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C
P
ORDLESS
HONE
3.9.5.3
3.9.5.4
30
•
Although the signal strength is good there are frame errors. The
frame error rate and signal strength can be measured with the port-
able device. Check frame errors in both uplink (towards the base
station) and downlink (towards the portable device). For information
on how to measure the frame error rate, see the user guide for the
site survey tool.
•
Often no problems when standing still but when you move around
there will be problems with mutes and clicks during speech.
•
Characteristics for reflective environment are large open spaces
(e.g. large buildings greater than say 20 meters), metal walls, metal
inventories and ceilings.
Location for base station in reflecting environment
Apart from the time delay spread there are a number of general rules to
consider when placing a base station:
•
Install a base station in line of sight, base station can see the user.
•
It is possible to increase the number of base stations at those loca-
tions that are important to the client. In a typical case, the speech
coverage area is 5-20 meter. This must be verified with site survey.
•
Place the base station as low as possible without having something
to be placed in front of the base station.
•
Ensure that the distance between the base station antennas and a
metal wall is at least 30 centimetres to avoid interference with the
impedance of the antennas.
•
To get a strong direct signal, the use of a directional antenna may
improve the situation.
Note: All these considerations, depend on the dimensions of the hall
and its reflective characteristics.
Customer acceptance
It is very important that the radio performance is verified before any
agreement is signed. Verify the radio performance with a site survey tool
and always use the same type of portables and also the same type of
base station that is going to be installed.
Make sure that the customer understands what kind of problem that can
occur because of the reflective environment. Ask the customer to listen
to the speech quality. If the speech quality is not accepted by the
customer, do not recommend an installation of the DECT system in this
reflective environment in order to avoid future severe problems.
5/1531-ANF 901 14 Uen D3 2013-11-28
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