User's Manual

50 mW

Indoor

only

5.15 5.25 5.35 5.47 5.725 5.825

Frequency (GHz)

250 mW

FCC proposal May03

1000 mW

Transmitter Power

Figure 10-4: Rules for 5 GHz Frequency Band.

The FCC’s proposed rule making of May 2003 opens the 5.47-5.725 GHz band

to ISM usage. This FCC proposal closely aligns the US band with the European

band usage. This common set of Rules is expected to achieve world-wide

acceptance.

Notice that the lower part of the band, 5.15-5.25 GHz, is limited to indoor use.

This is why the ARCell radios only use the 5.25 –5.35 GHz part of the lower sub-

band in the Upstream.

The high band, 5.725 – 5.825 GHz is allowed to use higher powers (1 Watt) and

the ARCell system uses this in the downstream path.

10.3 Line of Sight

All RF is attenuated by the materials in our environment:

1) Metal

2) Bricks and other building materials

3) Rain and bodies of water

4) Trees and other foliage

Most car antennas are outside the car because the car’s metal shell attenuates

radio broadcasts.

Most people who have tried listening to their FM radio at their desk have

experienced the loss of signal inside a commercial building.

Rain, fog, lakes and rivers all have their effects on RF.

ARCXtend manual, August 2003 10-4