VLC Aggregation Bitmap for Guard Channel Indication
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Solution Overview
Problem
The lack of standardized light sources and frequency bands in visible light communication (VLC) systems hinders widespread adoption, as existing light sources are chosen for aesthetics and manufacturing costs rather than communication purposes, leading to interference and inefficiencies.
Innovation Solution
A method and device that generate and transmit an aggregation bitmap to indicate active frequency bands used by VLC transmitters, allowing for channel aggregation and guard channel identification within the media access control (MAC) layer during link establishment, enabling flexible communication across multiple bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ordinary light sources selected for aesthetics and manufacturing costs are used in VLC, then manufacturing cost and aesthetic flexibility are improved, but communication reliability and interference resistance deteriorate
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the operating frequency band based on detected light source characteristics. Instead of requiring standardized light sources, the system measures the actual spectral properties of ordinary LED bulbs and adapts communication parameters (frequency, modulation scheme) to match the detected source characteristics, thereby maintaining communication reliability while allowing use of cost-effective non-standardized light sources
Solution Approach 2:
The patent implements feedback mechanisms where the receiving device measures the spectral properties of the transmitting light source and sends this information back to the transmitting device. This feedback loop enables the system to automatically adjust communication parameters based on the actual light source characteristics, resolving the contradiction between using ordinary light sources and maintaining communication reliability
2Adaptability or versatility
If ordinary light sources with non-standardized frequency bands are used, then adaptability to existing infrastructure is improved, but interference and communication efficiency deteriorate
Solution Approach 1:
The system dynamically changes communication parameters including frequency band selection, modulation depth, and symbol duration based on the detected spectral characteristics of the light source. This allows the system to adapt to existing non-standardized light sources while selecting optimal operating parameters that minimize interference and maximize communication efficiency
Solution Approach 2:
The patent performs preliminary spectral measurement and characterization of the light source before establishing communication. By measuring the spectral properties in advance and pre-calculating optimal communication parameters, the system avoids interference issues during actual communication while maintaining adaptability to various existing light sources
3Productivity
If channel aggregation using bitmaps is implemented, then data transmission capacity is improved, but device complexity and processing requirements increase
Solution Approach 1:
The patent segments the frequency spectrum into multiple discrete bands and uses bitmap representation to indicate which bands are active for communication. Each bit in the bitmap corresponds to a specific frequency band, allowing efficient representation of channel aggregation status. This segmentation approach enables high data transmission capacity through multi-band operation while keeping the signaling mechanism relatively simple through the use of compact bitmap structures
Data Source
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AI summary
A method, apparatus, and a non-transitory computer readable storage medium for supporting visible light communication (VLC) exchanges bitmaps for capabilities field exchange in a media access control (MAC) layer during link establishment and association with other VLC-enabled devices. An aggregation bitmap is generated to indicate whether a visible light communication (VLC) transmitter of a first device uses at least one aggregated band that comprises multiple active frequency bands. The aggregation bitmap is transmitted in a capabilities information exchange (CIE) signal to a second device. A guard bitmap that identifies a set of guard frequency bands is also generated and transmitted in the CIE signal. Each guard frequency band indicates leakage transmission from the VLC transmitter.