Wireless Packet Communication Apparatus Leakage Management

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Solution Overview

Problem

Conventional wireless packet communication systems using multiple channels face decreased throughput due to signal leakage, which causes improper virtual carrier sense and collision of packets, leading to reduced efficiency in channel utilization.

Innovation Solution

Implementing a method where a transmit-side STA sets transmission inhibition time on affected wireless channels based on leakage effects, ensuring proper virtual carrier sense by adding a predetermined time to the transmission time of the wireless packet, even if the channel cannot receive due to leakage, and adjusting inhibition times based on received power and error detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If transmission inhibition time is set on paired wireless channels to prevent signal leakage interference, then packet collision is reduced and reliability is improved, but channel utilization decreases and throughput is reduced

Engineering Contradiction:

Improvepacket transmission reliabilityVSAvoidchannel utilization

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by differentiating the treatment of wireless channels based on their susceptibility to signal leakage. Instead of uniformly setting transmission inhibition time on all channels, the system selectively applies inhibition only to paired channels that are actually affected by leakage from the transmitting channel. This selective approach maintains reliability where needed while preserving channel utilization where not required.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements preliminary action by setting transmission inhibition time on paired wireless channels before actual transmission occurs. The system proactively identifies channels that may be affected by signal leakage and pre-empts potential collisions by establishing virtual carrier sense restrictions in advance, thereby ensuring reliable transmission without waiting for interference to actually occur.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If transmission inhibition time is set on paired wireless channels to prevent signal leakage interference, then packet collision is reduced, but transmission delay increases

Engineering Contradiction:

Improvepacket transmission reliabilityVSAvoidtransmission delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent minimizes transmission delay by applying transmission inhibition selectively only to paired channels that are actually affected by signal leakage. Channels not subject to leakage interference are left available for immediate transmission, thereby reducing overall transmission delay while maintaining reliability where it is truly needed.

Inventive Principle:

Principle #3Local quality

3Productivity

If virtual carrier sense is used to control channel access, then channel sharing efficiency is improved, but signal leakage causes improper sense and reduces reliability

Engineering Contradiction:

Improvechannel sharing efficiencyVSAvoidvirtual carrier sense accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary anti-action by proactively setting transmission inhibition time on paired wireless channels before signal leakage can cause improper virtual carrier sense. This preemptive measure counteracts the harmful effect of leakage by establishing virtual carrier sense restrictions in advance on channels that would otherwise be incorrectly perceived as idle, thereby maintaining both channel sharing efficiency and sense accuracy.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent introduces an intermediary mechanism where the transmit-side STA acts as a mediator that proactively informs paired channels of upcoming transmissions by setting transmission inhibition time. This intermediary action prevents other STAs from incorrectly sensing the channel as idle due to signal leakage, thereby maintaining the accuracy of virtual carrier sense while preserving channel sharing efficiency.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances channel utilization by preventing unnecessary inhibition times and improving throughput by ensuring accurate virtual carrier sense, even in the presence of signal leakage, thereby reducing packet collisions and increasing overall efficiency.

Implementation Method 1

signal leakage, which causes improper virtual carrier sense and collision of packets

Methodology Applied

Scientific EffectSignal leakage:

Data Source

PatentUS7545781B2Wireless packet communication method and wireless packet communication apparatus

Publication Date: 2009.06.09 NIPPON TELEGRAPH & TELEPHONE CORP

AI summary

A transmit-side STA transmits a wireless packet using a wireless channel which has been determined to be idle by both a physical carrier sense for determining based on received power whether the wireless channel is busy or idle and a virtual carrier sense for determining the wireless channel to be busy during set transmission inhibition time. At this time, the transmit-side STA sets transmission time used for the virtual carrier sense to a paired wireless channel which is affected by leakage from a transmitting wireless channel. This allows for setting transmission inhibition time to a paired wireless channel even when the paired wireless channel cannot successfully receive due to the effect caused by leakage from the transmitting wireless channel.