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Currently my z-wave network with 16 Fibaro Dimmer 2's (FGD-212 v3.5) is much better than it was when I started setting it up couple years ago. Hopefully this post can provide help to someone cutting required time for troubleshooting from years to months. :)

It's still not as reliable and responsive as my Zigbee network, but after extensive troubleshooting and changes made (as described below) at least I can toggle lights and response is usually reliable and instant. Remaining issues are all related to network flooding that occurs when using lights grouped behind "one button" causing large number of z-wave packets to be sent and received at the same time.

I'm still slightly worried of flooding issues becoming worse in future since I have installed only half of z-wave dimmers and have number of sensors (FGMS-001) waiting to be installed. Maybe I need to setup two z-wave networks and split devices between them although they would still compete on same limited RF resources...


So, here's what I've tried. Some of changes were useful, some not so much.

-- relocated UZB dongle to avoid interference and minimize obstacles between dimmers and dongle
-> minor improvement, and even that only after adding usb extension cable to get dongle farther from PC itself

-- disabled 800MHz support from my LTE router as upstream channel is right next to EU Z-Wave channels
-> major improvement, previously entire z-wave network stopped working while uploading

-- replaced UZB dongle internal coil antenna with correct length external wire pigtail antenna
-> major improvement, amount of retries shown on timing page went down a lot and signal levels improved

-- adjusted pigtail antennas of z-wave devices with weakest signal
-> minor improvement, slightly better signal on those few devices

-- manually fixed in and out routes for some to be directly with z-way and some via devices with strongest signal (instead of always evolving mismatch of mesh links)
-> minor improvement, mostly made network function much more predictable instead of working fine one day and struggling on another day

-- disabled rssi polling by editing automation/modules/ZWave/index.js
-> no improvement

-- updated to Z-way to 3.2 with unsolicitedReportsOnSet feature
-> major improvement, reduction of traffic on network when toggling light due not sending duplicate get to light

-- changed from S0 security to no-security (FGD-212 doesn't support S2)
-> major improvement, large reduction of traffic on network due skipping nonce part (two thirds reduction)

-- disabled network statistics updating by editing automation/modules/ZWave/index.js
-> no improvement (I incorrectly stated on 1st version of this post that this one had major improvement)

-- disabled periodical sensor polling (Smarthome UI > hamburger menu > Apps > Periodical Sensor Polling)
-> major improvement, previously z-wave was unusable for 10 seconds every 10 minutes due sensor polling flooding network


So most important changes made were:
- removed interference caused by 800MHz LTE band 20
- changed from S0 security to insecure to reduce traffic
- update to z-way 3.2 with get optimizations to reduce traffic
- disabling network statistics polling to reduce traffic


Remaining issue:
- Fibaro Dimmer 2 (FGD-212 v3.5) sends spurious power level reports after on/off/dim causing extra network traffic.
- This is apparently due firmware bug causing device to ignore settings that are supposed to disable power monitoring.

(edit: removed incorrect info regarding network stats updating and replaced it with sensor polling change)

Very good investigation!
Thank you.

How do you change from s0 to no security ? Is there a setting for that ?

@vinisz: there is secure/unsecure toggle in Expert UI near Add/re-include button.

@A&A:
Very nice analysis. I'm especially interested in the LTE part - was it visible in the background noise? Are you in US? Is your Z-Wave frequency US or EU?

disabling network statistics polling to reduce traffic - can you please provide evidence of those issues? I'm surprised to read that

And very happy to hear that you appreciated our unsolicitedReportsOnSet feature! It will be even a bit better in v3.2.2

PoltoS wrote: ↑

26 Oct 2021 23:36

Very nice analysis. I'm especially interested in the LTE part - was it visible in the background noise? Are you in US? Is your Z-Wave frequency US or EU?

Finland with EU spec Z-Wave devices. Problem is only present when using Elisa's network in location with LTE Band 20 (800 MHz) network and sending large amount of data. Easiest way for me to reproduce this was doing backup to Backblaze using entire upstream capacity of my LTE connection. Same problem is also present when using cell phones, but due nature of moving around house with phone, short upload bursts, and phone usually being connected to WLAN for data when at home it's not really a problem.

When LTE router (Huawei B715s-23c) is near Z-wave dongle (say within 5 meters) and using LTE Band 20 it completely kills Z-wave. Very few packets get thru and even those few at 9600bps after multiple retries. More distance between dongle and LTE router reduces errors but causes still very visible problems and there's limit how far I can move them from each other. Easy solution was to entirely disable LTE Band 20 from router configuration as there's also LTE Band 3 (1800MHz) coverage.

We have three mobile operators with own networks in Finland. DNA B20 is 791 - 801 MHz downstream / 832 - 842 MHz upstream, Telia B20 is 801 - 811 MHz downstream / 842 - 852 MHz upstream and Elisa B20 is 811 - 821 MHz downstream / 852 - 862 MHz upstream.

Especially Elisa LTE upstream is known to cause problems with home weather stations and other devices on 863 - 870 MHz license free frequency range. This includes Z-wave networks using EU channels (CEPT 868.4 MHz, 869.85 MHz).

While actual LTE channel ends at 862 MHz and Z-Wave is far away at 868.4 MHz they're close enough for much higher power LTE to cause interference.

https://www.traficom.fi/en/communicatio ... e-networks
https://www.silabs.com/wireless/z-wave/global-regions

PoltoS wrote: ↑

26 Oct 2021 23:36

disabling network statistics polling to reduce traffic - can you please provide evidence of those issues? I'm surprised to read that

Good catch! That was my mistake when copy pasting from my notes. Changing network statistics polling DID NOT help but was one of things I tried while troubleshooting. I have edited my original post to avoid spreading wrong information.

Change made that DID help and fixed flooding of network every 10 minutes was disabling "Periodical Sensor Polling" app on Smarthome UI. App supports exclusions, change of schedules and risk of flooding is documented on app notes so proper way might be reconfigure it instead of completely disabling.

Perhaps sensor polling app could be modified to request only one sensor at a time and sleep few seconds between update requests? That would still allow sensor data to be updated but without risk of flooding larger z-wave networks.

PoltoS wrote: ↑

26 Oct 2021 23:36

And very happy to hear that you appreciated our unsolicitedReportsOnSet feature! It will be even a bit better in v3.2.2

Every improvement to reduce traffic on network is welcome as that seems to be major part of issues at least I've been seeing.

Hmm, LTE Band 20 uses 832 – 862 for uplink with channel width up to 20 MHz!!! This obviously overlaps with Z-Wave.

As for polling sensors - it is disabled by default for a year now - you should have an older installation where it was still enabled by default. Now we don't suggest it in the default scenario. So there should be no issues for new uers.

PoltoS wrote: ↑

28 Oct 2021 04:52

Hmm, LTE Band 20 uses 832 – 862 for uplink with channel width up to 20 MHz!!! This obviously overlaps with Z-Wave.

30 MHz total which has been divided to 10 MHz per operator in Finland. Share per operator of course depends on local market and regulatory rules.

PoltoS wrote: ↑

28 Oct 2021 04:52

As for polling sensors - it is disabled by default for a year now - you should have an older installation where it was still enabled by default. Now we don't suggest it in the default scenario. So there should be no issues for new uers.

Yes, at least two years ago. Some time ago I did clean install but restored backup so sensor polling setting was inherited.