Who is this guide for?
I have tried to make this guide to be a comprehensive collection of the most basic yet essential tips with a set of actions and best practice steps that should be applicable to all types of Zigbee setups, regardless of what type of Zigbee adapter/gateway/hub/bridge/devices that you are using.
This guide is meant for both those who are new to Zigbee as well as those who been using Zigbee devices for years but might not been aware of the underlying prerequisites to optimize for stability and performance.
It has been written with a point-of-view in mind of Zigbee solutions that use a Zigbee Coordinator adapter locally via USB dongle/stick or remotely using a serial server over a local network, etc. and as such it definitely applies to all users of Home Assistant ZHA integration, Zigbee2MQTT, and deCONZ (Phoscon).
Other docs
I have also submitted the essence of this guide to upstream ZHA integration and Zigbee2MQTT docs:
- https://www.home-assistant.io/integrations/zha#zigbee-interference-avoidance-and-network-rangecoverage-optimization
- https://www.zigbee2mqtt.io/advanced/zigbee/02_improve_network_range_and_stability.html#reduce-wi-fi-interference-by-changing-the-zigbee-channel
Whatâs in this guide?
Below are some basic yet essential tips and best practices for getting a good Zigbee setup starting point to relatively easily achieve the best possible signal quality, improved coverage, and extended range.
Most importantly it specifically covers what to do and what not to do, especially the importance of avoiding electromagnetic interference (EMI) and also adding many Zigbee Router devices (as repeaters/extenders), both of which are crucial to achiing a stable Zigbee network with no delays (i.e. zero dropped messages/packages and low latency).
Following all these optimization tips below should significantly improve the reception of your Zigbee radio adapter. The below insights describe working around the well-known limitations of low-power/low-bandwidth 2.4 GHz digital radios. It can that way resolve or avoid many known issues caused by interference or poor placement of your Zigbee radio adapter or devices.
Zigbee interference avoidance and network range/coverage optimization
Interference
Before you get started with Zigbee, or at least before starting troubleshooting issues/problems with Zigbee any deeper than maybe nessesary, you first need to be aware that all Zigbee devices, and especially the Zigbee Coordinator, can be extremly sensitive to electromagnetic interference (EMI, also known as RMI / Radio-Frequency Interference), as practically all sources of EMI/RMI are infamously known for sometimes leading to serious Zigbee transmission/reception loss or intermittant connection problems. Therefore you should always take the actions suggested in this guide to avoid keeping any sources of EMF/EMI/RMI interference close to the Zigbee Coordinator adapter or vice versa, (which includes any source with electricity emitting Electromagnetic Fields / EMF).
Symptoms of electromagnetic interference (EMI/RMI)
Symptoms of radio and electromagnetic interference commonly show themselves as reoccurring intermittent failures and errors when sending or receiving Zigbee messages/signals and can cause anything from significant communication problems to weird issues and random degradation in performance that either permanently or temporarily prevent devices from communicating properly with the Zigbee Coordinator, or sometimes even completely block/stops all Zigbee communication.
Home Assistantâs video to clearly show Zigbeeâs symptoms with electromagnetic interference:
Sources of EMI/RMI and EMF
While Wi-Fi routers and WiFi access-point are probably the most well-known sources of interference, you need to understand that all electric devices/appliances, especially computers and computer peripherals, do generate electromagnetic interference (also known as EMI/EMI/RMI, or signal noise in laymanâs terms), which can jam or interfere with signals transmissions on the 2.4 GHz radio band frequency, and degrade the wireless communication with your Zigbee adapter/devices.
For example, interference from USB 3.0 ports and unshielded USB peripheral cables are especially infamously known to affect 2.4 GHz radio reception for low-power/low-bandwidth devices. Therefore you should always place your Zigbee adapter far away as possible from any potential sources of EMI/EMI/RMI, preferably by using an adequately long shielded USB extension cable connected to a USB 2.0 port.
Network optimization (optimizing for mesh networking)
You have to understand and remember that each Zigbee device by itself has very limited coverage, short range and their weak signals have poor wall penetration, so to workaround this a Zigbee network technology relies heavily on its use of mesh networking architecture which forms "wireless mesh network, where âZigbee Routerâ devices (also known as âZigbee repeatersâ or âZigbee extendersâ) will help forward the communication so the messages/packets âhopsâ from Zigbee Router to Zigbee Router to rearch its final destination device when the Zigbee Coordinator is not within direct reach or have a week signal reception, and result is that it forms âmesh topologyâ (a instead of using a more classic âstar networkâ topology where every device would instead practically only talks directly with a single controller like you usually have in a common WiFi-network, which is a othjer type of network topology where the low-power signals from Zigbee devices do not work well at all).
