Support of superchannel formats in optical networks with legacy services and traffic churn [Invited]

The improved agility introduced at the electrical domain, via fast digital signal processing, and at the optical domain, enabled by coherent reception and fine-grained reconfigurable add-drop architectures, empowers optical communication systems with strong arguments to satisfy ever-growing bandwidth requirements. Superchannels are one of these arguments, but the exact network conditions in which this technology is going to be deployed are still a matter of discussion. Hence, this paper proposes to evaluate, from a networking perspective, how different factors can influence service satisfaction. The set of accounted factors includes different frequency grids, multiple client types, existence of legacy services, introduction of traffic churn, and others. The planning is done on a multiperiod basis with three reference topologies. The results obtained underline the importance of combining transmission formats with antagonistic properties (longer reach or higher spectral efficiency) to maximize the service adoption. When compared with purely incremental scenarios, traffic churn has a negative impact due to the associated spectrum fragmentation (which is further potentiated with fixed frequency grids). The presence of legacy services also leads to early capacity exhaustion. In addition, algorithmic options during the planning process, such as the spectrum assignment for legacy services and the demand ordering policy, are also shown to impair the network performance.