6.4. Disadvantages of RFID and Bar Codes The major disadvantages of both RFID and bar codes are as follows: Presence of obstacles. A bar code reader cannot read a bar code if there is any obstacle between the reader and the bar code. An RFID reader, depending on its operating frequencies and other factors, such as power and duty cycle, might not be able to read a tag if there are any RF-opaque obstacles, such as metal, or RF-absorbent material, such as water present between the reader and the tag. Presence of moisture. For bar code readers, the light beam might be refracted by water particles suspended in the atmosphere, resulting in focus distortion. For RFID readers operating in UHF and microwave frequencies, water particles suspended in the atmosphere might absorb RF energy, resulting in insufficient energy reaching the tags for proper data transfer. Speed. If the scan rate of a reader is exceeded by the speed of movement of the bar codes, a loss of reading accuracy, together with failure to read a bar code, might result. For RFID readers, if the speed of the tag is so great that the tag has insufficient time to optionally energize itself properly and transmit data back to the reader, a loss of reading accuracy, together with failure to read a tag, might result. Extrinsic identification schemes. A bar code or an RFID has to be applied externally to an object; these are not part of the object's physical characteristics. Therefore, if such an object is mislabeled or "mis-tagged," the object identity is in jeopardy. However, perhaps intrinsic properties could be used to uniquely identify an object. For example, a fingerprint or a retinal scan of a person can uniquely identify this person without any need to put an external identification scheme, such as a bar code or RFID tag, on the person.
You are now ready to explore what can be called the most-hyped potential of RFID in the media. |
