# An IoT-Based Participatory Antitheft System for Public Safety Enhancement in Smart Cities
## 2 Related Work  
In recent decades, urban populations have continuously increased by a rate that is greater than half a billion inhabitants per decennial on a worldwide basis [6]. This continuously growing urbanism has boosted the growth of various problems, which deteriorate the quality of living in civilian settlements.  
The concept of a smart city was introduced in the early 2000s [7]. It refers to urban municipalities that support the integrated use of not only methods and means but also policies and practices to manage resources, assets, and services and to improve the quality of life of their citizens in terms of prosperity, productivity, safety, and sustainability [8, 9, 10].  
The collection of data is an absolutely necessary procedure in the context of smart cities in order to gather information regarding various parameters that are related to all aspects of human activity. Additionally, the data collected have to be processed and transmitted over various distances. Modern technological advances have enabled the inexpensive massive fabrication of wireless sensor nodes that, despite their fairly small dimensions, have remarkable sensing, processing, and communication capabilities. This is the reason why wireless sensor networks (WSNs) and IoT, which have a continuously growing range of applications [11, 12, 13], are generally considered to be technologies that, when combined with the application of appropriate algorithms, are ideally suited to be deployed in the framework of smart cities [14, 15, 16].  
Regarding public safety, the advancement of technology has enabled the deployment of various surveillance systems for mobile assets since they are the most frequent object of theft.  
Specifically, the system proposed in [17] uses a camera to take images of anyone trying to access a vehicle and compares them with images stored of the legal owner of this vehicle, in order to either allow or deny access to the vehicle. Other antitheft systems that have been proposed for motor vehicles or other mobile assets use locating units installed in vehicles (e.g., GPS (Global Positioning System)) for positioning purposes, microprocessors for data processing, GSM (Global System for Mobile Communications) or GPRS (Global Positioning Radio Satellite) units for data transmission, and batteries for power supply [18, 19, 20, 21, 22].The question is whether the battery of such systems can be overcome, and, of course, it is directly dependent on the mobile provider. Another approach of antitheft technology, presented in [23], is more complex because it uses face recognition. In [24], a decentralized vehicle antitheft system using blockchain technology and smart contracts was proposed, aiming to improve the antitheft system's safety and data security by using a proper key that reduces the possibility of leakage of personal information.  
Other research teams have introduced schemes using free data transmission networks equipped with BLE devices. Bluetooth Low Energy 4.0 was introduced by the Special Interest Group (SIG) in 2010 [25]. BLE appliances can be powered by using coin-type batteries for a few years via different modes of power consumption [26]. Other studies have confirmed that BLE consumes low amounts of energy with a satisfactory effective range (50 m) [27, 28].  
Moreover, BLE supports flexible communication protocols, including the low-cost standard, and this makes this technology more competitive than other wireless technologies [26]. Another study presented the performance of experimental tests conducted regarding a BLE device mounted on a motorcycle on the road [29]. The results of these tests showed that the motorcycle antitheft system (MATS) was 100% accurate in all parts of the road at speeds of up to 70 km/h and 94.4% and 90% effective for speeds up to 80 km/h and 90 km/h, respectively.