--- title: "Demand responsive public transportation using wireless technologies" url: "https://maker.wiznet.io/Sushma_WIZnet/projects/demand-responsive-public-transportation-using-wireless-technologies/" markdown_url: "https://maker.wiznet.io/Sushma_WIZnet/projects/demand-responsive-public-transportation-using-wireless-technologies/md" type: "UCC: User Created Content" author: "Sushma_WIZnet" author_url: "https://maker.wiznet.io/Sushma_WIZnet/" original_author: "Prashanth S" original_url: "https://doi.org/10.1145/2185216.2185332" published: "2022-09-20" language: "en" likes: 4 views: 1288 comments: 1 source: "WIZnet Makers (https://maker.wiznet.io/)" --- # Demand responsive public transportation using wireless technologies > Air pollution has been the bane of society for which we still have not got a satisfying solution. Original author: Prashanth S (source: https://doi.org/10.1145/2185216.2185332) ## Article INTRODUCTION With the increasing population in large cities of today, existing problem of inadequate transportation services has grown to an alarming extent. Due to less availability of prior information about the arrival schedule of buses in particular, people have to wait longer on bus stops especially in peak hours when they have to reach the offices in time. The buses are overloaded for most of the times which often results in some kind of breakdown in bus services, and people get to their destinations negotiating delays. In addition, rapid population growth and spatial expansion is adversely affecting this issue. Consequently the dissatisfaction with the level and quality of public transportation service has lead those people who can afford it to turn to private modes of transportation. Owing to poor condition of roads in the country, the annual growth rate of vehicles has created problems in controlling the traffic flow resulting in traffic congestion on roads. Also with the increased number of vehicles, the content of air pollutants are found to be 10 times higher than World Health Organization (WHO) recommendations in central parts of any India metro city thereby deteriorating the environment and causing lung diseases [1,2]. In this paper, a transportation management system [3,4] is developed for enhancing public transportation services based on integration of GPS and other conventional communication technologies (GSM/Ethernet/Wi-Fi). GPS is used as a positioning device, while wireless device is used as communication link between different modules. These modules include Bus stop Module, In-Bus Module, and Center Server Module. The request for the Public Transport is sent from a hotspot through the microcontroller which is installed along with the wireless device. This request is then sent to the central server through the wireless device. The request is read by the central server, processed and it computes the vehicle that is to be sent to the requested hot-spot [5]. It computes the route in which the chosen vehicle must travel and the route is sent to the vehicle through the wireless device that is attached with the server. The vehicle carries a GPS that is installed along with the wireless device, and the microcontroller receives the information from the server and directs a bus on to the requested hot-spot. HARDWARE SPECIFICATIONS The Microcontroller A microcontroller is installed in all the hot-spots and also in the in-vehicle modules. This microcontroller is responsible in reading the input from the passenger and sends the input to the wireless device which will broadcast to the server in the case of the hot-spot module. In the In-Bus module the microcontroller is responsible in receiving the information from the server which again is done through the wireless device and this input displays on the screen that will assist the driver by drawing the route in which the vehicle must travel and also showing the next hot-spot. Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. The microcontroller on the board is programmed using the Arduino programming language (based on Wiring) and the Arduino development environment. This Arduino board is placed in the hot-spot and the in-vehicle module. GPS receiver In order to keep track record of the vehicle, a Garmin GPS35 receiver, is installed in each vehicle. The Garmin GPS35 is a complete GPS receiver and embedded antenna designed for a broad spectrum of OEM system applications. The GPS35 tracks up to twelve satellites at a time while providing one-second navigation updates and low power consumption. Its far-reaching capability meets the sensitivity requirements of land navigation as well as the dynamics requirements of high-performance aircraft. Internal memory backup allows the GPS35 to retain critical data such as satellite orbital parameters, last position, date, and