# LoRa Architecture for V2X Communication: An Experimental Evaluation with Vehicles on the Move
Moreover, with the increase of the range, each gateway has to communicate with an increased number of vehicles and predict traffic and directions which would overburden the computational unit and will introduce higher latency. Zigbee is low power wireless communication technology which is based on IEEE 802.15.4 [18]. It has been vastly used in ITS applications. Zigbee gained popularity in both indoor and outdoor applications due to its low power consumption and optimized mesh networking. It allows multi-hop communication where the routing is also optimized. As it has a very low range of transmission distance (up to 100 m), so to travel the same distances with Zigbee as other wireless technology like LoRa or WiMAX can offer, it must choose multi-hop communications instead of direct D-D communications. But Zigbee can introduce higher latency and packet drops with multi-hop communication due to multiple data handover. On the other hand, LoRa balanced between the transmission range and the data transmission rate. The transmission range of the LoRa is few kilometers with a data transmission rate of 300 bps-37.5 kbps [19]. It is also based on the low power communication standard of IEEE 802.15.4 [20]. Moreover, LoRa supports wireless area networks (WANs) through a LoRaWAN server which would be necessary for different applications of ITS. These properties of LoRa make it suitable for a simpler but efficient V2X communication which can transmit data reliably with low latency and low power consumption. One of the downsides is that it has a very low throughput, which may necessarily limit the amount of data that needs to be sent. However, 3 GPP LTE and 5G NR can offer very high throughput which can even allow steaming. As this technology also offer higher throughput with lower latency, it has the potential to offer autonomous driving and an automated traffic system. Even though substantial research is also going on in LoRa-based V2X communication, these research works have faced few challenges which include defining a robust and reliable architecture, testing the reliability and performance in real-world scenarios with actual vehicles at higher speeds. To address these existing challenges, a LoRa-based reliable and low power V2X communication architecture is proposed in this research. This work focuses on the fundamental aspects of V2X such as mobility of the vehicles, reliability of the architecture, latency, security, and energy consumption. Prototypes of the proposed architecture are designed which are based on low power microcontroller units and sensors. A performance evaluation is also conducted under practical scenarios with vehicles on the move to analyze the overall performances of the architecture. The results suggest the architecture can perform reliably under practical scenarios with vehicles on the move. It shows that LoRa presents great prospects for applications like V2X which presents mobility and a dynamic environment. The main contributions of this work are the following:  
* A LoRa architecture is proposed for V2X communication to ensure higher reliability by smooth data handover from one RSU to another. * A D2D based approach is considered in the architecture which improves the latency by enabling direct V2V and V2X communication which is missing in the literature of LoRa V2X. * RSSI-based algorithms are proposed for V2V and V2I communication that support good link quality at a higher speed of the vehicles which is not addressed yet by the state-of-the-art literature for LoRa V2X. * Prototypes of the OBU and RSU are designed with low power microcontrollers to maintain portability and to achieve better energy efficiency. * The performance of the architecture is evaluated under practical scenarios with vehicles on the move at different speeds which is not addressed in the relevant literature.