RAN-WLAN Aggregation via Reliable Transport Protocol

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Solution Overview

Problem

Current RAN-WLAN radio aggregation technologies face challenges in ensuring reliable user-plane data packet delivery and flow control, leading to potential packet losses and instability in dual connectivity scenarios, which can impact higher layer protocols and overall network performance.

Innovation Solution

Implementing a method that uses a reliable transport protocol, such as SCTP, for user-plane data forwarding between the RAN and WLAN, with performance feedback mechanisms to enable flow control and optimize data flow based on real-time performance metrics, ensuring reliable packet delivery and resource allocation between networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If user-plane data packets are forwarded over WLAN without a reliable transport protocol, then device complexity is reduced, but reliability of packet delivery deteriorates

Engineering Contradiction:
Improvetransport protocol complexityVSAvoidpacket delivery reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a WLAN transport layer as an intermediary between the RAN network element and the terminal. This transport layer provides reliable packet delivery mechanisms (acknowledgments, retransmissions, sequencing) specifically for the WLAN path, while leaving the upper PDCP layer unchanged. The intermediary handles the reliability requirements without complicating the existing cellular protocol stack.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If flow control mechanism is implemented for user-plane data forwarding, then productivity is improved, but device complexity increases

Engineering Contradiction:
Improvedata forwarding efficiencyVSAvoidflow control mechanism complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements flow control through a feedback mechanism where the WLAN transport layer monitors packet delivery performance (throughput, loss rate, delay) and provides feedback to the RAN network element. Based on this feedback, the RAN dynamically adjusts the data forwarding rate to the WLAN, optimizing productivity while keeping the control mechanism manageable through standardized feedback loops.

Inventive Principle:
Principle #23Feedback

3Reliability

If performance feedback mechanism is added for flow control, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveaggregation performance reliabilityVSAvoidfeedback mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The WLAN transport layer performs self-service by autonomously monitoring its own packet delivery performance and generating feedback reports. It measures throughput, packet loss, and delay metrics independently and provides this information to the RAN without requiring complex external monitoring systems. The terminal also participates by reporting received packet status, enabling the WLAN transport layer to self-assess delivery reliability.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3216264B1Interface functionality for ran-WLAN radio aggregation
Publication Date: 2019.09.18 NOKIA SOLUTIONS & NETWORKS OY
  • EP3216264B1 patent drawingFigure 1
  • EP3216264B1 patent drawingFigure 2
  • EP3216264B1 patent drawingFigure 3

AI summary

There are provided measures for enabling/realizing interface functionality for RAN-WLAN radio aggregation, i.e. radio level integration/aggregation between a cellular radio access network and a wireless area network. Such measures exemplarily comprise user-plane data forwarding from a cellular radio access network over a wireless local area network to a terminal, both the cellular radio access network and the wireless local area network providing radio level connectivity for the terminal, wherein in the user-plane data forwarding user-plane data packets according to a cellular data convergence protocol are transported, at least partly, using a reliable transport protocol over the wireless local area network to the terminal, providing feedback on performance of user-plane data packets transport using the reliable transport protocol, at least partly, from the wireless local area network to the cellular radio access network, and executing flow control on the basis of the performance feedback.