# Location-Aware Point-to-Point RPL in Indoor IR-UWB Networks
## 5 Performance Evaluation
As the distance between the source and the destination node is increased, the route discovery forwarding zone of LA P2P-RPL is increased close to the whole network size of 150 m \(\times\) 150 m, which results in increasing the route discovery forwarding overhead gradually close to P2P-RPL. LA P2P-RPL efficiently limits the route discovery forwarding zone with accurate self localization information, which improves the routing control overhead performance compared to ER-RPL too. \begin{table}
\begin{tabular}{l l} \hline \hline
**Parameter** & **Value** \\ \hline Radio environment & UDGM with distance loss \\ Transmission range & 20 \\ TX ratio (\%) & 99 \\ RX ratio (\%) & 97 \\ RPL mode of operation & Storing mode \\ Objective Function & MRHOF \\ Routing Metric & ETX \\ \(I_{min}\) & 64 ms \\ \(I_{max}\) & 256 ms \\ DIO redundancy (\(k\)) & 1 \\ Transmitter electronics (\(E_{TX\text{-}ele}\)) & 33.97 nJ/bit \\ Transmitter amplifier (\(\epsilon_{amp}\)) & 6 pJ/bit/m\({}^{2}\) \\ Receiver electronics (\(E_{RX\text{-}ele}\)) & 14.56 nJ/bit \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Simulation parameters. P2P-RPL and ER-RPL can fail to find the routing path successfully around 5% while P2P-RPL shows the routing path finding success rate is close to 1. Figure 10 shows that the average hop count of P2P-RPL, ER-RPL, and LA P2P-RPL. P2P-RPL can find the optimal (the smallest hop count) route path by forwarding the route discovery packets through the whole network. The proposed LA P2P-RPL can not find better route path (smaller hop count route path) than P2P-RPL, because LA P2P-RPL only searches the limited route discovery forwarding zone based on the source and the destination node location information. Figure 10 shows that the average hop count performance of LA P2P-RPL is degraded 2\(\sim\)3% in short distance region of less than 45 m, and 4%\(\sim\)6% in long distance region compared with P2P-RPL. Figures 11-13 show the overall performance results for the network size variations of 75 m \(\times\) 75 m, 150 m \(\times\) 75 m, and 150 m \(\times\) 150 m. The node density is the same for all simulations of 150 m \(\times\) 150 m with 200 nodes at every 75 m anchor node configuration. Figure 11 shows the number of routing control message overhead to the network size variations. The routing control overhead increases as the network size increases. In the network size of 75 m \(\times\) 75 m case, the performance difference is small among P2P-RPL, ER-RPL, and LA P2P-RPL. In the network size of 150 m \(\times\) 150 m case, the routing control message overhead of LA P2P-RPL is significantly reduced compared to P2P-RPL and ER-RPL. The routing packet forwarding zone of LA P2P-RPL is reduced efficiently for route discovery procedure, which is come from the accurate self localization information of LA P2P-RPL compared with ER-RPL localization performance. LA P2P-RPL defines the routing forwarding zone depending on the location of the source and destination nodes to restrict the unnecessary flooding of DIO control messages. LA P2P-RPL achieves more than 50% control overhead performance improvements compared with P2P-RPL, and more than 30% control overhead performance improvements compared with ER-RPL. Figure 11: Number of control message overhead vs. network size. Figure 12: Energy consumption [m]] vs. network size. In Figure 12, LA P2P-RPL reduces around 50% and 10% total energy consumption in comparison with P2P-RPL and ER-RPL, respectively. In LA P2P-RPL, a node re-broadcasts a P2P-DIO message only if it is located in the route discovery forwarding zone. This reduces the number of P2P-DIO messages both in transmitting and receiving states. The energy model considers the energy consumptions for transmitting and receiving states, and the energy for sensing and processing data is not considered. The energy performance difference is increased significantly as the network size increases.