Modulo Channel Assignment for Optical Beat Interference
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Solution Overview
Problem
Optical beat interference (OBI) occurs in optical point-to-multipoint networks due to collisions of optical signals from multiple transmitters with the same wavelength received by a single shared optical receiver, which existing technologies have not effectively prevented.
Innovation Solution
The solution involves configuring an optical point-to-multipoint communication network by assigning a unique channel number to each access point using modulo-N arithmetic and tuning the lasers to specific wavelengths based on the channel number, intrinsic wavelength, and channel spacing to prevent collisions at the shared optical receiver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If multiple access points use the same wavelength for communication, then the network can achieve simpler configuration and lower cost, but optical beat interference occurs at the shared receiver
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the wavelength parameter of lasers at different access points based on their position in the network. Each access point is assigned a unique wavelength from a available set, transforming the static wavelength configuration into a dynamic, position-dependent parameter assignment that prevents optical beat interference while maintaining network simplicity
Solution Approach 2:
The patent segments the single shared wavelength resource into multiple distinct wavelength channels, assigning each access point a unique wavelength segment. This segmentation of the wavelength domain allows multiple access points to communicate simultaneously without interference, as each occupies a distinct spectral segment
2Object-affected harmful factors
If each access point is assigned a unique wavelength, then optical beat interference is prevented, but the network requires more complex wavelength management and tuning mechanisms
Solution Approach 1:
The patent implements self-service by enabling each access point to autonomously determine its assigned wavelength based on its position identifier and the available wavelength set. The system automatically configures wavelengths without requiring manual intervention or complex centralized control, reducing operational complexity while maintaining unique wavelength assignment
Solution Approach 2:
The patent applies preliminary action by pre-defining a set of available wavelengths and establishing a systematic assignment rule before network operation. This preliminary configuration allows access points to independently calculate their assigned wavelength without real-time negotiation or complex management during operation
3Adaptability or versatility
If lasers with non-similar tunability bands are used, then more flexible wavelength assignment is achieved, but ensuring collision-free operation becomes more difficult
Solution Approach 1:
The patent applies dynamics by implementing a systematic wavelength assignment method that adapts to each access point's position and laser characteristics. The assignment dynamically selects from available wavelengths based on the specific access point's identifier, ensuring collision-free operation while accommodating diverse laser tunability bands through position-dependent wavelength selection
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures collision-free operation by assigning distinct wavelengths to each laser, allowing for the use of lasers with non-similar or overlapping tunability bands, thereby preventing optical beat interference and enhancing network performance.
Implementation Method 1
tuning the laser located in each of the plurality of N access points to a wavelength λ ui that is one of a set of M wavelengths
Data Source
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AI summary
Configuring an optical point to multipoint communication network includes assigning a channel number C i by modulo-N arithmetic to each of a plurality of N access points, each of the plurality of N access points i) including a laser and ii) coupled to a hub having a shared optical receiver; and tuning the laser located in each of the plurality of N access points to a wavelength λui that is one of a set of M wavelengths as a function of the channel number assigned to the access point in which the laser is located, a channel spacing Δλ and an intrinsic wavelength λuin of the laser to prevent optical beat interference at the shared optical receiver.