Restoration in carrier networks

Quality of service (QoS) is an important objective of large telecommunications carriers. Network restoration is the prime capability needed to achieve this objective. While a large body of publications study and propose different restoration methods and network optimization algorithms, very few have actually been implemented. To address this, we present background on how today´s large carrier terrestrial networks are constructed and operated. In particular we describe their segmentation, layering, and where, how and why network restoration is selectively implemented. We conclude with some observations where restoration research has the greatest need.