Alarm Coalescing via Distance-Based Delay in Sensor Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sensor networks experience congestion and message loss due to alarm storms, where a large number of devices generate alarms in response to an event, leading to network congestion and potential delays or losses, especially in large-scale networks like advanced metering infrastructure (AMI) networks.
Innovation Solution
The implementation of routing trees with delay values calculated inversely proportional to the distance from each node to the root node, allowing nodes to wait and coalesce upstream messages before transmitting their own alarms downstream, thereby reducing network traffic and eliminating duplicate messages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If nodes transmit alarms immediately upon detecting an event, then the alarm is transmitted quickly to the destination, but network congestion and message loss occur due to alarm storms
Solution Approach 1:
Nodes calculate delay values in advance based on their distance from the root node before any alarm events occur. When an alarm is generated, the node already has a pre-determined delay value to apply, enabling immediate timer initiation without computation overhead during the alarm event itself.
Solution Approach 2:
The patent implements periodic alarm transmission by using delay values that create staggered transmission intervals. Nodes transmit alarms at different times based on their pre-calculated delay values, transforming simultaneous alarm transmissions into a distributed periodic pattern that prevents network congestion while maintaining reliable delivery.
2Loss of time
If nodes transmit alarms immediately upon detecting an event, then the alarm response time is minimized, but network congestion leads to message delays and losses
Solution Approach 1:
Delay values are pre-calculated for each node based on its distance from the root node before alarm events occur. This preliminary computation eliminates processing delays during actual alarm events, as nodes simply initiate timers with pre-determined values rather than calculating delays in real-time.
Solution Approach 2:
The patent allows nodes to rapidly initiate alarm transmission by starting timers immediately upon event detection, then skipping the actual transmission until the timer expires. This approach minimizes response preparation time while ensuring messages are transmitted at optimal intervals that prevent network congestion.
3Quantity of substance
If all nodes transmit alarms simultaneously in response to an event, then complete alarm information is captured, but network congestion causes message loss
Solution Approach 1:
The patent transforms simultaneous alarm transmissions into a distributed periodic pattern where each node transmits at intervals determined by its pre-calculated delay value. This periodic distribution maintains comprehensive alarm information capture while preventing the network congestion that would result from simultaneous transmissions.
Solution Approach 2:
The patent changes the transmission timing parameter for each node based on its distance from the root node. By modifying the time parameter rather than the message content or volume, the system maintains complete alarm information while distributing transmissions over time to prevent network congestion and message loss.
4Quantity of substance
If nodes transmit alarms without delay, then the alarm storm captures all affected devices, but duplicate messages congest the network
Solution Approach 1:
The patent implements periodic alarm transmission with staggered intervals based on node distance from the root. This periodic pattern ensures all affected devices are captured in the alarm storm while distributing transmissions over time to reduce network traffic complexity and eliminate duplicate message congestion.
Solution Approach 2:
The patent modifies the time parameter of alarm transmission for each node based on its position in the network topology. By changing the transmission timing parameter rather than suppressing messages, the system maintains comprehensive device participation while reducing network traffic complexity through temporal distribution of alarms.
Data Source
AI summary
In one embodiment, a sensor device in a network detects an alarm condition. The sensor device generates an alarm message based on the detected alarm condition and waits for a delay whose length is inversely proportional to a distance between the sensor device and a downstream destination device for which the alarm message is destined. During the delay, the sensor device receives one or more additional alarm messages from one or more upstream sensor devices. The sensor device coalesces the one or more received alarm messages from the one or more upstream sensor devices with the alarm message generated at the sensor device, to form a coalesced alarm message, and transmits the coalesced alarm message downstream towards the downstream destination device, after expiration of the delay.