ost-level management entity. The MEC host is further split to include the MEC platform, applications, and the virtualization infrastructure. The network-level group consists of the corresponding external entities that are 3GPP radio access networks, the local networks, and the external networks. This layer represents the connectivity to local area networks, cellular networks, and external networks such as the Internet. Above everything is the MEC system-level management that by 102 Chapter 1 Radio Traffic network offload Communication Service information function service service registry (TOF) (RNIS) MEC application platform services MEC virtualization manager, laaS MEC application platform MEC virtualization layer MEC hardware resources MEC hosting infrastructure 3GPP radio network element Figure 1.46 Overview of ETSI MEC 46]. definition has the overall visibility to the entire MEC system. The MEC system consists of the MEC hosts and the MEC management necessary to run MEC applications within an operator network or a subset of an operator network [53]. An in-depth understanding of the MEC systems can be attained from the reference architec- ture depicted in Fig. 1.47, which defines the functional entities and their relationships. The reference architecture follows the earlier described functional grouping of the general framework and includes system-level and host-level functions; however, the network-level functional group is not visible because there are no MEC-specific reference points needed to access those entities. The MEC host is an entity consisting of the MEC platform and the virtualization infrastructure that provides computing, storage, and network resources for the MEC applications. In addition, the MEC host can provide storage and ToD information for the applications. The virtualization infrastructure includes a data plane that executes the for- warding rules received by the MEC platform and routes the traffic between the applications, services, and networks. The MEC server provides computing resour