Dynamic Power Management in Passive Optical Networks

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Solution Overview

Problem

Passive optical networks (PONs) face challenges in power efficiency as increasing bandwidth demands from applications like video streaming and cloud computing, along with mobile traffic, necessitate effective power saving mechanisms to reduce energy consumption without compromising performance.

Innovation Solution

The implementation of power saving mechanisms in PONs involves the optical line terminal (OLT) and optical network unit (ONU) coordinating power saving operations based on traffic intensity, service changes, distance, and absence of data transmission, using methods such as line rate adjustment, sleep modes, and modulation format changes, facilitated by PLOAM messages and power management state machines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If power saving operations are implemented in PON, then energy consumption is reduced, but network performance may be compromised

Engineering Contradiction:
Improvepower consumptionVSAvoidnetwork performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic power management by transitioning OLT and ONU between active and sleep states based on real-time traffic conditions. The system dynamically adjusts operational states rather than maintaining fixed power levels, allowing optimization of energy consumption while ensuring network performance requirements are met through conditional state transitions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes operational parameters including line rate adjustments and modulation format changes when transitioning between power states. By modifying these technical parameters based on traffic intensity and service requirements, the system achieves power savings while maintaining adequate network performance through parameter optimization.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If transmission power is reduced for power saving, then energy consumption decreases, but signal quality and data rate may deteriorate

Engineering Contradiction:
Improvetransmission powerVSAvoiddata rate
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The system dynamically adjusts transmission power based on traffic intensity and service type. During low-traffic periods, transmission power is reduced to save energy, while during high-traffic periods or when service quality requirements increase, power levels are adjusted upward to maintain data rate and signal quality.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs modulation format changes as a complementary parameter adjustment to transmission power reduction. By changing modulation schemes according to channel conditions and traffic requirements, the system maintains data rate performance even when transmission power is reduced, resolving the contradiction between power savings and speed maintenance.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If sleep modes are activated, then power consumption is reduced, but latency and response time increase

Engineering Contradiction:
Improvepower consumptionVSAvoidlatency
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent implements periodic wake-up mechanisms where OLT and ONU transition to active state at scheduled intervals to check for traffic and synchronize. This periodic activation pattern allows the system to maintain sleep modes for extended periods (reducing power consumption) while ensuring timely response to network events through regular wake-up cycles.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system performs preliminary actions by notifying the counterpart (OLT or ONU) before entering sleep mode, allowing the other end to buffer incoming data or adjust transmission timing. This preliminary notification prevents data loss and reduces wake-up latency, as the sleeping device can quickly resume operation when notified.

Inventive Principle:
Principle #10Preliminary action

4Use of energy by moving object

If line rate is adjusted downward for power saving, then energy consumption decreases, but bandwidth capacity is reduced

Engineering Contradiction:
Improvepower consumptionVSAvoidbandwidth capacity
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent implements dynamic line rate adjustment based on traffic intensity measurements and service type requirements. The system transitions between different line rates (e.g., 10G, 2.5G, 1G) according to actual network conditions, allowing bandwidth capacity to be scaled down during low-traffic periods for power savings while automatically scaling up when high bandwidth is needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters including line rate and modulation format in coordination with power state transitions. By adjusting these parameters based on traffic intensity and service requirements, the system optimizes the trade-off between power consumption and bandwidth capacity, achieving power savings during low-utilization periods while maintaining adequate capacity when needed.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3939205B1Power saving mechanisms for high speed passive optical network
Publication Date: 2025.01.08 ZTE CORP
  • EP3939205B1 patent drawingFigure 1
  • EP3939205B1 patent drawingFigure 2
  • EP3939205B1 patent drawingFigure 3

AI summary

A method of communication includes notify, by an optical line terminal (OLT), an optical network unit (ONU) a first time period assigned to a first power saving operation and a second time period assigned to a second power saving operation, and perform, by the OLT, the second power saving operation for a receiver of the OLT during the second time period and the first power saving operation for a transmitter of the OLT during the first time period.