re 9.1 Network topology evolution to include small cells in the proper locations. For example, if a small cell covers only a 100 m footprint the geolo- cation techniques used to estimate customer traffic must be within this criterion; otherwise, there is a risk that a small cell is placed too far away from the hotspots and the small cell may actually cause unintended interference into the macro network and decrease system capacity. The location of small cells is SO critical that this may present additional challenges when the time comes for zoning and site acquisition of suitable site candidate locations. Another challenge is providing suitable cost-effective backhaul solutions to the small cells that scale down proportionally with the expected decrease in radio access network (RAN) equipment and leasing costs. As the number and density of small cells increases over time the next challenge will be to optimize the coordination with the existing macro layer to further enhance the capacity. There are numerous features being standardized as discussed in Chapter 7 that will assist with creating a seamless experience and maximizing the offload to the small cell network while mitigating system interference issues. Optimization features as described in Chapters 7 and 8 will also play a key role in the operators' ability to manage the integration and optimization of potentially tens of thousands of small cells that may be needed. The challenges and enablers of the small cell deployments are shown Figure 9.2. Summary of Learnings from Small Cell Deployments The small cell products have been deployed in a number of commercial networks which allows engineers to get useful hands-on learnings from the field. The 10 main learnings from the small cell measurements are summarized in Figure 9.3: 1. The site location is very critical for maximizing the benefit from the small cell. The location is important relative to the users and relative to the macro cell signal level. If LTE Small Cell Optimization Build Optimize Operate Hotspo