Routing Information Update via Reboot Counter Comparison

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Solution Overview

Problem

In wireless ad hoc networks, nodes face challenges in rapidly updating routing information after a reboot, which can lead to delayed communication recovery, especially in scenarios like power outages affecting electric utility networks, where timely restoration assessment is critical.

Innovation Solution

Nodes assess the reliability of routing information from other nodes and update their own routing information by comparing stored and received reboot data, using more current information from nodes that have not recently rebooted, and employ neighboring nodes as proxies to relay messages to the central control facility upon power restoration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a node performs a full network discovery process after reboot to obtain routing information, then the routing information can be complete and reliable, but the time required for communication recovery is significantly increased

Engineering Contradiction:
Improverouting information reliabilityVSAvoidcommunication recovery time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having nodes store routing information in memory before reboot occurs. After reboot, nodes can retrieve this pre-stored routing information immediately without performing a full discovery process, thus maintaining reliability while reducing recovery time

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary approach by introducing a routing information retrieval mechanism that acts as a mediator between the rebooted node and the network. Instead of directly performing full discovery, the node first retrieves cached routing information through this intermediary process, then supplements it as needed

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If a node uses pre-stored routing information after reboot to quickly resume communications, then communication recovery time is reduced, but the reliability of routing information may be compromised

Engineering Contradiction:
Improvecommunication recovery timeVSAvoidrouting information reliability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-storing routing information in node memory before reboot. This cached information enables immediate resumption of communications while maintaining reliability through subsequent validation and supplementation processes

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback by having nodes validate their pre-stored routing information after reboot by comparing it with current network state. This feedback mechanism ensures that while quick recovery is achieved through cached data, reliability is maintained by detecting and correcting any outdated information

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the utility control facility waits for rebooted nodes to rejoin the network and report before detecting power restoration, then accurate node status information is obtained, but the detection time is delayed

Engineering Contradiction:
Improvepower restoration detection accuracyVSAvoidpower restoration detection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies skipping by allowing nodes to bypass the traditional sequential process of waiting for full network rejoining before reporting. Instead, nodes can report power restoration status immediately upon detecting power availability, rushing through the intermediate steps of complete network re-synchronization and thereby reducing detection time while maintaining accuracy

Inventive Principle:
Principle #21Skipping (Rushing through)

Data Source

PatentEP2272218B1Updating routing and outage information in a communications network
Publication Date: 2011.10.26 SILVER SPRING NETWORKS
  • EP2272218B1 patent drawingFigure 1
  • EP2272218B1 patent drawingFigure 2
  • EP2272218B1 patent drawingFigure 3

AI summary

A method of updating routing information in a network, where reboot information of other nodes in the network is used to determine whether a given node has recent route updates. If the reboot information indicates the given node has not recently rebooted, then routing information from that given node is used to update the routing information of the comparing node. The reboot information may be a reboot counter which is incremented by a node in response to the node going through a reboot process. When a node reboots, it may request the reboot counter from neighboring nodes. The received reboot counter is compared to the stored reboot counter for at least one node. The rebooting node may choose to receive routing information from a node which has not had its reboot counter changed from the stored reboot counter. In the event none of the neighboring nodes have an unchanged reboot counter, requests may be made for the reboot counters of other nodes, which may be compared to the corresponding stored reboot counters, until the rebooting node discovers a node which has not recently rebooted according to the reboot counter, and may then download routing information from that node. After power is restored to a node in a utility network, that node employs one or more of its neighboring nodes as proxies to route a message to a central control facility of the utility.