Multi-Wavelength PON Wavelength Negotiation for Conflict Reduction
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Solution Overview
Problem
The existing multi-wavelength passive optical network (PON) systems face challenges in efficient bandwidth utilization due to the time division multiplexing mechanism, leading to restricted user bandwidth and interference during wavelength negotiation, which prolongs registration times and affects communication between ONUs.
Innovation Solution
A wavelength negotiation method and apparatus that utilize a wavelength status table broadcast by the OLT, allowing ONUs to select upstream and downstream wavelengths based on available channels and registered ONU information, reducing conflicts and optimizing wavelength allocation for faster registration and improved system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ONU selects wavelengths at random during wavelength negotiation, then the wavelength selection process is simple and fast, but wavelength conflicts occur frequently, leading to repeated negotiations and prolonged registration time
Solution Approach 1:
The OLT performs preliminary actions by maintaining and broadcasting a wavelength status table that records the current usage state of each wavelength channel before the ONU performs wavelength selection. This allows the ONU to make informed wavelength selections without random trial-and-error, resolving the contradiction between negotiation speed and conflict rate by providing advance information about wavelength availability.
Solution Approach 2:
The OLT continuously monitors wavelength channel states and provides feedback to ONUs through the wavelength status table, which is broadcast periodically. This feedback mechanism enables ONUs to select wavelengths that are currently available, significantly reducing wavelength conflicts and repeated negotiations while maintaining fast registration processes.
2Reliability
If the OLT detects wavelength conflicts and delivers conflict indications to ONUs, then wavelength allocation can be corrected, but the registration process is prolonged and normal communication of other ONUs is interfered with
Solution Approach 1:
Instead of detecting conflicts after they occur and then correcting them, the system performs preliminary action by broadcasting the wavelength status table that shows which wavelengths are currently in use. This allows ONUs to proactively select non-conflicting wavelengths from the beginning, eliminating the need for conflict detection and correction cycles, thus reducing registration time while ensuring correct wavelength allocation.
3Device complexity
If multiple ONUs share the optical transmission path using TDM mechanism, then the network structure is simple and cost-effective, but the available bandwidth of users is restricted and fiber bandwidth cannot be effectively utilized
Solution Approach 1:
The patent merges TDM and WDM technologies into a hybrid PON system. The TDM mechanism maintains the simple network structure and cost-effective shared optical transmission path, while WDM technology is introduced to provide multiple wavelength channels that significantly increase the available bandwidth. Each wavelength channel can carry independent data streams, allowing multiple ONUs to communicate simultaneously at high speeds without increasing network complexity.
Solution Approach 2:
The patent transitions from single-dimensional TDM (time-based multiplexing) to multi-dimensional hybrid TDM-WDM (time-based plus wavelength-based multiplexing). By adding the wavelength dimension, the system can provide multiple parallel communication channels, effectively increasing user available bandwidth while maintaining the simple shared network structure of TDM.
Data Source
AI summary
This application provides a wavelength negotiation method of a multi-wavelength passive optical network, including: receiving a wavelength status table that is broadcast by an OLT over each downstream wavelength channel of a multi-wavelength PON system, where the wavelength status table is used to indicate information about available wavelengths of the multi-wavelength PON system and statistic information of registered ONUs of a corresponding wavelength channel; selecting an upstream transmit wavelength and a downstream receive wavelength according to the wavelength status table; and reporting information about the upstream transmit wavelength and information about the downstream receive wavelength to the OLT so that the OLT refreshes the wavelength status table. This application also provides a wavelength negotiation apparatus of the multi-wavelength passive optical network and a multi-wavelength passive optical network system.