based around an outdoor network within a city. Figure 4.6.10 highlights location, disaggregation, and platform choices suitable for this scenario and, while other combinations are possible, to provide an easy-to-understand example only one is selected. Location In this example the outdoor network requires space in a point of presence (PoP), where a PoP is a location within the mobile network where an operator installs equip- ment. For example, this could be an aggregation point bringing multiple base stations' data together, and in an urban area should be no more than 5-20 km from a base station. This outdoor network will require sites for each small cell, for example on street-lighting, and the connection between the CU and DU is likely to be fiber. Disaggregation - The CU is up to 20 km from the DU, which means that due to latency the real-time portion of the small cell is likely to reside in the DU. By centralizing the RRC and PDCP, this will still improve handover and interference management in the small cell network. The split between the CU and DU will follow the 3GPP F1 interface. 4.6 Small Cells Urban Area (1) Location (2) Disaggregation Virtualized Compute Software (3) Platform Fiber Hardware Memory Figure 4.6.10 Outdoor urban scenario. Platform - With much of the small cell in the DU this scenario is ideal for a SoC at the small cell site. The small cell functions at the PoP will be virtualized. Frequency - This example shows mm Wave and the small cell operating on licensed fre- quencies. The choice of mmWave can allow the network to reserve its sub-6 GHz frequen- cies for the overlaying macro cell network. Operational mode - This type of outdoor network is expected to be public and part of a HetNet solution for one mobile operator. Each mobile operator will have their own outdoor urban small cell network. 4.6.6.3 Private Network Example The third example of a small cell deployment scenario is a private network and is included since this is a new vertical market for small cells. An example of this scena