MDE-3664B TRIND® Start-up, Service, and Parts Manual · June 2013
Page A-5
Wireless Communication and Air Interface
Appendix A - Radio Frequency Identification Defined
Three carrier frequencies receiving early attention as representative of the low, intermediate,
and high ranges are 125 KHz, 13.56 MHz, and 2.45 GHz. However, there are eight frequency
bands in use around the world, for RFID applications.
Not all of the countries in the world have access to all of the frequency bands listed above, as
some countries have assigned these bands to other users. Within each country and within each
frequency range there are specific regulations that govern the use of the frequency. These
regulations may apply to power levels and interference as well as frequency tolerances.
Data Transfer Rate and Bandwidth
Choice of field or carrier wave frequency is of primary importance in determining data
transfer rates. In practical terms the rate of data transfer is influenced primarily by the
frequency of the carrier wave or varying field used to carry the data between the tag and its
reader. Generally speaking the higher the frequency the higher the data transfer or throughput
rates that can be achieved. This is intimately linked to bandwidth or range available within the
frequency spectrum for the communication process. The channel bandwidth needs to be at
least twice the bit rate required for the application in mind. Where narrow band allocations are
involved the limitation on data rate can be an important consideration. It is clearly less of an
issue where wide bandwidths are involved. Using the 2.4 - 2.5 GHz spread spectrum band, for
example, 2 MB per second data rates may be achieved, with added noise immunity provided
by the spread spectrum modulation approach. Spread spectrum apart, increasing the
bandwidth allows an increase noise level and a reduction in signal-to-noise ratio. Since it is
generally necessary to ensure a signal is above the noise floor for a given application,
bandwidth is an important consideration in this respect.
Frequency Range
Applications and Comments
Less Than 135 KHz
A wide range of products available to suit a range of applications, including animal
tagging, access control and track and traceability. Transponder systems that operate in
this band do not need to be licensed in many countries.
1.95 MHz
3.25MHz
4.75MHz
8.2MHz
Electronic article surveillance (EAS) systems used in retail stores.
Approx. 13 MHz
13.56MHz
EAS systems and Industrial, Scientific and Medical (ISM).
Approximately 27 MHz
ISM applications.
430 - 460 MHz
ISM Applications Specifically in Region 1.
902 - 916 MHz
ISM Applications specifically in Region 2. In the USA this band is organized with many
different types of applications with different levels of priorities. This includes Railcar and
Tool Road applications. The band has been divided into narrow band sources and wide
band (spread spectrum type) sources. In Region 1 the Gilbarco Security Module (GSM)
telephone network uses the same frequencies.
918 - 926 MHz
RFID in Australia for transmitters with Effective Isotropic Radiated Power (EIRP) less
than 1 watt.
2350 - 2450 MHz
A recognized ISM band in most parts of the world. IEEE 802.11 recognizes this band as
acceptable for RF communications and both spread spectrum and narrow band systems
are in use.
5400 - 6800 MHz
This band is allocated for future use. The FCC has been requested to provide a spectrum
allocation of 75 MHz in the 5.85 - 5.925 GHz band for Intelligent Transportation Services
use. In France, the TIS system is based on the proposed European pre-standard
(preENV) for vehicle to roadside communications communicating with the roadside via
microwave beacons operating at 5.8 GHz.