time. GSM modem A wireless link between the modules is provided with Nokia 12i GSM module. Nokia 12i offers advance GSM connectivity and supports EDGE/GPRS and HSCSD with automated GSM connection establishment It is equipped to provide reliable remote connections and offers application level watchdogs, inbuilt self check mechanisms and a reliable Virtual Machine (VM) for JAVATM. Nokia 12i also supports reliable inbuilt internet protocols: TCP/IP for reliable data transfer, UDP/IP for audio and video streaming and HTTP for accessing web pages. The module can also be connected to an external GPS device that supports National Marine Electronics Association (NMEA) standard. The inbuilt NMEA parser can parse the location data from the output that it receives from the GPS device. External microcontroller can use AT commands to communicate with Nokia 12i and simple remote I/O applications can be easily controlled via text messages. The GSM modem is the choice of wireless device in areas where we do not have wireless internet connections and places where it is difficult to set up Ethernet shields. Arduino Ethernet shield The Arduino Ethernet Shield allows an Arduino board to connect to the internet. It is based on the Wiznet W5100 Ethernet chip. The Wiznet W5100 provides a network (IP) stack capable of both TCP and UDP. It supports up to four simultaneous socket connections. Use the Ethernet library to write sketches which connect to the internet using the shield. The Ethernet shield connects to an Arduino board using long wire-wrap headers which extend through the shield. This keeps the pin layout intact and allows another shield to be stacked on top. The Ethernet Shield has a standard RJ-45 connection, with an integrated line transformer and Power-over-Ethernet enabled. The latest revision of the shield adds a micro-SD card slot, which can be used to store files for serving over the network. It is compatible with the Arduino Uno and Mega (using the Ethernet library). The on-board microSD card reader is accessible through the SD Library. The latest revision of the shield also includes a reset controller, to ensure that the W5100 Ethernet module is properly reset on power-up. Arduino Wi-Fi shield WiFly is the Wi-Fi shield that is attached along with the Arduino board. This wireless device is used in places where we have seamless wireless internet connection available so that the request can be sent faster to the server. The Wi-Fi shield has the advantage over the GSM and the Ethernet device as is mobile and can be set up anywhere provided the wireless internet connection is available at that spot. The WiFly Shield equips the Arduino the ability to connect to 802.11b/g wireless networks. The featured components of the shield are a Roving Network's RN-131C wireless module and an SC16IS750 SIP-to-UART chip. The SIP-to-UART bridge is used to allow for faster transmission speed and to free up the UART. Power is taken from the Vin pin of the Arduino, regulated to 3.3V, and provided to both the RN-131C and the SC16IS750. You'll communicate with the WiFly Shield over SPI using Arduino digital pins 10-13. The shield includes the RN-131C, SC16IS750 and their supporting components CASE STUDY AND MODEL In order to understand and realize the model, the entire Amrita University, Coimbatore campus has been mapped with a GPS (see Figure 1). Overview The entire map of the campus is shown in Figure 2. In the campus there is an internal bus transportation system which is used for the transportation between departments and blocks by the students and staff of the university. ![](https://maker.wiznet.io/upload/ckeditor5/285980416%5F1664308009%2Epng) ![](https://maker.wiznet.io/upload/ckeditor5/285980416%5F1664308067%2Epng) The entire system comprises of three modules: Hot-spot module, In-Vehicle module and the central server module. In order to have a better realization of the system the entire campus of Amrita University has been mapped with a GPS and that is taken as a prototype for the model. Henceforth, this map will be taken as the medium for discussion of he modules. The working and the interconnection of these modules are explained below. Hot-spot module The places where the buses would stop inside the campus is taken as a hot-spot. As mentioned earlier, a hot-spot will have a box installed which will have the micro-controller along with the GSM modem. This micro-controller is programmed in such a way that the input is obtained from the user through screen that is present in the hot-spot and this is sent to the server, making a request for a bus. ![](https://maker.wiznet.io/upload/ckeditor5/285980416%5F1664308160%2Epng) If the passenger inputs the destination place and requests for a bus, a message is sent from the GSM modem, which is installed to