Database Reference
In-Depth Information
3.1 RFID Technology
At the most basic level, the definition of Radio Frequency Identi-
fication (RFID) is as follows:
RFID is a technology which allows a
sensor (reader) to read, from a distance, and without line of sight, a
unique product identification code (EPC) associated with a tag
.Thus,
the unique code from the tag is transmitted to one or more sensor
reader(s), which in turn, transmit(s) the readings to one or more server(s).
The data at the server is aggregated in order to track all the different
product codes which are associated with the tags. We note that such
RFID tags do not need to be equipped with a battery, since they are pow-
ered by the sensor reader. This is a key advantage from the perspective
of providing a high life time to the tracking process. The sensor readers
provide a key intermediate layer between the data collection process and
network connectivity. The RFID tags typically need to be present at a
short distance from the readers in order for the reading process to work
effectively. From a data-centric perspective the major limitations of the
basic RFID technology are the following:
The basic RFID technology has limited capabilities in terms of pro-
viding more detailed sensing information, especially when passive
tags are used.
The range of the tags is quite small, and is typically of the order of
between 5 to 20 meters. As a result significant numbers of readings
are dropped.
The data collected is massively noisy, incomplete and redundant.
Sensor readers may repeatedly scan EPC tags which are at the
same location (with no addition of knowledge), and multiple read-
ers in the same locality may scan the same EPC tag. This leads to
numerous challenges from the perspective of data cleaning. This
cleaning typically needs to be performed in the middleware within
the sensor reader.
RFID collection technology leads to considerable privacy chal-
lenges, especially when the tags are associated with individual.
The tags are susceptible to a wide variety of eavesdropping mech-
anisms, since covert readers can be used in order to track the
locations of individuals.
A detailed discussion of the data-centric issues associated with RFID
technology may be found in [9].
