PDCP Status Report Request Mechanism for Wireless Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current PDCP status report mechanisms in 3GPP and LTE systems are limited to handover scenarios, failing to provide PDCP status information exchange between UE and eNB outside of handover, leading to packet loss and repeated transmissions due to transmission errors, especially in relay scenarios where accurate SN status is not available during handover.

Innovation Solution

A method and PDCP entity that transmit a PDCP Protocol Data Unit (PDU) to request and receive PDCP status reports, using identifier bits or PDCP status report request types in headers to facilitate the exchange of PDCP status information between PDCP entities, enabling accurate status knowledge and reducing packet loss and retransmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PDCP status report mechanism is limited to handover scenarios only, then device complexity is reduced, but reliability deteriorates due to packet loss and repeated transmissions in non-handover scenarios

Engineering Contradiction:
ImprovePDCP status information exchange reliabilityVSAvoidPDCP status report mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extends the PDCP status report mechanism to serve multiple scenarios: both handover scenarios and non-handover scenarios (such as packet loss recovery and relay scenarios). By making the mechanism universal, it resolves the contradiction by improving reliability across all scenarios while maintaining a unified, manageable complexity through standardized procedures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces configurable parameters to control when PDCP status reports are generated and exchanged. Through parameter changes (enabling/disabling status reports based on scenario, configuring thresholds), the system can adapt between simplicity and reliability needs, resolving the contradiction by allowing flexibility in complexity while ensuring reliability when needed.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If PDCP status report is made mandatory for all scenarios, then reliability is improved through comprehensive status information exchange, but loss of energy increases due to frequent status report transmissions

Engineering Contradiction:
ImprovePDCP status information availabilityVSAvoidEnergy consumed by status report transmissions
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent implements partial action by making PDCP status reports optional or conditional rather than mandatory in all scenarios. Status reports are generated based on specific conditions (packet loss detection, handover events, relay scenarios), providing sufficient status information when needed while avoiding unnecessary transmissions that would waste energy, thus resolving the contradiction.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent introduces feedback mechanisms where the receiving PDCP entity sends status reports back to the transmitting entity based on detected conditions (such as missing packets or handover events). This feedback-driven approach ensures reliability by providing status information when actually needed while minimizing unnecessary transmissions, thereby reducing energy loss while maintaining reliability.

Inventive Principle:
Principle #23Feedback

3Reliability

If PDCP status report is made optional in handover scenarios, then loss of time is reduced by avoiding mandatory status exchange, but reliability deteriorates due to missing status information in relay scenarios

Engineering Contradiction:
ImproveSN status information accuracyVSAvoidTime for status report transmission
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces scenario-specific parameters that control PDCP status report behavior. In relay scenarios, parameters are set to enable mandatory status reports to ensure accurate SN status information is available. In other scenarios, optional reporting is sufficient. This parameter-based control resolves the contradiction by adapting the mandatory/optional nature of status reports to specific scenario requirements, ensuring reliability where needed while minimizing time loss elsewhere.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2493239B1Method for acquiring packet data convergence protocol (PDCP) status report and PDCP entity
Publication Date: 2021.03.03 ZTE CORP
  • EP2493239B1 patent drawingFigure 1~2
  • EP2493239B1 patent drawingFigure 3~4
  • EP2493239B1 patent drawingFigure 5~6

AI summary

The present invention discloses a method for acquiring a Packet Data Convergence Protocol (PDCP) status report and a packet data convergence protocol entity. The method comprises the steps of: a PDCP entity transmitting to an opposite PDCP entity a PDCP Protocol Data Unit (PDU) used to request the transmission of a PDCP status report; and the PDCP entity receiving the PDCP status report which is transmitted from the opposite PDCP entity according to the PDCP PDU. By the present invention, the quality of service and the performance of the wireless communication system are improved.