ZigBee, WiFi, and other wireless considerations

The biggest problem I run into on job sites is poor wireless management on a job. If customers could see wireless management like they see rack wire management, I am sure more dealers would spend more time on wireless management.  No thought to making sure zigbee and the WiFi network are configured to play well with one another will cost you on a job. Leaving a wifi access point or zigbee to "auto" is just asking for problems at some point down the road as soon as the access point changes channels.

This 2.4 GHz chart is a good reference to keep handy. This chart shows you the relationship between zigbee channels and wifi channels. In general, most wifi will settle in on 1,6, and 11. Although this is not always the case, it is what usually happens. In general, you can set zigbee to channel 15, 20, or 25 and you will avoid most problems, but not always. This will avoid most interference between the wifi and zigbee networks. As you can see from the chart, wifi channel 1 overlaps zigbee channels 11-14.  Wifi channel 6 overlaps zigbee channels 16-19. Wifi channel 11 overlaps zigbee channels 21-24. Wifi channels cover a much wider band than zigbee. Wifi signal strength is usually much stronger than zigbee strength, so zigbee usually gets stomped on and looses. This will usually cause remotes to fall off the zigbee mesh network, or become very sluggish and annoying to use. Often you see intermittent behavior from remotes and keypads.

Wifi and Zigbee are quite often, not the only devices in the 2.4 GHz Band. I have found wireless baby monitors to be problematic when dealing with 2.4 GHz band.

This is a screen shot from a Metageek WI-SPY Chanalyzer software. www.metageek.com. You can see at the upper end of the spectrum where channel 11 is, zigbee is on channel 21, and a baby monitor is also on channel 11. This was a triple whammy. It caused zigbee to not work and it caused the wifi to be slow and the baby monitor just sat there spewing wireless filth all over the room.  The customer mainly had issues at night, ironically when the baby monitor was on. It also happened, that they had an Apple Airport Express and a 6 button keypad along with the baby monitor all on one nightstand. On the graph you will also note, that the more intense the colors the more data throughput being pushed through that band, that will also cause the interference on that particular bandwidth to be greater.

I have come across other non-Wi-Fi Zigbee devices that can create odd interference with zigbee such as wireless shades.

This graph shows wireless controlled shades that are putting out interference on channels 16-17, 22-21, and 24-25. This would certainly cause problems if you had zigbee near any of those channels. Ironically the installer had the wireless controller for these shades right on top of the Control4 controller that was also controlling zigbee. Wireless speakers can also be big culprits when it comes to wireless interference. Wireless sub-woofers can be a big problem. I have even heard of dishwashers causing problems sporadically and the only reason it was caught was by using the Metageek WI-SPY.

In conclusion, I recommend everyone own at least one Metageek WI-SPY with Chanalyzer software. www.metageek.com. This will save your bacon on a job. These can also be purchased through Control4. You will need to log in with your dealer credentials.https://dealer.control4.com/dealer/products/117_metageek. You can also purchase them straight from  Metageek, or other retailers such as Amazon or Newegg. Chanalyzer has an advantage over inSSIDer, because it will give you all traffic on the 2.4 GHz band whereas inSSIDer will only scan for networks. Chanalyzer also has a recording function so you can leave it running and see if intermittent signals come into play, it will give you the exact time that those signals are coming on.