LLN Node Transmit Power Control for Isolated Sub-DAG Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In low-power and lossy networks, isolated sub-Directed Acyclic Graphs (DAGs) face challenges in optimizing transmissions within confined areas due to node density, leading to unreliable communications with parent network devices and interference among neighboring nodes, which prevents the formation of a stable link layer mesh.
Innovation Solution
Each LLN device within the isolated area determines a self-estimated density value of neighboring nodes and adjusts its wireless transmit power accordingly, while an external edge node identifies the best LLN device to operate as a subroot, allowing for dynamic adjustment of transmit power and optimized communication within the isolated area without desensitizing neighboring receivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high transmission power values are used by LLN nodes inside the vault to communicate with parent network devices outside the vault, then reliable communications with external devices is improved, but interference with neighboring LLN nodes increases causing receiver desensitization
Solution Approach 1:
The patent applies local quality by allowing LLN nodes to use different transmission power values based on their location and role. Edge nodes use high transmission power to communicate with external parent devices, while internal nodes use lower transmission power for local communications. This localized differentiation resolves the contradiction by applying high power only where necessary (external communication) rather than uniformly across all nodes.
Solution Approach 2:
The patent segments the network into edge nodes and internal nodes based on their communication needs. Edge nodes are specifically identified and assigned different transmission power characteristics compared to internal nodes. This segmentation allows the system to optimize power usage for each segment's specific function, preventing overall interference while maintaining external communication reliability.
2Length of stationary object
If high transmission power values are used to overcome physical barriers, then communication reach is improved, but neighboring nodes must desensitize their receivers preventing link layer mesh formation
Solution Approach 1:
The patent implements local quality by differentiating transmission power behavior between edge nodes (which need long range) and internal nodes (which need local connectivity). Edge nodes transmit at high power to reach external parents, while internal nodes transmit at lower powers suitable for local mesh formation. This resolves the contradiction by applying appropriate power levels locally rather than globally.
Solution Approach 2:
The patent introduces edge nodes as intermediaries between internal nodes and external parent devices. Edge nodes handle the high-power external communications, acting as a buffer that protects internal nodes from causing interference. This intermediary role allows internal nodes to form meshes at lower powers while external connectivity is maintained through the intermediary edge nodes.
3Device complexity
If uniform transmission power is used across all LLN nodes, then device complexity is reduced, but optimization within isolated areas with different node densities is prevented
Solution Approach 1:
The patent applies local quality by enabling nodes to determine their own transmission power based on local conditions such as node density and role. Rather than uniform power control, each node adapts its power level to local requirements. This resolves the contradiction by introducing minimal complexity at the node level (simple density-based rules) to achieve significant adaptability in diverse environments.
Solution Approach 2:
The patent implements self-service by allowing nodes to autonomously determine appropriate transmission power values based on their observed local environment and role. Nodes self-adjust their power levels without requiring complex centralized control, using simple rules based on local node density and whether they are edge or internal nodes. This provides adaptability with minimal added complexity.
Data Source
AI summary
In one embodiment, a method comprises: determining, by a constrained network device in a low power and lossy network (LLN), a self-estimated density value of neighboring LLN devices based on wirelessly receiving an identified number of beacon message transmissions within an identified time interval from neighboring transmitting LLN devices in the LLN; setting, by the constrained network device, a first wireless transmit power value based on the self-estimated density value; and transmitting a beacon message at the first wireless transmit power value, the beacon message specifying the self-estimated density value, a corresponding trust metric for the self-estimated density value, and the first wireless transmit power value used by the constrained network device for transmitting the beacon message.