Dynamic Packet Relay for Sensor Network Coordinator Failure
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Solution Overview
Problem
In sensor networks, communication failures due to unstable coordinator operation can occur, especially in environments where equipment replacement is difficult, such as in trains, leading to instability in sensor data transmission.
Innovation Solution
A dynamic packet relay method and apparatus that monitor the coordinator's status, change the coordinator if defective, and utilize inactive periods for data transmission, ensuring continuous data transmission by switching roles among devices within the network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a coordinator is employed to extend transmission distance in sensor networks, then the coverage area is improved, but communication reliability deteriorates when the coordinator fails
Solution Approach 1:
The patent introduces intermediary devices (sensor nodes) that can act as relay coordinators. When the primary coordinator fails, these intermediary devices take over the coordination function, ensuring continuous communication. This resolves the contradiction by creating a backup mechanism that maintains both coverage area and reliability.
Solution Approach 2:
The patent implements dynamic coordinator selection where any sensor node can become the coordinator based on network conditions. This dynamic role assignment ensures that if one coordinator fails, another can take over, maintaining communication reliability while preserving the extended coverage area provided by the coordinator architecture.
2Use of energy by moving object
If the coordinator operates during active periods only, then power consumption is reduced, but data transmission capability deteriorates during inactive periods
Solution Approach 1:
The patent enables continuous data transmission by allowing the coordinator to receive and forward packets during both active and inactive periods. While the coordinator consumes more power during inactive periods to maintain transmission capability, this ensures uninterrupted data flow, resolving the contradiction between power consumption and transmission productivity.
Solution Approach 2:
The patent implements periodic data transmission where the coordinator alternates between receiving packets during inactive periods and forwarding them during active periods. This periodic operation maintains both power efficiency and transmission capability by strategically utilizing different operational periods.
3Reliability
If guaranteed time slot (GTS) operation is implemented for the coordinator, then data transmission reliability is improved, but device complexity increases due to IEEE 802.15.4 limitations
Solution Approach 1:
The patent segments the data transmission process into separate reception and forwarding phases. The coordinator receives packets from sensors during inactive periods and forwards them to the PAN coordinator during active periods. This segmentation simplifies the implementation by avoiding the need for complex GTS management while maintaining reliable transmission.
Solution Approach 2:
The patent enables the coordinator to autonomously manage packet forwarding without requiring complex GTS allocation mechanisms. The coordinator automatically receives packets during inactive periods and forwards them during active periods, providing self-service functionality that reduces device complexity while maintaining transmission reliability.
4Reliability
If the coordinator is replaced when defective, then communication reliability is improved, but system stability deteriorates during the replacement process
Solution Approach 1:
The patent implements preliminary coordinator selection where potential backup coordinators are identified and prepared in advance. When the current coordinator fails, the pre-selected backup can immediately take over without requiring a complex replacement process, thus maintaining both reliability and system stability.
Solution Approach 2:
The patent creates a cushioning mechanism by maintaining multiple potential coordinators in standby mode. This beforehand preparation ensures that when a coordinator failure occurs, the transition to a backup coordinator is smooth and stable, preventing system disruption while improving reliability.
Data Source
AI summary
A dynamic packet relay method of a personal area network (PAN) coordinator in a sensor network includes receiving a Child_Register message that includes information about a device associated with a coordinator and building or updating a network hierarchical structure; monitoring reception of a packet or a beacon from the coordinator and determining whether the coordinator is defective or not; and in response to a determination that the coordinator is defective, changing the current coordinator to one of devices belonging to a PAN as a new coordinator.