Communication Device Busy Signal Control for Hidden Node Avoidance

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Solution Overview

Problem

Existing communication systems face inefficiencies in avoiding the hidden node problem, particularly when full-duplex terminals fail to detect duration information, leading to interference from hidden terminals in other systems.

Innovation Solution

A communication device that determines whether a received data signal requires a busy signal and controls its transmission based on this determination, allowing full-duplex communication while minimizing interference by transmitting a busy signal only when necessary, thus protecting channel usage notifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full-duplex terminal transmits a busy signal upon detection of a data signal, then the hidden terminal problem is reduced for terminals that can decode duration information, but transmission opportunity for the hidden terminal is significantly reduced

Engineering Contradiction:
Improvehidden terminal problem avoidanceVSAvoidtransmission opportunity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the busy signal transmission conditional rather than automatic. The terminal dynamically determines whether to transmit a busy signal based on decoding success of duration information and compatibility with other communication systems. This conditional approach allows the system to adapt its behavior based on real-time conditions, preserving transmission opportunities when busy signals are not needed while maintaining hidden terminal protection when necessary.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of busy signal transmission from a fixed state (always transmit) to a variable state (transmit only when needed). By monitoring whether duration information can be decoded and whether the terminal is in a full-duplex mode, the system adjusts the busy signal transmission parameter accordingly, optimizing both hidden terminal protection and transmission efficiency.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If RTS/CTS frame exchange is used to solve the hidden node problem, then communication terminals can avoid collisions, but the time taken for frame exchange is overhead

Engineering Contradiction:
Improvecollision avoidanceVSAvoidframe exchange overhead
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the essential function of hidden terminal protection from the lengthy RTS/CTS frame exchange process. Instead of using the complete RTS/CTS protocol, the system extracts only the critical busy signal transmission mechanism that provides sufficient protection against hidden terminals while eliminating the unnecessary frame exchange overhead, achieving collision avoidance with minimal time loss.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent skips the lengthy RTS/CTS frame exchange process and rushes through to the essential busy signal transmission. By directly transmitting busy signals when needed rather than going through the full RTS/CTS protocol, the system achieves hidden terminal protection while significantly reducing the time overhead associated with frame exchange.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Object-affected harmful factors

If a busy signal is transmitted to protect data signal reception, then hidden terminal interference is reduced, but transmission opportunity is reduced

Engineering Contradiction:
Improvehidden terminal interferenceVSAvoidtransmission opportunity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent applies partial action by transmitting busy signals only partially - specifically, only when duration information decoding succeeds and the terminal is in full-duplex mode. This selective busy signal transmission provides sufficient hidden terminal protection without the excessive action of continuously transmitting busy signals, thereby preserving transmission opportunities when full protection is not needed.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3709753B1Communication device
Publication Date: 2023.11.29 SONY GROUP CORP
  • EP3709753B1 patent drawingFigure 1
  • EP3709753B1 patent drawingFigure 2
  • EP3709753B1 patent drawingFigure 3

AI summary

[Problem] A communication device that can more efficiently avoid the hidden node problem is provided. [Solution] The communication device includes a communication unit configured to receive a data signal from another communication device, a determination unit configured to determine whether the data signal received by the communication unit includes a request for transmission of a busy signal indicating that a channel is in use, and a control unit configured to control a process of transmitting the busy signal by the communication unit, in accordance with a determination result of the determination unit.