Dynamic Discard Timer for LTE User Equipment Buffer Management
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Solution Overview
Problem
The existing PDCP discard timer in LTE networks is static and does not adapt to changing channel conditions, leading to early packet discard or buffer congestion, which affects data transfer and throughput.
Innovation Solution
A dynamic discard timer system that adjusts its timeout value based on real-time channel conditions, specifically using the first hop round trip time and its variation to determine and update the timeout value, ensuring packets are discarded only when necessary, thereby optimizing buffer management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed timeout value is used for the discard timer, then the configuration is simple and consistent, but packets may be discarded too early or cause buffer congestion when channel conditions change
Solution Approach 1:
The patent applies the dynamics principle by transforming the static discard timer into a dynamic one that automatically adjusts its timeout value based on real-time channel conditions. The timer monitors packet transmission status and updates the timeout value dynamically, allowing it to adapt to varying network conditions without manual reconfiguration. This resolves the contradiction by making the system adaptable while maintaining relatively simple operation through automatic adjustment mechanisms.
Solution Approach 2:
The patent implements feedback by having the discard timer monitor whether packets are successfully transmitted or discarded, and use this information to adjust the timeout value. The system receives feedback about packet transmission status and uses this feedback to update the timeout parameter, creating a closed-loop control system. This feedback mechanism enables the timer to adapt to channel conditions while maintaining consistent operation through automated adjustment.
2Reliability
If the timeout value is set to a long duration, then packets remain in buffer longer avoiding early discard, but buffer congestion increases and memory usage grows
Solution Approach 1:
The patent applies dynamics by making the timeout value adjustable rather than fixed. When channel conditions are good, the timeout value is reduced, allowing packets to be discarded sooner and freeing buffer space. When channel conditions deteriorate, the timeout value increases, ensuring packets remain in buffer longer to maintain transmission reliability. This dynamic adjustment resolves the contradiction between reliability and buffer occupancy.
Solution Approach 2:
The patent changes the parameter of timeout value based on observed packet transmission behavior and channel conditions. The system monitors whether packets are successfully transmitted or discarded and adjusts the timeout parameter accordingly. This parameter change enables the system to optimize both reliability and buffer usage by extending timeout when needed for reliability and reducing it when buffer space should be freed.
3Productivity
If the timeout value is set to a short duration, then buffer space is freed quickly, but packets may be discarded before transmission resources are available
Solution Approach 1:
The patent applies dynamics by enabling the timeout value to adjust based on real-time channel conditions and packet transmission status. When channel conditions are favorable, the timeout is shortened to free buffer space quickly and improve throughput. When channel conditions deteriorate or transmission failures occur, the timeout is extended to ensure packets are not discarded prematurely, maintaining delivery reliability. This dynamic adjustment resolves the contradiction between productivity and reliability.
Solution Approach 2:
The patent implements feedback by monitoring packet transmission outcomes and using this information to adjust the timeout value. The system receives feedback about whether packets are successfully transmitted or discarded, and uses this feedback to optimize the timeout parameter. This feedback mechanism enables the system to balance throughput and reliability by shortening timeout for better performance when conditions allow and extending it when reliability is compromised.
Data Source
AI summary
Methods, systems and apparatus for a user equipment to implement a dynamic discard timer. The user equipment may generate a packet for transmission and store the packet in a buffer of the user equipment. The user equipment may then generate a timeout value for a discard timer for the buffer, where the discard timer discards the packet from the buffer when the timeout value is reached. After a predetermined amount of time, the user equipment may determine whether the packet has been discarded from the buffer and, when it is determined that the packet has not been discarded from the buffer, update the timeout value.