PDCP Discard Timer Adjustment for Congestion-Prioritized Packets
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Solution Overview
Problem
The existing packet discard mechanism at the PDCP layer reduces network effective capacity and user experience in XR services due to premature discarding of dependent data packets during network congestion, leading to unsuccessful parsing and transmission failures.
Innovation Solution
A method to dynamically adjust the discard timer duration at the PDCP layer based on indication information, prioritizing the discard of low-importance data during congestion and ensuring timely transmission of high-importance data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the PDCP entity uses a fixed discard timer duration for all data packets in a QoS flow, then the packet discard mechanism is simple to implement, but high-importance data packets may be discarded prematurely during network congestion, reducing network effective capacity and user experience
Solution Approach 1:
The patent applies local quality by differentiating packet discard behavior based on data importance. High-importance packets (e.g., I-frames) are protected from premature discarding while low-importance packets (e.g., P-frames) can be discarded earlier during congestion. This is achieved by maintaining different discard timer durations for different data importance levels within the same QoS flow, allowing selective quality treatment at the packet level.
Solution Approach 2:
The patent implements dynamics by making discard timer durations adjustable rather than fixed. The network device can dynamically configure different discard timer values for high-importance and low-importance packets based on current network conditions. This allows the system to adapt packet discard behavior in real-time, extending timers for critical packets during congestion while maintaining shorter timers for non-critical packets.
2Reliability
If the discard timer duration is extended to prevent premature discarding of high-importance packets, then data transmission reliability improves, but network resource pressure increases during congestion, reducing overall network capacity
Solution Approach 1:
The patent resolves this contradiction by applying different discard timer durations to different packet importance levels. High-importance packets receive extended timer protection to ensure reliable transmission, while low-importance packets maintain shorter timers that allow earlier discarding. This selective approach preserves network resources by not holding onto non-critical packets during congestion, thereby maintaining network effective capacity while protecting critical data.
3Productivity
If low-importance packets are discarded during congestion to alleviate network pressure, then network capacity is preserved, but dependent high-importance packets may fail to transmit successfully due to missing reference data
Solution Approach 1:
The patent applies preliminary action by having the network device proactively identify and protect high-importance packets before congestion occurs. The network device configures longer discard timer durations for high-importance packets in advance, ensuring they remain in the transmission queue during congestion events. This preemptive protection ensures that critical packets with dependency relationships are transmitted successfully even when low-importance packets are discarded.
Data Source
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AI summary
This application provides a packet discarding method and a communication apparatus, and relates to the communication field. The method includes: A second communication apparatus sends first indication information to a first communication apparatus, where the first indication information indicates to adjust duration of a discard timer that is at a PDCP layer and that corresponds to first data to second duration, and the first data is a first data packet or first data packet set of target importance; and the first communication apparatus adjusts the duration of the discard timer from first duration to the second duration based on the first indication information. According to the method, the first communication apparatus can quickly and flexibly adjust the duration of the discard timer for the first data, to adapt to different communication environments, increase an effective capacity of a system, and improve user experience. For example, in a scenario in which network congestion occurs, duration of a discard timer for data of low importance may be shortened. In this way, the data of low importance can be preferentially discarded, to ensure that data of high importance can be successfully transmitted.