Mitel SIP-DECT Site Survey Kit, Руководство пользователя

Страница: 26 / 31

SIP-DECT Site Survey Kit User Guide
22
DECT system by taking appropriate measures. In radio technology, there are many interference
factors that affect mainly the range and quality of the transmission.
In principle, we must differentiate between two types of interference factors:
• Interference by obstacles that attenuate and/or reflect radio propagation, causing dead spots
• Interference due to other radio signals (e.g. other non-synchronous DECT systems) which
lead to transmission errors.
The receive power of DECT signals can fluctuate a great deal, locally, within only a few
centimeters. This means that signal interference can be reduced or eliminated simply by altering
the position of the base station.
Obstacles may include:
• Moving metal objects such as lifts, cranes, carriages, escalators, blinds, especially ones that
are activated automatically (the influence of such obstacles varies and is therefore difficult
to assess).
• Metal-paneled rooms and large metal-clad objects such as air conditioners, computer rooms,
and metallized glassed areas (mirrored), fire protection walls, storage tank installations,
refrigerating units, boilers, and pipes.
• Building structures and installations such as steel-reinforced concrete ceilings and walls,
stairways, long corridors, rising mains, and cable ducts.
• Room furnishings such as metal shelves, and file cabinets.
Due to their typical furnishings/fixtures projects in the following environments must be regarded
as critical, e.g.:
• Garages/motor trade
• Scrap merchants
• Production plants
• Galvanizing plants
• Metal-working industry
BUILDING MATERIALS RANGE LOSS AS A % OF THE FREE RADIO HOP
Glass, timber, untreated approximately 10
Timber, treated approximately 25
Plasterboard approximately 27 -41
Brick wall, 10 to 12 cm approximately 44
Brick wall, 24 cm approximately 60
Aerated concrete wall approximately 78
Armoured glass partition approximately 84
Steel-reinforced concrete ceiling approximately 75 - 87
87 Metal-coated glass approximately 100