Schedule-Based Packet Priority Adjustment in Mesh Networks

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Solution Overview

Problem

In mesh networks, particularly Low Power and Lossy Networks (LLNs), outgoing packets often collide when approaching the root node due to the 'fan in' nature of the network topology, leading to reduced throughput and bandwidth inefficiency.

Innovation Solution

An intermediate node in a contention-based shared-media computer network determines a scheduled window for packet transmission and adjusts the packet priority based on whether the actual transmission time is before, during, or after this window, allowing the packet to be transmitted with reduced, assigned, or augmented priority accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If packets are transmitted in a fan-in mesh network topology toward the root node, then network connectivity and data flow are established, but packet collisions occur near the root node leading to reduced throughput

Engineering Contradiction:
ImprovethroughputVSAvoidpacket collisions
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by adjusting packet priorities before transmission based on predicted network conditions and historical data. The system proactively modifies transmission parameters in advance to prevent collisions near the root node, rather than reacting to collisions after they occur. This includes setting initial priorities based on packet type, source location, and expected traffic patterns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamics by continuously adapting packet priorities during transmission based on real-time network conditions. The system dynamically adjusts priorities as packets traverse the network, responding to changing traffic patterns, link quality, and congestion levels. This allows the network to optimize throughput under varying conditions and prevent collisions adaptively.

Inventive Principle:
Principle #15Dynamics

2Object-generated harmful factors

If packet transmission time is extended to avoid collisions, then packet collision probability is reduced, but transmission latency increases

Engineering Contradiction:
Improvepacket collision probabilityVSAvoidtransmission latency
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The patent applies parameter changes by modifying packet priority levels rather than uniformly extending transmission times. The system changes the temporal parameter of transmission by adjusting when packets are transmitted based on their priority, allowing high-priority packets to transmit sooner and low-priority packets to be deferred, thereby reducing collisions without systematically increasing latency for all packets.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent maintains continuity of useful action by ensuring that packet transmission continues without unnecessary delays. The priority-based scheduling system keeps the transmission medium actively utilized by continuously transmitting packets in an optimized sequence, avoiding idle periods that would increase latency while still preventing collisions through intelligent scheduling.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If priority adjustment mechanisms are implemented to manage packet collisions, then throughput is improved, but system complexity increases

Engineering Contradiction:
Improvebandwidth utilizationVSAvoidpriority management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by implementing priority adjustment at specific network nodes rather than requiring global coordination. Each node or intermediate router independently adjusts packet priorities based on local conditions and packet characteristics, eliminating the need for complex network-wide priority management systems while still achieving improved bandwidth utilization.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements self-service by enabling packets to carry their own priority information and by allowing network nodes to autonomously make scheduling decisions based on this information. The system does not require centralized control or complex coordination protocols; instead, each node independently manages its own transmission queue based on packet priorities, significantly reducing overall system complexity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2974184B1Schedule-based prioritization in contention-based shared-media computer networks
Publication Date: 2019.07.03 CISCO TECHNOLOGY INC
  • EP2974184B1 patent drawingFigure 1
  • EP2974184B1 patent drawingFigure 2
  • EP2974184B1 patent drawingFigure 3

AI summary

In one embodiment, an intermediate node in a contention-based shared-media computer network determines a scheduled window within which a packet (with an assigned priority) should be transmitted by the intermediate node. In particular, the intermediate node may specifically determine whether an actual transmission time is prior to, during, or after the window, and sets a priority of the packet as either i) a reduced priority when the actual transmission time is prior to the window, ii) the assigned priority when the actual transmission time is during the window, or iii) an augmented priority when the actual transmission time is after the window. As such, the intermediate node may then transmit the packet from the intermediate node with the set priority at the actual transmission time.