PRBs. The link budget calculation shows LTE1800 for reference with a maximum path loss of 155 dB including an 18 dBi antenna gain. That path loss typically gives a 500 kbps uplink data rate. The path loss value corresponds to a reference signal received power (RSRP) of - 122 dBm with 2 X 40 W downlink power. The path loss difference between 3.5 and 1.8 GHz is assumed to be 10 dB. Therefore, the LTE1800 path loss is shown as 165 dB in Figure 10.20 when converted to 3.5 GHz. The results for the uplink link budget are shown in Table 10.12 and for the down- link in Table 10.13. The results are summarized in Figure 10.20. We can make a few observations: PUSCH is the limiting factor for coverage for data rates above 100 kbps. 1 Mbps uplink coverage is approximately 15 dB shorter than the downlink 10 Mbps coverage or uplink control channel coverage. The PUSCH coverage issue can be solved by using a lower band uplink transmission. The SRS is the next limiting factor for coverage. Even with 4 PRB transmission, the SRS link budget is short because the full beamforming gain cannot be used for the SRS. One option is to use UE feedback for beamforming to get around the SRS coverage limitation or to use pre-filtering for SRS reception to get the beamforming gain. PRACH and PUCCH have good enough coverage to take benefit of low band LTE for uplink with the dual connectivity solution. The 5G downlink can still provide more than 10 Mbps data rate where the control channel coverage ends. The 5G downlink link budget and data rate are heavily depen- dent how many users share the downlink power. This calculation assumes that a single user is allocated 50% of 200 W power. 10.5 Link Budgets Max. path loss dB 160 Figure 10.20 Link budget benchmarking for different physical channels. Table 10.12 Uplink link budget for sub-6-GHz TDD. System PUSCH PUSCH PUSCH Long PUCCH PRACH parameter 10 (Mbps) 1 (Mbps) 0.1 (Mbps) 1 (ACK) format 1 Data rate (Mbps) Tx power (W) Tx power (dBm) Subcarrier spacing (kHz) Uplink share Antenna gain (dBi) Interfe