User manual

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4.3.3 Antenna placement
The antenna should be placed away from electronic devices or other antennas. The recommended
minimum distance between adjacent antennas, operating in a similar radio frequency band, is at least
50cm. If signal strength is weak, it is useful to face a directional antenna at the closest radio base
station. This can increase the strength of the signal received by the modem. The modem’s peak output
power can reach 2W. RF field strength varies with antenna type and distance. At 10cm from the
antenna the field strength may be up to 70V/m and at 1m it will have reduced to 7V/m. In general, CE-
marked products for residential and commercial areas, and light industry can withstand a minimum of
3V/m.
4.3.4 The antenna cable
Use 50Ω impedance low-loss cable and high-quality 50Ω impedance connectors (frequency range up to
2GHz) to avoid RF losses. Ensure that the antenna cable is as short as possible. The Voltage Standing-
Wave Ratio (VSWR) may depend on the effectiveness of the antenna, cable and connectors. In addition,
if you use an adapter between the antenna cable and the antenna connector, it is crucial that the
antenna cable is a high-quality, low-loss cable. Minimize the use of extension cables, connectors and
adapters. Each additional cable, connector or adapter causes a loss of signal power.
4.3.5 Possible communications disturbances
Possible communication disturbances include the following:
Noise can be caused by electronic devices and radio transmitters.
Path-loss occurs as the strength of the received signal steadily decreases in proportion to the distance
from the transmitter.
Shadowing is a form of environmental attenuation of radio signals caused by hills, buildings, trees or even
vehicles. This can be a particular problem inside buildings, especially if the walls are thick and reinforced.
Multi-path fading is a sudden decrease or increase in the signal strength. This is the result of interference
caused when direct and reflected signals reach the antenna simultaneously. Surfaces such as buildings,
streets, vehicles, etc., can reflect signals.
Hand-over occurs as you move from one cell to another in the GSM network. Your mobile application call
is transferred from one cell to the next. Hand-over can briefly interfere with communication and may
cause a delay, or at worst, a disruption.
4.4 Additional Software Configuration
4.4.1 Activating / Deactivating 3G Mode
By default, 3G mode may be de-activated on the device. In order to enable to device to search for 3G
networks, please use the following commands to activate or de-activate this feature:
What do you want to do
Send the AT command
Device Response
Check the current setting
at+ws46?
2G Only mode is activated
+WS46: 12
3G Only mode is activated
+WS46: 22
2G / 3G mode is activated
+WS46: 25
Activate 3G Mode
at+ws46=25