Binary search tree based hierarchical placement algorithm for IoT based smart parking applications

Abstract

With the increasing numbers of vehicles, the parking space management is becoming a critical issue especially for congested settlement areas. Especially during the peak hours, the difficulty of finding a parking spot can introduce significant challenges to drivers. In order to locate the parking spot, most of the time drivers rely on their own limited knowledge of where the parking spaces are available at a given time. Even in these cases, large numbers of vehicles may try to access limited numbers of parking spaces which in turn leads to traffic congestion. Furthermore, when the parking region is rather complicated with large numbers of spots, the identification of a suitable parking spot becomes an expensive process since it often causes an increase of vehicle traffic which in turn also causes a consequent increase of pollution. Therefore traffic on roads and parking space has been an area of concern in the majority of smart city studies and applications. Parking monitoring is known in the literature as one of the promising solutions to these issues. In this paper, we present a hierarchical approach based on the binary search tree (BST) for parking monitoring systems that helps users to reach a free parking spot easily. The solution proposed introduces an approach which makes searching process in car parking applications efficient in terms of time and energy. Two levels of hierarchy are employed for this purpose. In the first level, our algorithm only checks for the nearest car park. At the second level, the algorithm focuses on the car park that is the nearest and checks the nearest parking spot in that car park. Using this hierarchical approach, the search for an empty spot becomes more time efficient. Simulation results are presented in this study to show the efficiency of the proposed hierarchical approach with BST. Non-hierarchical, hierarchical and hierarchical with BST support approaches are employed for same scenarios in order to show the effectiveness of the new approach. According to simulation results, hierarchical approach with BST is superior in terms of search time and energy efficiency.