Dynamic Duty Cycle Management for LTE-U WiFi Coexistence

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Solution Overview

Problem

Current wireless communication systems face challenges in co-existing with WiFi in unlicensed bands, particularly due to interference from LTE transmissions, and existing interference management mechanisms are inadequate for heterogeneous wireless protocols.

Innovation Solution

A method and device for managing wireless communications by monitoring traffic on unlicensed bands, dynamically varying the duty cycle of time slots to avoid collisions with WiFi signals, and coordinating access to ensure fair and efficient data transmission across licensed and unlicensed bands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If LTE transmissions are deployed in unlicensed bands to improve coverage and spectral efficiency, then data rates and mobility reliability are improved, but interference and collisions with WiFi signals occur

Engineering Contradiction:
Improvedata ratesVSAvoidinterference with WiFi signals
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic duty cycle adjustment where the LTE-U system adapts its transmission timing based on detected WiFi activity. The base station monitors WiFi signals and dynamically varies the duty cycle of uplink time slots, extending or compressing them based on channel conditions, thereby avoiding fixed scheduling conflicts with WiFi transmissions

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs periodic monitoring of WiFi traffic patterns and adjusts LTE-U transmissions in periodic cycles. By observing WiFi activity over multiple time slots and adapting the duty cycle periodically, the system achieves coordinated access that reduces collisions while maintaining efficient data transmission

Inventive Principle:
Principle #19Periodic action

2Reliability

If interference management mechanisms are implemented for heterogeneous wireless protocols, then co-existence between LTE and WiFi is improved, but system complexity increases

Engineering Contradiction:
Improveco-existence between LTE and WiFiVSAvoidinterference management mechanisms
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a co-existence module as an intermediary component that specifically handles WiFi-LTE interaction. This dedicated module monitors WiFi signals and coordinates with the LTE-U scheduler, acting as a mediator that simplifies the overall system architecture by isolating the complexity of heterogeneous protocol management from the core LTE functions

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback mechanisms where the base station continuously monitors WiFi traffic patterns and feeds this information back to adjust the LTE-U duty cycle. This closed-loop control enables adaptive co-existence management, where transmission parameters are dynamically optimized based on real-time channel conditions without requiring complex centralized coordination

Inventive Principle:
Principle #23Feedback

3Reliability

If traffic monitoring is performed on unlicensed bands to avoid WiFi collisions, then transmission reliability is improved, but time slot utilization efficiency decreases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidtime slot utilization
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial monitoring where the base station monitors WiFi traffic only during specific uplink time slots rather than continuously across all slots. By selectively monitoring only the time slots allocated for LTE-U uplink transmissions, the system achieves sufficient collision avoidance while minimizing the overhead associated with continuous monitoring, thus maintaining better time slot utilization

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3332601B1Techniques for using traffic monitoring for co-existence with unlicensed networks
Publication Date: 2019.12.25 QUALCOMM INC
  • EP3332601B1 patent drawingFigure 1
  • EP3332601B1 patent drawingFigure 2
  • EP3332601B1 patent drawingFigure 3

AI summary

Systems and techniques are disclosed to manage coexistence of wireless technologies, including 5G unlicensed transmissions, with 802.11 transmissions in the unlicensed band. Aspects of the present disclosure include channel selection and 802.11 traffic monitoring and coordinated access. The systems and techniques include implementing a dynamic duty cycle on a selected channel of an unlicensed 802.11 band and dynamically varying the duty cycle based on traffic load on the selected channel. Other aspects, embodiments, and features are also claimed and described.