Wavelength Reconfigurable Optical Network Architecture
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Solution Overview
Problem
Existing optical network architectures require costly OEO conversion at each optical line terminal (OLT) and fixed wavelength add-drop multiplexers, limiting flexibility and reconfigurability in wavelength assignment and reuse.
Innovation Solution
A unified metro-access optical network architecture utilizing reconfigurable optical add-drop multiplexers (ROADMs) and a metro hub for all-optical transmission, allowing wavelength reconfigurability and reuse without intermediate OEO conversion, with ONUs capable of transmitting upstream signals at any wavelength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If OEO conversion is performed at each OLT, then signal transmission reliability is improved, but network cost increases significantly
Solution Approach 1:
The patent extracts the OEO conversion function from distributed OLTs and consolidates it at centralized metro edge nodes. This eliminates the need for expensive OEO conversion equipment at each access node while maintaining signal integrity through all-optical transmission in the access network.
Solution Approach 2:
The patent introduces reconfigurable OADMs as intermediary devices at metro edge nodes to perform wavelength routing and signal management. These intermediaries enable all-optical signal switching and wavelength conversion without requiring OEO conversion at access nodes, thus reducing cost while maintaining reliability.
2Device complexity
If fixed wavelength add-drop multiplexers are used, then device simplicity is maintained, but wavelength flexibility and reconfigurability are limited
Solution Approach 1:
The patent replaces fixed wavelength OADMs with reconfigurable OADMs that can dynamically change their wavelength routing configuration. This allows the network to adapt wavelength assignments based on traffic demands and service requirements while maintaining a relatively simple device architecture through standardized reconfigurable components.
Solution Approach 2:
The patent enables wavelength parameter changes by using reconfigurable OADMs that can switch between different wavelength configurations. This allows the same physical infrastructure to support multiple wavelength assignments and service types without requiring additional fixed wavelength equipment.
3Stability of the object's composition
If dedicated fixed optical transmitters are used at OLT, then signal transmission stability is ensured, but network reconfigurability and wavelength reuse are reduced
Solution Approach 1:
The patent makes optical transmitters universal by enabling them to operate at multiple wavelengths through reconfigurable OADMs. Instead of dedicated fixed-wavelength transmitters, the system uses multi-wavelength capable transmitters that can be dynamically assigned to different wavelengths based on network needs, achieving both stability and reconfigurability.
Solution Approach 2:
The patent introduces dynamic wavelength assignment where optical transmitters can change their operating wavelength over time based on network conditions. This dynamic capability allows the same transmitter to serve multiple wavelength channels sequentially, improving network reconfigurability while maintaining stable transmission through controlled wavelength switching.
4Quantity of substance
If multiple wavelengths are allocated to each ONU, then bandwidth capacity is increased, but device complexity and cost at access nodes increase
Solution Approach 1:
The patent extracts the wavelength multiplexing function from access nodes and moves it to metro edge nodes. Access nodes only handle single-wavelength optical signals, while the complex wavelength management and multiplexing functions are performed at the metro edge using reconfigurable OADMs, thus maintaining high bandwidth capacity without increasing access node complexity.
Solution Approach 2:
The patent uses reconfigurable OADMs at metro edge nodes as intermediaries to manage multiple wavelengths. These intermediaries perform wavelength routing, multiplexing, and demultiplexing functions, allowing multiple wavelengths to be allocated to ONUs without requiring complex wavelength management equipment at the access nodes themselves.
Data Source
AI summary
The invention provides a unified optical network architecture for metro and access communication networks, wherein a metro ring network interfaces access PONs through one or more reconfigurable Optical Add/Drop Multiplexers to provide wavelength-reconfigurable all-optical transmission of communication signals from the metro ring network to designated optical network units associated with the end-users, and wherein one metro hub located in the metro ring network is utilized to set transmission wavelengths and timing for both downstream and upstream signal transmission for multiple access PONs.