Naslov
Automatic Position Reporting System: A Perfromance Validation Study

Autori
Filjar, Renato ; Dešić, Saša ; Bandalović, Neven ; Štefanec, Mario

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of 2nd ESA Workshop on Satellite Navigation User Equipment Technologies (NAVITEC 2004) / - , 2004

Skup
2nd ESA Workshop on Satellite Navigation User Equipment Technologies (NAVITEC 2004)

Mjesto i datum
Noordwijk, Nizozemska, 08.12.2004. - 10.12.2004

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
APRS; GPS; position

Sažetak
Efficient and reliable positioning, and position reporting systems are in the heart of every location-based service (LBS). Determination of position is usually performed by utilisation of one or more basic and advanced positioning methods (satellite positioning: GPS, Glonass, EGNOS, Galileo ; or network-based: CGI, TOA, E-OTD), with the aim to obtain the best position estimate at the time. Positioning method performance establishes the foundation level of LBS quality of service (QoS). However, getting the best position estimate means only a part of complete solution. Position information should be distributed among the elements of the LBS architecture in order to initiate a wide variety of services, usually aimed to deliver some sort of position-related information content. A separate entity should be established in order to provide position-related data exchange, usually in a form of position reporting system. Performance of this system determines another layer of LBS QoS. In an effort to develop a general framework for various LBS development, the Automatic Position Reporting System (APRS) was outlined. APRS is aimed to provide both development and test tool for different LBS solutions, based on integration of standard satellite positioning and mobile communications technologies. It is a client-server system that supports continuous position reporting in predetermined time intervals. Position data are transferred using mobile data communications technology (Internet over GSM/GPRS) commercially available at the time of testing. As an additional feature, APRS sends position information to a simple LBS application that prepares and displays essential position-related content. In its practical prototype implementation, APRS consists of mobile client (rover) and APRS server. APRS mobile client consists of satellite positioning (GPS) receiver, laptop computer running mobile client software, and mobile telephone for operating GSM/GPRS connections. So far, only the standard satellite positioning (GPS) is implemented, with plans for future implementation of advanced (assisting & augmentation) systems. In order to verify the APRS performance, a field study was performed in sub-urban and rural areas of Zagreb, Croatia in 2004. Both positioning and position reporting performance were investigated during the field trial, with final conclusion of surprisingly good general achievement. This article presents APRS structure and describes the performance validation experiment. First, the importance of APRS for LBS development is briefly discussed and comprehensive description of performance related parameters presented. Then, the APRS architecture is presented, with the emphasis given to practical prototype realisation. APRS validation experiment description is given, along with collected results. Finally, experimental results are discussed and correlated with performance parameters requirements stated previously. In conclusion, both positioning and position reporting processes generally expressed rather high performance level. Further work will be performed in order to improve several aspects of positioning process (continuity of positioning service, positioning accuracy, positioning availability) significantly affected by urban environment.

Izvorni jezik
Engleski

Znanstvena područja
Elektrotehnika

POVEZANOST RADA