LWA Mobility Group Aggregation for Cloud-RAN Coverage

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Solution Overview

Problem

In large deployments of small-cell LTE wireless service using LTE-WLAN Aggregation (LWA), managing multiple Xw interfaces and LWA mobility groups becomes complex, leading to overhead and potential gaps in coverage due to differing hand-over boundaries between licensed and unlicensed spectrum areas.

Innovation Solution

A system with a controller communicatively coupled to a wireless service provider's core network and multiple radio points using a switched Ethernet network, where the controller establishes a single LWA mobility group with a WLAN access controller and access points to manage wireless service, reducing the need for complex tracking and minimizing coverage gaps by using a single super cell and LWA mobility group.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple small cell base stations are deployed throughout a coverage area to provide LTE service, then network coverage and capacity are improved, but the complexity of managing multiple Xw interfaces and LWA mobility groups increases significantly

Engineering Contradiction:
Improvecoverage areaVSAvoidmanagement complexity of Xw interfaces and LWA mobility groups
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent merges multiple LWA mobility groups into a single unified mobility group that spans the entire coverage area. Instead of having separate mobility groups for each small cell base station, the system creates one aggregate mobility group that manages all WLAN access points across all small cells, thereby reducing management overhead and complexity while maintaining expanded coverage.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a universal Xw interface that can serve multiple small cell base stations simultaneously. Rather than requiring dedicated Xw interfaces for each small cell, the system creates a multi-functional Xw interface that aggregates connections to multiple base stations, reducing the total number of interfaces needed and simplifying management.

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

2Adaptability or versatility

If separate Xw interfaces and LWA mobility groups are implemented for each small cell, then granular control over each base station is achieved, but overhead associated with tracking UEs and determining appropriate LWA mobility groups increases

Engineering Contradiction:
Improvegranular control over each base stationVSAvoidoverhead for tracking UEs and determining LWA mobility groups
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent combines multiple granular mobility group management functions into a single aggregate mobility group. Instead of tracking UEs across numerous separate mobility groups, the system uses one unified mobility group that manages all WLAN access points, significantly reducing the overhead associated with UE tracking and mobility group determination while maintaining the ability to provide granular control when needed.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If centralized WLAN AC is used to manage WLAN APs, then centralized control and management is simplified, but user traffic experiences hairpinning as it flows from remotely located small cell to centrally located WLAN AC and then back to remotely located WLAN AP

Engineering Contradiction:
Improvecentralized control and managementVSAvoidtraffic flow delay due to hairpinning
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent extracts the user traffic flow from the centralized WLAN AC path by establishing direct Xw interfaces between small cell base stations and WLAN access points. While the WLAN AC retains centralized control and management functions, user data traffic bypasses the WLAN AC and flows directly between the small cell and WLAN AP, eliminating the hairpinning delay while preserving centralized management capabilities.

Inventive Principle:
Principle #2Taking out (Extraction)

4Manufacturing precision

If multiple LWA mobility groups are used to match small cell deployments, then precise mapping between licensed and unlicensed spectrum coverage is achieved, but gaps in LWA coverage result due to differing hand-over boundaries

Engineering Contradiction:
Improvemapping precision between licensed and unlicensed spectrum coverageVSAvoidcoverage continuity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent merges multiple discrete LWA mobility groups into a single aggregate mobility group that spans the entire coverage area. This aggregation smooths out the hand-over boundaries between individual small cells and WLAN access points, eliminating coverage gaps that occur when UE handovers between licensed and unlicensed spectrum. The single mobility group ensures continuous LWA coverage while maintaining precise mapping capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3552420B1LTE-wifi aggregation (LWA) support in a cloud-ran system
Publication Date: 2023.03.08 COMMSCOPE TECHNOLOGIES LLC
  • EP3552420B1 patent drawingFigure 1
  • EP3552420B1 patent drawingFigure 2
  • EP3552420B1 patent drawingFigure 3

AI summary

One embodiment is directed to a system to provide wireless service to user equipment using licensed radio frequency spectrum and unlicensed RF spectrum. The system comprises a controller and a plurality of radio points to transmit and receive radio frequency signals to and from the user equipment using the licensed RF spectrum. The system further comprises a wireless termination to transmit and receive radio frequency signals to and from the user equipment using unlicensed RF spectrum. The controller is configured to use a mobility group for providing the wireless service to the user equipment using the unlicensed RF spectrum and a plurality of WLAN access points. The controller is configured to establish an interface with the wireless termination for the mobility group to communicate control plane data to the wireless termination associated with providing the wireless service to the user equipment using the unlicensed RF spectrum. Other embodiments are disclosed.