Wireless Communications is fast becoming recognized as a flexible and reliable medium for data communication applications. It offers numerous benefits over hard-wiring, such as...

• Lower Cost – Transmitters eliminate the need for miles of expensive wiring, including the high cost of installation in new sites and retrofitting existing sites.
• Less Environmental Impact – Buying cable and stringing wire is environmentally invasive and requires a large investment to reconstruct the area. Transceivers significantly reduce the footprint of these installations, reducing the impact and damage to the area.
• System Protection – Transceivers allow for the isolation of sensitive equipment. This reduces the chance of full system failure due to power surges or lightning strikes. In addition, transceivers eliminate the possibility of broken connections due to damaged or severed cables.
• Greater Flexibility – Sensors and controllers are no longer tied to the location of the hardwired terminal. This offers flexibility in relocating equipment within a building or over large outdoor distances.

Spread spectrum was developed during World War II by the U.S. military to provide secure battlefield communications. It is still used today for secure military communications in addition to civilian communications. Spread spectrum transceivers spread their data over a range of frequencies, and there are two types of spread spectrum radios: Frequency Hopping Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS).

ATi's Long Range products are FHSS transceivers. FHSS transceivers transmit their signal by sending a small burst, or packet, of data on one frequency and then "hopping" to another frequency to transmit a second burst. This hopping continues throughout the transmission. For the transmission to be successful, both transceivers must be synchronized, consistently hopping to the same frequency and remaining there for the same amount of time. This provides for reliable, interference-resistant communication. In the event that a packet of information cannot be sent on one frequency due to "jamming", the packet will be sent on the next frequency.

Direct-sequence transceivers spread their signals over a wide range of frequencies. Data bits are mapped into chips by the transmitting transceiver, and then the chips are mapped back into a bit at the receiver. DSSS transceivers provide for higher data transfer rates than FHSS transceivers. However, DSSS transceivers are more vulnerable to interference and multipath problems because they use many frequencies at once. ATi's FHSS transceivers to provide lower cost, less interference and multipath resistance.

ATi 2.4 GHz transmitters enable users to create co-located independent networks through the use of system identification numbers or by specifying one of up to 77 different frequency-hopping patterns. Receivers communicate only within their assigned group, isolating other networks of ATi's transceivers as well as other transceivers.

The 2.4 GHz to 2.4835 GHz band has been reserved virtually worldwide for industrial applications, without the need for individual site licensing. OEMs can design one transceiver which will be usable worldwide.