http://en.wikipedia.org/wiki/Radio-f...identification
http://en.wikipedia.org/wiki/Transponder_timing
Hard to say, but it's all RFID, and re-purposing of that technology, which is partly why it seems strange that we can pay $150 for a transponder, because the envisioned future of all RFID products was 10 cents tags.
Admittedly for the sake of the speeds used in motor sports, we do need a powered tag in substitute of a very high powered loop, but even so, finding powered tags being used by other companies still brings up products that are a fraction of the cost of what we pay in RC.
Ever since I looked at the timing in RC, I have thought somewhere along the line, RC got screwed, we got locked in by one company, who charges what they want, and did a whole lot to keep other companies out.
I'll admit RFID readers are likely worth a bit (depending), but the tags/transponders should not be worth as much as companies like MyLaps sell them for (I see something worth about $20-$30 when I look at one).