# Beam-Hopping-Based Resource Allocation in Integrated Satellite-Terrestrial Networks
## 6 Simulation Results
### Simulation Results for MWSC
The RRA scheme takes no account of the capacity requirements, so the average transmission capacity of each terrestrial system remains unchanged, and the resources allocated to each satellite terminal cannot match its capacity requirement. When the DRA scheme is adopted, both the satellite and terrestrial systems cannot achieve the desired capacity because of the lack of available resources. Figure 4: Terrestrial system capacity with varying requested capacity of satellite system. Figure 3: Satellite system capacity with varying requested capacity of satellite system. Figure 5 shows the sum of the variance between the requested capacity and the transmission capacity of each satellite terminal during one second. The variances of the proposed algorithms are always lower than those of the RRA and DRA schemes. This is because the proposed algorithms can allocate an appropriate number of resources to the satellite terminals, which implies that the algorithms can achieve better matching between the requested capacity and the transmission capacity. The performance of the proposed algorithms is close to that of the MTCS scheme, especially the greedy algorithm. As mentioned in Section 4.2, the greedy algorithm gives priority to the satellite terminals with higher remaining requested capacity during the resource allocation process, so the transmission capacity of each satellite terminal is closer to its requested capacity. Figure 6 presents the cumulative distribution function (CDF) of the CDR of the satellite terminal, i.e., \(C_{i}^{sat}/R_{i}^{sat}\). Since the optimization objective of P1 in (11) depends on the minimum value of \(C_{i}^{sat}\) and \(R_{i}^{sat}\), the transmission capacity allocated to most of the satellite terminals is relatively close to their requested capacity when the proposed algorithms and the MTCS scheme are adopted. As shown in Algorithm 1, the greedy algorithm no longer allocates the time slots to the satellite terminals if their requested capacities have been met, so almost all satellite terminals have the CDRs less than two, which relieves the resource waste. The RRA scheme does not schedule the resources according to the requested capacity of the satellite terminals, which results in a larger number of satellite terminals with high CDRs and a larger number of satellite terminals with low CDRs. Because of the halving of the transmission bandwidth, the DRA scheme can only meet the requested capacity of about 40% of the satellite terminals. Table 2 presents the satisfaction of the terrestrial systems with varying average total requested capacity of the satellite system. Satisfaction is defined as the proportion of the terrestrial systems whose minimum capacity requirements are satisfied. Because of constraint (15), the proposed optimal algorithm and greedy algorithm can provide enough transmission resources to the terrestrial systems, so the satisfaction is always 100%. As the average requested capacity increases, the MTCS scheme allocates more time slots to the satellite terminals, so the satisfaction of the terrestrial systems gradually decreases. The satisfaction of the RRA scheme is around a certain value since it is not affected by the change in the capacity requirements. When using the dedicated frequency band, the available resources are fixed and limited, so about half of the terrestrial systems cannot achieve their minimum required capacity. Figure 5: The variance between the requested capacity and the transmission capacity in the satellite system.