Optical Line Terminal Power Conservation via Burst Scheduling

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Solution Overview

Problem

Optical network power conservation is challenging, particularly in high-data-rate applications like 50 G PONs, where OLTs consume more power due to continuous operation, and existing approaches focus more on ONU power conservation rather than OLT efficiency.

Innovation Solution

The Optical Line Terminal (OLT) minimizes downstream and upstream transmission periods, schedules bursts in a substantially continuous manner with minimal guard times, and orders ONU bursts based on optical powers to maximize idle periods, allowing the OLT to enter a sleep mode during these periods, reducing power consumption by powering off or reducing functionality of components like SerDes, DSP, ADC, and LD during idle times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the OLT operates continuously to maintain high data rate transmissions, then transmission quality and reliability are improved, but power consumption increases

Engineering Contradiction:

Improvetransmission qualityVSAvoidOLT power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The OLT alternates between active transmission periods and idle sleep periods. During active periods, the OLT performs burst transmissions to ONUs and receives upstream bursts. During idle periods, the OLT enters sleep mode to conserve power. This periodic operation allows the system to maintain transmission quality when needed while reducing power consumption during low-activity periods.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The OLT dynamically adjusts its operational state based on traffic conditions. The transmitter and receiver are configured to operate in burst mode, transitioning between active and idle states. The OLT minimizes downstream and upstream transmission periods and schedules bursts continuously to maximize idle time, allowing dynamic power management that adapts to varying network conditions.

Inventive Principle:

Principle #15Dynamics

2Use of energy by moving object

If the OLT minimizes transmission periods and maximizes idle periods to save power, then power consumption is reduced, but transmission efficiency may deteriorate

Engineering Contradiction:

ImproveOLT power consumptionVSAvoidtransmission efficiency

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The OLT schedules upstream bursts from multiple ONUs in a substantially continuous manner during active periods, minimizing guard times between bursts. This continuous scheduling maximizes the utilization of active transmission time, ensuring high transmission efficiency when the OLT is awake. The receiver is configured to receive bursts continuously during active periods without unnecessary idle gaps.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The OLT obtains optical powers associated with ONUs and generates transmit order instructions in advance during active periods. The processor configures the transmit order based on optical powers before transmissions occur, allowing efficient power management without real-time delays. This preliminary configuration enables the OLT to maximize idle periods while maintaining transmission efficiency.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If the OLT schedules bursts in continuous manner with minimal guard times, then transmission efficiency is improved, but difficulty in managing optical power variations increases

Engineering Contradiction:

Improvetransmission efficiencyVSAvoidpower management complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The processor generates transmit order instructions that schedule bursts from different ONUs in a specific order based on their individual optical power characteristics. ONUs with higher optical powers are scheduled to transmit before ONUs with lower optical powers. This local optimization at each ONU level, coordinated by the OLT, allows continuous burst scheduling while managing optical power variations through ordered transmission sequences.

Inventive Principle:

Principle #3Local quality

4Use of energy by moving object

If the OLT enters sleep mode during idle periods, then power consumption is reduced, but response time to resume transmissions increases

Engineering Contradiction:

ImproveOLT power consumptionVSAvoidresume time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The OLT extracts and maintains essential functionality during sleep mode. The processor and transceiver components are configured to enter low-power states while maintaining the ability to quickly resume operations. The OLT minimizes the duration of sleep periods by scheduling bursts continuously during active periods, thereby reducing the overall impact of resume time on system performance.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS11375299B2Optical network power conservation

Publication Date: 2022.06.28 HUAWEI TECH CO LTD

AI summary

An OLT comprises a processor configured to: obtain optical powers associated with ONUs, and generate an instruction instructing a transmit order of transmissions based on the optical powers; a transmitter coupled to the processor and configured to transmit the instruction to the ONUs; and a receiver coupled to the processor and configured to receive the transmissions from the ONUs based on the instruction. An apparatus comprises a receiver configured to receive an instruction instructing a transmit order of transmissions based on optical powers associated with ONUs; a processor coupled to the receiver and configured to process the instruction; and a transmitter coupled to the processor and configured to transmit a transmission based on the instruction.