1 - 10-3 to discuss the communication performance in the above three cases, respectively. 14 Optimizing Resource Allocation in URLLC for Real-Time Wireless Control Systems 14.5.2 Communication Performance From the perspective of wireless communication, we assume that the bandwidth of each subcarrier is 1 kHz, the single-sided noise spectral density is -174 dBm/Hz, and the dis- tance between the BS and the plants is 100 m. For the URLLC, the maximum packet trans- mission error probability is Eth=10-5, the maximum transmission time delay for the uplink is Tth = 0.5 ms, and the maximum number of allocation subcarriers is 60. In addition, we consider the traditional method only considering the communication aspect in [7] for com- parison, where the authors intended to minimize transmission power. Figure 14.5 demonstrates the wireless resource allocation when payload information Am is different. Figure 14.5a shows the total power allocation. In the figure, the total resource allocation (i.e. multiplying transmission power by frequency bandwidth) increases with the communication reliability increasing from Case III to Case I. This is reasonable since high reliability needs more communication resource to support. Figure 14.5b,c show the allocated transmission power on each subcarrier and the allocated number of subcarriers for the m-th sensor. From Figures 14.5a-c, both the allocated subcarriers and allocated transmission power of the method that was explained earlier in Section 14.4 increase Case I Case II Case III Traditional method in Case II Payload information, Am (bit) Figure 14.5 Optimal resource allocation with different payload information Am. (a) Total resource allocation with different payload information Am. (b) Optimal power allocation with different payload information Am. (c) Optimal subcarrier allocation with different payload information Am. 14.5 Simulations Results Case I Case II Case III Traditional method in Case II Payload information, Am (bit) Case I Case II Case III Traditional method in Case II P