English
17
fig. 33:
taBle 2
GSM with Panel Antenna
2 metres
4 metres
2 metres
GSM with Omnidirectional
6 metres
12 metres
6 metres
Antenna 0dBi
DCS 1800 with Patch Antenna
8 metres
16 metres
8 metres
DCS 1800 with Omnidirectional
24 metres
48 metres
24 metres
0dBi
system
Base station antenna
patch
dipole
eXternal
When the Base Station is used outdoors in conjunction with a Sync Unit,
primary lightning protection is required. This should be placed at the point in
the junction box where the multi-pair cable is divided for each individual Base
Station.
The Base Station should be at least 2 metres below the top of the elevated
object to which it is attached.
To ensure full receiver performance the Base Station should not be mounted too close to strong emitting devices
such as the GSM/DCS1800 Base Station.
As the frequencies used by the DCS 1800 and the DECT are very close to each other, the worst interference is
caused by the DCS 1800 system.
The Base Station should be sited a minimum distance from interfering systems as shown in
table 2
, below.
These requirements are based on the following assumptions:
The Base Station is mounted below/above the GSM panel antenna.
The feeding power from the Base Station power amplifier: Max +43 dBm (20 watts)
GSM panel antenna gain in vertical direction:
Max -10 dBi
GSM omnidirectional gain in vertical direction:
Max 0 dBi
If the Base Station is located directly in the main beam of the DCS 1800 antenna (horizontally) the distance should
be at least 100 metres from the antenna to have the same interference from the DCS antenna.
If the Base Station is located directly in the main beam of the GSM antenna (horizontally) the Base Station
should be at least 50 metres from the antenna.
