ZigBee interference with 2.4 GHz 802.11 Wireless

[rsw686]

I installed a ZIM and two Omnistats 9 months ago and everything worked great until recently. The 802.11 wireless was originally setup on channel 1. Two weeks ago I had a chance to use a spectrum analyzer and noticed that channel 11 had less utilization, from my close neighbor's networks, so I switch my wireless to that channel. I didn't notice it right away, but it was causing lots of interference with Zigbee. The OmniPro would show 0 for the temps and changes to the temp settings wouldn't always go through to the Omnistats. As soon as I switched the Wifi channel back to 1 everything went back to normal.
 
I'm not sure how the ZIM picks which ZigBee channel to use. The lower ZigBee channels 1 - 10 are in the 915 MHz and the higher 11 - 26 are 2.4 GHz and overlap wireless. It looks like it was using one of the high channels which overlap 802.11 channel 11. Lesson is if your Zigbee ZIM is having issues communicating try changing your wireless channel

 

[pete_c]

Thanks rsw686!
 
Still not getting into testing or playing with Zigbee yet.  That said I am using Z-Wave (playing with) and do have multiple AP's in place (playing with).  Still currently using serial to my Omnistat2 thermostat.

 

[Automate]

Are you sure the ZIM supports channels 1-10 in the 915 MHz range?
 
I found this quote here http://cocoontech.com/forums/topic/22182-not-very-reliable-zigbee-locks/?p=180865

One other thing I can offer is that when a ZIM comes online and has no existing network (out the box or you disbanded all) it will perform an energy scan to pick a good channel (CH11->Ch26). Sometimes a situation arises where that channel can be later saturated, but not at the location where the ZIM would see this and instruct all devices to move to a new channel. If you suspect there is a chance this could be happening, look to see what your existing channel is (Menu->Device Details) and send me a PM with that information. For experimental purposes I can send you a firmware that chooses a channel of my choosing to see if any RF performance improves.

Ryan

 

 

[Automate]

Some general information on Zigbee interference with other protocols here https://docs.zigbee.org/zigbee-docs/dcn/07-5219.PDF
 
Zigbee Channel to frequency list here http://www.metageek.net/control4/zigbee-channels/
 
and WiFi Chanels here http://en.wikipedia.org/wiki/List_of_WLAN_channels

 

[Automate]

Thanks rsw686!
 
I am using Z-Wave (playing with) and do have multiple AP's in place (playing with)

 
Z-wave should not ever interfere with WiFi since it uses sub 1 GHz frequencies
http://www.z-wave.com/modules/xoopsfaq/index.php?cat_id=2#q21

 

[rsw686]

Are you sure the ZIM supports channels 1-10 in the 915 MHz range?
 
I found this quote here http://cocoontech.com/forums/topic/22182-not-very-reliable-zigbee-locks/?p=180865

 
I just listed 1-10 as part of the Zigbee specification. I think you are right in that the ZIM only can use 11-26. It looks like if I turned the ZIM off and on it would have picked a different channel. I'm going to leave the ZIM alone so it stays on an upper channel and is reliable. Since I live in a townhouse the 2.4 GHz wireless is saturated especially on channels 1 and 6. The plan is to start using 5 GHz wireless as the range is shorter and I'm not picking up any signal from the neighbors.
 
I purchased two Cisco 1142n dual band 2x3 MIMO access points, which are capable of 300 Mbps. I'm planning to mount them to the ceiling of the upper and middle floor of my townhouse. The current model Cisco 1600 access point is 3x3 MIMO, but still only 300 Mbps. You have to move up to the Cisco 2600, which is more than I want to spend, with 3x4 MIMO to reach 450 Mbps. The lightweight 1142n can be purchased for around $220 on eBay and the autonomous firmware can be flashed to make them usable without the controller. These seem like the best bang for the buck currently.

 

[pete_c]

Thanks rsw686!
 
Here I am looking to test the new Ubiquiti UniFi AP and new Securifi 802.11ac AP and Zigbee stuff shortly.
 
I am working on getting a Gb wireless client to test.  (only two exists right now).
 
I currently have three Z-Wave networks that I play with (HAI OPII, Homeseer Z-Troller and micasaverde controller)
 
Adding # 4 Z-Wave network with the Securfi Z-Wave controller shortly.
 
I want to replace my Omnistat2 with a combo Zigbee and serial Omnistat2 device.
 
Modding openframe device with build in Zigbee chip to use it.
 
Adding Securfi Zigbee devices shortly.

 

[rsw686]

I had strongly considered Ubiquiti UniFi, but decided to go with Cisco as I am familiar with them. With Ubiquiti I don't like the entry UnFi AP and UnFi AP LR models as they are passive PoE and not standards compliant 802.3af. The UnFi AP PRO is 802.3af, dual band, and has 3x3 MIMO for 2.4 GHz and 2x2 MIMO for 5 GHz. The specs list it as 450 Mbps for 802.11n 2.4 GHz and I would assume 300 Mbps for 5 GHz due to the 2x2 MIMO. From reading it looks like the only way to configure the access points is by loading their software on a PC. I wish they had a CLI or WebGUI to directly connect to and configure the access point.

 

[pete_c]

not standards compliant 802.3af

 
Yup; not liking this issue too related to the two Aircams I have in place along with the one currently installed Ubiquiti AP relating to my current configured at home POE set up.
 
I have not read anything yet on the UniFi AP. 
 
Last thing that I want to do is use a separate controller or application to manage the UniFi AP right now as my preferences relate to a plugnplay set up.

 

[ano]

ZigBee and Wi-Fi should have absolutly NO interference problems between them.  The president of Control4 recently stated that in the several years of deploying ZigBee based products, he hasn't once seen an interference problem between Wi-Fi and Zigbee. 
 
Having said this, there has been some problems with the ZIM and HAI's implementation of ZigBee whereby the ZIM's control of channel switching was not as robust as it should have been.  I worked with an HAI engineer on this some time back, and he admitted the problem to me.  Back then HAI had a beta fix for this, but also these fixes have been slow to make it into user's hands. I'm not here to bash HAI, but I have encountered several bugs in HAI's ZigBee implementation.

 

[rsw686]

It looks like HAI's implementation of Zigbee has issues then. The only change I made was moving to channel 11 and for the next two weeks I had issues with the Omnistats. I could change the temp with Haiku and sometimes the Omnistat would receive the command and other times it wouldn't. As soon as I changed the wireless channel back the Zigbee issues were gone.

 

[ano]

One of the problems is that the ZIM, once it picks a channel, never seems to want to give it up.  You can see your Zigbee channel on the ZIM by looking at the device details. If I had to take a wild guess, wait I'm putting on my swami hat, I would say channel #24. At least that is the only channel mine seems to use. And Zigbee channel 24 falls directly on Channel 11 on Wi-Fi.