Indoor positioning using CoLDE: An IEEE 802.11 connectionless extension

Abstract

Acquiring current position information from the GNSS is a straightforward procedure outdoors. Any mobile device, equipped with a GNSS receiver, having a line of sight with enough numbers of satellites can calculate its location. The mobile device does not need a full connection with any of these satellites. In the indoor positioning using the Wireless Ethernet IEEE 802.11 (Wi-Fi) standard, some accurate methods require the mobile device to send some initial data from its environment to a server, the server utilizes the data to calculate the exact location. The mobile device should be able to connect to this server, either by having an association with a Wi-Fi access point or using 3G/4G if the server is accessible from the Internet. In some cases, having a connection to the Internet is not possible, either because of the absence of the 3G/4G, or the Wi-Fi access points and the server are not for the public. This study aims to make the Wi-Fi indoor positioning systems available to all the mobile devices, exactly as the GPS, without even the need to be connected, either to the Internet, or to any of the Wi-Fi access points. In order to achieve this goal, we developed an extension, CoLDE (Connectionless Data Exchange), for the protocol IEEE 802.11. CoLDE utilizes the management frames to allow Wi-Fi devices and access points to exchange small amounts of data without having an association. Using CoLDE, the access points can relay the initial data (which they) received from the mobile device to the server, and send the exact position back to the Wi-Fi device. CoLDE can be utilized regardless of the used Wi-Fi indoor positioning. This paper gives the description and the implementation of the protocol used and the proposed method, in addition to the experimental results gathered in a feasibility study to validate some of the basic concepts of this approach.