Dynamic Sleep Time Control for Optical Network Power Saving
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In optical networks, especially those performing point-to-multi-point communication, the physical broadcast of signals from the OLT to all ONUs leads to increased power consumption when ONUs are in a non-communication state, and existing power-saving methods may cause disconnection or frame transmission delays due to careless determination of communication states based on known traffic characteristics.
Innovation Solution
An optical line terminal (OLT) and optical network unit (ONU) system that dynamically determines a sleep time for non-used functions based on observed traffic information such as frame arrival intervals, instantaneous bandwidth, and queue lengths, using threshold values and equations to calculate optimal sleep times, ensuring efficient power saving without degrading communication quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If the OLT performs physical broadcast to all ONUs in point-to-multi-point communication, then communication coverage is ensured, but power consumption increases when ONUs are in non-communication state
Solution Approach 1:
The patent implements dynamic sleep time determination by having the OLT observe traffic information (frame arrival intervals, bandwidth, queue lengths) and calculate optimal sleep times using threshold values and equations. This allows the ONU to dynamically adjust its sleep duration based on real-time network conditions, ensuring power saving while maintaining communication quality. The sleep time is not fixed but adapts to traffic patterns, resolving the contradiction between power consumption and communication reliability.
Solution Approach 2:
The system employs feedback mechanisms where the OLT monitors traffic characteristics and provides control signals to the ONU regarding sleep state entry requests and sleep time durations. The ONU uses this feedback information to determine when to enter sleep state and for how long, ensuring that power saving actions do not compromise communication quality. The feedback loop allows the system to balance power consumption and communication reliability based on observed traffic patterns.
2Use of energy by stationary object
If sleep time is determined based on known traffic characteristics, then power saving is achieved, but disconnection or frame transmission delays occur
Solution Approach 1:
The patent transitions from static sleep time determination based on known traffic characteristics to dynamic sleep time calculation based on real-time observed traffic information. The OLT continuously monitors frame arrival intervals, instantaneous bandwidth, and queue lengths, then calculates sleep times using threshold values and equations. This dynamic approach allows the system to adapt to changing traffic conditions, preventing disconnections and delays while maintaining power saving benefits.
Solution Approach 2:
The system changes the parameter used for sleep time determination from fixed known traffic characteristics to variable observed traffic parameters (frame arrival intervals, bandwidth, queue lengths). By using multiple observable parameters and threshold-based calculations, the system can more accurately determine appropriate sleep times that prevent communication issues while achieving power savings. The sleep time parameter becomes a function of multiple dynamic variables rather than a fixed value.
3Use of energy by stationary object
If the ONU stops non-used functions for power saving, then energy consumption decreases, but communication responsiveness deteriorates
Solution Approach 1:
The patent implements periodic monitoring of traffic information by the OLT and periodic calculation of sleep times based on observed parameters. The ONU enters sleep state periodically when traffic conditions warrant it, and wakes up when the sleep period ends or when traffic conditions change. This periodic action allows the system to achieve power savings during low-traffic periods while maintaining responsiveness when traffic arrives, as the ONU can quickly wake up and resume normal operation.
Data Source
AI summary
An optical line terminal which includes an observing unit that observes information of any one or all of an arrival interval of frames, an instantaneous bandwidth under use of a flow, a queue length of a queue temporarily storing the frames, and a traffic type, and a stop determining unit that dynamically determines a sleep time to be a period in which a sleep state where partial functions of the ONU are stopped is maintained, on the basis of the information obtained by the observing unit. The ONU is entered into a sleep state, immediately after communication ends, after a predetermined waiting time passes from when the communication ends, or after a waiting time determined on the basis of the information passes from when the communication ends.