Yukihiro Fujimoto

Study and Demonstration of Sleep and Adaptive Link Rate Control Mechanisms for Energy Efficient 10G-EPON

This paper describes sleep and adaptive link rate (ALR) control functions to reduce the power consumption of optical network units (ONUs) in 10 Gb/s Ethernet passive optical network (10G-EPON) systems. A hybrid mechanism that includes both sleep and ALR control functions is proposed with a view to further improving the power-saving performance. The sleep control function switches the ONU mode, i.e., active or sleep, depending on the presence or absence of traffic. The ALR control function switches the downlink rates between an optical line terminal (OLT) and an ONU, i.e., 1 Gb/s or 10 Gb/s, depending on the quantity of traffic. The proposed hybrid mechanism offers effective power management of ONUs on the basis of the traffic conditions. The proposed hybrid mechanism is validated by a numerical simulation and an experiment.

Sleep and Adaptive Link Rate Control for Power Saving in 10G-EPON Systems

This paper proposes a novel power-saving mechanism for the 10 Gbit/s Ethernet passive optical network (10GEPON) systems that are currently being discussed in IEEE 802.3av. The proposed power-saving mechanism includes a sleep control function and an adaptive link rate (ALR) control function. The sleep control function switches the modes of optical network units (ONUs), i.e. active and sleep modes, depending on the presence or absence of traffic. The ALR control function switches the link rate between the optical line terminal (OLT) and an ONU, i.e. 1 Gbit/s or 10 Gbit/s, depending on the quantity of traffic. The proposed hybrid mechanism offers effective power management of ONUs on the basis of the traffic conditions. The proposed hybrid mechanism is validated by some numerical simulations.

Application of Ethernet Technologies to FTTH Access Systems

SUMMARY A significant growth in FTTH access rates has been seen in the last year. This paper overviews the deployed FTTH access systems and the recent application of Ethernet technologies. The standardization activities and further study issues are also discussed.

Advanced Internet Congestion Control Using a Disturbance Observer

This paper presents a novel Internet congestion control scheme, the active queue management (AQM) scheme, that supports transmission control protocol (TCP) flows and avoids serious congestion by suppressing bottleneck nodes. The proposed controller includes a proportional-derivative (PD) controller and a disturbance observer (DOB). PD control is performed to keep the queue length below the buffer size, and the DOB is implemented for robust congestion control. The DOB can estimate and compensate the variations in network parameters, e.g., the number of TCP connections. This paper also describes a design methodology of the proposed congestion controller including the PD controller and the DOB. The validity of the proposed method is shown by simulation results.

Adaptive optical network unit for point-to-point and point-to-multipoint Gigabit Ethernet-based optical access networks

This paper proposes and demonstrates an optical network unit (ONU) that is adaptive in both point-to-point (P2P) and point-to-multipoint (P2MP) optical access networks (OANs) based on Gigabit Ethernet. Use of the proposed ONU makes it possible for network operators to reduce their operational expenditure (OPEX) by controlling/managing necessary inventories as well as handling troubles due to ONU mis-connection.

Adaptive Optical Network Unit for Point-to-Point and PON Systems Based on Gigabit Ethernet

This paper proposes an optical network unit (ONU) that works in point-to-point (P2P) optical access systems as well as passive optical network (PON) systems and so reduces the operational expenditure of optical access networks in the full FTTH era. First, we discuss its design and implementation; after clarifying the requirements for the adaptive ONU, we describe how it should work while focusing on Gigabit-Ethernet-based P2P and PON systems. Next, we study its feasibility through experiments on a prototype. Also, we provide some additional considerations regarding the implementation and future application of the adaptive ONU.