That means that all devices in a Zigbee network need it to be a âmesh networkâ and thus really depend heavily on having a swarm of mains-powered âZigbee Routerâ devices that are always-on so they can help forward messages within the network, acting both as a signal repeater and range extended by transmitting data over long distances, stengthening the total coverage and distances possible by passing data messages through the Zigbee network mesh of intermediate devices to reach more distant Zigbee devices, (which may or may not have week signals).
Therefore the key to a great and healthy Zigbee network mesh is to add/have many âZigbee Routerâ devices relatively close to each other (and always powered on) in order for the Zigbee network as a whole to get good coverage and range, as well as improving the overall robustness and robustness and resilience in the network to handle the loss of some Zigbee Routers in case of failures. So often you more or less just need to add several mains-powered Zigbee devices that can act as âZigbee Routerâ devices to get a stable network with good coverage, and keep adding even Zigbee router products to achieve a great Zigbee network.
Simple actions that will improve most Zigbee setups and common root causes of interference
Zigbee adapter hardware
Issue: Bad performance from old/outdated/obsolete Zigbee adapter hardware or poor Zigbee adapter antenna
Action: Buy and use a supported Zigbee USB adapter based on newer/modern chip hardware
Tips:
- Consider a Zigbee adapter that has an external antenna
- While older adapters might work, they could have obsolete hardware or old firmware, which prevents reliable operation
Issue: Poor or outdated Zigbee adapter firmware on the Zigbee adapter
Action: Update to a later Zigbee chip firmware on the Zigbee adapter. Updating firmware is usually straightforward if the manufacturer or the chip maker provides one
Zigbee adapters are RFI sensitive and can be very susceptible to all types of EMI/EMF interference
Issue: Poor placement of the Zigbee adapter or wrong orientation of the Zigbee adapter antenna
Actions:
- Use a long USB extension cable to place the Zigbee adapter away from interference and obstacles
- Ensure the USB extension cable is adequately shielded (thick cables usually have this)
- Try different physical placement and orientations of the Zigbee adapter or its antenna
Tips:
- A USB extension cable makes orienting the Zigbee adapter/antenna easier
- The optimal placement of the Zigbee adapter is close to the middle of the house as possible
- Try to place the Zigbee adapter at some distance away from walls, ceilings, and floors
- Try different orientations of the adapterâs external antenna (or the whole Zigbee adapter)
Issue: USB 3.0 ports/computers/peripherals are known culprits of RFI/EMI/EMF disruption. (See Ref. 1 and 2)
Action: Make sure to only connect the Zigbee USB adapter to a USB 2.0 port (and not to a USB 3.x port)
Tips:
- If your computer only has a USB 3.x port then buy and connect the adapter via a powered USB 2.0 hub
- Using via USB 2.0 hub will in practice convert USB 3.0 to a USB 2.0 port and thus avoid USB 3.0 EMF
- A USB 2.0 hub that uses an external power supply will ensure power requirements are fulfilled
Action: Shield any unshielded computers/peripherals/devices by adding all-metal enclosures/chassis/casings
Tips:
- Single-board-computers and USB 3.x hard drives are especially known as sources of EMF/EMI/RFI
- Be aware metal casings can decrease the performance of internal/built-in Zigbee adapters
- Also, be sure to use adequately shielded USB cables for any such peripherals/devices too
Getting better range and coverage
Action: Add more and decrease the distance between Zigbee devices in Zigbee network mesh
Tips:
- Zigbee uses mesh networking and depends on having many âZigbee Routerâ devices to extend range and coverage
- Recommendation is to add additional mains-powered Zigbee devices known to be good Zigbee Router devices
- Note that not all mains-powered devices have firmware that makes them act as a Zigbee Router device
- Some brands/models of Zigbee Router devices are known to only work well with the same brand of devices
Action: Buy a few known good dedicated Zigbee Router products and place them strategically as Zigbee repeaters. Personally, I suggest buying and adding at least three such devices.
Tips
- Examples of suitable producets: the âIKEA Tradfri Signal Repeaterâ and âAeotec Range Extender Ziâ are products that work very well out-of-the-box, while a more powerful alternative is to make yourself some semi-DIY variant by flashing the correct Zigbee Router firmware to Zigbee Coordinator USB dongles and then using them as stand-alone Zigbee Signal Repeater devices in USB-chargers for power, like, for example, either the Sonoff ZBDongle-E (EFR32MG21 based) or the Sonoff ZBDongle-P (CC2652P) work great as dedicated stand-alone Zigbee Signal Repeaters with recommended firmware.
