Investigation for a Global AVL System

Real-time reporting systems are now becoming widely available, in order to aid emergency dispatch assistance and traffic control management as being an important part of intelligent transportation systems (ITS). Based on the fact that the Global System Mobile (GSM) standard is widely accepted as being the most comprehensively deployed of all the various second generation digital cellular telephony standards, studies have been focused on using it as a communication link for real-time application reporting. This paper introduces a study made on an integrated system incorporating a Global Positioning System (GPS) receiver, a control area network (CAN) and the Short Message Service (SMS) of GSM as the transmission media. The goal of the research study conducted, is to measure the end to end delays experienced, and consequently its practicality, when using a CAN bus and the GSM-SMS bearer service for position reporting for use in an ITS environment. The paper initially presents the previous research that has been carried out relevant to this study. Following it outlines the system architecture of the integrated system studied together with its functionality in an ITS environment. The results obtained from the various simulation scenarios are presented as well as an estimation algorithm that aims to diminish the positioning error incorporated from the transmission delays occurred. Concluding this paper discusses the advantages of using this integrated system as a solution for position reporting in ITS as well as proposing further research to be conducted.