LWA PDU Routing via Adaptation Layer Encapsulation

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Solution Overview

Problem

Current LTE-WLAN aggregation (LWA) technologies face challenges in efficiently routing LTE packet data units (PDUs) and identifying them within WLAN AP modems, which hinders effective data aggregation and resource management across different radio access networks.

Innovation Solution

The implementation of an adaptation layer that encapsulates LTE PDUs as Ethernet frames or GRE packets, using VLAN configurations, and employs EtherType values, source addresses, and GRE headers for identification and routing, allowing for efficient data aggregation and forwarding between LTE and WLAN networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If LTE PDUs are routed through WLAN AP without encapsulation, then routing complexity is reduced, but PDU identification and correct forwarding between LTE and WLAN networks cannot be achieved

Engineering Contradiction:
Improverouting complexityVSAvoidPDU identification capability
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent introduces an adaptation layer as an intermediary component between the PDCP layer and WLAN MAC layer. This adaptation layer encapsulates LTE PDUs with Ethernet headers containing BSSID and destination address, enabling the WLAN AP to identify and forward packets correctly without increasing overall system complexity. The encapsulation mechanism acts as a mediator that translates between LTE and WLAN protocols.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If encapsulation is used for LWA PDU routing, then PDU identification and forwarding accuracy are improved, but device complexity and processing overhead increase

Engineering Contradiction:
ImprovePDU identification accuracyVSAvoidencapsulation processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the parameter structure of PDU packets by adding Ethernet header parameters (BSSID, destination address, source address) to the encapsulated packets. This parameter transformation enables precise identification and routing while keeping the encapsulation process standardized and manageable through defined header formats.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If LTE and WLAN networks are aggregated, then system capacity and throughput are improved, but resource management complexity and coordination overhead increase

Engineering Contradiction:
Improveaggregate throughputVSAvoidresource management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the resource management functions by introducing separate adaptation layers at both the eNB and WLAN AP ends. Each adaptation layer independently handles encapsulation and decapsulation of packets, dividing the complex aggregation task into manageable segments that can be processed locally without requiring complex end-to-end coordination.

Inventive Principle:
Principle #1Segmentation

4Reliability

If PDCP layer is used as common layer between LTE and WLAN, then security procedures are reused, but U-plane bearer splitting and packet routing become difficult to implement

Engineering Contradiction:
Improvesecurity procedure reuseVSAvoidbearer splitting implementation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The adaptation layer serves as an intermediary between the security functions at the PDCP layer and the routing requirements of the U-plane bearer splitting. It allows security procedures to operate at the PDCP layer while enabling complex routing and bearer management at the adaptation layer, decoupling these functions to reduce implementation complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3213580B1Method and apparatus of LWA PDU routing
Publication Date: 2019.04.17 HFI INNOVATION INC
  • EP3213580B1 patent drawingFigure 1
  • EP3213580B1 patent drawingFigure 2~3
  • EP3213580B1 patent drawingFigure 4A~5

AI summary

Apparatus and methods are provided for LWA PDU routing. In one novel aspect, LTE PDU packets are routed through a WLAN AP to a UE by encapsulation of the data packets. An adaption layer encapsulate the whole packet as an Ethernet frame by appending the Ethernet MAC header to the payload. In other embodiments, the adaption layer encapsulates LTE PDU as GRE packet, configures VLAN for WLAN AP. In another novel aspect, the LTE PDU is identified by at least one of methods comprising the EtherType value, the source address, the GRE header, and the GTP header. In another embodiment, the default path is always used for LWA routing. In yet another novel aspect, the LTE PDU is forwarded by the MAC address, by the GRE tunnel configuration, or by the GTP tunnel configuration.