the server. If a Wi-Fi or an Ethernet shield is installed instead of a GSM, a request is sent to the http server, which is the centralized server (see Figure 3). This request will have the source hot-spot number and destination hot-spot number. In-bus module The in-bus module consists of a GPS a micro-controller along with a display of the map and a GSM modem if GSM is used in hot-spots or an Ethernet / Wi-Fi shield otherwise. The GPS installed in the bus constantly updates the central server module. The message that is sent from the server is received by the GSM modem and read by the microcontroller. The microcontroller, based on the request from the server, displays the route that the bus driver has to take on a graphics display unit present in the bus (see Figure 4). If an Ethernet / Wi-Fi connection is used, the Ethernet shield in the bus is loaded with an HTTP client and it reads the data sent from the server and hence updates the display in the bus with the requested route. ![](https://maker.wiznet.io/upload/ckeditor5/285980416%5F1664308196%2Epng) Central server module The central server module comprises of a PC which will act as a server. This server is always ON and will have a GSM modem installed with it, in order to receive the messages from the hotspot (Table 1). If an Ethernet shield or a Wi-Fi shield is installed in the hot-spot, the server will consist of a HTTP server which will be listening to a particular port and it will get the request from the HTTP client which is present at the hot-spot. Once the server gets the request from the hot-spot, it will lookup for the suitable bus which is present closer to the requested hot-spot's location based on the GPS co-ordinates which are being polled by the server from the GPS present in the buses (see Figure 5). Based on the co-ordinates the server computes a path according to Djikstra's algorithm and sends it to the bus. ![](https://maker.wiznet.io/upload/ckeditor5/285980416%5F1664308238%2Epng) OPTIMUM ALGORITHM FOR ROUTING AND SCHEDULING Overview of the A-Star (A*) algorithm The choice of algorithm for this map is the A* algorithm[6]. A* is like other graph-searching algorithms in that it can potentially search a huge area of the map. The A-Star algorithm is a flexible cost based algorithm, which can help satisfy all our requirements. The cost function must be admissible, i.e. the estimated cost must be less than the actual cost. This produces computationally optimal results. The most essential part of the A-Star algorithm is a good heuristic estimate function. This can improve the efficiency and performance of the algorithm, and depends on the specific state space being explored. Generally, the A-Star algorithm maintains two lists, an open list and a closed list. The open list is a priority queue of states, where we can pick out the next least costly state to evaluate. Initially, the open list contains the starting state. When we iterate once, we take the top of the priority queue, and then initially check whether it is the goal state. If true, then the process is complete. Otherwise, we calculate all adjacent states and their associated costs, and add them into the open queue. A-Star is complete with respect to finding a unique solution. DISCUSSIONS AND CONCLUSION In this paper, design and development of a low cost transportation management system based on the demand of the passengers, with the integration of wireless technologies like Ethernet, WI-Fi and GSM data is described. The system comprises various modules which are wirelessly linked with the GSM modems. Cost effective SMS service of GSM network is used for the transfer of data between the modules. A better way of traveling is proposed to facilitate the better usage of the public transportation. The bus route on the Amrita University campus has been studied and a solution has been provided to implement demand-based transportation using the wireless technology. This helps in changing the present scenario of schedule-based public transportation, since it is more efficient and time saving for the commuters. This system is robust and optimal in smaller maps with fewer routes, but when considering a map as huge as a metropolitan city it needs complex algorithms to optimally choose between a shorter path or a shorter time for the passengers inside the vehicle. In situations like this it is more of a trade-off between the two attributes. In addition to this, the whole system can be made automated such that we will not require a driver for the vehicle. We can have automated vehicles which simple follow a particular track based on the demand and the destination provided by the in-bus module. --- Source: https://maker.wiznet.io/Sushma_WIZnet/projects/demand-responsive-public-transportation-using-wireless-technologies/