Journal of Microwaves, Optoelectronics and Electromagnetic Applications, Vol. 12, No. SI-2, July 2013 Brazilian Microwave and Optoelectronics Society-SBMO received 240 Apr 2013; for review 24 May 2013; accepted 26 June 2013 Brazilian Society of Electromagnetism-SBMag © 2013 SBMO/SBMag ISSN 2179-1074 156 Abstract— Reconfigurable optical add and drop multiplexers (ROADMs) are key components to increase the dynamicity and flexibility of optical networks. In its first generation, solely based on PLC and WSS-technology, ROADMs allowed service providers to automate some of its network operations, reducing the OPEX and improving the quality of service offered to the customer. However, the current solution is limited to several constrains such as direction, color and contention, and still demands truck rolls and manual reconfiguration depending on the desired operation. To address this limitation, new optical components are emerging and particularly two node architectures are being considered as most promising candidates: multicast switch with optical amplification array and dense low loss fiber optical cross-connect with MUX/DEMUX AWGs. This paper compares both solutions, and a third variation using fiber OXC in conjunction with WSS, from a CAPEX and OPEX perspective. It concludes that depending on the network scenario one solution is more suitable than the others and probably, in the next generation reality, different node architectures will be required in different portions of a same network. Index Terms— ROADM, next generation optical network, multicast switch, cross-connect, WSS. I. INTRODUCTION All-optical switching network presents several advantages over electronic switching networks like SDH (synchronous digital hierarchy) and OTN (optical transport network) such as: lower power consumption, lower cost per bit, much higher bandwidth capacity and no need for optical-electrical- optical (OEO) conversion in the core nodes. Besides that, it is agnostic to the signal modulation format and rate, characterizing a future-proof solution. With the advance of integrated optics technology, 2-degree ROADM using PLC (planar lightwave circuit) switches that started to be deployed in the telecom operator´s networks in the mid 2000s, followed by N-degree ROADM using WSS (wavelength selective switch) few years later. PLC switches allowed the deployment of ring topologies and WSS switches the interconnection of rings and, more recently, mesh topologies. Through the use of ROADMs, lightpaths can be configured remotely in wavelength granularity. Node Architectures for Next Generation ROADMs: A comparative study among emergent optical solutions Eduardo C. Magalhães, Marcelo R. Nascimento, Vinícius G. de Oliveira, Bruno C. C. Angeli, Juliano R. F. de Oliveira, Júlio C. R. F. de Oliveira Optical System Division, CPqD – Telecom & IT Solutions, Campinas, Brazil, {eduardom}@cpqd.com.br Aldário C. Bordonalli DMO, FEEC, UNICAMP, Campinas, Brazil, {aldario}@dmo.fee.unicamp.br