Powerline PHY Header Tone Mask Identification
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Solution Overview
Problem
In powerline communications, especially with high-voltage to low-voltage transformer crossings, the receiver often fails to decode data payloads due to severe signal attenuation, leading to inefficient tone mask allocation and potential collisions, which degrade network performance.
Innovation Solution
The method involves including tone mask identification information in a single tone PHY header portion of a data frame, allowing the data payload to be transmitted over multiple tone masks, enabling efficient tone usage and avoiding collisions by informing receivers about the correct tone masks for decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the data payload is transmitted over multiple tone masks, then the data rate and network performance are improved, but the receiver fails to decode the data payload due to severe signal attenuation at MV/LV crossings
Solution Approach 1:
The patent segments the data transmission by separating the PHY header (transmitted on a single tone mask) from the data payload (transmitted on multiple tone masks). This segmentation allows the receiver to first decode the header to learn which tone masks contain the payload, then selectively decode the payload on the correct tone masks, resolving the decoding failure issue while maintaining high data rates
Solution Approach 2:
The patent applies preliminary action by transmitting the tone mask identification information in the PHY header before the data payload. This allows the receiver to预先 know which tone masks will carry the payload, enabling proper tuning and decoding of the payload on the correct frequency bands despite signal attenuation
2Device complexity
If the receiver listens on one tone mask at a given time, then the device complexity is reduced, but the node cannot decode the data payload when the payload is transmitted over different tone masks
Solution Approach 1:
The receiver performs preliminary action by first decoding the PHY header on a single tone mask to obtain the tone mask identification information. This preliminary step provides the necessary information about which tone masks contain the payload, allowing the receiver to then switch to and decode the payload on the correct tone masks without requiring simultaneous monitoring of all possible tone masks
3Reliability
If the node sets VCS to EIFS value when unable to decode the payload, then the collision avoidance is improved, but the network performance degrades due to inefficient tone mask allocation
Solution Approach 1:
The patent implements feedback by including tone mask identification information in the PHY header that tells receivers which tone masks contain the payload. This feedback mechanism prevents receivers from incorrectly setting VCS to EIFS when the payload is on different tone masks than expected, thereby avoiding unnecessary collision avoidance delays and maintaining high network performance while still providing reliable collision avoidance when needed
Data Source
AI summary
A method of powerline communications (PLC) includes compiling a data frame for physical layer (PHY) by a first communications device at a first communications node on a powerline of a PLC network. The data frame includes a single tone PHY header portion and a data payload portion in a set of tones including at least one tone having a frequency different from a frequency of the single tone. The PHY header portion includes tone mask identification information identifying the set of tones. The first communications device transmits the data frame over the powerline to a second communications device at a second communications node on the powerline. The second communications device receives the data frame, and decodes the data payload using the tone mask identification information in the PHY header portion.