 3.5 GHz. The conclusion is that a high gain (19 dBi) passive antenna with an RF head can provide quite good COV- erage compared to massive MIMO, but the capacity will be lower than with massive MIMO beamforming. The RF head next to the passive antenna could be utilized if the site space is very limited. In general, we can note that there are more antenna and RF options available for 5G deployment compared to LTE. Most LTE networks use a passive antenna with 2 X 2 or 4x4 MIMO. 10.7.5 Distributed MIMO Inter-cell interference is one of the main challenges in the mobile networks in the sub-6-GHz bands. One solution for improving the performance is distributed Multiple Input Multiple Output (dMIMO), which refers to coherent transmission and reception from multiple cells SO that a set of devices is served simultaneously with many more dynamically controllable antenna elements than the number of devices. The concept is shown in Figure 10.45. The solution is known also as multi-TRP (TX/RX point) or Coordinated Multipoint (CoMP). Figure 10.46 illustrates the distribution of the number of cells that can serve each user with 10 and 20 dB windows in a macrocell environment. The median number of cells with a 10 dB threshold is approximately 2 and with a 20 dB threshold is more than 5. The cell edge values (90%) are correspondingly 5 and 15 cells. It shows that there is a major potential to use multicell transmission and reception for improving the performance, especially for cell edge users. Figure 10.47 shows the uplink user data rates in four different cases: 1) No distributed MIMO. Just single cell uplink reception. 2) Intra-site distributed MIMO. This approach is relatively simple since there are no transport requirements for multi-site coordination. Intra-site uplink CoMP is com- mercially deployed in most LTE networks today. 3) Inter-site distributed MIMO with 10 dB threshold. 4) Inter-site distributed MIMO with 20 dB threshold. The results show that intra-site dMIMO can improve the performance by 40%, and it clearly m