Transmit Power

Many field issues look like protocol failures: intermittent offline events, poor coverage at the edge, phones working while sensors do not, or range dropping after an enclosure change. Before debugging the state machine, ask a lower-level question: does the wireless link have enough energy margin?

Antenna, transmit power, and link budget decide how much usable signal remains after the signal leaves the transmitter and passes through space, walls, people, enclosure material, and antenna direction.