Applications of ROADMs and Control Planes

Today's optical networks are static in nature, with quasi-static SONET/SDH TDM and dynamic packet layers as payloads. It is commonly agreed that SONET/SDH will vanish over the next 10-15 years, and that future networks will be exclusively packet-minded. Major intermediate steps include a flexible optical layer using Reconfigurable Optical Add/Drop Multiplexers - ROADMs - together with a control plane. ROADMs can lead to significant operational cost reductions. Their behavior however also differs as compared to electrical cross connects which limits their use in certain applications. In addition, precaution is necessary when considering them in upcoming ultra-broadband networks. This paper discusses relevant ROADM applications and implications.