Wireless Mesh Network Load Balancing for HVAC Controller Connectivity

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Solution Overview

Problem

Large HVAC systems with numerous roof-top units (RTUs) face connectivity challenges due to over-populated mesh networks, leading to poor connectivity, increased latency, and reduced performance as the network size grows, causing inefficiencies in data transmission.

Innovation Solution

Implementing a load balancing system where gateway controllers manage the number of controllers within local mesh networks by releasing controllers from over-populated networks and adding them to under-populated ones, reducing hops and improving network performance through resource optimization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the number of RTUs in the mesh network increases to accommodate more HVAC units, then the network coverage and system capacity improve, but the connectivity quality and network performance deteriorate due to increased hops and latency

Engineering Contradiction:
Improvenumber of RTUsVSAvoidconnectivity quality
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent divides the large mesh network into multiple smaller sub-networks by introducing gateway controllers that manage clusters of RTUs. Each gateway controller maintains a local mesh network with a limited number of controllers (e.g., 5-10 RTUs per gateway), preventing any single network from becoming over-populated. This segmentation resolves the contradiction by allowing the system to accommodate many RTUs overall while maintaining small, high-performance local networks.

Inventive Principle:
Principle #1Segmentation

2Productivity

If more controllers are added to a local mesh network to increase system capacity, then the overall network coverage improves, but the latency and data transmission speed increase due to more hops

Engineering Contradiction:
Improvesystem capacityVSAvoidlatency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent implements local quality by ensuring that each local mesh network managed by a gateway controller maintains optimal performance characteristics. By limiting the number of controllers per local network and managing controller distribution across multiple gateways, the system ensures that data transmission within any local network experiences minimal hops and latency, while the aggregate system capacity scales through the addition of more gateway controllers.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If the mesh network size increases to accommodate more HVAC controllers, then the system can manage more equipment, but the throughput and speed of data communication decrease

Engineering Contradiction:
Improvenumber of controllersVSAvoiddata transmission throughput
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent introduces a hierarchical dimension to the network architecture, with gateway controllers forming an upper layer that manages multiple local mesh networks. This dimensional change allows the system to scale the number of controllers vertically across multiple gateway-managed networks rather than horizontally within a single large network, maintaining high throughput in each local network while accommodating a large total number of controllers system-wide.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3961996B1Load balancing wireless mesh networks for heating, ventilation, and air conditioning systems
Publication Date: 2023.12.27 LENNOX IND INC
  • EP3961996B1 patent drawingFigure 1
  • EP3961996B1 patent drawingFigure 2
  • EP3961996B1 patent drawingFigure 3

AI summary

A system (100) that includes a plurality of controllers (102) that are each configured to operate at least a portion of a Heating, Ventilation, and Air Conditioning (HVAC) system (104). The system (100) further includes a gateway controller (103) that is configured to determine a mesh network size for a local mesh network (110), to broadcast the mesh network size to other gateway controllers (103A-D) within a local area network (112), and to receive mesh network size information from the other gateway controllers (103A-D). The gateway controller (103) is further configured to compute an average mesh network size for the local area network (112) and to compare the mesh network size for the local mesh network (110) to the average mesh network size. The gateway controller (103) is further configured to modify the number of controllers (102) within the local mesh network (110) based on the comparison.