HEMS Controller Re-certification Sequence Optimization

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Solution Overview

Problem

Home energy management systems (HEMS) face significant delays in re-certification processes, especially under poor communication conditions, when multiple devices need to be re-certified, leading to prolonged times for completing the re-delivery of group keys.

Innovation Solution

A communication device with a certifier that suspends re-certification for non-responsive devices and prioritizes re-certification of other devices, allowing for parallel processing and dynamic priority determination based on communication history and schedules, while providing unique unicast keys and a common multicast key via multicast communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the HEMS controller performs sequential re-certification for multiple devices after restart, then each device receives proper certification, but the total re-certification time becomes excessively long especially under poor communication conditions

Engineering Contradiction:

Improvecertification completenessVSAvoidre-certification time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the re-certification process into two distinct phases: (1) individual unicast communication for key delivery to each device, and (2) group multicast communication for simultaneous key distribution to multiple devices. This segmentation allows the system to first establish reliable individual connections and then efficiently broadcast to all devices, resolving the contradiction between ensuring complete certification and reducing total time

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent merges sequential unicast communication with parallel multicast communication. After individual key delivery via unicast, the system combines all certification operations into a single multicast broadcast that reaches multiple devices simultaneously. This merging of communication methods eliminates the time-consuming sequential process while maintaining certification reliability

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If the HEMS controller waits for responses from all devices before proceeding with re-certification, then communication reliability is maintained, but the re-certification process is delayed by unresponsive devices

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidre-certification throughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by first establishing individual unicast communication channels and delivering keys to each device before proceeding to group multicast communication. This preliminary step ensures that each device is individually acknowledged and ready, allowing the subsequent multicast phase to proceed without being blocked by unresponsive devices, thus maintaining reliability while improving throughput

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent inverts the traditional approach by switching from waiting for individual device responses to a push-based multicast model. Instead of pulling responses from each device sequentially, the system pushes certification keys to all devices simultaneously via multicast, inverting the communication paradigm from request-response to broadcast-acknowledge, thereby eliminating bottlenecks caused by unresponsive devices

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS11362892B2Communication device, certification method, and computer readable recording medium for recertification of devices

Publication Date: 2022.06.14 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A home energy management system (HEMS) controller certifies a plurality of devices participating in an HEMS network. When a request for re-certification is issued to a given device among the plurality of devices and when a response is not available from the device, the HEMS controller suspends a re-certification process for the device and performs a re-certification process for another device first.