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3.6
3.7
3.8
5/1531-ANF 901 14 Uen D3 2013-11-28
In outdoor applications good coverage is usually required instead of
capacity. Omnidirectional antennas can be used for large areas like
parking places. Directional antennas can be used for example to cover
large walking distances between buildings. For outdoor placing of base
stations, a special protection case is available for wall or pole mounting.
See chapter 3.2.3 Outdoor housing on page 11.
Absorption and reflection
The cell size is very dependent on the material of which walls, ceilings
and floors are made.
•
Glass, concrete, wood and plaster all absorb and pass radio signals
in different ways.
•
Metal walls and large metal cabinet rows reflect all signals,
resulting in a greatly reduced coverage behind these areas. They
can also cause reflections and bit errors.
•
X-ray rooms in hospitals protected by lead walls or computer rooms
in banking buildings protected against unwanted interference do
not allow radio signals to enter.
•
Exhibition halls or production halls may give reflections due to huge
metal structures. This causes interference and bit errors, which
reduces the capacity, coverage range per base station, speech
quality and the practical coverage area.
Architecture
•
Central areas giving access to stairs and elevators may require
extra base stations due to heavier constructions.
•
Coverage in elevators may require base stations close to or in the
elevator shaft.
•
Corners and irregularities in the construction have influence.
•
Physical fire walls and closed fire doors can have great influence.
Physical location of a base station
To reduce the traffic load in each Media Gateway, and between Media
Gateways, it is recommended to pay special attention to the physical
B
ASE STATION PLANNING
17
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