# Investigation of Data Quality Assurance across IoT Protocol Stack for V2I Interactions
## 1 Introduction  
Smart cities have continued to grow worldwide, giving rise to various innovations such as smart agriculture, smart buildings, smart health, and smart transportation. At the core of this growth is the Internet of Things (IoT) [1, 2, 3]. The shift to ubiquitous computing has led to the interconnection of smart and embedded devices, resulting in the generation of substantial amounts of data, aka \"big data\" [4]. The continuous increase in IoT-generated data underscores the critical importance of data quality (DQ) [5]. The success of this IoT paradigm shift relies heavily on DQ guarantees [6]. However, ensuring DQ under the current big data collection and transmission methods of IoT networks becomes a challenge for various applications. The multifaceted nature of big data, characterised by the five Vs, volume, velocity, variety, veracity, and value, are some of the constraints faced in ensuring data quality [7]. These complexities demand the adoption of meticulous data quality management methodologies encompassing comprehensive validation, cleaning, and integration techniques for big data applications in various smart city segments. DQ is essential across various domains of smart cities, including the cooperative intelligent transportation system (C-ITS), which is defined by its interactive components, facilitating various communications crucial for its operation. These components include communication between Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), Vehicle-to-Network (V2N) and Vehicle-to-Pedestrian (V2P). The integration of communication technologies intotransportation has ushered in a transformative transference from autonomous systems to cooperative ones, which is an integral aspect of smart cities requiring high DQ for efficiency and effectiveness. Communications between these components of C-ITS are reliant on several protocols to transmit data between nodes, and hence, the need to ensure DQ within each of the protocols is paramount. Over the past three decades, network protocols have defined and maintained principles of data communications and provided foundational protection for data transmission [8]. With the emergence of IoT, network protocols have experienced an evolution due to the dynamic and constrained nature of IoT devices and networks. Such characteristics pose a major challenge, as identified by [PERSON] et al. [9], in integrating the existing Transmission Control Protocol/Internet Protocol (TCP/IP) [10] in IoT networks. Despite these challenges, IoT supports interoperability with the TCP/IP protocol stack, which, however, faces some drawbacks such as throughput, link delay, and energy consumption--are metrics that the current TCP/IP protocol stack struggles to meet in IoT applications. Furthermore, without optimisation, the TCP/IP protocol stack is inadequate for IoT communications within the cloud and distributed computing services [11]. To mitigate these challenges, suitable and lightweight IoT protocols have been revealed in the literature as fixable alternatives for constrained devices [12]. These advancements have led to the application of IoT in transportation to increase road safety and enhance cooperative driving and traffic management [13]. However, vehicular communications must be precise, which requires advanced embedded DQ measures to achieve efficiency, safety, and sustainability. Some protocols in the TCP/IP protocol stack do not meet specific criteria, such as ensuring the dimensions of DQ for vehicular communications. For example, certain protocols lack agility, while others are unreliable or vulnerable to cyber-attacks, which impedes the accurate flow of data in vehicular communications. Vehicular communication networks are still an active area of research [14, 15], although several technologies have emerged to support C-ITS. V2I, specifically, is an integral part of vehicular communication technologies that promises to optimise the efficiency of transportation systems.