SDMM Adaptive MAC Scheduling for Wireless Mesh Network Bottlenecks
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Solution Overview
Problem
Conventional topology routing mechanisms in large wireless mesh networks, such as RPL, lead to performance issues like increased latency, throughput variability, and resource bottlenecks due to funnelling effects and contention in unreliable radio conditions, particularly in industrial IoT applications with diverse local networking requirements.
Innovation Solution
The Software Defined Massive Mesh (SDMM) method dynamically schedules communication timeslots using a hybrid approach that combines contention-based and schedule-based MAC protocols, adapting to required throughput, node density, and hidden node percentages to optimize data transmission in multi-hop wireless networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional topology routing mechanisms (such as RPL) are used in large wireless mesh networks, then the network can be established with minimal infrastructure and low cost, but performance deteriorates due to increased latency, throughput variability, and resource bottlenecks from funnelling effects
Solution Approach 1:
The network is segmented into multiple root nodes, each managing a subset of child nodes. This divides the single-point bottleneck into multiple distributed points, eliminating the funnelling effect where all traffic must converge to one root node. Each root node handles only its assigned children's traffic, distributing the load across the network infrastructure.
Solution Approach 2:
The patent introduces a hierarchical dimension to the network topology by creating multiple root nodes at different logical levels. Instead of a flat single-root structure, traffic can be routed through different root nodes based on destination, adding a dimensional aspect to path selection that reduces congestion and latency.
2Device complexity
If all child nodes transmit data to a single parent node in RPL, then the parent node can forward all messages to the root node, but contention and retransmissions increase due to unreliable local radio conditions
Solution Approach 1:
Different MAC protocols are assigned to different child nodes based on their local conditions. Nodes experiencing poor radio conditions are assigned to protocols better suited for unreliable environments, while nodes with good conditions use more efficient protocols. This local differentiation optimizes reliability without requiring complex global routing changes.
Solution Approach 2:
The system dynamically changes MAC protocol parameters (such as contention window sizes, transmission powers, and retry limits) based on observed radio conditions. When conditions deteriorate, parameters are adjusted to improve packet delivery reliability; when conditions improve, parameters are optimized for higher throughput.
3Device complexity
If a single root node is used in RPL, then routing is simplified with minimal information requirements, but buffer and spectrum resources near the root node are overused due to funnelling effects
Solution Approach 1:
The network is segmented into multiple root nodes, each managing a subset of child nodes. This divides the single-point bottleneck into multiple distributed points, eliminating the funnelling effect where all traffic must converge to one root node. Each root node handles only its assigned children's traffic, distributing the load across the network infrastructure.
Solution Approach 2:
Multiple root nodes provide universal service across the network, with each root node capable of handling traffic from its assigned children. This multi-functionality distributes the resource burden that would otherwise concentrate on a single root node, balancing buffer and spectrum usage across multiple points.
4Reliability
If local clusters experience contention due to unreliable radio conditions, then nodes can attempt retransmissions, but different QoS requirements for multiple applications cannot be satisfied
Solution Approach 1:
Different MAC protocols are assigned to different child nodes based on their local conditions. Nodes experiencing poor radio conditions are assigned to protocols better suited for unreliable environments, while nodes with good conditions use more efficient protocols. This local differentiation optimizes reliability without requiring complex global routing changes.
Solution Approach 2:
The MAC protocol assignment is dynamic rather than static. The system can adapt protocol assignments based on changing conditions and QoS requirements. Different applications can receive different levels of service through protocol selection, allowing the system to dynamically respond to varying demands while maintaining reliability.
Data Source
AI summary
Method for transmitting data from a plurality of child nodes to a parent node in a wireless network, wherein each child node is configured to send messages directed to a root node of the network via the parent node, the method comprising the parent node: dividing a first time period into a plurality of timeslots; assigning a MAC protocol to one or more child node for transmission of data to the parent node during the first time period; allocating one or more of said plurality of timeslots into which the first period is divided to said one or more child nodes for transmission to the parent node according to the MAC protocol assigned to them; transmitting details of the respective assigned MAC protocol and allocated timeslot to said one or more child nodes.