it is to analyse the UE power headroom. UEs report the available transmission power which indicates the available power resources for the uplink transmission. The distribution of the power headroom reports is shown in Figure 9.10. The UE power headroom increased considerably with the deployment of the small cell indicating clearly better coverage in the area. The user data rate measurements in selected indoor locations are shown in Figure 9.11. The coverage was weak in those spots before the small cell installation and the data rate was just a few megabits per second. The small cell installation boosted the data rates considerably with uplink data rates exceeding 6 Mbps and downlink even higher. The ability to improve indoor data rates with outdoor small cells is incredibly important. Studies have shown that close to 80% of mobile data usage is generated indoors. Small cells are designed to better address modern mobile data traffic that is more nomadic in nature compared to more voice- centric mobile networks. These indoor measurement locations are in areas you would expect to see mobile data usage such as popular coffee shops that contain large lounge areas where LTE Small Cell Optimization SINR distribution Before After <-5 dB -5 to 10 to 15 to >20 dB 5 dB 10 dB 15 dB 20 dB Figure 9.9 SINR levels in drive testing before and after small cell installation mobile data is consumed. Enhancing the coverage and user data rates in these locations can vastly improve the customers' perception of the quality and reliability of their wireless connection. 9.6.3 Macro Cell Offloading and Capacity The total data volume carried by the macro cell and by the small cell is shown in Figure 9.12. The statistics shows that the total data volume carried together by the macro and the small cell has increased while the data volume by the macro cell has decreased. The results indicated Power headroom distribution Before After Figure 9.10 Distribution of UE power headroom reports Learnings from Small Cell Deployments User data rate Pico 