Upstream Optical Transmission Assignment Based on Power
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Solution Overview
Problem
Current time- and wavelength-division multiplexing (TWDM) passive optical networks (PONs) face significant upstream crosstalk issues due to interference between upstream wavelength channels, which existing scheduling approaches fail to effectively address, especially as the number of optical network units (ONUs) increases.
Innovation Solution
Implementing a cross-layer scheme that assigns upstream transmissions based on ONU transmission powers, dictating both the wavelengths and time slots for transmission, using a media access control (MAC) layer to instruct the physical layer, thereby reducing crosstalk by separating ONUs with stronger and weaker transmission powers across different wavelengths and time slots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple ONUs transmit on the same wavelength channel, then the network capacity increases, but upstream crosstalk and interference increase
Solution Approach 1:
The patent segments the upstream transmissions by grouping ONUs into different classes based on their transmission power levels. High-power ONUs are assigned to different wavelength channels or time slots compared to low-power ONUs, effectively segmenting the previously shared resource to reduce interference while maintaining overall network capacity.
Solution Approach 2:
The patent applies local quality by assigning different transmission characteristics (wavelength channels or time slots) to different groups of ONUs based on their specific transmission power levels. This localized differentiation ensures that each ONU group transmits under optimized conditions suitable for its power level, reducing crosstalk while preserving network capacity.
2Device complexity
If existing scheduling approaches are used, then the system structure remains simple, but crosstalk between upstream wavelength channels cannot be effectively reduced
Solution Approach 1:
The patent changes the scheduling parameter from simple time-slot assignment to power-based classification and assignment. By introducing transmission power level as a key parameter for scheduling decisions, the system achieves effective crosstalk reduction through a relatively straightforward extension of existing MAC layer functionality.
Data Source
AI summary
An apparatus comprises a receiver configured to receive first messages, a processor coupled to the receiver and configured to process the first messages, determine transmission powers associated with the first messages, and generate a transmission scheme based on the transmission powers, and a transmitter coupled to the processor and configured to transmit a second message comprising the transmission scheme. An apparatus comprises a transmitter configured to transmit a first message indicating a transmission power of the apparatus, a receiver configured to receive a second message, wherein the second message assigns to the apparatus a wavelength based on the transmission power, and a processor coupled to the transmitter and the receiver and configured to process the second message, and instruct the transmitter to transmit a third message at the wavelength.