Enabling Location-Based Services on Wireless LANs

Abstract- The wide deployment of IEEE 802.11 Wireless Local Area Networks (WLANs) has made possible the development of application services on WLANs. Due to the small cell size in WLANs, it is practical to develop location dependent services based upon the awareness of the WLAN access points (AP) that mobile devices currently access. In this paper, we propose a location determination technique using the inherent SNMP support in WLAN APs. It is shown that the location of a mobile device can be determined effectively from the SNMP traps sent by APs. Our SNMP-based approach doesn’t need any particular software or hardware in mobile devices. This paper also considers how to determine the location of a mobile device by its IP address. In general, only the IP address of a mobile device can be seen by location-based services. However, APs identify each mobile device by its MAC address. Hence, we propose effective techniques for the mappings between IP addresses and MAC addresses. Through the address mappings, the location of a mobile device can be determined by its current IP address. We further propose a web service framework to enable WLAN location-based services in WWW environments. To verify our approach, we also develop a location-based campus map service based on the web service framework. I