peburns

LORAN would be easy but it appears the USG doesn't want to fund it. It's still unidirectional and could suffer similar spoofing attacks as GPS, though this seems less likely. This article describes a sort of bi-directional LORAN alternative that would support encryption and uses inexpensive OTS components.

DDG's allure now is its independence. Acquisition by a FAANG would doom it almost immediately.

Stay the course.

BLE was included to demonstrate that the convention for "low power" IoT devices is usually expressed in terms of years (of battery life). This is not saying BLE is a LPWAN, but in the minds of customers the expectation, like for LoRa, Sigfox, or active RFID, low power means years of battery life.

How about a LPWAN endpoint with GPS that last 2+ years? Like this: http://bit.ly/2pBcYqp