Planning and Site Survey
15
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RF interference fields: PCs and other electronic equipment can affect radio
transmission in the vicinity either intermittently or permanently.
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Base stations and DECT phones generate pulsed RF signals. These can affect
sensitive electronic equipment (control systems, measuring sensors, sensors,
diagnostics equipment on intensive- care wards in hospitals, etc.) permanently or
temporarily.
PREPARING THE MEASUREMENTS
Drawing up a situation plan:
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The situation plan records approximately the number and size of the coverage ranges
required.
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The measurements provide the ideal locations for the base stations.
Radio coverage and area determination
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Make a note of the connection capacity required (number of simultaneous calls) for each
area to determine the number of base stations.
Global coverage in the supply range
•
First, ensure that the surface area of the planned supply range is satisfactorily covered. The
ideal locations for the base stations are determined using practical measurements.
HANDOVER OVERLAP AREAS: BASE STATION SYNCHRONIZATION
TDM and IP-Base stations
•
To guarantee a seamless handover, the base stations should be fitted in such a way that the
-60dBm overlap area is guaranteed.
•
When conducting survey measurements in unfinished buildings, the limits should be
increased by 10dB.
IP-Base stations (sync over air)
•
To guarantee synchronisation, you need to arrange the base stations of a cluster in such a
way that there is at least one other base station within the -70 dBm limit! Aim to achieve an
overlap with other base stations (fail-safe setup).
TRAFFIC DENSITY
Once the supply range has been located and covered, the locations for the base stations are
known. In the second phase, you must consider other requirements: traffic volume, determined
by the number of DECT phones; and the frequency and duration of connections in an area defined
by the customer. In most cases, such an area does not match the coverage range of a base
station.
Note:
Take note of safety distances and safety regulations. In areas subject to explosion
hazards take note of the relevant rules and regulations.
Note:
Cluster defines a group of RFPs which synchronise among themselves and
among which a handover is possible; Up to 256 cluster can be set up for each system.