This paper investigates the suitability of small and unamplified multicast switches to cost-effectively realize highly flexible optical transport networks. A comprehensive modelling exercise considering four possible generations of line interfaces, operating at increasingly higher symbol rates, is reported. The
simulation results obtained over a reference network topology provide evidence that small and unamplified multicast switches will have little to no effect in limiting the usable network capacity and, as a result, can be exploited to design lower cost contentionless architectures in next-generation optical networks
exploiting C- or SuperC-band fiber transmission.