PON OLT Bandwidth Map Scheduling for ONU Power Reduction
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Solution Overview
Problem
Passive optical networks (PONs) face inefficiencies in power consumption due to continuous downstream broadcast transmission, where customer premises equipment remains powered on at all times, leading to significant energy wastage as less than 10% of downstream data is relevant to each user, resulting in high power consumption without energy-saving benefits.
Innovation Solution
An optical line terminal (OLT) determines a downstream bandwidth map transmission frequency and generates a message indicating active and inactive periods for each optical network unit (ONU), allowing ONUs to power off data processing units during inactive periods, thereby reducing power consumption without affecting service quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous downstream broadcast transmission is used, then service quality is maintained, but power consumption increases significantly
Solution Approach 1:
The patent implements periodic downstream transmission by alternating between active transmission periods and inactive sleep periods. The OLT transmits data in periodic bursts rather than continuously, allowing ONU receivers to power down during inactive periods while maintaining service quality through scheduled reactivation when data needs to be transmitted.
2Reliability
If ONU receiver is kept powered on at all times, then data reception is ensured, but energy efficiency deteriorates
Solution Approach 1:
The patent introduces dynamic power management where the ONU receiver transitions between active and inactive states based on transmission schedules. The system dynamically adjusts receiver power state according to whether downstream data transmission is occurring, eliminating the need for continuous powering while ensuring data reception when needed.
Solution Approach 2:
The OLT sends preliminary control signals indicating upcoming active periods before data transmission begins. This allows the ONU receiver to anticipate when it needs to be powered on, transitioning to active state just in time for data reception rather than remaining continuously powered on.
3Duration of action of stationary object
If downstream transmission is continuous, then service continuity is maintained, but energy waste increases
Solution Approach 1:
The system implements periodic transmission cycles with defined active and inactive periods. Service continuity is maintained through the periodic reactivation of transmission during active periods, while energy waste is reduced by allowing receivers to remain inactive during non-transmission periods.
Data Source
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AI summary
An OLT comprising a processor configured to calculate a downstream bandwidth map that indicates an active period of time when the OLT is scheduled to transmit a data frame to an ONU, and generate a message comprising the downstream bandwidth map, and a transmitter coupled to the processor and configured to send the message to the ONU via a PON, wherein the message instructs the ONU to power off at least one ONU receive data processing unit outside the active period. Also disclosed is a computer program product comprising computer executable instructions stored on a non-transitory computer readable medium such that when executed by a processor cause an ONU to receive a message indicating an active period, wherein the active period indicates a scheduled period during which data communicated over a PON is relevant to the ONU and power down an ONU receive data processing unit outside the active period.