Cabletron Systems 9033073 manual Calculating Range & Clearance

Calculating Range & Clearance

The Dynamic Range Budget

NOTE

The minimum clearance in Table D-3 on page D-6 should be interpreted as follows:

•In open areas without obstacles in the signal path, clearance is measured as height above the surface of the earth. For example, if the antenna is mounted on the roof, this height includes the height of the building plus the height of the mast above the rooftop.

•In areas with obstacles in the signal path between the two antenna(s), the clearance should be measured as height above the highest obstacle(s) in the signal path.

•In dense urban areas, the clearance should be measured as height above the highest rooftop or any other obstacle(s) in the signal path between the two antennas.

The values listed in Table D-3 are based upon calculations that assume optimal radio conditions. There is no guarantee that the same maximum distance can be achieved at your location.

Different performance figures may result from:

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Sources of interference or unexpected reflections in the signal path that affect the communications quality of the radio signal (see Antenna Placement on page 2-11).

Incorrect antenna alignment (see page 2-17).

When selecting equipment for an outdoor antenna link, make sure you consider an extra safety margin for the maximum range of 100 m (300 ft) or more.

Outdoor Antenna Installation Guide D-7