This slow attenuation over distance allows far-field transmissions to communicate effectively over a long range.
In current commercial implementations of near-field communications, the most commonly used carrier frequency is 13.56 MHz and has a wavelength (λ) of 22.1 meters.
Near-field magnetic induction technology has been in use by the company FreeLinc, using NFMI to create a secure wireless communication between two-way radio accessories.
This magnetic bubble has a radius of approximately 1.5 meters, is immune from radio frequency (RF) interference and virtually secure from eavesdropping.
An eavesdropper would have to be standing next to the radio, within the magnetic bubble, to intercept wireless transmissions to and from a microphone or headset.