# What is 5G? Emerging 5G Mobile Services and Network Requirements
## 6 5G Core Network Architecture and Requirements  
The technical requirements of 5G core networks are summarized in Table 6. These core network requirements are described in three aspects to support various 5G services in Section 4: functional requirements (F), architectural requirements (A) and operational requirements (0) [30]. For example, to meet the core network requirement F1, the 5G core network should support seamless mobility regardless of cell type and radio access technologies (RATs) where macro-cell base stations (BSs), small-cell BSs, personal-cell BSs, wireless local area network (WLAN) access points (APs) and relay stations are mixed and overlapped. In addition, to provide IoT-related 5G services, the 5G core network should provide the requirement, A2. In order to provide lightweight signaling, the 5G core network should have a lightweight signaling protocol to support a variety of terminals such as massive machine-type communication (MTC) terminals. In addition, fine grained location tracking is one of the \begin{table}
\begin{tabular}{l l} \hline \hline
**Technical Requirements** & **Description** \\ \hline \multirow{2}{*}{v1: Ultra high speed} & Provide tens of Gbps peak data rate \\  & Provide up to 1 Gbps user experienced data rate \\  & Provide areal capacity of 10 Mbps per square meter \\ \hline \multirow{2}{*}{w2: Massive connection} & Identify all devices (maximum of one trillion devices) over the world \\  & Provide services to a million terminals per square kilometer \\ \hline \multirow{2}{*}{w3: High reliability} & Provide 99.999\% service availability even in an extreme situation \\  & Guarantee a single packet transmission failure per 10,000 or 100,000 transmissions \\ \hline \multirow{2}{*}{w4: Ultra-low latency} & Provide less than 1 ms latency over radio interface \\ \hline \multirow{2}{*}{w5: High mobility} & Guarantee seamless connectivity to moving terminal at speed of 500 km/h \\ \hline \multirow{2}{*}{w6: High energy efficiency} & Improvement of 100 times energy efficiency per bit, in both network and device sides \\  & Energy harvesting capabilities can be applied to sensors \\ \hline \multirow{2}{*}{w7: High cost effectiveness} & Improve cost effectiveness in network side even handling huge volume of traffic \\  & Reduction of devices’ cost especially in sensors \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Technical requirements for 5G wireless networks. most important requirements for user-aware (or context-aware) 5G services. The 5G core network should provide the functionality to trace the mobile terminal's location with a fine granularity for advanced location based services. Table 7 shows the relationship between 5G services and 5G core network requirements. Therefore, we are herein able to check the required functionalities in the 5G core network in order to support each service addressed in Section 4. To provide 5G-based mobile virtual reality and augmented reality services, the 5G core network should provide the functionalities: F1-seamless mobility, F2-wired/wireless terminal switching, F3-context aware best connection, A4-fine grained location tracking, 01-flexible reconfiguration and upgrade and 02-network on-demand. In other words, the 5G core network needs to satisfy these essential requirements to offer an immersive and realistic user experience. Figure 12 shows a software-centric 5G core and access network architecture designed to support various 5G mobile services. In particular, the 5G network should create optimized service environments for supporting a variety of vertical services via 5G mobile networks [14; 22; 26; 27]. In order to efficiently manage physical and logical network resources, the 5G core network appropriately manages and orchestrates these various vertical services as virtualized network slices (1:VR/AR, 2:MCS, \(\cdots\), n:ES) as shown in Figure 12. In this figure, the fronthaul and the backhaul represent the interface between access units (AUs) and the edge cloud and the interface between the edge cloud and the core cloud, respectively.