# A Study of 5G Edge-Central Core Network Split Options
## 6 Split Models Assessment  
In this section, we give a targeted assessment of the core network and of the network management split models as evaluated in Section 5 towards their usability in the current beyond 5G vertical markets deployments. For this to be translated to use cases and to applications, a first intermediary step would be to compare the different solutions in terms of connectivity features they are offering and the trade-offs with the potentially available resources at the edge of the network and of the backhaul capacity. In Table 6, the major functional elements from which the connectivity service provided by the core network are shortly summarized for the different deployment options. The three core network split options are differentiated from each other from the way they treat the control and the data plane. For the control plane, the local offload requires all the procedures to be executed synchronously with the central node while the locally administrated edge requires only partially this and the autonomous edge none. Similarly, data paths can be local or end-to-end with the help of central entities. These differences bring variations in the connectivity functionality spanning from central handling in the local offload, partial local handling in the locally administrated edge and completely local in case of the autonomous edge. The variations impact the access control functionality including the authentication and authorization of the subscribe \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Feature** & **Local Offload** & **Locally Administered Edge** & **Autonomous Edge** \\ \hline Control Plane & Centralized & Half-distributed & Distributed \\ Data Plane & Split & Split & Local only \\ Access Control & Centralized & Assisted by central & Local \\ Mobility & Full network transparent & Coherent changes in network zones & Only local support \\ QoS & Centrally defined & Mixed between local and central & Local \\ Privacy at the edge & Local data paths & Local control and data paths & All communication \\ Backhaul reliability dependency & Large & Partial & Limited \\ \hline Number of interactions & & Same as in a 5G system with multiple UPFs & \\ \hline Number of components to be & & & \\ managed (with available edge & +UPFs at each edge & +AMF, SMF and UPF at each edge & +complete core at each \\ compute resources) & & & edge \\ \hline Suitable network management & Centralized & Distributed & Distributed \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Core network split models assessment. management decisions are taken and the resource reservations and QoS for the different data sessions. Furthermore, they impact the privacy of the communication. The inclusion of additional network functions at the edge of the network is dependent on the available compute resources. Previous benchmarks have shown that the 3 GPP systems can be considered linearly scalable for a very large number of subscribers due to the almost complete independence of the subscriber procedures [16]. This implies that with more subscribers, more compute resources will have to be allocated to the network functions at the edge and obviously, with more network functions at the edge, even more compute resources are needed. As such, a proper dimensioning of the edge infrastructure should be performed. The most important aspect when choosing one of these functional splits is the backhaul reliability dependency. It is expected that in situations with very reliable and high capacity backhauls, such as for most of the wide area network operators, a local offload solution is the best. However, in this case, an edge network is not needed, as the complete data traffic can be centralized with a minimal delay. For situations with less reliable backhauls such as best-effort Internet or with dedicated resources through a third-party operator, it would be better to use a locally administrated solution.