ayload information, Am (bit) Figure 14.5 (Continued) 14 Optimizing Resource Allocation in URLLC for Real-Time Wireless Control Systems monotonically with Am, which means that more payload information needs more resources for transmission. From Figure 14.5b, the allocated transmission power on each subcarrier of the method that was explained earlier in Section 14.4 increases with communication reliability increasing from Case III to Case I. However, from Figure 14.5c, the allocated subcarriers of the method that was explained earlier in Section 14.4 decrease with commu- nication reliability increasing from Case III to Case I. This is reasonable since the method that was explained earlier in Section 14.4 in Algorithm 14.1 leads to an increasing power allocation from Case III to Case I, which further leads to the subcarrier allocation reducing from Case III to Case I while maintaining total resource allocation increasing from Case III to Case I as shown in Figure 14.5a. In summary, higher control performance needs more communication resources. In addition, compared with the traditional method in [7], the number of allocated subcarriers of the method that was explained earlier in Section 14.4 is significantly reduced. For instance, the number of the allocated subcarrier is reduced from 60 to 8 when the payload information is 50 bits in Figure 14.5c, while the allocated transmission power on each subcarrier of the method that was explained earlier in Section 14.4 in Figure 14.5b is increased from -65 to -22 dBm, and the total allocated transmission power of the method that was explained earlier in Section 14.4 in Figure 14.5a is increased from -50 to -20 dBm. This is reasonable since the traditional method aims to minimize the transmission power with maximum allocated bandwidth, which leads to lower total power allocation for the traditional method as shown in Figure 14.5a. Figure 14.6 shows the spectral efficiency when payload information Am is different. From the figure, it is easy to infer that all the curves incre