User's Guide

Chapter 29 Troubleshooting
LTE Series User’s Guide
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Note: It is best to reboot the Zyxel Device before each test measurement is taken to ensure
that it is not camping on the previous cellular site. This is because the Zyxel Device can
‘lock’ onto the previous cellular site even when the new cellular site is at a much better
signal level and quality.
Although installing the Zyxel Device as high as possible is the usual rule of thumb, it is sometimes possible
that the Zyxel Device is in a weak coverage spot at that specific height. Adjust the height to achieve the
best service possible.
Note: Cellular network signals and quality can fluctuate. A measurement taken now and a
few moments later can differ substantially even if nothing apparent has changed – this
can be due to many aspects, such as fading, reflections, interference, capacity due to
high network traffic, etc.
It is possible that the network topology and usage changes over time, even from one minute to the next
as network utilization increases. If poor performance is experienced at a later stage, re-test different
installation locations again. It is possible that the current serving cellular site has become over utilized or
is out-of-service. As the network design and topology changes, so will the experience change, either for
the better or for the worse.