MPTCP Link Processing for Timeout-Based Failure Prediction

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Solution Overview

Problem

In mobile terminals using the Multipath Transmission Control Protocol (MPTCP), link failures due to unstable wireless networks lead to retransmission timeouts, causing data to be blocked in the send buffer and affecting overall network performance, as it takes six retransmission timeouts to detect a link failure, hindering the use of resources and impacting parallel multipath transmission.

Innovation Solution

A link processing method that detects timer timeouts, sends a probe information packet instead of data packets when timeouts exceed one but are less than or equal to five, and uses the preferential slow start threshold algorithm to select an alternative link for retransmitting lost data, marking the link as unavailability predictable to notify the mobile terminal of potential risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If data is retransmitted simultaneously on another link and the original link when retransmission timeout occurs, then data integrity is ensured, but the send buffer becomes blocked and network throughput decreases

Engineering Contradiction:
Improvedata integrityVSAvoidnetwork throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by detecting link quality degradation through timeout counting before complete link failure occurs. When the timeout count reaches a threshold (greater than 1 and less than or equal to 5), the system proactively marks the link as unpredictably unavailable and stops sending data packets, preventing the buffer blocking issue that would occur with traditional retransmission approaches.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the mobile terminal waits for six retransmission timeouts to detect a link failure, then link failure detection is accurate, but data transmission is blocked for an extended period

Engineering Contradiction:
Improvelink failure detection accuracyVSAvoiddata transmission blocking time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary detection by counting timeout events and comparing against a threshold (greater than 1 and less than or equal to 5). This allows the system to identify deteriorating link conditions and take preventive action before the traditional six-timeout failure detection period elapses, significantly reducing the time data transmission is blocked.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously monitoring timeout events on each link and using this information to dynamically adjust data transmission decisions. The timeout count serves as feedback that triggers link status changes and data routing decisions, enabling the system to respond to link degradation in real-time rather than waiting for complete failure.

Inventive Principle:
Principle #23Feedback

3Reliability

If data is always restored in the send buffer during N retransmissions, then data integrity is maintained, but the limited send buffer cannot accept subsequent data

Engineering Contradiction:
Improvedata integrityVSAvoidsend buffer management complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system takes preliminary action by detecting link degradation through timeout counting and proactively marking the link as unpredictably unavailable before the send buffer becomes full. This prevents the scenario where the buffer is blocked by repeated retransmissions, allowing subsequent data to enter the buffer without waiting for retransmission completion.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If another link with good performance cannot obtain available data for normal sending, then parallel multipath transmission efficiency is reduced, but resources of the entire network cannot be fully used

Engineering Contradiction:
Improveparallel multipath transmission efficiencyVSAvoidnetwork resource utilization
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by detecting link degradation and marking the affected link as unpredictably unavailable before complete failure occurs. This allows the MPTCP system to redirect data transmission to alternative healthy links, ensuring that parallel multipath transmission continues efficiently and network resources are fully utilized rather than being blocked by a single deteriorating link.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2996275B1Link processing method and mobile terminal in multiplexing control protocol
Publication Date: 2018.04.04 HUAWEI DEVICE CO LTD
  • EP2996275B1 patent drawingFigure 1~2
  • EP2996275B1 patent drawingFigure 3~4
  • EP2996275B1 patent drawingFigure 5~7

AI summary

The present invention provides a link processing method in the Multipath Transmission Control Protocol and a mobile terminal. The method includes: detecting that a timer of a link i times out, where i is a natural number; obtaining a quantity Ni of times the timer of the link i times out, where Ni is a natural number; and if the quantity Ni of times the timer of the link i times out is greater than 1 and less than or equal to 5, sending a probe information packet through the link i. The mobile terminal includes: a detecting module, an obtaining module, and a sending module. The solutions provided by embodiments can effectively reduce impact of a link with poor performance or a link that fails unexpectedly on parallel multipath transmission.