Layer-2 Forwarding Header for Low-Rate Wireless Mesh Networks
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Solution Overview
Problem
In low-rate wireless mesh networks, frequent encryption/decryption and compression/decompression processes consume significant computing resources and power, particularly in nodes using microcontrollers, leading to reduced service life and efficiency.
Innovation Solution
Implementing a packet forwarding method that uses a layer-2 forwarding header to enable direct layer-2 forwarding based on MAC addresses, avoiding the need for decompression and decryption at intermediate nodes, thus reducing resource consumption and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If frequent encryption/decryption and compression/decompression processes are performed at intermediate nodes, then network security and packet delivery are ensured, but computing resources and power are consumed significantly
Solution Approach 1:
The patent segments the forwarding process into two distinct modes: layer-2 forwarding for intermediate nodes (which only requires MAC address comparison and does not require decryption or decompression) and layer-3 routing for end nodes (which perform full packet processing). This segmentation allows intermediate nodes to forward packets without consuming significant computing resources, while still ensuring security through selective processing at end nodes.
Solution Approach 2:
The patent introduces a layer-2 forwarding header as an intermediary structure that contains MAC addresses for intermediate forwarding. This header enables intermediate nodes to perform efficient forwarding without needing to process the encrypted and compressed IPv6 packet payload, thus reducing power consumption while maintaining the ability to deliver packets securely to end nodes.
2Measurement precision
If decompression and decryption are performed hop by hop to obtain destination IPv6 address, then accurate routing is achieved, but processing resources are consumed
Solution Approach 1:
The patent divides the packet into different processing zones: the layer-2 forwarding header is processed by intermediate nodes using simple MAC address comparison, while the encrypted and compressed IPv6 packet payload is only fully processed at end nodes. This segmentation eliminates the need for intermediate nodes to perform complex decompression and decryption operations.
Solution Approach 2:
The patent performs preliminary routing setup by establishing layer-2 forwarding paths based on MAC addresses before packets are transmitted. Intermediate nodes use pre-configured MAC address forwarding tables to forward packets without needing to perform real-time decompression and decryption to determine routing, thus reducing processing complexity.
3Reliability
If layer-3 routing based on destination IPv6 address is used, then accurate packet delivery is achieved, but forwarding efficiency is reduced
Solution Approach 1:
The patent segments forwarding operations into layer-2 forwarding for intermediate nodes (using MAC addresses from the layer-2 forwarding header) and layer-3 routing for end nodes (using destination IPv6 addresses). This segmentation enables high-speed forwarding at intermediate nodes while maintaining accurate packet delivery at end nodes.
Solution Approach 2:
The layer-2 forwarding header acts as an intermediary that carries MAC addresses specifically for intermediate forwarding operations. This intermediary structure enables efficient MAC-based forwarding at intermediate nodes without compromising the accuracy of final packet delivery, which is ensured by the complete IPv6 packet processing at end nodes.
4Quantity of substance
If compression and encryption are performed at each node, then packet size is reduced and security is enhanced, but service life of battery-powered nodes is shortened
Solution Approach 1:
The patent segments the packet processing responsibilities so that compression and encryption are only performed at end nodes (source and destination), not at intermediate forwarding nodes. This segmentation significantly reduces the cumulative processing load on battery-powered nodes in the network, extending their service life while still achieving packet size reduction and security enhancement where needed.
Data Source
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AI summary
A packet forwarding method applied to a low-rate wireless mesh network is disclosed. A network node encapsulates an IPv6 packet into a data frame including a layer-2 forwarding header and a MAC header, where the data frame includes a 6LoWPAN compressed IPv6 packet, and the layer-2 forwarding header and the MAC header are located in an outer layer of the 6LoWPAN compressed IPv6 packet. The network node obtains a MAC address of a next-hop node based on a final MAC address in the layer-2 forwarding header, and sends the data frame to the next-hop node, so that the next-hop node forwards the data frame directly based on the layer-2 forwarding header. In this way, for an IPv6 packet that undergoes compression (or even encryption) processing in the low-rate wireless mesh network, an intermediate forwarding node performs layer-2 forwarding directly based on the layer-2 forwarding header, and there is no need to perform decompression to obtain a destination IPv6 address and perform layer-3 routing. Therefore, packet forwarding efficiency is improved, and processing resources and power of the node are saved.