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  • What is RFID ?
  • Wireless communication and
          the air interface
  • Carrier frequencies
  • Data transfer rate and bandwidth
  • Range and Power Levels
  • RFID System Components
  • Transponders/Tags
  • Basic features of an RFID transponder
  • The Reader/Interrogator
  • RF Transponder Programmers
  • RFID System Categories
  • Areas of Application for RFID
  • Standardisation
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    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 megabits 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.