Companion PAN Support for Dual-Protocol Zigbee Sleep Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dual-protocol personal area network (PAN) devices face challenges in managing simultaneous communication with multiple protocols, leading to increased power consumption, network disruptions, and inefficient reconnection processes due to clock drift and channel interference, particularly in low-power Zigbee and Thread networks.
Innovation Solution
A companion PAN device is delegated to temporarily assume a subset of Zigbee communication stack responsibilities, including MAC ACK and frame buffering, to maintain network connectivity when the primary PAN device is busy with another protocol, reducing power consumption and network disruptions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single radio hardware subsystem is shared between multiple protocols, then device cost and complexity are reduced, but protocol interference and network reliability deteriorate
Solution Approach 1:
The patent segments the radio subsystem operations by creating separate MAC layer instances for each protocol (Thread and Zigbee). Each protocol gets its own logical radio interface with dedicated MAC state machines, allowing simultaneous operation without interference while sharing the physical radio hardware. This segmentation resolves the contradiction by providing protocol isolation at the software layer.
Solution Approach 2:
The patent introduces a protocol scheduler as an intermediary layer between the MAC sublayers and the physical radio subsystem. This mediator allocates radio access time to different protocols, manages channel isolation, and coordinates transmission timing. The scheduler acts as a buffer that prevents direct protocol interference while maintaining reliable network operations for both Thread and Zigbee.
2Device complexity
If time-sharing is used between multiple protocols on the same radio, then device cost is reduced, but timing precision and network performance worsen
Solution Approach 1:
The patent applies preliminary action by pre-configuring separate MAC layer instances and protocol-specific radio parameters before operation. Each protocol's MAC layer is initialized with protocol-specific timing parameters and channel configurations in advance. This pre-setup allows the system to switch between protocols without reconfiguration delays, maintaining timing precision despite time-sharing the physical radio.
3Reliability
If channel isolation is implemented for dual protocol support, then network reliability improves, but device complexity and software design complexity increase
Solution Approach 1:
The patent segments the software architecture into separate MAC layer instances for Thread and Zigbee protocols. Each MAC instance maintains independent state machines, association tables, and communication buffers. This segmentation provides automatic channel isolation without requiring complex software coordination, as each protocol operates in its own logical namespace with dedicated data structures.
4Use of energy by moving object
If sleepy ZEDs use low power clock sources during sleep, then energy consumption is reduced, but clock drift and timing accuracy worsen
Solution Approach 1:
The patent implements feedback mechanisms where the MAC layer monitors timing deviations in sleepy ZEDs and adjusts their wake schedules accordingly. When clock drift is detected through missed acknowledgments or timing errors, the system sends timing correction messages to ZEDs, which then adjust their low-power clock operations. This feedback loop maintains timing accuracy while ZEDs continue to use energy-efficient low-power clock sources during sleep.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for delegating personal access network, PAN, responsibilities to a companion PAN device comprises: receiving, at the companion PAN device, at least one configuration parameter from a multiple-protocol PAN device configured to support Zigbee™ and another communication protocol; and entering a sleep mode by the multiple-protocol PAN device. The configuration parameter comprises instructions to temporarily enable the companion PAN device, during periods of inactivity in supporting the another communication protocol, to perform the following: receiving at least one medium access control, MAC, access request from at least one child device associated with the multiple-protocol PAN device; and performing a subset of roles of a full Zigbee™ communication stack therefor, that includes: responding with an acknowledgement; and buffering and storing frames from the child device. The companion PAN device subsequently receives a wake-up message from the multiple-protocol PAN device; and forwards retrieved stored frames to the multiple-protocol PAN device.