The number of vehicles on the road increases daily, causing many fatal accidents and wasting much time for the average commuter every day due to congestion. Vehicular ad hoc networks (VANETs) were introduced to overcome these issues by enabling vehicle-to-vehicle communication and vehicle-to-infrastructure communication. The prime challenge in VANETs is the necessity of very low communication delays, especially for safety-related applications due to the high mobility nature of vehicles. The VANET architecture introduces a network component, the Road Side Unit (RSU), to meet the required delay limitations. Even though the RSU is a critical component in VANETs, as expected, the RSUs were not deployed throughout the world because of their high investment cost. As a solution, the idea of mobile RSU (mRSU) was introduced, and, ever since, several techniques of mRSU deployment strategies have been proposed. In this survey, we first analyze the importance of the RSU to the VANET architecture with real-world data incorporating the new 5G standard. Then, we investigate the research done in the areas of mRSU and exploit the pros and cons of each mRSU deployment strategy. Finally, we also discuss the future research directions of mRSU, and we explain the challenges connected to these future trends.

The Internet of Things (IoT) is one of the most important emerging technologies, spanning a myriad of possible applications, especially with the increasing number and variety of connected devices. Several network simulation tools have been developed with widely varying focuses and used in many research fields. Thus, it is critical to simulate the work of such systems and applications before actual deployment. This paper explores the landscape of available IoT and wireless sensor networks (WSNs) simulators and compares their performance using the Low Power Wide Area Network (LPWAN) communication technology called LoRa (Long Range), which has recently gained a lot of interest. Using a systematic approach, we present a chronological survey of available IoT and WSNs simulation tools. With this, we categorized and content-analyzed published scientific papers in the IoT and WSNs simulation tools research domain by highlighting the simulation tools, study type, scope of study and performance measures of the studies. Next, we present an overview of LoRa/LoRaWAN technology by considering its architecture, transmission parameters, device classes and available simulation tools. Furthermore, we discussed three popular open-source simulation tools/frameworks, namely, NS-3, OMNeT++ (FLoRa) and LoRaSim, for the simulation of LoRa/LoRaWAN networks. Finally, we evaluate their performance in terms of Packet Delivery Ratio (PDR), CPU utilization, memory usage, execution time and the number of collisions.

Vehicular Ad-Hoc Networks (VANETs) were introduced to avoid vehicular-related accidents and to improve the safety of both vehicular passengers and other road users. In VANETs, the vehicles are expected to communicate with neighbouring vehicles to increase awareness about the surrounding by using V2V (vehicle-to-vehicle) communication links. Since the introduction of VANETs, much research has focused on developing state-of-the-art algorithms to increase safety. However, real-world testing of these developed algorithms has become challenging due to the required high cost and multiple practical reasons. Therefore, simulation-based testing is commonly used for VANETs related applications. Using real datasets inside a simulation can significantly increase the results’ accuracy and help to achieve realistic results. In this study, we present a dataset called ’CN+’, which consists of more than 25,000 vehicles collected over 32 hours at a signalized intersection in Bremen, Germany. paper

Road safety has become a major concern in recent decades due to the growing number of vehicles, which is expected to double in the next decade. This increase is likely to result in more accidents and greater financial costs due to traffic congestion. Vehicular Ad Hoc Networks (VANETs) offer a promising solution to address these issues by facilitating information exchange, thereby enhancing situational awareness. One of the key VANET safety applications, Collective Perception (CP) services, aims to improve awareness of both V2X and non-V2X objects during the transition period before full V2X vehicle market penetration. Traditionally, Collective Perception Messages (CPMs) are generated by V2X vehicles or specialized Road Side Units (RSUs) equipped with sensors and are shared with other V2X vehicles within a single-hop communication range. This work proposes using mobile RSUs to disseminate RSU-assisted CPMs by aggregating received CPM objects, rather than relying on conventional fixed RSUs. The mobility of RSUs can increase the chances of distributing CPMs to a larger number of vehicles, thereby enhancing overall situational awareness. Additionally, we introduce a novel dynamic CPM generation mechanism for RSU-assisted CPMs, which adjusts the CPM dissemination rate based on the current environment, reducing channel load compared to the traditional periodic CPM generation approach. We begin by conducting simulations in a city scenario to evaluate the performance of fixed and mobile RSU-assisted dissemination methods. We explore the critical question of whether mobile RSUs are more effective for CPM dissemination than fixed RSUs. Our results show that the proposed mobile RSU-assisted CPM dissemination mechanism distributes on average 3.7 times more CPM objects to V2X vehicles than fixed RSUs. Moreover, the proposed dynamic CPM generation rate control mechanism maintains overall latency below 100 ms while adapting the CPM generation interval according to the current environment. After confirming the feasibility of using mobile RSUs for CPM dissemination with simulations, we model the proposed system for an n-lane road segment scenario, validating its performance by comparing it with simulation results. Finally, we perform a detailed parameter analysis on the model to evaluate the benefits of the proposed CPM dissemination mechanism across various scenarios.

Opportunistic networks rely on intermittent direct contacts between devices to exchange and disseminate information. While the development of data dissemination protocols is still ongoing, their evaluation is particularly challenging and complex. An evaluation usually relies on simulation scenarios and no consensus exists in the community about their setup and parameters. In this paper, we aim to improve the reproducibility and cross-comparability of OppNets data dissemination protocols by defining a benchmark suite with realistic mobility and traffic scenarios, mostly based on real traces. It currently includes 11 scenarios and together with a simulation-as-a-service platform offers a unique tool to foster and ease research in OppNets. First results with sample data dissemination protocols show that no protocol is better than all others in all scenarios, demonstrating the importance of a benchmark.

Vehicular Adhoc networks (VANETs) are composed of vehicles connected with wireless links to exchange data. VANETs have become the backbone of the Intelligent Transportation Systems (ITS) in smart cities and enable many essential services like roadside safety, traffic management, platooning, etc with vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. In any form of research testing and evaluation plays a crucial role. However, in VANETs, real-world experiments require high investment, and heavy resources and can cause many practical difficulties. Therefore, simulations have become critical and the primary way of evaluating VANETs' applications. Furthermore, the upfront challenge is the realistic capture of the networking mechanism of VANETs, which varies from situation to situation. Several factors may contribute to the successful achievement of a random realistic networking behavior. However, the biggest dependency is a powerful tool for the implementation, which could probably take into account all the configuration parameters, loss factors, mobility schemes, and other key features of a VANET, yet give out practical performance metrics with a good trade-off between investment of resources and the results. Hence, the aim of this research is to evaluate some simulators in the scope of VANETs with respect to resource utilization, packet delivery, and computational time.