# Designing and Managing a Smart Parking System Using Wireless Sensor Networks
## 2 Existing Smart Systems for Parking Management
### Mass Protocols  
Mass protocols are self-organization protocols based on the deployment of WSNs in car parks allowing the creation of clusters or tree structures. The following systems use these protocols in car park management:  
In [10], a new smart parking system (PGIS) is proposed, based on the use of networks of wireless sensors to control and manage parking by implementing a guidance system using LED screens. This system is based on a WSN which consists of three types of sensor nodes: a monitoring node (for detecting the presence of vehicles in parking spaces), a routing node (for routing and to route the detected information to the sink node), and the sink node (which gathers all information from the network to transfer it to the information and management centre). These nodes are installed in the car park and they form a tree topology. The PGIS uses a guidance system using LED screens that are installed at the entrance and in the corners of the car park so that drivers can orient themselves and find the assigned parking space efficiently and effectively. The PGIS information and management centre supports the management and maintenance of the entire system, processes the data collected by the monitoring nodes, calculates the optimal parking space for the new car, manages the parking costs of each parked car and controls all parking screens. In [11], the author proposes a smart parking system that is based on the implementation of networks of wireless sensors for the management of vacant parking spaces for drivers who are looking for empty spaces. This system uses less expensive sensors (light sensors) to collect information on the status of parking spaces in order to send them to a central server through an aggregated server. The central server is installed and connected via the Wi-Fi network, and it receives all the information of all integrated web servers of each parking available in the city. This system uses a mobile application so that drivers can get information on vacant parking spaces. The light sensors used are influenced in most cases by ambient light and are sensitive to pollution, which can affect the quality and on the reliability of vehicle detection in parking spaces. In [12], the author proposes a new smart parking system based on the implementation of various technologies, such as WSNs, RFID, and ZigBee. The network of wireless sensors is used to detect the presence of vehicles in the parking spaces with ultrasonic sensors installed in these spaces, and which inform the base station on the states of these locations (empty or full). These sensors are composed of two types of nodes: monitoring nodes that are installed in the parking locations, and the routing nodes that are responsible for transferring the information collected by the monitoring nodes to the base station by creating a tree topology. The communication between the various sensors and the base station is based on ZigBee technology which allows short distance communication and with reduced energy consumption. This parking system offers a new RFID technology that has a very important role in identifying vehicles which have just parked in an empty space and has a crucial role in pricing by controlling the time between check-in and check-out. In [13], the author has developed s smart parking system based on the use of hybrid wireless sensors (infrared sensors + RFID), which form a cluster-tree structure. Each of them is equipped with three LEDs (red, green, blue) to control and manage the availability of parking spaces. This proposed system consists of four essential modules that are the online booking module, the input module, the output module, and the parking management module. In [14], the author created a new smart parking system (SIMERT) based on the installation of two wireless sensors in each parking space to detect the presence of vehicles and to control the good parking of vehicles in the parking spaces.