Iridium side note -- I was testing a RockBlock (rock7) recently. They are really easy to use, ~$200. Awesome that this stuff is getting more approachable.

http://www.rock7mobile.com/products-rockblock

https://www.sparkfun.com/products/13745

Interesting.

It's $180 for the module then $11/mo and $12 for 100 credits (5kb of data transfer). So to get up and running would be $312 a year for what would be at most a location beacon (6B per 24 digit location transfer).

Not at all unreasonable for how much of an offline system this is.

I agree. What’s interesting is that it’s compatible with most devices/libraries (arduino etc), compared to using a consumer level garmin device with sms/data functionality that requires a contract (to be affordable at least).

Also, even though location info is typically the main feature, I believe it’s included automatically in the msg envelope (a kind of satellite caller id), which means you can use that more expensive bandwidth for your own requirement, while still getting the lat/lon metadata.