Optical Code Grouping for OCDMA Routing and Security
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Solution Overview
Problem
Current OCDMA networks face challenges in efficiently routing and securing groups of spectrally phase-encoded optical code division multiple access signals, particularly due to tunable encoders and fixed decoders which can lead to eavesdropping and code collisions, and lack the ability to handle composite code groups effectively.
Innovation Solution
An optical network architecture that includes a transmitting station for labeling optical signals with group-specific codes, a variable coder for re-labeling incoming signals, and the use of Walsh-Hadamard codes and 2x2 crossbar switches to route and decode signals efficiently, allowing for passive routing of composite code groups.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If tunable encoders and fixed decoders are used in OCDMA networks, then routing flexibility is improved, but security deteriorates due to eavesdropping risks
Solution Approach 1:
The patent applies dynamics by making both encoders and decoders tunable rather than fixed. The decoder can dynamically adjust its code selection based on the received signal characteristics, and the encoder can dynamically select codes for different routing paths. This dynamic adaptation prevents eavesdropping by continuously changing the coding scheme, while maintaining routing flexibility through the tunable nature of both components.
Solution Approach 2:
The patent changes the parameter of code selection dynamically. Instead of using fixed codes at encoders and decoders, the system varies the code parameters based on routing requirements and security needs. The decoder can change its expected code pattern, and the encoder can change its transmitted code pattern, thereby maintaining both routing adaptability and security through parameter variation.
2Productivity
If code grouping is implemented for passive routing, then routing efficiency is improved, but device complexity increases due to variable coders and switches
Solution Approach 1:
The patent segments the code space into different groups that can be handled by simpler processing elements. By dividing the full code set into manageable groups, the system can use simpler variable coders and switches to route signals between groups, rather than requiring complex processing for all possible codes. This segmentation reduces the complexity of individual components while maintaining overall routing efficiency.
Solution Approach 2:
The patent introduces variable coders and switches as intermediary elements between the encoder and decoder. These intermediaries handle the code translation and routing functions, allowing the main signal path to remain simpler. The variable coders act as mediators that convert codes between different groups, reducing the direct complexity requirements of the encoder and decoder while enabling efficient routing.
3Productivity
If spectral phase encoding is used for OCDMA signals, then data throughput is improved, but multi-user interference increases
Solution Approach 1:
The patent uses dynamic code selection and switching to manage multi-user interference. By dynamically changing the codes assigned to different users and routing paths, the system can avoid persistent interference patterns. The variable coders and switches allow for adaptive code assignment that responds to network conditions, thereby maintaining high data throughput while reducing the impact of multi-user interference through dynamic reconfiguration.
Data Source
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AI summary
The invention is directed to code labeling in an optical network. The network includes a transmitting station operable to transmit an optical signal. The network also includes an encoder coupled to the transmitting station operable to label the optical signal composed of a group of codes. A receiving station operable to receive the labeled group of optical codes is also provided. The receiving station is operable to read the optical signal if the label of the received group of codes corresponds to the group of codes assigned to the receiving station.