# An Adaptive Scheduling Mechanism Optimized for V2N Communications over Future Cellular Networks
## 4 Simulation Environment  
The considered urban simulation environment follows a network model, composed by one 5G NR macro cell (gNB) placed in the center of an urban intersection, following the characteristics of an urban grid for connected vehicles [24]. Parameters regarding the urban intersection are summarized in Table 2. Through this model, several scenarios have been explored, as explained in detail in the next section. The following paragraphs elaborate on the parameters used in all simulation scenarios and briefly present the mobility models used.  
The above-described topology was implemented with SUMO (Simulation of Urban MObility), an open-source, highly portable, multi-modal traffic simulation package designed for vehicular networks. The vehicle flows are also modeled using SUMO and their characteristics can be found in Table 3.  
In our simulations, the latest ns-3 release has been used (i.e., v3.37), along with the NR module Version 2.3. Ns-3 is a discrete-event network simulator, providing an open simulation environment for networking research, aligned with the simulation needs of modern networks. The NR module is a pluggable module for ns-3 that can be used to simulate 5G NR cellular networks. The network parameters in the scenarios simulated are based on [24] and are summarized in Table 4.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Channel model & 3 GPP TR 38.913 [24] \\  & A range of bands from 3300–4990 MHz identified for WRC-15 are currently being considered and around 4 GHz is chosen as a proxy for this range [24] \\ Channel bandwidth & 100 MHz \\ Carrier frequency & 4 GHz \\ Shadowing & enabled \\ Beamforming method & NO \\ MIMO & NO \\ MCS & Adaptive \\ gNB Tx power & 49 dBm \\ UE Tx power & 33 dBm \\ Schedulers & Proportional Fair vs. SOVANET \\ \hline \hline \end{tabular}
\end{table}
Table 4: Network simulation parameters.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Number of Innes & 2 in each direction (4 lanes in total in each street) \\ Lane width & 3.5 m \\ Road size by the distance before and & 75 m \(\times\) 75 m \\ after intersection & 164 m \(\times\) 164 m \\ \hline \hline \end{tabular}
\end{table}
Table 2: Road parameters for urban intersection.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Number of Vehicles & 10, 25, 40, 60 \\ Max speed & 35 km/h \\ Vehicle’s Length & 4.5 m \\ Sigma & 0.5 (driver’s imperfection, 0–1) \\ Depart position & Random \\ Traffic Lights & Yes, with fixed phase durations \\ \hline \hline \end{tabular}
\end{table}
Table 3: Vehicles-traffic characteristics.  
In the initial ns-3 implementations, the PF scheduler was used in the OFDMA mode and the above-mentioned parameters. Four different cases of vehicle density were considered with 10, 25, 40 and 60 vehicles, respectively. As the number of vehicles increased the number of vehicles requiring ToD and HDM UCs was also increased, trying to represent different traffic conditions in the urban intersection. Then, the simulation was repeated with the use of the implemented SOVANET scheduler.