- Search community forums for more âZigbee signal repeaterâ or âZigbee range extenderâ Zigbee Router tips
- Buy a few additional new Zigbee USB adapters to use after re-flashing them with Zigbee Router firmware
Issue: Zigbee could have overlapping frequency ranges with Wi-Fi. Wi-Fi and Zigbee both operate within the same radio frequency range (2.4 GHz) and that means that they can interfere with each other, or rather since Wi-Fi radios use high-power radios its signals can drown out Zigbeeâs low-power signals. You can also simply have 2.4 GHz RF Interference (RFI) from Wi-Fi Routers and Wi-Fi Access Points or other devices.
Actions:
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First of all, try to place your Zigbee adapter away from Wi-Fi access points or sources of WiFi
- Place Zigbee adapters far away from electrical/power wires/cables, power supplies, and household appliances
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Read this article about Zigbee and WiFi coexistence â https://support.metageek.com/hc/en-us/articles/203845040-ZigBee-and-WiFi-Coexistence
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Read and follow the ZHA integration and Zigbee2MQTT documentation respectively regarding changing/defining Zigbee channel use, see â https://www.home-assistant.io/integrations/zha#defining-zigbee-channel-to-use and https://www.zigbee2mqtt.io/advanced/zigbee/02_improve_network_range_and_stability.html#reduce-wi-fi-interference-by-changing-the-zigbee-channel
Note! ZHA channel selection dialog does mention that interference needs to be addressed before this!
Additional general Zigbee tips not mentioned in the above linked pull request:
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Texas Instruments CC2652P or CC1352P based adapters are recommended for Zigbee2MQTT (while Z2M technically also support ConBee/RaspBee and Silicon Labs adapters but they are not recommended for Zigbee2MQTT as they do not offer full feature-parity, for more information see â Zigbee buyer's guide ).
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While both ZHA and Zigbee2MQTT do support older Zigbee Coordinator adapters based on the old Texas Instruments CC253x (CC2530 and CC2531) they are not recommended any longer, so spare yourself the potential grief and instead just buy a newer Zigbee Coordinator adapter from the start.
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Migration from an older Zigbee Coordinator adapter to a new Zigbee Coordinator adapter (with later firmware) a is a nice feature that both ZHA and Zigbee2MQTT have but if you are having problems with your Zigbee network after migration then it is generally recommended to cut your losses instead or troubleshooting and so just reset the new Zigbee Coordinator adapter to factory settings and join/pair devices manually one by one after factory resetting each device.
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Be sure to factory reset devices that have previously been paired/added to another Zigbee gateway/hub/bridge as otherwise, they might not show up during the search when trying to join/pair/add the Zigbee device.
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Before adding any devices, check that you have enough Zigbee router devices close to the new device that you want to add if it is not in the same room or within 10 feet from the Zigbee Coordinator adapter.
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Zigbee router devices are mains-powered devices that are also known as Zigbee signal repeaters or range extenders, and if you do not have any, invest and add some mains-powered devices that will work as Zigbee routers. You use routers to increase the both the range and coverage as well as total number of Zigbee devices that can be used in a Zigbee network. The total number of Zigbee devices that you have on a Zigbee network depends on a few things, but you should know that Zigbee coordinator hardware and firmware only play a larger role in Zigbee networks with a lot of devices. More important is how many directly connected devices (âdirect childrenâ) versus how many routers are connected to your Zigbee coordinator.
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Aim to start out with mains-powered devices before adding battery-operated devices as a âweakâ Zigbee network mesh (e.g., the device is too far from the Zigbee coordinator or a Zigbee router) may prevent some devices from being paired. Zigbee router devices are also needed to increase the maximum of devices that can be connected to your Zigbee mesh network.
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If possible try to pair your Zigbee devices in their intended final location, (and not pair it next to the Zigbee coordinator and then need to move it after).
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Pairing a Zigbee device next to the Zigbee coordinator and then moving it later can result in dropped/lost connections or other issues.
- If the device you want to add is not brand new and as such never paired before then you always have to make sure to first manually reset the device to its factory default settings before you will be able to add/pair it.
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Cheap devices like those manufactured by Tuya and Aqara/Xiaomi are infamously known for not following the standard Zigbee specifications and can have issues pairing and sometimes even cause stability issues in a Zigbee network, especially when used either as a Zigbee Router or when it connects via an other Zigbee Router instead of connecting directly to the Zigbee Coordinator.
