LTE-U Base Station RTS/CTS Coordination for WLAN Interference

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Solution Overview

Problem

Current technologies fail to efficiently manage interference between LTE and WLAN systems operating in unlicensed bands, leading to noise issues and inefficient resource allocation, as they lack effective coordination and redundancy in resource sharing.

Innovation Solution

Implementing an RTS/CTS procedure that allows for coordinated resource allocation between LTE-U and WLAN modules, enabling the LTE base station to control and synchronize data transmissions to minimize interference, using the LTE-U module to perform the RTS/CTS procedure in conjunction with or independently of the WLAN module, and sharing resources to optimize data transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If LTE and WLAN systems operate in unlicensed bands simultaneously, then network capacity and coverage are improved, but interference and noise between systems increase

Engineering Contradiction:
Improvenetwork capacityVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a reservation mechanism where LTE-U transmissions are scheduled in advance using RTS/CTS procedures. The base station reserves time-frequency resources before actual data transmission, preventing WLAN systems from occupying the same resources and causing interference. This preliminary reservation action enables coexistence while maintaining high network capacity.

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If carrier selection is performed to detect and avoid used channels, then interference with other equipment is minimized, but resource allocation efficiency decreases

Engineering Contradiction:
ImproveinterferenceVSAvoidresource allocation efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements a feedback mechanism where the base station monitors WLAN activity and dynamically adjusts LTE-U resource allocation. The RTS/CTS exchange provides feedback about channel availability, allowing the system to optimize resource allocation in real-time based on actual WLAN presence, thereby improving both interference management and allocation efficiency.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If LTE-U base station controls and synchronizes transmissions, then resource allocation coordination is improved, but device complexity increases

Engineering Contradiction:
Improveresource allocation coordinationVSAvoidcontrol mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements a universal control mechanism where the LTE-U base station's existing scheduling and resource allocation functions are extended to handle WLAN coordination. The same control channel and signaling infrastructure used for LTE resource management is reused for RTS/CTS procedures, avoiding additional complex hardware or control planes while achieving coordinated resource allocation.

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

Data Source

PatentEP3038411B1Radio communication device and method for transmission resource allocation in a telecommunication network
Publication Date: 2023.10.11 IPCOM GMBH & CO KG
  • EP3038411B1 patent drawingFigure 1
  • EP3038411B1 patent drawingFigure 2
  • EP3038411B1 patent drawingFigure 3

AI summary

The present invention is directed towards a method for transmission resource allocation in a telecommunication system, especially in a wireless mobile telecommunication system. In particular, it relates to a synchronized combination of transmission technology being adapted to operate according to the IEEE 802.11 family of standards, commonly known as Wi-Fi or WLAN and technology adapted to operate in accordance with mobile communication standards such as the "long term evolution", LTE for short, transmission technology (or its successor technology "LTE Advanced").