# Blockchain-Enabled NextGen Service Architecture for Mobile Internet Offload
## 4 Case Studies and Result Analysis  
The proposed framework was implemented using the ns-3 network simulator [24]. Various ns-3 nodes were created to simulate the different entities, namely, MN, MNO, WP, BK and a Data Server. To implement the blockchain functionality, the Ethereum [25] blockchain is implemented on the Docker [26] platform. Each node in the ns-3 network is connected to a Docker container using the tap-bridge arrangement of ns-3 [27]. In the simulation environment, the subscriber is initially connected to the MNO node, and when the smart contract is executed, the connection is switched over to the WP. The simulation was carried out for 350 s on an Ubuntu Linux-based computer running a virtual machine with 8 GB RAM, an Intel i5 2.50 GHz processor, and 100 GB of allocated memory. The experimentation was conducted over five separate case studies. The first case study takes the global average of Internet speed and latency for fixed broadband and mobile Internet. The bandwidth given for the fixed broadband is assigned to the WP link, whereas the bandwidth given for the mobile Internet is assigned to the MNO link. In this case study, the MN is offloaded from mobile Internet to fixed broadband as per the speed suggested by the global average. In the subsequent case studies, the MN is offloaded from 3G, 4G, 4G-LTE, and 5G mobile Internet to fixed broadband i.e., the WP. The various data transfer speeds and latencies considered for all case studies are provided in Table 1.  
Figure 4 shows the packet delivery percentages for all case studies. The packet delivery is analyzed for all types of flows, such as when the subscriber's packets are not offloaded, for offloaded packets, packets transmitted through the WiFi link, and other packets of different users which are being transmitted through the MNO network. \begin{table}
\begin{tabular}{l c c c c} \hline
**Case Studies** & **Network Generation** & **Average Speed (Mbps)** & **Latency (ms)** & **Reference** \\ \hline Case Study 1: & Fixed Broadband & 92 & 21 & [28] \\ Global Average & Mobile Internet & 46 & 36 & [28] \\ \hline Case Study 2: & Fixed Broadband & 241 & 13 & [28] \\ Comparative & 5G & 71 & 20 & [28] \\ Average & 4G-LTE & 50 & 50 & [29] \\  & 4G & 10 & 100 & [29] \\  & 3G & 1.5 & 500 & [29] \\ \hline \end{tabular}
\end{table} 
Table 1: Case Studies and Associated Parameters. For the global average case, the packet delivery percentage is the same for all cases except for the MNO flows; however, this difference is insignificant. In this case, 99.96% of packets are delivered for non-offloaded flows, offloaded flows, and WiFi flows, whereas 99.94% of total packets are delivered for the MNO flows. For all other case studies, it is evident from Figure 4 that 100% of offloaded flows are delivered, primarily because of the enhanced data speed of the WiFi link. A slightly smaller number of packets are delivered in the global average case study, compared with all other case studies, because the fixed broadband speed of the global average is lower when compared with other case studies. As the data transfer speed decreases in the 4G and 3G case studies, we can see an increase in packet drop ratio for non-offloaded and MNO flows. If these flows are offloaded to the WiFi network, then the packet delivery ratio rises to a better quality of service requirement. Figure 5 displays the time taken to deliver a 500 MB file, and a total of 10 such requests are made for each WiFi and MNO network. One request to transfer a 500 MB file is then offloaded to a high-speed network. From this figure, it is evident that the time taken to transfer files is significantly reduced in the case of the offloaded flow. In the global average case study, the non-offloaded flow takes 10.23 s to transfer one file, whereas the time is reduced to 0.91 s if the request is offloaded. Similarly, the graph shows a drastic reduction in delivery time in all other case studies.