# LoRa Architecture for V2X Communication: An Experimental Evaluation with Vehicles on the Move
## 3 Related Works in LoRa V2X and Applications  
As LoRa supports long-range low power communication with decent performances in outdoor scenarios, it can play a vital role in V2X communication. Though LoRa has low transmission throughput for applications like video streaming, it is enough for necessary data transmission for applications like accident avoidance, automatic traffic signaling, congestion prediction. Due to its modularity, it can provide an excellent solution for all the legacy vehicles to be V2X enabled that are already prevalent in the roads [57], so it has inspired many researchers to focus on LoRa based vehicular communication infrastructure and applications. [PERSON] et al. proposed a LoRa-based V2X communication scheme and conducted performance tests with different parameter configurations [58]. This research made a point that LoRa should be configured with higher bandwidth and lower spreading factor in V2X to avoid fast fading which is caused by the Doppler effect. But this work doesn't consider the scenarios with higher vehicular density. This research group has introduced LoRa and enhanced machine-type communication (eMTC) for V2X communication in [59]. This work simulates the bit error rate (BER) performance of LoRa under different scenarios of speed and different Doppler shifts, but this work is not tested under practical scenarios with vehicles on the move where the dynamic environment and mobility of the vehicles may hamper the communication performances. [PERSON] et al. focus on integrating LoRa in-vehicle communication using IPv6 to interconnect with future internet scenarios and evaluating its performance under real environment conditions [60]. Experiments are conducted in the V2I architectures and V2V schemes. In the V2I scenario, a suburban environment with different obstacles is evaluated. The obtained coverage is found to be much longer than the range obtained by a high-bandwidth technology, such as 4G. The V2V coverage is studied on a college campus and it is found that it covered the entirety of the campus with no shadow areas, so any incident can be reported anywhere on campus. It facilitates long-distance communication but any critical information from one vehicle to another also has to be transmitted via gateways and servers which eventually increases the latency and worsens the time criticality of the applications. One of the advantages of this architecture is that it offers reliability and a high communication range with actual vehicles on the move, but the work emphasizes only notifying traffic incidents rather than a continuous update of the vehicular information. [PERSON] et al. addressed the security issues of LoRa- based V2V and V2I communications with the physical layer key generation technique which uses RSSI values as consensus information for generating keys [61]. The proposed security system improves the key generation rate and it can reach up to 20 bit/s. Moreover, all the binary key sequences passed the statistical test suite of the National \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Wireless** & **Network Type** & **Spectrum** & \begin{tabular}{c} **Transmission** \\ **Range** \\ \end{tabular} & \begin{tabular}{c} **Transmission** \\ **Throughput** \\ \end{tabular} & \begin{tabular}{c} **Mobility** \\ **Support** \\ \end{tabular} \\ \hline WiMAX [51] & \
\begin{tabular}{c} Wireless \\ Broadband \\ \end{tabular} & 5.8 GHz & 50 km & 70 Mbps & Yes \\ \hline C-V2X [52] &
\begin{tabular}{c} Cellular \\ Wireless \\ Broadband \\ \end{tabular} & 5.9 GHz & \textgreater{}DSRC \& LoRa & \textgreater{}DSRC \& LoRa & Yes \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Cont. Institute of Standards and Technology (NIST). This key generation scheme is implemented with LoRa based V2V and V2I communications and tested in outdoor environments. But this model is not tested at higher speeds with actual vehicles on the road under a dynamic environment. [PERSON] et al.