Wavelength Assignment in Star-Type Optical Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wavelength multiplexed optical communication networks require costly optical components like light sources, multiplexers, demultiplexers, and optical receivers for monitoring light, especially in star-type networks, which increases costs and complexity.
Innovation Solution
An optical transmitter and receiver device that assigns wavelengths without using monitoring light, allowing for the elimination of these components and enabling automatic wavelength assignment using a simple algorithm, suitable for network expansion with reduced startup costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If monitoring light is used to transmit wavelength information and control signals, then wavelength management and power control are achieved, but costly optical components such as light sources, multiplexers, demultiplexers, and optical receivers are required
Solution Approach 1:
The patent extracts the monitoring function from the optical domain and relocates it to the electrical domain. By detecting wavelength information through electrical signals at the receiver end and transmitting this information back to the transmitter, the system eliminates the need for separate monitoring light paths and associated optical components like monitoring light sources, multiplexers, and receivers.
Solution Approach 2:
The patent replaces the optical monitoring system with an electrical signal-based system. Instead of using optical components to detect and transmit wavelength information, the system uses electrical detectors and signal processing circuits to accomplish the same function, thereby reducing optical component complexity.
2Adaptability or versatility
If monitoring light is used in star-type networks, then wavelength assignment and control are enabled, but the cost increases due to required demultiplexers and optical receivers at each subscriber terminal
Solution Approach 1:
The patent removes the monitoring light functionality from subscriber terminals by extracting it to the central office. Subscriber terminals only need basic optical receivers and electrical processing capabilities, while the complex wavelength monitoring and assignment functions are performed centrally, eliminating the need for expensive demultiplexers and optical receivers at each terminal.
Solution Approach 2:
The patent makes the central office equipment perform multiple functions: it handles both the primary optical signal transmission and the wavelength monitoring, detection, and assignment tasks. This multi-functional approach consolidates complexity at the central office while keeping subscriber terminals simple and cost-effective.
3Productivity
If more channels are provided in the network, then capacity is increased, but maintaining constant light power on each channel becomes more difficult requiring additional monitoring information processing
Solution Approach 1:
The patent replaces complex optical monitoring and power adjustment mechanisms with electrical signal processing. By using electrical detectors to monitor wavelength information and digital signal processing to calculate average power and generate control signals, the system can efficiently manage multiple channels without requiring complex optical power adjustment equipment at each node.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to the present invention, a star-type wavelength multiplexed communication network using optical TX/RX devices capable of assigning the wavelengths can be provided without using the monitoring light. In an embodiment of the present invention, an optical TX/RX device for transmitting and receiving a wavelength-multiplexed signal light comprises an optical receiver capable of varying the RX wavelength and an optical transmitter capable of varying the TX wavelength. The optical TX/RX device detects RX wavelengths not in use via the optical receiver, and assigns the RX wavelength of the optical receiver to one of the RX wavelengths not-in-use, and assigns the TX wavelength of the optical transmitter to a TX wavelength corresponding to the RX wavelength according to a correspondence table of TX and RX wavelengths in the memory. Then, the optical TX/RX device transmits a signal light on this TX wavelength, and detects the response on the RX wavelength. If the response is detected, communication is initiated using the assigned TX wavelength and the RX wavelength. If the response is not detected, the operation is repeated from the detection of RX wavelengths not in use to the transmission of the signal light on TX wavelength again.