 the network. Developing and deploying a sRAN architecture using con- ventional technologies is difficult because there is not necessarily a single optimal split point for all configurations, and because (unlike the cRAN architecture) a flexible sRAN architecture generally requires changes to the BBU hardware and software. While the cRAN architecture can take advantage of SDN and NFV, the sRAN architecture thrives on it. The sRAN architecture generally will require a hardware redesign, SO the move to the extended AIC architecture shown in Figure 11.2 can be a natural approach. The sRAN architecture requires disaggregating the software components of the BBU, which also aligns well with the transi- tion to SDN and NFV. Most importantly, the optimal "split point" for the sRAN architecture varies Local Backhaul Midhaul Part 2 Part 1 virtualized Cell Site Central Site FIGURE 11.15 Block diagram of the sRAN architecture. Building the Network of the Future with specific traffic and network conditions, which makes legacy sRAN implementations difficult. In the new extended architecture, all of the BBU functions are disaggregated and virtualized, and the ONAP system will be able to instantiate and manage the virtualized functions as needed to optimize cost and performance. With the new extended AIC architecture, the split architecture is not limited to two types of locations as shown in Figure 11.15. As an oversimplified example, layer 1 functions could be implemented at the cell site in the figure, layer 2 functions at the central site, and layer 3 functions in a large data center site, potentially collocated or integrated with virtualized mobile core network functions (discussed in Chapter 14). As the next section will show, 5G technologies and the 5G architecture will, in general, look more like the sRAN architecture, making them a strong fit for NFV and SDN implementation. But the advantages that this new architecture will provide to 5G go beyond the architecture. The key characteristic of 5G-the characteristic that wi