IBM presented their backend processing infrastructure to capture, process and present the RFID information at Devoxx. Looked really very complex -- not sure if such a complex setup was needed or if it was just a way to demo their Tivoli monitoring infrastructure.
I was more interested by the RFID-technology itself:
- the used RFID readers had a 5 meter detection range, but they stilled missed about 20% of all tags.
- depending on the frequency used, some RFID tags can be 'shielded' from the readers by water. This can explain the 20% error range because a human body mostly consists of water.
- the RFID readers can't tell if you're entering or leaving a room. This is deduced by the backend system by correlating the different individual tag-readings. E.g. if a tag is detected in room A and then in room B after 30 minutes, it supposes that you were out for those 30 minutes
- RFID tags exist in several types, each with its own usage patterns and pros and cons:
- 'active': the tag has its own battery and radio
- 'active backscatter': the tag has a battery embedded
- 'passive': no battery nor radio
- RFID tags come also in different form factors:
- single use: as 'printed' labels. This was used for the Devoxx badge
- rugged reusable tags.
- the RFID readers are actually quite advanced systems that contain a built-in JVM. This provides opportunity to do some basic processing when retrieving the scanned data.
- the classical questions on privacy / security / health remain.
It was an interesting experience to get 'live' in touch with the RFID technology, its pros&cons and its technical and ethical issues.