container for the encap- sulated digitized radio transport frames. The standard further defines a structure-aware mapper for CPRI frames and payloads to/from Ethernet encapsulated frames. It must be noted that the structure-agnostic encapsulation is not restricted to CPRI. CPRI Forum has developed a new specification (eCPRI) for fronthaul interface which includes increased efficiency in order to meet the foreseeable requirements of 5G mobile networks. Note that the widely used CPRI (radio over fiber) specifications were also developed by this special interest group in the past. The eCPRI specification is based on new functional partitioning of the cellular base station functions within the physical layer. The new split points enable significant reduction of the required fronthaul link capacity. The required bandwidth can scale flexibly according to the user-plane traffic transport over the Ethernet. The use of Ethernet opens the possibility to carry eCPRI traffic and other traffic simultaneously in the same switched network. The new interface is a real-time traffic interface enabling use of sophisticated coordina- tion algorithms and guaranteeing the best possible radio performance. The eCPRI inter- face is meant to be future proof, allowing new feature introduction by software updates IEEE 1914 Working Group, Next Generation Fronthaul Interface, http://sites.ieee.org/sagroups-1914/. CPRI, http://www.cpri.info/. Introduction and Background xlv in the radio network. In addition to the new eCPRI specification, the special interest group continues to further develop the existing CPRI specifications in order to maintain a competitive option for all deployments with dedicated fiber connections in the fronthaul including 5G wireless systems. As shown in Fig. 11, an NGFI switch network connects CU and one or more DU(s) entities. The use of NGFI interface allows flexible configuration and deployment of CU and DU entities in different deployment scenarios. In case of ideal fronthaul, the deployment of DU can also be centr