# Insights from the Experimentation of Named Data Networks in Mobile Wireless Environments
## 4 Experimentation Setup and Results
### NDN Using Multiple Radio Wireless Interfaces
When we consider both technologies to share efforts in requesting a file to the network, improvements are noticeable in all aspects. On the one hand, by sharing the wireless medium in different bands it alleviates the collision problem, which implies greater reliability in the delivery of packets. On the other hand, by sharing the burden over two different physical interfaces we can minimize the occurrence of issues caused by the forwarding of several packets simultaneously, as is noticeable by the reduced number of packets attended by each of them. Ultimately, the delivery of the full sized file over two different technologies presented better results over using solely Wi-Fi and worse results over using solely ITS-G5, although these values may change when congestion starts to occur in the network due to the increased number of nodes taking part in the wireless medium communications. Tables 5 and 6 present the results regarding the use of the pipelined application in which all content requests are sent in bulk. We identify a significantly worse general performance when using a single communication technology, both under the unicast or multicast methods. Multicast methods suffered several Interest timeouts, due to the insufferable congestion introduced into the wireless medium, that resulted in increased periodicity to deliver the intended file. However, by using both Wi-Fi and ITS-G5 to forward the content, we were able to obtain much better performance under the form of reduced interest timeouts which ultimately resulted in lower times to retrieved the file successfully. \begin{table}
\begin{tabular}{l c c c c} \hline \hline  & **Time** & **OutInts** & **InData** & **TimedOuts** & **Average Delay per Chunk** \\ \hline
**Multicast** & 149 s & 1448 & 1422 & 26 & 42.76 ms \\ \hline
**Unicast** & 42 s & 1422 & 1422 & 0 & 38.57 ms \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Total download time using multi-technology and non-pipelined application. \begin{table}
\begin{tabular}{l c c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**ITS-G5**} & \multicolumn{4}{c}{**Wi-Fi**} \\ \hline \multirow{3}{*}{**Multicast**} & **Time** & **OutInts** & **InData** & **TimedOuts** & **Time** & **OutInts** & **InData** & **TimedOuts** \\  & 69 s & 719 & 711 & 8 & 149 s & 729 & 711 & 18 \\  & & Average delay per chunk: 28.16 ms & & & Average delay per chunk: 57.37 ms & & \\ \hline \multirow{3}{*}{**Unicast**} & **Time** & **OutInts** & **InData** & **TimedOuts** & **Time** & **OutInts** & **InData** & **TimedOuts** \\  & 14 s & 711 & 711 & 0 & 42 s & 711 & 711 & 0 \\  & & Average delay per chunk: 18.41 ms & & & Average delay per chunk: 58.73 ms & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Non-Pipelined results—full 6 MB file using both ITS-G5 and Wi-Fi (3 MB to each interface). \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & **Time** & **OutInts** & **InData** & **TimedOuts** & **Average Delay per Chunk** \\ \hline
**Multicast** & 149 s & 1448 & 1422 & 26 & 42.76 ms \\ \hline
**Unicast** & 42 s & 1422 & 1422 & 0 & 38.57 ms \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Total download time using multi-technology and non-pipelined application. \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline  & \multicolumn{4}{c}{**ITS-G5**} & \multicolumn{4}{c}{**Wi-Fi**} \\ \hline \multirow{3}{*}{**Multicast**} & **Time** & **OutInts** & **InData** & **TimedOuts** & **Time** & **OutInts** & **InData** & **TimedOuts** \\  & 331 s & 27,441 & 711 & 26,730 & 212 s & 11,857 & 711 & 11,146 \\  & & Average delay per chunk: 516.93 ms & & & Average delay per chunk: 2957.79 ms & & \\ \hline \multirow{3}{*}{**Unicast**} & **Time** & **OutInts** & **InData** & **TimedOuts** & **Time** & **OutInts** & **InData** & **TimedOuts** \\  & 19 s & 1551 & 711 & 840 & 37 s & 2650 & 711 & 1939 \\  & & Average delay per chunk: 1644.91 ms & & & Average delay per chunk: 3019.83 ms & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Pipelined results—full 6 MB file using both ITS-G5 and Wi-Fi (3 MB to each interface).