## 5 Experiment
### Main Results  
Figure 3 shows the URLLC link throughput under HSCRS, SARL, RAC, and mMTCP as the mMTC traffic volume increases. As can be observed from the figure, the throughput of the URLLC link decreases with increases in mMTC traffic. As the mMTC traffic increases, the required transmission delay also increases. To meet the delay limit, the transmission power of the mMTC link needs to be increased, causing greater interference to the URLLC link and resulting in a degraded throughput performance of the URLLC link. When the mMTC traffic volume is small, the performance of mMTCP is better than that of HSCRS. This is because the transmission delay with small mMTC traffic is also small and mMTC prioritizes mMTC traffic transmission, enabling it to complete the transmission task earlier. However, the transmission delay increases as the mMTC traffic increases, which leads to more interference to the URLLC link, reducing the throughput performance of the URLLC link. When the mMTC traffic is 256 Kbytes, the mMCP performance is 8 percent lower than that of the HSCRS proposed in our paper.  
Figure 4 illustrates the access success rates of HSCRS, SARL, RAC, and mMTCP algorithms for varying mMTC traffic levels. As shown in Figure 4, HSCRS, RAC, and mMTCP demonstrate a superior access performance when the mMTC traffic volume is low. At the same time, the access probability of SARL is low, because it refuses to access the mMTC service with strong interference to ensure the performance optimization of a single communication link. As the mMTC traffic increases, all algorithms experience a rapid deterioration in access performance. This is because the transmission delay increases, which makes it impossible to complete the transmission task within the delay limit.  
Figure 5 compares the changes in the traffic volume of each communication link over time steps, for the HSCRS and RAC algorithms, when the traffic volume of each mMTC link is fixed at 4 KBytes. As can be seen from Figure 5, the proposed HSCRS algorithm is able to rapidly transmit all mMTC services, in contrast to the RAC algorithm shown in Figure 5, where only three mMTC links complete the transmission task. This is because all mMTC links compete for resources simultaneously in the RAC algorithm, resulting in fewer resources obtained by each communication link, which increases the transmission delay and slows down the initial traffic volume transmitted in the stage. As one of the mMTC communication links completes its transmission task, the remaining communication links can obtain more resources, resulting in a rapid increase in the traffic volume transmitted.  
Figure 3: The comparison of the URLLC link throughput.  
However, due to the suboptimal resource scheduling in the early stage, excessive time is consumed, and one communication link is unable to complete the transmission of all traffic.  
Figure 4: The comparison of the success rates of mMTC service access.  
Figure 5: mMTC transmission traffic in HSCRS and RAC algorithm. (**a**) mMTC transmission traffic in HSCRS algorithm. (**b**) mMTC transmission traffic in RAC algorithm.  
Figure 6 shows the transmission rate of each communication link. In the HSCRS, each mMTC link operates in a cooperative manner. When a communication link performs a transmission task, the other links transmit at a lower rate to reduce the transmission delay of that link. Moreover, in Figure 6b, each mMTC communication link competes to obtain resources, and while each link can obtain a certain amount of resources, the cooperative resource allocation scheme in HSCRS results in a better network performance.