Marquee™ Point-to-MultiPoint Series User Guide
Section 4
Troubleshooting
4.1 Introduction
If you followed the advice highlighted in Section 2.1 and configured and tested your units in a “mini-
network” setup before of actually deploying them in the field, the majority of the potential problems that
you may face will be dealt with well in advance.
Once deployed, there are a number of issues that can cause a Marquee link not to work. Listed below are
some of the most common:
1. Cabling or installation (e.g., line of site, multipath, interference, or antenna alignment).
2. Configuration.
3. Actual equipment failure.
4.2
Cabling or Installation Issues
Slow speeds are generally signal related. Poor signal or bad signal fluctuations can be caused by a faulty
jumper connection (the cable that goes from the unit to the antenna), line of site and multipath issues,
interference, and/or antenna alignment.
Check that all your cables are properly and firmly connected. If necessary, swap suspecting cables with
known good cables to eliminate points of failure.
Once the cables are cleared, check possible installation issues. One of the most useful tools to isolate
these kind of problems is the Wireless Link test located under the
Analyze
tab of the Configurator. In
here you input the address of the unit you want to run the test from and it will list all the possible partners
you can test it with (see Section 2.8 and Figures 2.12 to 2.16).
One little known fact is that although there are several configuration items that need to match between
the Base and Satellites, only one thing needs to match in order to run a link test, and that is the channel
being used. As long as the units are in range and on the same channel you should be able to run a link
test.
At different transmit rates you will have a different SNR “knee”: this is where the SNR is low enough that
the performance drops. At 36 Mbps the knee is 17 SNR. At 24 Mbps the knee is 14 SNR. At 6 Mbps the
knee is 4 SNR.
You can check your current SNR through the Wireless Link test option under the
Analyze
tab. Select it,
and enter the IP address and password of the unit you want to run the test FROM (Fig. 2.14). It will give
you a list of possible test partners (Fig. 2.15). Select the one you want and click the Link Test button (or
double-click the partner unit). You will get the SNR on both sides (Fig. 2.16). Recommended SNR at all
times is 25 or greater. Lots of signal fluctuations can indicate cable problems (which you already have
checked), interference, or moving obstructions in your path. Try different frequencies to avoid any
interference that may be in the area. Double check your path for any obstructions.
If the problem persists, then either the units are out of range or alignment, there are too many
obstructions, a cable is loose, an internal software problem has happened, there is a power issue, or an
actual equipment failure has occurred. In any of these cases the best thing to do would be to get all units
in your lab for testing. This will eliminate interference, Line of Site, range, or multipath issues. Then you
must check the configuration.
Version 1.3(a)
Page 20
Jul 2005
