TSCH MAC Layer Collision Avoidance via Deterministic Timeslot Allocation

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Solution Overview

Problem

Mesh radio networks face inefficiencies due to message collisions and traffic congestion, particularly in dynamic and non-hierarchical networks like TSCH networks, where static resource allocation and three or four-way handshakes increase latency and reduce bandwidth.

Innovation Solution

The implementation of an extended MAC layer that reserves specific timeslots for downstream and broadcast messages, and uses pseudo-random channel selection based on destination node ID and ASN, to minimize collisions and optimize message transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dedicated timeslots are allocated to each link in TSCH networks to avoid collisions, then message collision avoidance is improved, but device complexity and network overhead increase significantly

Engineering Contradiction:

Improvemessage collision avoidanceVSAvoidtimeslot allocation complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a self-service mechanism where nodes autonomously select transmission timeslots using a deterministic algorithm based on their node ID and destination node ID. This eliminates the need for complex centralized timeslot allocation and handshaking protocols, reducing device complexity while maintaining collision avoidance through self-organized resource allocation

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent changes the approach from static dedicated timeslot allocation to dynamic timeslot selection based on node identifiers. The transmission timeslot is determined by a function of the source node ID and destination node ID, allowing the network to adapt to changing traffic patterns without complex reconfiguration, thus reducing overhead while maintaining reliability

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If static resource allocation is used in networks, then resource management is simplified, but network efficiency deteriorates when traffic flow and routing paths change constantly

Engineering Contradiction:

Improveresource allocation managementVSAvoidnetwork efficiency

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent implements dynamic resource allocation where transmission timeslots are determined by a deterministic function of node identifiers rather than being statically assigned. This allows the network to automatically adapt to changing traffic patterns and routing paths without complex centralized control, maintaining both simplicity and efficiency

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent performs preliminary action by pre-defining the deterministic algorithm for timeslot selection based on node IDs. This allows nodes to autonomously determine appropriate transmission timeslots without real-time centralized coordination, achieving adaptive efficiency while maintaining simple resource management

Inventive Principle:

Principle #10Preliminary action

3Reliability

If three or four-way handshake protocols are used for resource allocation, then resource allocation reliability is improved, but network latency increases due to additional traffic

Engineering Contradiction:

Improveresource allocation reliabilityVSAvoidnetwork latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the essential function of resource allocation from complex handshake protocols and implements it directly through deterministic timeslot selection based on node identifiers. This eliminates the need for multi-way handshaking while maintaining reliable resource allocation, significantly reducing the latency associated with setup procedures

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements self-service resource allocation where nodes independently determine their transmission timeslots using a deterministic algorithm based on their node ID and destination node ID. This eliminates the need for centralized resource allocation handshakes, maintaining reliability through consistent deterministic selection while reducing latency by removing multiple exchange steps

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS20250048340A1Method and apparatus for performing message collision avoidance in a communications network

Publication Date: 2025.02.06 TRILLIANT NETWORKS INC

AI summary

A method and apparatus for performing collision avoidance in a time slotted, channel hopping (TSCH) communications network. A media access control (MAC) layer controls message addressing and channel access, wherein the MAC layer performs at least one of the following:(1) allocating specific timeslots for messages being communicated downstream from a border router to a destination node;(2) selecting a transmission channel for messages on a pseudo-random basis using a TSCH absolute slot number and a destination node identification; or(3) allocating specific timeslots to broadcast messages.