Protection Methods Analysis in a Hybrid C/C+L Optical Network

The use of multi-band elastic optical networks (MB-EONs) over $\mathrm{C}+\mathrm{L}$ bands is considered as a realistic mediumterm solution to extend the capacity of current C-band optical networks. In this kind of networks, different levels of survivability can be offered, as we showed in a previous work in which we analysed the impact of these techniques in fully upgraded $\mathrm{C}+\mathrm{L}$ networks. However, postponing the high CAPEX cost of activating the L-band for all the optical fibers within a network has shifted the attention of the network operators to partially upgraded networks. Thus, we now focus on partially upgraded networks and demonstrate that it is necessary to modify the protection method that we previously proposed for fully upgraded networks in order to efficiently work in these environments. The performance of the modified method is then evaluated in terms of request blocking ratio in both partially and fully upgraded networks, and we show that the introduced variation outperforms the original method.