(
Near
Field
Magnetic
Induction) A close range communications technique that uses a modulated magnetic field to induce a current into a receiving coil. More power efficient than radio frequency (RF) methods, NFMI signals can maintain their integrity in the midst of Wi-Fi, Bluetooth, cellular and other radio waves.
NFMI operates within a couple meters with transmission rates up to 600 Kbps. Multiple NFMI signals can co-exist and not interfere with each other even when devices are transmitting the same frequency only a short distance apart. Digital hearing aids use NFMI, and the FBI uses advanced forms for ultra-secure communications. See
telecoil mode.
NFC Payment Terminals Are NFMI
Along with four other radio technologies found in smartphones (Wi-Fi, Bluetooth, cellular, GPS), NFC (near field communications) is used for extremely short distances such as tapping credit cards on payment terminals and exchanging data between devices (see
NFC).