Wireless Indoor Geolocation Techniques

The advanced wireless indoor geolocation techniques are based on RSS, AOA, TOA, and TDOA; out of these TDOA is the most popular technique for use indoors.

This technique involves the usage of advanced RF location systems and requires only time synchronization in between the receivers to minimize the range difference estimation error; here’s more to it.

Classification

Wireless geolocation can be classified into two basic types:

• Handset based geolocation: The Mobile Station (MS) receives signals from Fixed Stations (FS) and estimates its own location.
• Network based geolocation: In this type, FS receives signals from MS and transmits the details to a Control Station (CS) to compute the MS’s location.

Major Hindrances

Exploiting location details is also very popular for user applications as well as wireless service providers. The two main problems faced in finding the location in indoor areas are intricacies involved in radio propagation and the ad hoc characteristics of the infrastructure. Because of these challenges, many signaling methods and location finding algorithms are being developed for wireless indoor geolocation.

Accuracy of Wireless Indoor Geolocation Techniques

Accuracy of TDOA technique depends up on factors like indoor environment (multipath, NLOS), algorithm used to estimate time or time difference of arrival, number of fixed stations used, algorithm used to compute user’s location and geographical location of mobile station relative to fixed station.

Applications of Wireless Indoor Geolocation

There is a need for these systems in commercial places like hospitals to locate the patients or equipments; similarly military and public safety applications also have a need for wireless geolocation. These networks also help soldiers, police men and fire fighters to accomplish their mission successfully. All these requirements have led to the development of indoor geolocation services.

Wireless indoor geolocation has emerged as an ideal way to render localization and navigation for people and personnel inner buildings where capabilities are limited for outdoor geolocation.