With the passage of
time, new technologies are sprouting every day. Our responsibility is
how we use it for making our daily life easier. The present era is an
era of modern and advanced technology, i.e. Indirectly you can say,
it is an era of wireless technology. Wireless phones, wireless
devices, Wireless machines, wireless communication....Almost
everything is wireless. The revolution in wireless technology eases
and comforts our daily life.
Now, when it comes
to recent technology, Star Link India is always front of the race in
using recent trends in its devices. So, today we are going to discuss
the method of marking attendance. This can be done by showing a
simple card and that card is known as RFID card.
What
is RFID?
RFID stands for
Radio Frequency Identification. It is a generic term used for
technology that uses radio waves to automatically (contact less)
identify people or objects. This card contains microchip connected to
an antenna. The microchip usually stores the data or generally it
contains Unique serial number (UID), whereas antenna convert
electromagnetic waves to electrical power/signal and receive waves
from the reader.
The chip with
antenna together is called RFID transponder or RFID tag.
How
RFID works?
An RFID system
consists of a tag, which is made up of a microchip with an antenna,
and an interrogator or reader with an antenna. The reader sends out
electromagnetic waves. The tag antenna is tuned to receive these
waves. A passive RFID tag draws power from field created by the
reader and uses it to power the microchip’s circuits. The chip then
modulates the same waves using ASK (Amplitude Shift Keying) and
reader demodulate signals and convert to digital data and in response
reader modulates the same wave and tag demodulates. So in this way
half duplex communication takes place on the same wave.
Types
of RFID
There are basically
two types of Tags or RFIDs – Read-only and Read-Write.
Read-only microchips
have information stored on them during the manufacturing process. The
information on such chips can never been changed.
Read-write
tags
usually
have a serial number (UID) that can't be written over. Additional
blocks of data can be used to store additional information about the
items the tag is attached to.
How
secure it is?
Whenever
we use any technology, the security is the major concern that should
be kept in mind. So in RFID a cryptography engine is used that
prevents from illegal reading of information. Challenge Response
Authentication is commonly used to foil repeated transfer of messages
between tag and readers, preventing repeated transmission.
For
reliability, CRC (Cyclic Redundancy Check) is used.
Standards
and Protocols for RFID
Depending
on the use and applications, a number of organizations have set a
different parameters and protocols. These organizations include ISO, IEC, ASTM International, DASH7 alliance and EPC global.
Out
of numerous protocols and standards we use ISO/IEC 14443. This
standard is a popular HF (13.56 MHz) standard for HF RFID which is
being used as the basis of RFID-enabled passports under ICAO 9303.
The Near Field Communication standard that lets mobile devices act as
RFID readers/transponders is also based on ISO/IEC 14443.
Frequency
of RFIDs
Depending
on the application, three major frequency ranges for RFIDs are there.
They are Low frequency, High Frequency (HF) and Ultra High Frequency
(UHF).
LF
are in the range of 125-200 KHz, HF-13.56 MHz and UHF - 850-900 MHZ.
But
in our application of Attendance System and Access Control, we use
LFIDs and HFIDs.
Now
let us discuss, how we use this RFID tag and incorporate with our
technology. Basically the information of the employee like the
fingerprint template or other information are written in it. After
that, any employee can use this card as his identity, only he has to
show this to the device installed.
This
method is very effective and efficient in the companies with larger
employee strength. Helps the Management to save a lot of time and
money as well.
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