- Note that some Zigbee devices are also not fully compatible with all brands of Zigbee router devices. Xiaomi/Aqara devices are for example known not to work with Zigbee router devices from Centralite, General Electrics, Iris, Ledvance/OSRAM, LIGHTIFY/Sylvania, Orvibo, PEQ, Securifi, and SmartThings/Samsung. Better results can usually be achieved by using mains-powered devices IKEA and Nue/3A Home or dedicated DIY routing devices based on Silicon Labs EFR32MGxx, Texas Instruments CC253x/CC26x2, or XBee Series 2/3 Zigbee radios.
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Both ZHA and Zigbee2MQTT require handlers/converters for non-standard Zigbee clusters and attributes so be prepared to either code your own handler/converter or open a new device support request if buying a newly released device or old odd devices that are not commonly used so no one has previously coded handlers/converters for it if it does not follow standard Zigbee clusters and attributes specifications.
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Such a custom handlers/convertersâ are scripts that workaround deviations by acting as a translator, translating and converting non-compliant device messages and instead presenting them to the application as coming from a virtual compliant device that parse custom messages to and from Zigbee devices.
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Some battery-operated Zigbee devices are known to have problems with pairing if they have Low battery voltage.
- Some people have reported replacing the battery on their newly received Xiaomi/Aqara devices solved pairing issues.
Rechargeable NiMh batteries each supply 1.2v vs. Alkaline with 1.5v. Some reliability issues are due to lower voltage batteries.
- If joining/pairing do not work properly due to the interview failing try to join/pair the device again and be patient as the pairing of some Zigbee devices may require multiple attempts and you may sometimes need to try again and again.
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Some devices, like example those from Xiaomi/Aqara, are also known to not be 100% compliant with the standard Zigbee specifications for joining/pairing and may therefore require many paring attempts over 10-20 minutes or even more.
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If joining/pairing fails try resetting the device to factory default settings.
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If joining/pairing still fails you can try pairing the device closer to the Zigbee Coordinator adapter but be aware that depending on the device you might not be able to then move it further away as it could be that it will then not automatically re-pair to a Zigbee router device so manual re-pairing will be nessesary.
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- General tip to new Zigbee users is that, while there is no official list of supported devices, some ZHA users take comfort that blakadder maintains an unofficial Zigbee Device Compatibility Repository which anyone can submit compatibility reports to, it can be found at zigbee.blakadder.com and currently contains independent compatibility lists and device pairing tips for several home automation gateway/bridge/hub software, including but not limited to open source Zigbee implementations such as; ZHA, Tasmota, Zigbee2MQTT, deCONZ, Zigbee for Domoticz, and ioBroker.
Other reputable guides or tutorials and resources/research related to this topic:
- ZigBee and Wi-Fi Coexistence â https://support.metageek.com/hc/en-us/articles/203845040-ZigBee-and-WiFi-Coexistence
- Best practices to avoid pairing and/or connection issues â https://www.home-assistant.io/integrations/zha#best-practices-to-avoid-pairingconnection-difficulties
- ZHA info on using Zigbee Router devices (repeaters/extenders) â https://www.home-assistant.io/integrations/zha#using-router-devices
- Zigbee interference avoidance and network range/coverage optimization â Zigbee Home Automation - Home Assistant
- Actions to optimize Zigbee Coordinator radio hardware â Zigbee Home Automation - Home Assistant
- Actions to avoid or workaround EMI/EMF/RMI interference â Zigbee Home Automation - Home Assistant
- Zigbee2MQTT tips on how to improve network range and stability â https://www.zigbee2mqtt.io/advanced/zigbee/02_improve_network_range_and_stability.html#usb-based-adapter
- Hubitat tutorial How to Build a Solid Zigbee Mesh â https://docs.hubitat.com/index.php?title=How_to_Build_a_Solid_Zigbee_Mesh
- Xiaomi & Aqara Devices - Pairing & Keeping them connected â https://community.hubitat.com/t/xiaomi-aqara-devices-pairing-keeping-them-connected/623
- Zigbee Range: You Must Know The Truth
- Radio propagation modeling and real test of ZigBee based indoor wireless sensor networks â https://www.sciencedirect.com/science/article/abs/pii/S138376211400112X
PS! Many of the above tips will also apply to Thread and Bluetooth based adapters/devices as well.
- https://www.home-assistant.io/integrations/bluetooth/#bluetooth-interference-with-other-devices
- https://www.home-assistant.io/integrations/thread