.4.5 Traffic Density The 5G target is to provide 0.75 Tbps/km2 traffic density in urban hot spots. The traffic density is not dependent only on the technology but is also rather dependent on the amount of spectrum and on the deployment scenario. This section illustrates example estimates about the achievable traffic densities. Three scenarios are considered: a typical hot spot case in a live LTE network, maximum practical traffic density with LTE-Advanced Pro, and a 5G case using mmWave. We assume that LTE currently uses 50 MHz of downlink spectrum, LTE-Advanced Pro 200 MHz including usage of 5 GHz unlicensed band, and 5G a total of 3000 MHz spectrum at mmWave. The base station site densities are 30, 50, and 300 per km². More sites could be added at LTE bands below 6 GHz, but it makes more sense to use higher bands for dense networks because there is more spectrum available at higher frequencies. The high bands can be efficiently used in dense networks from the propagation point of view. We assume 2.5 sectors on average per site. The spectral efficiency is assumed to grow from 2.0 bps/Hz/cell to 6.0. We also consider the unequal traffic distribution between the cells. The assumption for LTE is that the highest loaded cell carries four times more traffic than the average cell. When the site density increases, we assume that the traffic distribution becomes more unequal. The high site density assumption is 6 for LTE-Advanced Pro and 15 for 5G. The calculations show that the typical LTE network carries approximately 2 Gbps/km2 traffic density, LTE-Advanced Pro can carry more than 20 Gbps/km ², and 5G at mmWave can carry even 1 Tbps/km2. We can conclude that LTE cannot fulfill 5G traffic density requirements at below 6 GHz frequencies (Table 16.4). 16.4.6 Device Density The 5G target is to enable a device density of 1 M/km². We consider the maximum device density from two perspectives: setup capacity and connected UE capacity. We assume a dense deployment of 50 sites/km² and 2.5 sectors per site. We further assume 10