reasing the peak data rate. The maximum bandwidth was increased from 20 MHz in Release 8 to 100 MHz in Release 10 and up to 640 MHz in Release 13. The number of multistreams was increased from two to eight in Release 10 and the modulation from 64-QAM to 256-QAM in Release 13. The maximum downlink peak data rate is more than 20 Gbps in Table 16.2, and the uplink rate more than 5 Gbps in Table 16.3. It is straightforward to achieve the high theoretical data rate simply by adding more spectrum. The real challenge is how to find the spectrum. 16.4.2 Cell Edge Data Rate The 5G target is to provide a minimum data rate of 100 Mbps for the whole coverage area including cell edges. LTE-Advanced simulations [7] show a cell edge spectral efficiency of 0.07 bps/Hz/cell. A cell edge data rate of 100 Mbps would then require 1400 MHz of spectrum for FDD downlink or 1800 MHz for TDD (80:20), which clearly is not practi- cal. The low cell edge efficiency is explained by the simulations having 10 simultaneous users. With a lower number of users, the cell edge data rate would be higher. If the cell density is increased, the number of simultaneous users is lower per cell, and the cell Table 16.2 LTE-Advanced Pro downlink peak data rate for TDD operation. Peak data Bandwidth streams Modulation LTE Release 8 20 MHz 64-QAM 0.13 Gbps LTE Release 10 100 MHz 64-QAM 2.6 Gbps LTE Release 13 640 MHz 256-QAM 22 Gbps Uplink: Downlink configuration 5 and special subframe 3. Table 16.3 LTE-Advanced Pro uplink peak data rate for TDD operation. Peak data Bandwidth streams Modulation LTE Release 8 20 MHz 64-QAM 0.04 Gbps LTE Release 10 100 MHz 64-QAM 0.89 Gbps LTE Release 13 640 MHz 64-QAM 5.73 Gbps Uplink: Downlink configuration 0 and special subframe 3. 16 LTE-Advanced Evolution Cell edge data rate in TDD downlink Mbps 200 2 users + IC 2 users 10 users Spectrum [MHz] Figure 16.25 Cell edge data rate with TD-LTE. edge data rate can be increased. Therefore, the practical cell edge data rate is not only dependent on the technology but is also depend