Interesting paper from Chris Paget (http://www.tombom.co.uk/extreme_rfid.pdf) about accessing epc gen2 tags from very long ranges (100's of metres) using equipment built for less than $1000. Basically he increases the range by increasing the power of the transmitter and using a more directional antenna, thus increasing the power density in the region of the tag. You do need a ham radio operators licence to broadcast at these powers though...
This is really not new - physics is physics but the "loophole" of the ham radio licence is new.
Aside from the fact that you could use this approach to pick up Bin Ladins underpants assuming they are tagged, this may open the way to other applications - eg a foursquare-like (http://foursquare.com/) scanning RFID reader that you could install in particular locations, or long-range tracking in warehouses, assuming safety - he is using 70watts output - and regulatory compliance
Showing posts with label range. Show all posts
Showing posts with label range. Show all posts
Thursday, September 2, 2010
Wednesday, September 24, 2008
Getting RFID to work- and how to say it
Apart from the perennial question is - are they pronounced AR FID or AR-EF-EYE-DEE, one of the biggest issues for research in this area is the continuing improvement/update of "standards".
In particular tags seem to be gaining memory and range extremely quickly. This is not a problem except that range in particular is important for some of the assited living and navigation solutions we are developing. Too little range is bad, but too much range is no good either if you are trying to use RFID for navigation. The original "Where are my glasses ?" paper http://www.naccq.ac.nz/bacit/0402/2006Parry_Glasses.htm envisaged 30-100cm ranges for tags. This seems to be a little difficult to achieve with HF tags having shorter ranges and UHF tags now easily moving into 2-3 metres. Of course the power output of the reader can be changed, and one of the current projects running in the AURA lab is to look into adaptive ranging ie reducing power outputs when there are lots of tags detected and then reversing the process if nothing can be seen. Of course if you tag the person and have multiple readers thats not such a problem, but having the reader on the person has advantages in terms of cost - assuming number of people<< number of locations - and in associating objects with people.
By the way I'm a AR-EF-EYE-DEE person myself...
In particular tags seem to be gaining memory and range extremely quickly. This is not a problem except that range in particular is important for some of the assited living and navigation solutions we are developing. Too little range is bad, but too much range is no good either if you are trying to use RFID for navigation. The original "Where are my glasses ?" paper http://www.naccq.ac.nz/bacit/0402/2006Parry_Glasses.htm envisaged 30-100cm ranges for tags. This seems to be a little difficult to achieve with HF tags having shorter ranges and UHF tags now easily moving into 2-3 metres. Of course the power output of the reader can be changed, and one of the current projects running in the AURA lab is to look into adaptive ranging ie reducing power outputs when there are lots of tags detected and then reversing the process if nothing can be seen. Of course if you tag the person and have multiple readers thats not such a problem, but having the reader on the person has advantages in terms of cost - assuming number of people<< number of locations - and in associating objects with people.
By the way I'm a AR-EF-EYE-DEE person myself...
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