USER MANUAL
PrestoAdvancedAD101_AD301_UG_000_UK
Descriptions and non-contractual illustrations in this document are given as an indication only.
M2M Design reserves the right to make any modification
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Apendix
A. How to Achieve Maximum Signal Strength with PRESTO Advanced Router?
The best throughput comes from placing the device in an area with the greatest Received Signal
Strength Indicator (RSSI). RSSI is a measurement of the Radio Frequency (RF) signal strength between the
base station and the mobile device, expressed in dBm. The better the signal strength, the less data
retransmission and, therefore, better throughput.
RSSI information is available from several sources:
The LEDs on the device give a general indication.
Via the PRESTO Advanced Router local user interface.
Signal strength LED indicator:
-101 or less dBm = Unacceptable (running LED)
-100 to -91 dBm = Weak (1 LED)
-90 to -81 dBm = Moderate (2 LED)
-80 to -75 dBm = Good (3 LED)
-74 or better dBm = Excellent (4 LED)
0 is not known or not detectable (running LED).
Antenna placement
Placement can drastically increase the signal strength of a cellular connection. Often times, just
moving the router closer to an exterior window or to another location within the facility can result in
optimum reception.
Another way of increasing throughput is by physically placing the device on the roof of the building
(in an environmentally safe enclosure with proper moisture and lightning protection).
Simply install the PRESTO Advanced Router outside the building and run an RJ-45 Ethernet
cable to your switch located in the building.
Keep antenna cable away from interferers (AC wiring).
Antenna Options
Once optimum placement is achieved, if signal strength is still not desirable, you can experiment
with different antenna options. Assuming you have tried a standard antenna, next consider:
Check your antenna connection to ensure it is properly attached.
High gain antenna, which has higher dBm gain and longer antenna. Many cabled antennas
require a metal ground plane for maximum performance. The ground plane typically
should have a diameter roughly twice the length of the antenna.
NOTE: Another way of optimizing throughput is by sending non-encrypted data through the device.
Application layer encryption or VPN put a heavy toll on bandwidth utilization. For example, IPsec ESP
headers and trailers can add 20-30% or more overhead.
