Hiroko Nomura

Bandwidth scheduling techniques in TDM-PON supporting inter-ONU communication with network coding for smart grid applications

In next-generation passive optical networks (PONs), the traffic exchanged among optical network units (ONUs) belonging to the same PON, i.e. inter-ONU traffic, will increase because of emerging applications and services such as the smart grid. Applying network coding (NC) techniques to the inter-ONU traffic will improve throughput, security and reliability. However, the implementation of NC causes additional queuing delay at the optical line terminal (OLT), and degrades the fairness among coded and uncoded inter-ONU flows in terms of latency. This paper proposes a novel bandwidth scheduling technique, i.e. a grouped random scheduling (GRS) algorithm, to reduce the additional queuing delay at the OLT. In addition, a priority index (PI) is defined to further reduce the latency of coded inter-ONU flows, and an adaptive priority scheduling (APS) algorithm is proposed to improve latency fairness among coded and uncoded inter-ONU flows. The proposed techniques are validated by numerical analyses and simulations.

Highly-efficient ONU power-saving technique with HGW-determined sleep pattern toward next-generation optical access systems

We propose a novel power-saving technique by interworking with the home network via the home-gateway. Numerical simulations show it is highly effective even if the UNI throughput is 100 Mbit/s; it has moderate buffer size requirement. It is also shown that the optical and electrical components and command processing for the state transitions must offer quick response times for higher power efficiency.

Coordinating energy-efficient CPEs on IEEE 1904.1 compliant systems Via ONU for enhanced power savings: Proposal and demonstration

We propose a novel energy-efficient power saving technique coordinating CPEs via ONU. In addition, we first evaluate the proposal in a 10G-EPON system whose ONU sleep mechanism complies with IEEE Std. 1904.1 SIEPON and IEEE 802.3az EEE. It is revealed that the proposal yields ONU power savings of the order of 42 %. Moreover, it reduces the excessive latency by 40 % compared to unsynchronized power saving control.