User's Manual

OS2400 Radio Module Exhibit 21: User Manual 3 FCC ID: OQ7OS2400
3
Product Overview
Summary of Function and Use
The OS2400s radios have been designed to provide a wireless replacement for any
serial cable. Any two devices which could otherwise function together with a physical
serial cable between them can be incorporated into a wireless network and continue to
function as before.
Spread spectrum: These radios transmit using a technique known as “spread
spectrum, frequency hopping communications”. Using the spread spectrum technique a
narrow band signal is spread over a broader portion of the radio frequency band.
Frequency hopping: A radio which rapidly changes its operating frequency several
times per second following a pre-determined sequence of frequencies is defined as
“frequency hopping”. The receiving and transmitting radios are programmed to follow
the same frequency hopping sequence.
The OverAir design takes advantage of these characteristics which are inherent to the
spread spectrum technique:
?? increased immunity to noise. Radios are designed to detect specific radio
frequencies. “Noise” is defined as an unwanted signal which has been
transmitted at the same frequency as the radio was designed to detect. There
are many man-made and natural sources of “noise”. Due to the spread spectrum
and frequency hopping techniques, the OS2400 operates more efficiently than a
radio which operates using conventional technology.
?? multiple users can share the same frequency at the same time. As an example
of this, cellphone use is dependent upon spread spectrum transmission.
Under FCC rules, users of FCC certified spread spectrum products do not require their
own license from the FCC. The manufacturers of the products are required to apply for
and be granted an FCC license for the device. OverAir has been granted a license by
the FCC for the use of its OS2400 radios.