Distributed Proxy Coordination for Multi-Channel Wireless Networks

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Solution Overview

Problem

In multi-channel wireless networks, coordinating devices across different frequency channels to share information efficiently is challenging due to limitations in existing frequency hopping techniques, particularly in supporting broadcasting, multicasting, and opportunistic spectrum usage, where channel availability changes over time, and the overhead of maintaining a dedicated rendezvous channel.

Innovation Solution

A distributed coordination method where devices on different channels use proxy devices to relay broadcast information, minimizing overhead and delays by allocating dedicated resources and beacon slots, enabling multi-hop communication across channels without a common rendezvous channel, and supporting robust coordination, synchronization, and spectral utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a dedicated rendezvous channel is used for coordination, then information sharing among devices on different channels is enabled, but overhead and resource requirements increase significantly

Engineering Contradiction:
Improveinformation sharingVSAvoidoverhead
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent extracts the coordination function from a dedicated rendezvous channel and distributes it to individual channels. Each channel performs local coordination tasks independently, eliminating the need for a separate overhead channel while maintaining information sharing capabilities.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent makes each channel multi-functional by enabling it to perform both data transmission and coordination functions. Channels can act as master or slave roles dynamically, allowing any channel to handle coordination tasks, thus eliminating the need for a dedicated rendezvous channel.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If frequency hopping techniques are used to improve spectrum utilization, then spectral efficiency increases, but protocol design problems arise such as support for broadcasting and multicasting

Engineering Contradiction:
Improvespectrum utilizationVSAvoidbroadcasting and multicasting support
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements dynamic channel assignment where channels can switch between master and slave roles based on current network conditions. This dynamic flexibility allows the system to maintain frequency hopping benefits while adapting to broadcasting and multicasting requirements by designating appropriate channels for specific functions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces master channels as intermediaries that handle broadcasting and multicasting functions. These master channels act as mediators between slave channels and the network control plane, enabling efficient group communication without requiring all channels to participate in frequency hopping simultaneously.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If devices are tuned to different frequency channels, then spectrum utilization improves, but coordination and information sharing among devices becomes challenging

Engineering Contradiction:
Improvespectrum utilizationVSAvoidcoordination information
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent segments the network into multiple independent channels, each capable of autonomous operation. This segmentation allows devices to operate on different frequency channels simultaneously while maintaining coordination through defined master-slave relationships, preventing information loss across channel boundaries.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback mechanisms where slave channels report status information to master channels, which then propagate necessary coordination information to other channels. This feedback loop ensures that all devices remain synchronized and informed about network state changes despite operating on different frequencies.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2335440B1Mac protocol for multi-channel wireless networks
Publication Date: 2016.03.23 KONINKLIJKE PHILIPS NV
  • EP2335440B1 patent drawingFigure 1~3
  • EP2335440B1 patent drawingFigure 2

AI summary

A distributed coordination of a wireless network operating on different channels is provided by dispatching a device on each 'home' channel to regularly visit other 'foreign' channels to propagate and listen to broadcast information on these channels. The information in the broadcast packets transmitted on the home channel is relayed to the devices on the foreign channels by the dispatched device, as a 'proxy device' that operates on behalf of the other devices in the home channel. In a preferred embodiment, various aspects of this proxy process are optimized to reduce overhead and delays. Each channel is configured to distinguish home devices from foreign devices, to avoid contention between home and foreign devices. Acquired beacon slots on foreign channels are reserved to facilitate returning proxy devices. At the home channel, an anchor device alerts other devices of the proxy device's temporary absence and preserves the proxy device's beacon slot on the home channel.