User Guide

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Angles, Orientations, and Reflections
While we’re talking about wireless antennas, note that an antenna’s angle/orientation (relative to the device it’s communicating with) can have a pretty big effect on
how well this communication works.
First, let’s look at the ideal antenna (for home automation), one which emits electromagnetic radiation in all directions with equal power.
Yup, it’s a balloon. Pretend the balloon is inflating and think of the surface of the balloon as representing an electromagnetic wave that is propagating away from
the center (the transmitter) equally in all directions. This is good because it means we can reach our home automation devices in all directions, plus bounce the
signal off all concrete walls.
Now here is the worst possible antenna.
A flashlight concentrates its light in a beam in a single direction. If an antenna behaved like that, any device not in the path of its beam would appear to be
completely out of range, even if very close by. There are some situations in which a “flashlight antenna” (or what we actually call a highly directional antenna ) is a
good thing, for example satellite uplink/downlink antennas, because we really only want to talk to a single faraway device and we know where it is. But this type of
antenna pattern is not good for home automation.
Finally, here is a more realistic antenna because, as is so often the case in the real world, the ideal antenna cannot physically be built and exists only in our minds.
There are some angles at which the antenna radiates well, others at which it has “blind spots”, and overall it’s a very complicated three-dimensional radiation
pattern.
Normally, you don’t have to worry about the antenna pattern, but you may just be unlucky and have a device and the Hub (or its parent) aligned in such a way that
they are in each other’s antenna blind spots. If you have a device that always seems to be struggling to perform well, and physical distance or obstacles are not
major factors, consider rotating it or shifting its position just a little bit, just in case the issue is one of alignment.
Remember, too, that we count on reflections off walls, doors, and other objects to compensate for the blind spots in the antenna pattern, and for not having true
line-of-sight between devices in the network and the Hub. It is helpful, therefore, to make sure that the Hub has its highest-power orientation pointed towards the
center of the house, where reflections can happen, rather than away from the house where the signal will go out of the home.
Here is a picture showing the hub and the maximum-power directions for both the ZigBee and Z-Wave antennas.
(https://smartthings.com)