Optical Network Unit Spaced Sleep Mode Power Control
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Solution Overview
Problem
Passive Optical Networks (PONs) face challenges in reducing Optical Network Unit (ONU) power consumption, as existing power-saving modes require ONUs to remain powered up for potential immediate data transmission opportunities, limiting the ability to power down transmitters between allocations.
Innovation Solution
Implementing a 'spaced sleep' mode where the OLT communicates to the ONU an earliest time for transmit opportunities in subsequent frames, allowing the ONU to power down its transmitter during idle periods and reducing overall power consumption by ensuring no allocations occur before the indicated time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ONU remains powered up to capture immediate data transmission opportunities, then the reliability of data transmission is improved, but the power consumption increases
Solution Approach 1:
The OLT sends a control message to the ONU in advance, indicating the earliest time during upcoming upstream frames when the ONU will be allocated a transmit opportunity. This preliminary information allows the ONU to proactively power down its transmitter during idle periods while ensuring it is ready to transmit immediately when allocated, thus reducing power consumption without compromising transmission reliability.
2Use of energy by moving object
If the ONU powers down its transmitter between allocations to save energy, then the power consumption is reduced, but the ability to respond to immediate data transmission opportunities is worsened
Solution Approach 1:
The OLT provides feedback to the ONU about future transmit opportunity allocations through control messages. This feedback mechanism allows the ONU to make informed decisions about when to power down its transmitter, ensuring it remains powered up only during periods when transmission is needed, thus optimizing both power consumption and response speed.
3Adaptability or versatility
If the OLT provides detailed allocation information for every upstream frame, then the adaptability to changing data loads is improved, but the device complexity increases
Solution Approach 1:
Instead of providing complete allocation details for every upstream frame, the OLT provides partial information - specifically, the earliest time during upcoming frames when transmit opportunities will be allocated. This partial information is sufficient for the ONU to make power management decisions without requiring complex detailed scheduling information, thus reducing control message complexity while maintaining adaptability.
Data Source
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AI summary
A method of controlling an Optical Network Unit, ONU, in a Passive Optical Network, PON, is provided. The method comprises communicating a control message from an Optical Line Terminal, OLT, to the ONU. The control message comprises an indication of an earliest time during an upstream frame and one or more subsequent upstream frames at which the ONU will be allocated an opportunity to transmit data to the OLT.