WDM Optical Communication System Using Single Light Source
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Solution Overview
Problem
Current optical communication systems in data centers face challenges in efficiently managing high-speed data traffic, particularly in supporting the rapid growth of data-center traffic exceeding 1 to 10 Pbit/second, and require innovative solutions to optimize optical transport technologies.
Innovation Solution
The proposed communication system employs wavelength-division-multiplexed (WDM) optical signals, using a single multi-wavelength light source to provide carrier wavelengths for both uplink and downlink traffic, with optical transceivers, wavelength multiplexers, and demultiplexers to modulate and demodulate data on unmodulated signaling dimensions, enabling efficient data transmission and redundancy through optical-path redundancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single multi-wavelength light source is used for both uplink and downlink traffic, then device complexity and cost are reduced, but signal interference and transmission reliability may worsen
Solution Approach 1:
The patent segments the WDM signal spectrum into distinct wavelength ranges: one range (e.g., C-band) is allocated for downlink traffic from the single light source, while another range (e.g., L-band) is allocated for uplink traffic. This spectral segmentation allows bidirectional communication using a single physical light source, eliminating the need for separate light sources while preventing signal interference through wavelength separation.
Solution Approach 2:
The patent transitions from temporal multiplexing (TDM) to wavelength division multiplexing (WDM) as the primary dimension for separating uplink and downlink signals. By utilizing the wavelength dimension rather than just time slots, the system achieves full-duplex communication with a single light source, improving bandwidth efficiency and reducing complexity while maintaining reliability through spatial-spectral isolation of signals.
2Productivity
If WDM optical signals are used for high-speed data transmission, then data transmission capacity increases, but system complexity and signal management difficulty increase
Solution Approach 1:
The patent employs a single multi-wavelength light source that performs multiple functions: generating both downlink and uplink carrier wavelengths, providing optical clocks for synchronization, and enabling bidirectional communication. This universal light source replaces what would traditionally require separate light sources, modulators, and synchronization mechanisms, thereby increasing transmission capacity while managing system complexity through functional integration.
Solution Approach 2:
The patent introduces optical filters and wavelength selective switches as intermediary devices that automatically route different wavelength components to their designated destinations. These intermediaries simplify signal management by providing automatic wavelength-based routing and filtering, reducing the need for complex electronic signal processing and manual configuration while enabling high-capacity WDM transmission.
3Productivity
If optical transceivers modulate data onto unmodulated signaling dimensions, then bandwidth efficiency improves, but modulation complexity and power consumption increase
Solution Approach 1:
The patent utilizes different modulation formats and signaling dimensions (e.g., phase modulation, frequency modulation, amplitude modulation) for uplink and downlink transmissions. By changing the modulation parameters based on traffic direction and requirements, the system optimizes bandwidth efficiency for each direction while managing power consumption through adaptive modulation schemes that adjust complexity based on channel conditions and traffic priorities.
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 solution enables high-speed data access to servers in data centers by efficiently managing WDM signals, providing redundancy for fault protection, and optimizing the use of a single light source for both uplink and downlink traffic, thus addressing the challenges of high-speed data transmission.
Implementation Method 1
The uplink WDM signals are generated at the server end of the system by modulating with data the unmodulated WDM components received through the downlink
Implementation Method 2
transport data using wavelength-division-multiplexed (WDM) optical signals
Data Source
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AI summary
A communication system that can be used, e.g., to provide high-speed access to the servers of a data center. In an example embodiment, the communication system transports data using WDM optical signals. The downlink WDM signals have some WDM components that are modulated with data and some WDM components that are not modulated with data. The uplink WDM signals are generated at the server end of the system by modulating with data the unmodulated WDM components received through the downlink. Appropriately connected wavelength multiplexers, wavelength demultiplexers, and/or optical filters can be used to properly apply the various modulated WDM components to the corresponding optical receivers and the unmodulated WDM components to the corresponding optical transmitters. The resulting system architecture advantageously enables, e.g., the use of a single, conveniently located multi-wavelength light source to provide carrier wavelengths for both uplink and downlink optical traffic.