Wavelength-Routing Capability of Reconfigurable Optical Add/Drop Multiplexers in Dynamic Optical Networks

According to their underlying switching technologies, reconfigurable optical add/drop multiplexers (ROADMs) can be classified into three categories: Category I consists of a single large optical switch; category II is composed of a number of small optical switches aligned in parallel; and category III has a single optical switch and only one wavelength being added/dropped. To evaluate the wavelength-routing capability of ROADMs of various categories in dynamic optical networks, a theoretical routing-power model is developed, taking into account different ROADM architectures and dynamic traffic. Numerical simulations show that different category ROADMs differ considerably in their wavelength-routing capabilities, which are significantly dependent upon dynamic traffic. It is also observed that among these three ROADM architectures, category I (III) ROADMs offer the greatest (lowest) wavelength-routing capability and the lowest (highest) susceptibility to dynamic traffic. In particular, to maximize the ROADM-based network flexibility and connectivity, a set of practically applicable criteria is identified on designing/choosing optimum ROADMs for given dynamic optical networks