Next Generation Mobile Fronthaul and Midhaul Architectures [Invited]

Centralized processing is expected to bring about substantial benefits for wireless networks both on the technical side and on the economic side. While this concept is considered an important part of future radio access network architectures, it is more and more recognized that the current approach to fronthauling by employing the Common Public Radio Interface protocol will be inefficient for large-scale network deployments in many respects, and particularly for the new radio network generation 5G. In this paper, an overview is given of currently available optical fronthaul technologies, and of recently started activities toward more efficient and scalable solutions, and finally an outlook is given into which 5G specific service characteristics may further impact future backhaul, midhaul, and fronthaul networks.