# Positioning Information Privacy in Intelligent Transportation Systems:
## 1 Introduction  
Today, the technology is penetrating most of the modern digital systems [1]. Billions of interconnected devices are already deployed, and many would join them soon in the race towards smart interconnected world [2]. One of the promising paradigms is the utilization of Intelligent Transportation Systems (ITS), which is driven by one of the biggest markets being automotive [3]. The technologies covered by ITS are usually split into two major groups: vehicle-to-vehicle (V2V) [4, 5] and vehicle-to-infrastructure (V2I) [6, 7]. In an attempt to cover the challenges from both groups, a new trend called vehicle-to-everything (V2X) [8, 9] has recently emerged, focusing on interconnecting cars with other surrounding objects. Different standardization communities are already working hard to standardize the technological requirements, thus aiming for the same goal: to develop a unified ecosystem that would allow reliable, fast and secure communications between vehicles and roadside infrastructure. Such technologies as Dedicated Short Range Communications (DSRC) in the USA [10; 11] and ETSI ITS-G5 in Europe [12; 13] are actively developing aiming at being deployed in the oncoming decade. Moreover, DSRC has recently been selected as a V2X communications technology in the USA which means that all the newly produced cars would be equipped with a wireless IEEE 802.11p module [14] that could also be used for positioning tasks [15]. Japan is also actively involved in equipping the vehicles with DSRC aiming to have more than 100,000 operational by 2025 [16]. Previously, V2X development was not so widespread as smart cars were limited in numbers, highly priced and thus inaccessible to the majority of the world's population. In this paper, we will focus only on the vehicular positioning privacy in an urban scenario where a conventional Global Navigation Satellite System (GNSS) can be affected negatively by propagation in complex environments issues [17]. Nowadays, this problem becomes exceptionally significant due to the fast development of vehicle use delegation [18] in the car-sharing business [19; 20]. Indeed, GNSSs proved themselves to be inefficient in urban-canyon operation scenario [21] also known as multipath interference phenomenon, caused by tall buildings blocking lines of sight (LOS) from the receiver to the navigation satellites. Some works have proven that no-line-of-sight (NLOS) signals could still be used for positioning if longer integration times and data wipe-off are present [22; 23]. Many solutions were proposed to mitigate the challenges of efficient vehicle location determination. Simultaneously, operation in the city allows broad communication possibilities due to high coverage of various wireless technologies including conventional cellular and other heterogeneous techniques [24; 25]. Overall, several radio-ranging-based cooperative positioning (CP) techniques were already proposed to enable vehicular localization in urban environment [26]. Nonetheless, the localization problem in conventional Mobile ad hoc networks (MANETs) with range measurements is often tackled by trilateration and multilateration to some fixed or mobile anchor nodes [27]. The internode distance is commonly measured using radio-ranging or range-rating techniques such as the time of arrival (TOA), time difference of arrival (TDOA), received signal strength (RSS), and other techniques [28]. The infrastructure in ITS provides the nodes not only with precise positions on the trusted infrastructure units but could also deliver regularly updated maps of the RSS based on the devices involved. Despite common V2I infrastructure nodes, the development of cellular networks beyond 5G would allow more precise positioning by utilizing specific synchronization signals with 5G New Radio (5G NR) even under high mobility constrains [29]. Since vehicular positioning mostly relies on the data provided by the Location Solution Provider (LSP), many concerns arise in regard to controlling personal information of the user [30].