However, note that these mechanisms should have no impact on current reliability and QoS levels, that is , they need to be well designed and to account for adequate security margins on failure events. e.g., they should be applied to protection resources that do not carry useful information under normal operation. Moreover, the issue of maintaining proper QuS and protection levels must betaken into account also in the design of new energy-efficient devices(i.e., they should have acceptable lifetimes) and network architectures (proper resource over-provisioning is still needed).
During trend project, several works dealt with energy-efficient protection schemes, demonstration that relevant savings can be obtained by setting protection resources into sleep state (in the order of 60% ), or exploiting differentiated QoP schemes and rate-adaptive technologies such as EON (in the order of 20%)