PON Sleep Mode Protocol for Power Reduction
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Solution Overview
Problem
Existing passive optical networks (PONs) face challenges in reducing power consumption while maintaining service continuity, as prior methods for low-power operation of optical-network units (ONUs) and optical-line terminals (OLTs) cannot guarantee continuous service.
Innovation Solution
Implementing a sleep mode for ONUs and OLTs that minimizes power consumption by scheduling them to enter a sleep period, buffering data during this time, and ensuring seamless recovery without re-registration or packet loss, with a protocol that includes repeated transmission of command messages for reliability and backward compatibility with legacy systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If ONUs enter sleep mode to reduce power consumption, then power consumption is reduced, but service continuity may be compromised
Solution Approach 1:
The system performs preliminary actions by buffering data at the OLT before the ONU enters sleep mode, and by pre-configuring wake-up procedures. This ensures that when the ONU wakes up, all necessary data is already prepared and waiting, maintaining service continuity without requiring re-registration or causing packet loss.
Solution Approach 2:
The patent implements feedback mechanisms where the OLT monitors ONU status and sends wake-up signals when needed. The ONU also sends status reports to the OLT. This continuous feedback loop ensures coordinated sleep-wake cycles that maintain service continuity while optimizing power consumption.
2Use of energy by moving object
If ONUs are scheduled for sleep mode with data buffering, then power consumption is reduced and service continuity is maintained, but network complexity increases
Solution Approach 1:
The patent makes the OLT multi-functional by having it perform both normal data forwarding and sleep-mode coordination functions. The OLT buffers data, manages wake-up signals, and coordinates sleep schedules for multiple ONUs, consolidating multiple functions into a single device to avoid increasing overall network complexity.
Solution Approach 2:
The patent merges the sleep-mode management functions into the existing OLT infrastructure rather than creating separate dedicated components. The shared queuing system and existing MAC layer protocols are enhanced to handle sleep-wake coordination, combining multiple functions into existing structures to minimize additional complexity.
3Use of energy by moving object
If sleep mode is implemented with coordinated scheduling, then power consumption is reduced and service continuity is maintained, but protocol complexity increases
Solution Approach 1:
The patent employs periodic action through scheduled sleep-wake cycles where ONUs and OLTs operate in periodic intervals rather than continuously. This periodic operation pattern simplifies the protocol by using time-division multiplexing and periodic signaling, reducing the complexity of coordination compared to continuous operation protocols.
Solution Approach 2:
The patent maintains continuity of useful action by ensuring that data transmission continues uninterrupted through the sleep-wake cycle. The OLT continuously buffers data during ONU sleep periods, and wake-up transitions are seamless, maintaining continuous service flow without requiring complex interrupt-handling protocols.
4Use of energy by moving object
If active time of ONUs is minimized to reduce power consumption, then power consumption is reduced, but service handling latency increases
Solution Approach 1:
The system performs preliminary actions by pre-buffering data at the OLT before the ONU enters sleep mode. This ensures that when the ONU wakes up, data is already ready for immediate transmission, minimizing latency. The OLT anticipates wake-up times and prepares data in advance during the ONU's sleep period.
Solution Approach 2:
The patent implements dynamic adjustment of sleep schedules based on actual traffic conditions and ONU wake-up needs. The system can dynamically modify sleep durations and wake-up times to optimize the balance between power consumption and latency, adapting to varying network conditions rather than using fixed schedules.
Data Source
AI summary
The present invention discloses methods for reducing power consumption in a PON while maintaining service continuity, the method including the steps of: providing an OLT operationally connected to at least one ONU; triggering a sleep request for at least one requesting ONU; upon receiving a sleep acknowledgement, activating a sleep mode for at least one requesting ONU according to a sleep period designated in the sleep request; and terminating the sleep mode according to the sleep period. Preferably, the sleep acknowledgement is transmitted from the OLT to the requesting ONU. Preferably, the sleep period is executed by a sleep command in the sleep acknowledgement. Preferably, the method further includes the step of: upon completion of the sleep period, transmitting buffered data traffic from the OLT to a sleeping ONU. Preferably, the step of transmitting is performed without the sleeping ONU being re-registered and without causing packet reordering.