PDCP PDU Discard Timer for Wireless Redundancy Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communications networks, particularly in LTE and 5G, the duplication of PDCP PDUs for redundancy leads to latency issues due to potential delays in receiving duplicate packets, which can render them outdated and ineffective in improving reliability or reducing latency.
Innovation Solution
Implementing a timer-based mechanism where PDCP PDUs are submitted to multiple physical layers for transmission, with a predetermined time limit after which any untransmitted duplicates are discarded, ensuring that only successfully transmitted packets are maintained and reducing the transmission of outdated duplicates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PDCP PDU is transmitted over multiple physical layers for redundancy, then reliability is improved, but latency increases due to delays in receiving duplicate packets
Solution Approach 1:
The patent applies the discarding principle by introducing a discard timer that automatically discards duplicate PDCP PDUs after a predetermined time period. When the timer expires, any undelivered duplicate packets are discarded, preventing them from causing unnecessary latency. This resolves the contradiction by maintaining reliability through initial duplication while eliminating time loss through timely discarding of outdated duplicates.
Solution Approach 2:
The patent implements preliminary action by pre-configuring discard timers and discard thresholds before transmission begins. These parameters are set in advance to control the behavior of duplicate packet handling, allowing the system to proactively manage the trade-off between reliability and latency without requiring real-time decisions during transmission.
2Reliability
If duplicate PDCP PDUs are transmitted for redundancy, then reliability is improved, but device complexity increases due to multiple transmission paths
Solution Approach 1:
The discard mechanism simplifies the system by providing a clear rule for when to stop tracking duplicate packets. Instead of maintaining complex state information indefinitely, the discard timer and threshold provide simple, automated criteria for discarding duplicates, reducing the complexity of tracking and managing multiple transmission paths while preserving reliability.
3Reliability
If duplicate PDCP PDUs are transmitted for redundancy, then reliability is improved, but unnecessary overhead is generated from outdated duplicates
Solution Approach 1:
The patent directly addresses overhead reduction through the discard timer mechanism. By automatically discarding duplicate packets that exceed the predetermined time threshold or discard threshold, the system eliminates unnecessary transmission overhead from outdated duplicates while maintaining the reliability benefits of duplicate transmission for packets that are still timely and useful.
Data Source
AI summary
A method of discarding PDCP PDUs submitted for transmission includes submitting the PDCP PDU to a first entity for transmission over a first physical layer, and submitting the PDCP PDU to a second entity for transmission over a second physical layer. In response to determining that a predetermined time period has elapsed since the submission of the PDCP PDU, the first entity and the second entity are instructed to discard the PDCP PDU without transmission, or one of the first entity and the second entity are instructed to discard the PDCP PDU in response to an indication of transmission or delivery of the PDCP PDU by the other entity. Related apparatus and computer program product(s) are disclosed.