## 5 Simulation Results and Analysis
### Simulation Analysis
#### 5.2.2 Effect of Data Scheduling Strategies  
This experiment aims to explore the impact of data scheduling strategies on multipath transmission performance. Here, we also use the topology of Figure 4. In this experiment, we set the data receiving rate of the data receiver not to exceed 50 Mbits/s, and the number of available paths k = 4. The four paths are PATH1 (C1-R1-R3-R7-R2-S1), PATH2 (C1-R1-R4-R8-R2-S1), PATH3 (C1-R1-R5-R9-R2-S1) and PATH4 (C1-R1-R6-R10-R2-S1). To simulate the difference in path bandwidth, we set the bandwidth ratio of the four sub-paths to 4:3:2:1. Except for the difference in path bandwidth, other network metrics of the 4 sub-paths are the same. This experiment attempts a variety of data scheduling strategies, the first is random selection strategy, followed Round-Robin strategy. The random selection strategy will randomly select one from the multipath forwarding information table stored locally by the edge node, and the Round-Robin strategy will select one by one. In addition, in order to give full play to the advantages of multipath, we have designed a new multipath data scheduling strategy WCDS, which can allocate data chunks according to the weight of the path. The weight value of the path is calculated by Equation (3). This experiment will analyze three data scheduling strategies from two aspects of data transmission completion time and throughput. It can be seen from Figure 7 that when the path bandwidth difference between sub-paths is large, the random selection strategy and the Round-Robin strategy are not as good as our proposed strategy of allocating data  
Figure 6: Relation of Data Transfer Completion Time with \(\alpha\) and k when \(\beta\) = 0, 0.5, 1. (**a**) The variation trends of data transfer completion time when \(\beta\) = 0. (**b**) The variation trends of data transfer completion time when \(\beta\) = 0.5. (**c**) The variation trends of data transfer completion time when \(\beta\) = 1.  
chunks according to path weights. This is because, in the scenario of path bandwidth differences, the completion time of data transmission based on random and Round-Robin strategies is limited to the completion time of data transmission on sub-paths with the lowest path bandwidth. However, our proposed strategy can allocate the number of data chunks according to the weight of the path, which leads to the completion time of data transmission being only related to the overall size of the data and the total bandwidth of the four sub-paths, not limited to a specific sub-path. In addition, we note that as the number of data chunks transmitted increases, our proposed strategy has a shorter transmission completion time. This shows that our proposed strategy can achieve better results in the scenario of big data transmission. Figure 8 shows the throughput difference between the three data scheduling strategies in the scenario of transmitting 10 data chunks, each data chunk size is 2 M. From Figure 8a,b, we note that the throughput at the data receiver decreases over time. This is because in the scenario of path bandwidth difference, the sub-path with higher bandwidth resources takes the lead in completing the data chunk transmission task assigned to the path. However, at the same time, the sub-path with lower bandwidth resources still has more data chunks to transmit, resulting in a decrease in the throughput of the data receiver. As the throughput decreases, the data transmission completion time at the data receiver gradually increases. From Figure 8c, we can see that our proposed strategy can maintain high throughput for a long time. This is because our proposed strategy can allocate the number of data chunks according to the weight of the path, which leads to the completion time of data transmission no longer being limited to the bandwidth resources of a specific path but the total bandwidth resources of all sub-paths. Figure 8: Throughput under Different Scheduling Strategies. (**a**) The variation trends of the throughput under the Random strategy.