Note: Descriptions are shown in the official language in which they were submitted.
CA 02405894 2002-10-16
Compact Bluetooth, 802.11 and RS-232 Enabled RFID Reader
Background
This invention merges RFID technology with high speed communication protocols,
specifically Bluetooth, 802.11 and RS-232, to create a mobile, handheld
wireless RFID
reader capable of interfacing to a host of wireless enabled devices. Radio
Frequency
Identification (RFID) is an emerging wireless technology that allows RFID
readers to read
and/or write RFID tags. This is accomplished by a radio frequency medium,
which can
occur at a number of different frequencies ranging from 125kHz to several GHz,
depending
on the use of the tag. RFID has several key advantages over barcode
technology, which
make it suitable for numerous applications. Specifically, it is non-line-of
sight, it can store
data on board the tag, and this data can be read and written dynamically. The
applications of
this technology are myriad, from retail to manufacturing and beyond. Even
modest market
estimations predict that this market will explode in the near future, as the
ability to transfer
information directly between tagged objects and IT systems is applicable to
virtually every
market sector.
Bluetooth and 802.11 are wireless technologies of a different kind. Operating
in the
unlicensed 2.4GHz band, both of these protocols serve to allow two
"intelligent" devices to
communicate. Where as RFID deals with storing and retrieving data on a tag
that is placed
on an object, such as a tool, Bluetooth and 802.11 would be used to connect
two computers
for the function of sharing files or connecting a PC and printer, for the
purpose of printing
documents. RS-232 is a much more common protocol, found on virtually every PC.
While
slower, RS-232 is ubiquitous, trading speed, for simplicity and convenience.
RFID, as mentioned, is an emerging technology that is finding use in an ever-
increasing
number of applications. From security access, to asset tracking, to livestock
identification,
anything that can be labeled has an RFID application. In fact, due to the
potential of the
technology, things that historically have not been labeled can now be tagged
and tracked.
The support technology for RFID, necessary to make it convenient and easy-to-
use, are
somewhat lagging however. The remote and decentralized location of many tags,
require the
use of handheld RFID readers, which are capable of extracting and modifying
the data stored
on the tag. This has been attempted in three main ways; using an expansion
module in
Handspring Visor PDA's (Personal Data Assistants), attaching an expansion
module onto
common PDA's such as the Palm series of PDA's, and finally by building custom,
proprietary handheld readers. All three of these solutions are less than
optimal and have met
with limited success as they either limit users to a single type of PDA, which
may not be
suitable for all functions, or they make the PDA so unwieldy that it becomes
impractical, or
finally the introduction of an additional handheld has compatibility issues
and increases the
number of accessories that a worker must carry.
Additionally, links via PDA tend to introduce information lag, as the main
database is only
updated when the PDA is synchronized with the PC, requiring a physical
connection.
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A search of filed patents revealed no patent remotely comparable to the
proposed technology.
This is reasonable, as both RFID and Bluetooth are emerging technologies;
advanced
combinations of the two are outside the scope of most common applications.
Summary of the Invention
The proposed technology addresses all of the aforementioned issues by merging
the benefits
of RFID technology with the flexibility of robust wireless communication
protocols, namely
Bluetooth and 802.11. In addition the inclusion of the RS-232 protocol permits
a physical
connection in addition to a wireless link, further expanding the scope of
application. This
allows the RIFD reader to be independent of a PDA, making it much smaller and
more
compact. As well, the new readers' wireless capabilities allow it to
communicate with any
devices that support these protocols, which are very numerous and continuously
expanding,
be that a PC, a PDA, a router, a repeater, or another RFID reader. This makes
the RFID
reader very flexible in both a functional and mobile sense. As well, because
the RFID reader
communication interface is common to many devices, its use is not restricted
to any
particular device, making it platform-independent.
Fig. 1 is a block diagram of the system architecture for the RFID reader. This
figure shows
the basic components of the system and their fiW ctional interaction and
relationships
Fig. 2 is a systems level diagram showing the interrelationship between the
RFID reader and
various other devices. This figure illustrates the application aspects of the
RFID reader. The
physical embodiment of the device in this figure is for illustration purposes
only and could
take on many other physical forms.
Detailed Description of Invention
The RFID readers' modular design consists of four main components; the power
supply ( 1 ),
the antenna (4), the RFID encoder/decoder (3), and~the communication
transceiver (2). The
power supply (1) provides the energy requirements for all of the modules of
the RFID reader.
The antenna module (4) is responsible for reading from and writing to, the
RFID tag (9).
This can be done at a number of frequencies to allow compatibility with
numerous types of
tags. The antenna (4) signal is both controlled and interpreted by the RFID
encoder/decoder
(3) module. The RFID encoder/decoder (3) outputs (modulates) electrical
signals to the
antenna (4) which in turn communicate with the tags (9). Conversely, when an
RFID tag (9)
is outputting wireless information, the antenna (4) picks up those signals
which are in turn
read by the RFID encoder/decoder (3) and interpreted into useful data. The
final module is
the communication (2) module, which is responsible for communicating between
other
devices such as a repeater (5), a PDA (6), or a PC (8) and the adjacent RFID
encoder/decoder
(3). The communication module (2) is capable of both sending and receiving
information via
Bluetooth and 802.11. This module (2) acts as a translator between the RFID
encoder/decoder (3) and other peripheral devices. To illustrate, if a piece of
software on a
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PDA (6), such as a Palm Pilot, wanted to write to and then read from an RFID
tag (9) via the
Bluetooth RFID reader (7), the procedure would occur as follows. The software
on the PDA
(6) would send digital data to the Bluetooth transceiver ( 10) onboard the PDA
(6). This
wireless signal would be sent by the PDA Bluetooth transceiver (10) and picked
up by the
communication module (2) of the Bluetooth RFID reader (7). This node (2) would
then
interpret this wireless signal, back into an electrical digital signal that
the RFID
encoder/decoder (3) could understand. The RFID encoder/decoder (3) would use
this digital
data to modulate (encode) a signal onto the antenna module (4), which would in
turn output a
wireless signal, of the appropriate frequency for the RFID tag (9). The
antenna (11) on the
RFID tag (9) would pick up this signal originating from the Bluetooth RFID
reader (7) and
then interpret it as data. This process would constitute a write operation by
the PDA (6).
A mirror image process would occur for a subsequent read operation. The RFID
tag (9)
would emit a wireless signal, which is picked up by the Bluetooth RFID readers
(7) antenna
(4). This signal is then decoded into a digital format by the RFID
encoder/decoder (3)
module. This digital information is then passed to the Bluetooth communication
module (2)
to be broadcast as a wireless signal, which is detected by any Bluetooth
enabled devices in
the vicinity of the signal (5, 6 or 8).
Please note that the signal originator could be any device capable of
communicating via the
Bluetooth or 802.11 wireless protocols. As well, though Bluetooth was cited in
this example,
the procedure is identical for communication via the 802.11 and the RS-232
protocols.
Areas with very high electromagnetic (EM) noise may cause interference with
the wireless
communication of the RFID reader (7).
