Cost Feasibility Analysis of Translucent Optical Networks With Shared Wavelength Converters

Abstract

Abstract-Translucent optical networks have emerged as potential yet feasible candidates to bridge the gap between the opaque and transparent network architectures. By allowing electrical 3R signal regeneration only at selected points in the network, translucent architectures represent a cost-effective, power-efficient solution. Concurrently, forecasts predicting highly dynamic traffic patterns make it crucial for next-generation transport networks to engage highly agile technologies that include sub-wavelength switching (SWS). In translucent SWS networks, contention resolution is achieved through the still technologically immature all-optical wavelength converters (WCs). Since WCs are expected to be expensive, power-consuming devices, there has been significant research effort on devising WC-sharing architectures, which aim at minimizing the number of these devices in the network. WC sharing, however, requires complex switching fabrics that involve a much higher number of optical gates and stronger degradation due to physical layer impairments (more electrical 3R regenerators). It is clear, then, that the technological interest in WC-sharing architectures mainly depends on the cost trade-offs existing between these three components. For this reason, in this work, we carry out a comprehensive cost feasibility analysis of translucent networks based on asynchronous WC-sharing packet switches. After modeling a set of translucent WC-sharing switching fabrics, we assess their performance in an isolated node scenario in terms of the number of WCs and optical gates required. Given the results obtained, we select the shared-per-node (SPN) architecture to compare its hardware requirements with those of a network based on dedicated WC nodes (i.e., one WC per wavelength and input port). To this end, an iterative simulation algorithm is used to dimension translucent SWS networks considering a broad range of continental-scale topologies. The results are first analyzed using relative cost values, and finally the viability/feasibility of WC-sharing schemes is discussed considering state-of-the-art technology. Our main conclusion is that, for SPN-based architectures to become cost effective, the cost of WCs has to be at least two orders of magnitude higher than that of the optical gate and similar to or lower than that of the electrical 3R regenerator.

Sharing Distributed and Heterogeneous Resources toward End-to-End 5G Networks: A Comprehensive Survey and a Taxonomy

“…Wang et al in [66], as well as Khandaker et al in [64,65], studied the concept of statistical spectrum sharing in the optical domain, enabling switching between base and peak rates through SDO. Many other researchers recognized the potentials in sharing optical devices [66][67][68] and in cooperative spectrum sharing [69,70].…”

“…Two other shareable optical devices are presented by Ali [28] and Pedrola et al [67], namely Optical-Electrical-Optical (OEO) regenerators and the pure all-optical converters. OEO regenerators are necessary for dealing with optical transmission impairments and/or realization of wavelength conversion [28].…”

“…Almost 10 years later, Pedrola et al [67] tackled this issue of complexity increase due to sharing. They consider FCNs as networks that require high agility, for example implementing Sub-Wavelength Sharing (SWS), in order to cope with highly dynamic traffic patterns.…”

“…The trade-off thus becomes one of relative costs between converters and optical gates. The outcome of their study highlight the conditions that need to be met in order for the sharing architecture to pay off: the cost of pure all-optical converters has to be at least two orders of magnitude higher than that of the optical gates, and similar or lower than the cost of 3R regenerators [67].…”

Preparation of Waveguide Polymer and its Simulation Study of Thermo-Optic Switch at the Infrared Communication Wavelength 1.55 μm

“…Optical switches are the devices that route an optical signal from one or more input ports to one or more output ports [7]. Their characteristics play important roles in optical networks as it determines the optical networks performance, optical crossconnection, signal transmission, wavelength division multiplexing, information exchange and optical line protection [8][9][10].…”