Hang on, these radio tags actually transmit? They're so tiny! $200 for each¹. Damn, radio transmitters are way lower-energy than I thought. This is fascinating.
Only run for 12h a day, transmitting every few seconds, and transmitting very few bytes.
Even so! I thought I was moderately familiar with battery powered radios, but Lotek claims the NTQB2-1, which masses 0.26 grams, can last for 103 days at a 29 second interval. Their product photo shows it attached to a dragonfly!
None of their documentation says what the EIRP is. I wonder about the effective radius. If you miss a transmission, that data is gone forever, of course. No way can it afford the power budget for acknowledgement packets.
