Reconciliation Module for Multidrop Bus Collision Avoidance

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Solution Overview

Problem

Collisions on multidrop bus networks lead to decreased efficiency and throughput, as multiple nodes attempting to transmit data simultaneously result in corrupted data, time-outs, and loss of bus capacity.

Innovation Solution

A reconciliation module is introduced between the MAC and PHY modules, which asserts a collision signal to stop data transmission upon receipt and controls a sense signal to enable re-transmission during an upcoming transmit opportunity, thereby avoiding collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple nodes transmit data simultaneously on a multidrop bus network, then data transmission activity increases, but collisions occur causing decreased bus efficiency and throughput

Engineering Contradiction:
Improvebus throughputVSAvoiddata transmission reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The reconciliation module performs preliminary actions by asserting collision signals before actual data transmission occurs. When the MAC module attempts to transmit data, the reconciliation module proactively asserts collision signals to prevent simultaneous transmission, thereby avoiding collisions before they can degrade bus efficiency and throughput.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the reconciliation module continuously monitors transmission status and adjusts collision signal assertion accordingly. The MAC module receives feedback about transmission success or failure, and the reconciliation module modifies its collision signal behavior based on this feedback to optimize bus efficiency while maintaining data reliability.

Inventive Principle:
Principle #23Feedback

2Reliability

If the reconciliation module asserts collision signals to prevent collisions, then bus efficiency improves, but transmission opportunities may be lost if not synchronized properly

Engineering Contradiction:
Improvecollision avoidanceVSAvoidtransmission timing loss
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The reconciliation module dynamically adjusts collision signal assertion timing based on the current transmission state. Rather than using fixed timing, the module adapts its behavior to synchronize collision prevention with actual transmit opportunities, ensuring that data transmission is blocked only when necessary and that legitimate transmission attempts are not unnecessarily delayed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent replaces traditional mechanical timing mechanisms with a more flexible signal-based synchronization system. The reconciliation module uses logical signal coordination rather than rigid temporal scheduling to manage transmission opportunities, allowing for more flexible timing that prevents collisions without sacrificing transmission efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the MAC module delays resending data after collision, then data can be transmitted at upcoming transmit opportunity, but additional wait time is required

Engineering Contradiction:
Improvedata re-transmission efficiencyVSAvoidwait time after collision
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The reconciliation module ensures continuity of useful action by maintaining the sense signal in an asserted state during the wait period after collision detection. This prevents the MAC module from prematurely attempting re-transmission and ensures that the transmission opportunity is reserved and ready when the data is ready for re-send, eliminating unnecessary delays.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system performs preliminary preparation for data re-transmission by maintaining the sense signal assertion during the collision recovery period. This preliminary action ensures that when the data is ready for re-transmission, the transmission opportunity is already prepared and synchronized, eliminating the need for additional wait time after the collision is resolved.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4542937A1A reconciliation module and associated method for collision avoidance
Publication Date: 2025.04.23 NXP BV
  • EP4542937A1 patent drawingFigure 1~2
  • EP4542937A1 patent drawingFigure 3
  • EP4542937A1 patent drawingFigure 4

AI summary

A reconciliation module for a node of a multidrop bus network, the reconciliation module comprising circuitry configured to: receive data sent from a MAC module of the node as part of a first attempt by the MAC module to transmit the data; assert a collision signal by default on receipt of the data from the MAC module to stop the MAC module from continuing to send the data; and control a sense signal to cause the MAC module to resend the data as part of a second transmission attempt such that the data may be transmitted on the multidrop bus network via a PHY module of the node at an upcoming transmit opportunity.