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DECT installations in special environments
Several buildings
Planning a DECT installation for several buildings or for separate parts of buildings
requires clarification of the following points:
u
Should calls only be possible within the internal rooms or across the whole site, even
in the outside area?
u
In which area should handover be guaranteed?
The cheapest way to connect separate parts of buildings with the PABX is to use separate
clusters (subnet). In this case, only the wiring of the different buildings or building parts
via the LAN must be ensured. All telephones registered to the PABX can be used every-
where; however, handover is not always possible.
Outside area
The outside area of a building can often be included in the DECT network through a base
station close to a window. The prerequisite for this is that the glass in the window must
not contain any metal (metal film, wire mesh).
If the outside area cannot be covered by base stations within the building, a base station
can also be installed in the outside area. The base station should then be mounted in a
suitable external housing to protect it against weather conditions (available from third-
party manufacturers). The limit values for the operating temperature of the base stations
(+5° to + 40°) must be taken into consideration.
The installation can be on a mast (not metal), on the roof or on a wall of the building.
Please note that the LAN connection must be guaranteed, as this supplies the device with
power and is also required for the connection to the DECT Manager.
The range on the site is up to 300 m, but may be restricted by other buildings, walls or
trees. A base station mounted in the outside area can also cover further indoor parts of
buildings if the walls of these areas do not reduce the radio signal too strongly.
For measurements outside, please note that weather conditions, e.g., rain or snow, can
significantly influence the send and receive properties. If necessary, perform further
measurements in different weather conditions; plan the radio coverage generously if you
want to guarantee secured reception. Changes in the vegetation (leaves on the trees,
growth of bushes) can also affect the radio conditions.
Handover over the whole site
If handover is to be achieved over the whole site, including all buildings, the transition
areas between internal rooms and the outside area must be planned and measured care-
fully.
Example: the building can only be accessed through a metal door with 100% absorption.
In this case, when the door is open the handover between the nearest base station
indoors and the base station for the outside area must be guaranteed. Both base stations
must be synchronised and (with the door open) have the required overlap area.
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