## 5 Simulation Results and Analysis
### Simulation Analysis
#### 5.2.4 Comparison with Existing Data Transmission Schemes  
We compare our multipath transmission scheme with the common data transmission schemes, Single-TCP and ECMP. In this experiment, we simulate the transmission scenarios of four data streams (C1-S1, C2-S2, C3-S3, C4-S4). The network topology is shown in Figure 4. The access bandwidth of the data receiver and the data sender is set to 50 Mbps, and the delay is set to 1 ms. The link bandwidth is set to 10 Mbps and the delay is set to 10 ms. In this experiment, 10 M data is first sent from S1 to C1. Then a data stream is started every 5 s. The Single-TCP scheme adopts the TCP implementation scheme of the NS3 network simulator, and the ECMP scheme adopts the scheme implemented in the Reference [42]. The granularity of data transmission is packet granularity. In our multipath transmission scheme, the data receiver requests the same size of data from the data sender, and the granularity of data transmission is chunk granularity.  
Figure 12 shows the throughput changes of Single-TCP, ECMP and our proposed schemes and the completion time of each flow. Single-TCP has a long flow completion time and large transmission jitter. This is because, in the Single-TCP scheme, four flows choose the same path, resulting in network congestion, thereby reducing the sending rate. The ECMP scheme has a shorter flow completion time than the Single-TCP scheme. This is because, in addition to the default path, the ECMP scheme re-selects another path, thereby reducing the interaction between flows. However, in the ECMP scheme, three flows also chose the same path, failing to take full advantage of multipath. In our scheme, the peak traffic per flow can reach 40 Mbps, while Single-TCP and ECMP can only reach 10 Mbps. This is because each flow of Single-TCP and ECMP can only select one path, whereas our scheme can use more paths and split the data flow, thereby reducing the data flow completion time.  
Figure 11: Packet Loss Rate under Different Node Selection Strategies.  
Figure 13 shows each flow completion time and the average flow completion time in Single-TCP, ECMP, and our proposed scheme. We can see that our proposed scheme has a shorter flow completion time and an average flow completion time than Single-TCP and ECMP. This is because our scheme can provide multipath resources for each flow, while in Single-TCP and ECMP schemes, only one path can be selected for each flow. Therefore, our scheme can give full play to the advantages of multipath and is independent of specific flows.  
Figure 12: Throughput under different data transmission schemes. (**a**) The variation trends of the throughput under the Single-TCP scheme. (**b**) The variation trends of the throughput under the ECMP scheme. (**c**) The variation trends of the throughput under the MITS-ICN scheme.  
Figure 13: Data Transmission Completion Time under Different Data Transmission Schemes.  
As seen from Table 2, MPTS-ICN has the shortest flow completion time, and Single-TCP has the longest flow completion time. Furthermore, MPTS-ICN outperforms Single-TCP method by 83.6% and the ECMP method by 79.7% in average flow completion time.