# Networked Roadside Perception Units for Autonomous Driving
## 5 Evaluation
### Simulation Analysis  
To evaluate communication performance about PDR and delay under several situations, the RSPUs were implemented over the framework titled Artery ([[https://github.com/riebl/artery](https://github.com/riebl/artery)]([https://github.com/riebl/artery](https://github.com/riebl/artery))) which denotes an extension of vehicular network simulation framework (Veins [[http://veins.car2x.org](http://veins.car2x.org)]([http://veins.car2x.org](http://veins.car2x.org))) wherein the network is simulated on OMNeT++ ([[https://omnetpp.org](https://omnetpp.org)]([https://omnetpp.org](https://omnetpp.org))) with the simulation of vehicular traffic taking place on SUMO ([[http://sumo.dlr.de/](http://sumo.dlr.de/)]([http://sumo.dlr.de/](http://sumo.dlr.de/))). We conducted the simulation experiments by utilizing maps covering the University of Tokyo and the region near Paris, as shown in Figures 9 and 10. OpenStreetMap wiki was used to take both maps. All chosen intersections had an RSPU. In addition, all RSPUs were interconnected through an Ethernet cable. The RSPUs of Paris and Tokyo maps were 32 and 49, respectively, with each maintaining the routes to others via routing information protocol. The red lines denote obstacles or buildings. In addition to attenuating wireless radio, these obstacles can also be seen to be blocking the line of sight between the source and destination codes. All building edge impedes a path that the signal attenuates by 9 dB; 0.4 dB per meter attenuates the signal that passes via a building. The results of experiments encompassing both scenarios were as follows: (1) Isolated use of network RSPUs, and (2) combination of distance priority algorithm and using networked RSPUs. Table 2 lists the simulations' parameters. The radio frequency, data rate, reception sensitivity, and transmission power were 5.89 GHz, 18 Mbps, \(-89\) dBm, and 126 mW, respectively. The peak range of radio was restricted to 150 m for reflecting the usual limitations of radio coverage in urban areas. The frequency of all messages generated by RSPUs was 10 Hz. The length of the queue was 1000 packets, while the peak distance was 1000 m. The speed of simulated vehicles traveling via intersections on two routes was 50 km/has \begin{table}
\begin{tabular}{c l c} \hline \hline
**Type** & **Variable Name** & **Value** \\ \hline \multirow{3}{*}{Radio} & IEEE802.11p datarate & 18 Mbps \\  & Attenuation per building edge & 9 db \\  & Attenuation through building & 0.4 db/m \\  & Radio range & 150m \\ \hline \multirow{3}{*}{RSPU} & Queue length & 1000 packets \\  & Maximum distance (\(d_{max}\)) & 1000 m \\  & \(CPM_{CAM}\) frequency & 10 Hz \\ \hline \multirow{3}{*}{Vehicle traffic} & Vehicle speed & 50 km/h \\  & Vehicle num per sec per intersection & 2 \\ \cline{1-1}  & CAM frequency & 10 Hz \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Parameters of Simulations. Figure 10: Map of Paris. shown in Figures 9 and 10. There were no stoppages as each vehicle traveled since the roads were not assumed to have any traffic signals; every second, a couple of vehicles passed via the intersections. This vehicle traffic's frequency is the traffic that finds mention in the Japanese Police Department's official statistics of traffic outlined in the corresponding map shown in Figure 9.  
After detecting 5, 10, or 15 vehicles at the end of every 0.1 s, each RSPU transmitted UDPs across to all adjoining RSPUs. Under the assumption that the coverage of sensor detection was 50 m, the sensors encompassed 200 m in four directions that pointed outward from the intersection. Thus, the traffic rate in the scenarios was fixed at 25, 50, and 75 vehicles/km for the purpose of reflecting the tracing of 5, 10, and 15 vehicles per 200 m, respectively. The performance of communication was measured at intersections, wherein both routes crossed. To take the measurements, an evaluation node deployed in close proximity to the intersection was deployed for receiving \(CPM_{CAM}\)s from all RSPUs via IEEE802.11p.