Wireless Lighting Occupancy Messaging Reliability

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Solution Overview

Problem

In wireless networked lighting systems, message loss or delay can result in lamps not being switched on or switching on too late, affecting reliability and user experience.

Innovation Solution

A device with a target detector and transmitter that sends multicast messages to both the controller and lamps when rapid response is needed, and unicast messages when speed is not essential, using wireless protocols like ZigBee or 6LoWPAN, to ensure timely and reliable lamp activation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a unicast message is transmitted from the sensing device to the central controller, then the system uses less network bandwidth and energy, but the message may be lost or delayed causing lamps to not switch on or switch on too late

Engineering Contradiction:
Improvelamp activation reliabilityVSAvoidlamp switching delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The sensing device proactively transmits occupancy information directly to lamps in addition to the controller, preemptively ensuring lamps receive the information before any potential message loss occurs. This preliminary direct communication eliminates the single-point-of-failure bottleneck at the controller.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention introduces lamps as intermediary recipients of occupancy information. Instead of relying solely on the controller as an intermediary, lamps directly receive multicast messages from sensing devices, creating redundant communication paths that bypass potential controller bottlenecks or message losses.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If a multicast message is transmitted to both the controller and lamps simultaneously, then the response speed and reliability improve, but the network traffic increases

Engineering Contradiction:
Improvelamp switching response speedVSAvoidnetwork message quantity
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The system applies different communication strategies to different parts of the network: multicast messages are sent to lamps that are locally present and can immediately act on the information, while unicast messages are used for controller communication. This localized optimization reduces unnecessary network traffic while maintaining fast local response.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system uses multicast messaging selectively rather than universally - only when lamps are present and need immediate activation. This partial application of multicast (rather than excessive use) balances network traffic with the need for fast response, applying the higher-bandwidth protocol only where and when necessary.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3320756B1Occupancy messaging in wireless networked lighting system
Publication Date: 2022.12.21 SIGNIFY HOLDING BV
  • EP3320756B1 patent drawingFigure 1
  • EP3320756B1 patent drawingFigure 2
  • EP3320756B1 patent drawingFigure 3~4

AI summary

Devices (10) comprise target detectors (11) for detecting presences of targets in first areas (1) and transmitters (12) for in response to detected presences transmitting multicast messages to controllers (20) and lamps (21-24) in wireless networked lighting systems. Such multicast messages increase reliabilities of the systems. The multicast messages switch on the lamps (21-24). Preferably, the multicast messages are only transmitted in case relatively small amounts of light are detected in second areas (2). In case relatively large amounts of light are detected in the second areas (2), unicast messages are in response to detected presences transmitted from the devices (10) to the controllers (20) that in response control the lamps (21-24) to be switched on. The first and second areas (1, 2) may be at least partly overlapping areas. The devices (10) may comprise internal light detectors (13) for detecting the amounts of light in the second areas (2) or receivers for receiving light detection information from external light detectors.