Spectrum-efficient hybrid protection with dedicated and shared paths in elastic optical data center networks

Spectral efficiency is essential for ensuring the survivability of service requests that require multi-level protection in elastic optical data center networks (EODCNs). To tackle the survivability issue, we first create a system model that includes a network model, a service request model, and a dedicated and shared paths model. Next, we develop an integer linear programming (ILP) model aimed at minimizing the maximum index of allocated frequency slots (FSs) for various service requests with dedicated path protection (DPP) and shared backup path protection (SBPP) levels. Following this, we propose a spectrum-efficient hybrid protection algorithm (SEHPA) for survivable routing, modulation level, and spectrum assignment. Finally, we solve the ILP problem in a small-scale topology and evaluate the SEHPA algorithm in different large-scale topologies. Simulation results indicate that the SEHPA algorithm can reduce the percentage of unserviced requests by 16.1% while utilizing fewer network resources.