WLAN Transceiver Scheduling via LTE Downlink Sub-frame Notification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing protocols restrict WLAN transceivers from transmitting during LTE downlink sub-frames, leading to interference and reduced throughput due to inefficient time division scheduling in coexistence scenarios.

Innovation Solution

A new protocol allows WLAN transceivers to use portions of LTE downlink sub-frames for transmission or reception by determining if LTE data downlink is scheduled, using WCI-2 messages to notify the WLAN transceiver and override existing synchronization protocols, enabling concurrent LTE and WLAN uplink transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If WLAN transceivers are restricted from transmitting during LTE downlink sub-frames to avoid interference, then interference is reduced, but throughput is reduced due to inefficient time division scheduling

Engineering Contradiction:

ImproveinterferenceVSAvoidthroughput

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent implements dynamic time-division scheduling where the WLAN transceiver's transmission permissions are adjusted in real-time based on LTE downlink activity. Instead of static restrictions, the system dynamically grants WLAN transmission rights during LTE downlink sub-frames when no actual downlink data is scheduled, optimizing both interference management and spectral utilization

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the scheduling parameter from a fixed prohibition of WLAN transmission during all LTE downlink sub-frames to a conditional permission system. By monitoring LTE downlink scheduling decisions and adjusting WLAN transmission parameters accordingly, the system achieves better throughput while maintaining interference avoidance

Inventive Principle:

Principle #35Parameter changes

2Productivity

If WLAN transceivers transmit during LTE downlink sub-frames to improve throughput, then spectral efficiency is improved, but interference occurs with LTE reception

Engineering Contradiction:

ImprovethroughputVSAvoidinterference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary signaling mechanism (WCI-2 messages) that mediates between LTE and WLAN transceivers. This intermediary system conveys LTE downlink scheduling information to the WLAN transceiver, enabling informed transmission decisions that balance throughput optimization with interference prevention

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements a feedback loop where LTE downlink scheduling decisions are communicated to the WLAN transceiver, which then adjusts its transmission behavior accordingly. This feedback mechanism ensures that WLAN transmissions occur only when they will not interfere with LTE operations, achieving both high throughput and clean spectrum sharing

Inventive Principle:

Principle #23Feedback

3Object-affected harmful factors

If existing synchronization protocols are followed to coordinate LTE and WLAN transmissions, then interference avoidance is maintained, but time utilization is inefficient due to restricted WLAN access

Engineering Contradiction:

Improveinterference avoidanceVSAvoidtime utilization

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the LTE transceiver communicate upcoming downlink scheduling intentions to the WLAN transceiver in advance. This allows the WLAN transceiver to prepare and execute transmissions during LTE downlink sub-frames when safe, maximizing time utilization while maintaining interference avoidance through pre-coordinated scheduling

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9504059B2WLAN and LTE time division based scheduling devices and methods

Publication Date: 2016.11.22 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

A device with concurrent long-term evolution (LTE) and WLAN uplink transmission includes a WLAN transceiver coupled to an LTE transceiver via an interface. The LTE transceiver includes an LTE Layer-1 module that determines whether an LTE data downlink activity is scheduled for an LTE downlink sub-frame of an LTE time frame, based on information in a first portion of the LTE downlink sub-frame. When determination is made that the LTE data downlink activity is not scheduled for the LTE downlink sub-frame, a message may be communicated through the interface to notify the WLAN transceiver that the second portion of the LTE downlink sub-frame is available for WLAN communication. The LTE time frame includes multiple LTE downlink sub-frames each including the first portion and a second portion. The first portion provides the information that indicates whether the LTE data downlink activity is scheduled for the second portion of that LTE sub-frame.