Building dependable Next Generation Networks (NGNs): A new BlueGreen design philosophy

To compensate for the neglected aspect of service resilience in current green networking studies, this paper proposes a new BlueGreen network design philosophy for rethinking and redesigning network protocols and architectures to satisfy the criteria of being simultaneously service resilient, energy efficient and eco-friendly. Next Generation Networks (NGNs) are required to satisfy both extremely high levels of service resilience by means of network survivability mechanisms such as over provisioning of diversity and backup network resources (i.e., Blue criteria), as well as minimizing consumption of energy by switching off unused network resources as much as possible (i.e., Green criteria). There is an inherent contradiction involved in satisfying both these Blue and Green perspectives simultaneously. We model this challenging problem as a global optimization problem, where the network´s working and backup components, and their energy consumption are considered as a resource, and the utilization is minimized while guaranteeing the required degrees of service resilience. The case studies presented confirm that the BlueGreen approach shows promise for integrating service resilience and energy efficiency in core networks to achieve specified BlueGreen targets.