Energy efficiency in passive optical networks: where, when, and how?

Abstract

This article provides an overview of current efforts in reducing energy consumption in passive optical access networks. Both ITU-T and IEEE standardized PONs are considered. The current solutions proposed by standardization authorities, industry, and academia are classified based on the layer they address in the standardized architectures: physical layer, data link layer, and hybrid. Then, the article provides answers to major questions, such as where, when, and how to reduce PON energy consumption in TDM PONs by means of a quantitative evaluation. Results show that to reduce energy consumption, ONUs must be provided with physical devices that are not only power-efficient but also provide improved services (e.g., fast synchronization) to upper layers. For this latter purpose, novel physical ONU architectures are proposed to speed up the synchronization process and enable effective data link layer solutions. Finally, the feasibility of switching ONUs to low power mode in idle slots is assessed through a testbed implementation.

Energy saving in carrier-grade networks: A survey

“…Going further, more emphasis is given regarding saving energy in optical networks; among others: [175][176][177][178][179][180][181][182][183][184][185][186][187][188][189][190].…”

Provisioning 1 Gb/s symmetrical services with next-generation passive optical network technologies

“…Concerning OPEX, only first-year costs are considered, including system support and energy consumption, as a markup of the active (4 percent) and passive (1 percent) infrastructure [10,11]. Since they are considered as a percentage, OPEX costs are uniformly distributed over the CAPEX costs.…”

A Low-Energy Rate-Adaptive Bit-Interleaved Passive Optical Network

“…However, recent extensive research [8]- [10], [33] indicates that energy savings attainable by applying sleep modes in TDM PON are far lower, as a result of the following issues.…”

“…The power of the Bi-PON and XG-PON ONT OI in the active state is considered to be 750 mW, where PD, TIA and LA is estimated to be about 625 mW [33] and the CR power is assumed to be 125 mW based on our ASIC measurements.…”