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A05-0473-010
Measuring Wall Attenuation
The following method can be used to record the actual RF signal
attenuation caused by a wall.
1) In the room containing the wall to be measured, take a
Link
Quality
measurement across an open part of a room. Set up
the two measuring devices with device #2 nearest to the wall to
be checked. The dongle should be within range (a few metres)
of device #1.
2) When satisfied that the measurement is stable,
STOP
the
recording and make a note of the attenuation value.
3) Move device #2 to the other side of the wall, ensure it is in the
same orientation as before and take a second measurement,
again noting the attenuation value.
4) Subtract the first attenuation value from the second attenuation
value; the result is the attenuation in signal strength resulting
from the wall. This figure can be used for the wall attenuation in
the design simulation and should be entered into the
Edit Wall
information box as a
Custom
value.
Not able to generate a Network
If the mesh wizard cannot simulate a reliable RF network from the
data it has, the
Not possible to create a mesh
message appears.
The wizard will give a brief reason for the failure where possible.
The design layout and/or RF criteria will need to be amended to
realise an acceptable system. Some possible changes that may
help to find a suitable network include:
● Move the gateway to provide wider connectivity with the Agile™
RF devices
● Re-arrange the Agile™ RF devices to minimise link lengths
● Allow longer links or repeaters to be used
● Add a repeater (or another Agile™ RF device) to a marginal or
poor link
● Consider if the wall attenuation is set too high and can be
reduced
How to Resolve a Poor Link Quality in General
Where possible, re-position RF devices to improve the line-of-sight
between two linked devices which have a poor link signal. If this is
not possible consider the use of a repeater.
How to Resolve a Poor Link Quality in a Long Corridor
To provide a resilient RF system, the mesh is designed to have
multiple communication paths back to the gateway. Each device
must have at least two links to other devices. In a long corridor this
is sometimes difficult to achieve and some long links may suffer
from poor signal strength. The solution may be to include one or
more repeaters in, or adjacent to, the corridor.
How to Resolve a Poor Link Quality through Walls
Walls can significantly reduce RF signal strength and hence the
link quality between nodes. If the link quality through a wall is poor,
the solution may be to include one or two repeaters on either or
both sides of the wall between the nodes in question. (See also
Measuring Wall Attenuation
.)
In all these suggestions, any Agile™ RF device can be substituted
to act as a repeater.
