the processing window. This allows the access network element to immediately schedule packets in the next downlink scheduling window without waiting for the processing window to complete, thereby reducing scheduling delay while maintaining processing efficiency.
3Device complexity
If multiple downlink service packets for multiple access network elements are processed sequentially, then processing is simple, but resource utilization decreases and processing conflicts occur
Solution Approach 1:
The patent applies preliminary action by having the application server or user plane network element adjust sending times for multiple downlink service packets destined for different access network elements before they arrive. By calculating and applying appropriate time adjustments for each packet based on the expected arrival time and first delay, packets are staggered to arrive within their respective first scheduling windows, avoiding processing conflicts at the access network elements while improving resource utilization without significantly increasing processing complexity.
Data Source
AI summary
This application provides a downlink transmission method. A session management network element obtains duration, namely, a first delay, between an expected moment at which a downlink service packet arrives at an access network element and an estimated moment at which the downlink service packet arrives at the access network element, the expected moment is within a first scheduling window, and a next scheduling window adjacent to the first scheduling window is a downlink scheduling window. Then, the session management network element sends the first delay to an application network element, where the first delay is used by an application server to determine a second moment at which the downlink service packet is sent, and a moment at which the downlink service packet sent at the second moment arrives at the access network element is within the first scheduling window.