Unlicensed Carrier Sensing for Fair Multi-Service Spectrum Access

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Solution Overview

Problem

The fair sharing of unlicensed spectrum resources among users of different service types, such as WiFi, LTE, and 5G, is not adequately addressed in current technologies, leading to potential interference and inefficient data transmission.

Innovation Solution

A data sending method and communications device that utilize carrier sensing mechanisms to determine channel availability, allowing fair contention and coexistence by randomly selecting carriers based on probability and duration, ensuring efficient access to multiple channels for improved data transmission rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple users of different service types access the unlicensed spectrum resource simultaneously, then the data transmission rate and throughput are improved, but interference and channel contention conflicts increase

Engineering Contradiction:
Improvedata transmission rateVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies listen-before-talk (LBT) mechanism where users perform carrier sensing and clear channel assessment before transmitting data. This preliminary action of detecting channel availability prevents simultaneous transmissions that would cause interference, allowing multiple users to access the unlicensed spectrum efficiently without harmful conflicts

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic backoff mechanisms where transmission delays are adjusted based on channel conditions and contention outcomes. Users dynamically modify their transmission timing and power levels in response to detected interference and channel occupancy, enabling adaptive coexistence that maintains high data rates while reducing harmful interference effects

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If users perform carrier sensing to determine channel availability, then fair contention is achieved, but transmission delay increases

Engineering Contradiction:
Improvefair contentionVSAvoidtransmission delay
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent implements partial carrier sensing where users sense only specific frequency sub-bands or carriers rather than the entire unlicensed spectrum. This partial action reduces the sensing time and transmission delay while still achieving fair contention by allowing users to find available channels more quickly without requiring complete channel assessment

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent uses pre-configured sensing parameters and predetermined backoff counters that are initialized before contention begins. This preliminary setup allows users to rapidly execute the sensing and transmission sequence without repeated negotiations, reducing overall transmission delay while maintaining fair access through standardized procedures

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If the sensing duration is extended to ensure accurate channel detection, then detection precision is improved, but the time required for data transmission increases

Engineering Contradiction:
Improvechannel detection precisionVSAvoidsensing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent divides the unlicensed spectrum into multiple carriers or sub-bands that can be sensed independently and in parallel. This segmentation allows the sensing process to be distributed across multiple frequency channels simultaneously, maintaining detection precision for each carrier while reducing the total sensing time through parallel processing of segmented frequency portions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements truncated sensing where users perform carrier sensing for a minimum required duration to achieve adequate detection precision, rather than extending sensing to maximum possible lengths. This partial sensing action achieves sufficient channel detection accuracy while limiting the time consumed, allowing faster transition to data transmission

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3621404B1Method for sending data, and communication device
Publication Date: 2026.01.07 HUAWEI TECH CO LTD
  • EP3621404B1 patent drawingFigure 1
  • EP3621404B1 patent drawingFigure 2
  • EP3621404B1 patent drawingFigure 3

AI summary

The present invention discloses a data sending method and a communications device. The method includes: sensing, by a communications device, a carrier located in a first unlicensed frequency band, where the first unlicensed frequency band includes at least one carrier; and sending, by the communications device, data on a carrier whose channel state is sensed to be idle. The communications device senses a first carrier in the first unlicensed frequency band, and sends the data on the first carrier that is successfully sensed. Another communications device may also sense in the first unlicensed frequency band, and send data in the first unlicensed frequency band when sensing successfully. Therefore, users of different services may fairly contend and coexist in an unlicensed frequency band.