oors as shown in Figure 5.7. Other sources of location information can be obtained, for example, from the social media. When people upload pictures to social media, the picture can also include the location infor- mation. By combining the information from large number of uploaded content from different media can give further information about the location of the traffic for the future small cell Nokia Networks 3D Geolocation Tool Figure 5.6 Geolocation solution identifies the location of traffic Small Cell Deployment Options Traffic mapped in 3D Very high Medium Reasonable Figure 5.7 3D geolocation solution location. Also 3GPP Minimization of Drive Testing (MDT) can provide useful information for the network upgrades. 5.6 Indoor Small Cells Indoor cells provide a viable coverage and capacity solution in dense indoor traffic hotspots such as train stations, airports, shopping malls or enterprise buildings. The different indoor solutions are introduced in this section. The indoor solutions are presented in Reference 2 and the traffic steering is discussed in Reference 3. 5.6.1 Distributed Antenna Systems Distributed Antenna System (DAS) is the traditional solution for indoor coverage in high rise buildings and in large public premises. The DAS uses passive distributed antenna system and a high power base station. The DAS concept is illustrated in Figure 5.8. DAS includes a large number of small indoor antennas, the coaxial cabling and splitters. A high power base station is connected to DAS. The setting up of DAS requires heavy work because the cable installation takes a lot effort. The DAS should preferably be installed during the building construction phase. Once installed, DAS has a number of benefits. DAS can provide consistent coverage because it uses several indoor antennas which help keeping indoor users connected to the indoor cells instead of having ping-pong between indoor and outdoor cells. The main benefit of DAS solution is that the same antenna network can be shared by multiple bands, multiple technol