key performance indicators (KPIs). One reason may be that most hardware and software components are shared with macro cells. 10. The main challenge with the small cells was the site acquisition, backhaul and power. It does not help to have low-cost product if the site and backhaul cost more than 10 kEUR. The following figures show a few examples from the small cell measurements. Figure 9.4 illustrates drive test measurement results from co-channel small cell deployment at 2.6 GHz band. The small cells provide a considerable improvement in the signal level and also in the SNR. The median signal level improvement in this case is 7 dB and SNR improvement 3 dB, LTE Small Cell Optimization Signal level +7 dB Macro only Macro + small cell RSRP (dBm) Signal-to-noise ratio +3 dB Macro only Macro + small cell SNR (dB) Figure 9.4 Improvement in signal level and signal-to-noise level with small cells indicating that the typical small cell deployment improves the radio network quality which turns into higher user data rates. The higher signal level and quality leads to higher user data rate. The data rate can be illustrated with the used modulation and coding scheme (MCS). Figure 9.5 shows MCS in five different small cells and the average value in the macro cells. We can observe that the Average downlink MCS Small cell Small cell Small cell Small cell Small cell Macro cell no. 1 no. 2 no. 3 no. 4 no. 5 average Figure 9.5 Modulation and coding scheme (MCS) in small cells and in macro cells Learnings from Small Cell Deployments Traffic volume Traffic in 2 co- channel small cells Traffic in 3 macro cells Day 1 Day 10 Figure 9.6 Offloading with micro base station small cells can provide very high MCS values and, respectively, high data rates. We can also observe that there is large variance in the small cell MCS values depending on the small cell location illustrating the importance of the small cell antenna location. Figure 9.6 illustrates the data volume carried by the macro cells and by the small cells. The total data volume 