Interplay between energy efficiency and survivable network planning with shared backup resources

Backbone network infrastructures are deployed with redundant resources taking into account the backup capacity for protection in order to be resilient against link failures, serving extremely large amount of data transmission. This goes together with increasing power consumption of backbone networks. In this study the impact of green network design and flow routing mechanisms on different protection schemes is analyzed thoroughly by proposing models to obtain optimum solutions under various objectives: Minimizing consumption of (I) Capacity, (II) Capacity+Energy, and (III) Energy. Two different shared backup protection (SBP) schemes (1) SBP-ind (failure independent) and (2) SBP-dep (failure dependent) are compared with dedicated path protection (DPP). It is assumed that network links utilized by only backup paths can be put into sleep mode. It can be observed that when energy consumption is minimized, the backup sharing decreases in SBP and, in the extreme case, it behaves similar to DPP. The models are generalized and valid for both IP traffic flow routing and lightpath routing. It is shown that for a sample network topology, to save e.g., 32.33% power, capacity consumption increases significantly e.g., in SBP-ind up to 127.53%. In order to achieve a good compromise between power and capacity consumption we propose a multi-objective approach. Moreover this study presents a complete picture of various survivability mechanisms when power consumption is minimized together with the capacity consumption.