A location and tracking system becomes very important to our future world of
pervasive computing, where information is all around us. Location is one of
the most needed information for emerging and future applications.
Since the public use of GPS satellite is allowed, several state-of-the-art
devices become part of our life, e.g. a car navigator and a mobile phone with a
built-in GPS receiver. However, location information for indoor environments
is still very limited. Several techniques are proposed to get location
information in buildings such as using a radio signal triangulation, a radio
signal (beacon) emitter, or signal fingerprinting. Using radio frequency
identification (RFID) tags is a new way of giving location information to users.
Due to its passive communication circuit, RFID tags can be embedded almost
anywhere without an energy source. The tags stores location information and
gives it to any reader that is within a proximity range which can be up to 10-15
meters for UHF RFID systems. We propose an RFID-based system for
navigation in a building for blind people or visually impaired.
The system relies on the location information on the tag, a userpsilas
destination, and a routing server where the shortest route from the userpsilas
current location to the destination. The navigation device communicates with
the routing server using GPRS networks.
We build a prototype based on our design and show some results. We found
that there are some delay problems in the devices which are the
communication delay due to the cold start cycle of a GPRS modem and the
voice delay due to the file transfer delay from a MMC module.
