In this paper, we propose an optimization model to establish the best ROADM switching connectivity to maximize the grade of service, for a given number of ports. We show that the grade of service can vary significantly, up to 30, depending on the switching connectivity. | HNUE JOURNAL OF SCIENCE DOI Natural Sciences 2020 Volume 65 Issue 10 pp. 36-48 This paper is available online at http OPTIMAL PROVISIONING OF OPTICAL NETWORKS WITH ASYMMETRIC NODES Luong Van Hieu1 and Do Trung Kien2 1 Faculty of Infomation Technology Hanoi College for Electro-Mechanics 2 Faculty of Infomation Technology Hanoi National University of Education Abstract. Wavelength Switched Optical Networks WSONs have been designed to take advantage of all optical switching fabrics with a high level of automation and efficiency. Therein the Wavelength Selective Switches WSS represent the core switching elements with a technology enabling multi-degree Reconfigurable Optical Add Drop Multiplexers ROADM architectures with colorless and directionless switching. In this paper we propose an optimization model to establish the best ROADM switching connectivity to maximize the grade of service for a given number of ports. We show that the grade of service can vary significantly up to 30 depending on the switching connectivity. Besides the larger the network is the more the variance increases from 20 to 30 when the number of nodes varies from 14 to 24. Keywords asymmetric networks ROADM routing wavelength assignment. 1. Introduction Recent developments in the Wavelength Selective Switch WSS technology enable multi-degree Reconfigurable Optical Add Drop Multiplexers ROADM architectures with colorless directionless and contention-less switching. WSS is regarded as a very promising enabler for future reconfigurable wavelength division multiplexing WDM mesh networks see . 1 . WSS selects individual wavelengths from multiple ingress ports and switches them to a common egress port a key property of the WSS based ROADM referred to as Asymmetric Switching in an optical switching element the optical signal from one direction can only reach a subset of other directions. Such restrictions have been hardly considered in the studies on the
