A Mobile Application Implementing Hybrid Method for Localization for Public Bus Service Using Multilateration and Fingerprinting Technology

In this paper, our main aim is to track the public buses in an area and update the information about the where abouts of the buses to passengers using GSM-based hybrid localization, that is multilateration and fingerprinting technology. A GSM modem will be able to get the CELL’s location and extract the received signal strength from the neighboring cells. By using the multilateration concept the localization error can be reduced to a range of less than 50 meters. The difficulty in solely using multilaterating method using Signal Strength (SS) is in determining a way to convert SS to Transmitter-Receiver (T-R) distance accurately. So along with multilaterating method, fingerprinting concept is also applied which is to, initially, establish a database that contains the measurements of wireless signals (that is, the SS) at some Reference Points (RP). Then the location of the Mobile User (MU) can be identified by comparing their Signal Strength (SS) measurements with the reference data. This concept can be used for public bus tracking system instead of currently tested GPS tracking system as this will be very much cost effective. Knowing the where abouts of the bus, the people waiting in the bus stops can be alerted and the estimated time of arrival of the bus can be displayed. In this paper we have enhanced the above mentioned feature by creating a mobile application the makes the users clearly informed about the arrival of the next bus for the same route thereby predicting their travel.