Huge growth in smart home gadgets is sending wireless communication into overdrive, causing serious traffic jams. Zigbee and Wi-Fi channels are taking a hit since they share the same frequencies.
In this article, we will show you how you can arrange these channels properly to create a more efficient smart home network.
What Are Channels?
Every wireless network operates within a specified frequency bandwidth. For example, Wi-Fi operates in 2.4 GHz and 5 GHz bands. This frequency band is further divided into smaller bands, known as channels. If you have multiple wireless routers operating in close vicinity, you can set a separate channel for each router. Channels help prevent overcrowding on the same frequency range, resulting in less interference.
Zigbee Channels
Zigbee has different frequency allocations for global, European, and North American consumers. 2.4 GHz is the global Zigbee band, and it is further divided into 16 channels – channels 11 to 26. Each channel supports a transmission rate of up to 250 Kbps.
Europe
In Europe, the allocated Zigbee frequency band is 868 MHz. This band operates with only one channel – channel 0. This channel offers a transmission rate of up to 20 Kbps.
North America
The third Zigbee frequency band is 915 MHz, available for North American consumers only. This band is subdivided further into 10 channels. These channels include channels 1 to 10. Each channel can deliver a transmission rate of up to 40 Kbps.
Does Wi-Fi Cause Interruptions?
Wi-Fi and Zigbee channels both operate in the 2.4 GHz frequency band. Therefore, the possibility of interference remains intact. When placing both Zigbee and Wi-Fi routers in close vicinity, planning must be done to ensure minimal to no interference is present between the channels of both networks. The best and most permanent solution to this problem is the deployment of 5 GHz Wi-Fi.
Overlapping Channels
Unfortunately, the three non-overlapping Wi-Fi channels – channels 1, 6, and 11 – and some Zigbee channels operate on the same frequencies. Another issue is the greater width of the Wi-Fi channels. A single Wi-Fi channel (22 MHz wide) can interfere with more than one 2 MHz wide Zigbee channel.
Proper channel planning is necessary before deploying or extending either a 2.4 GHz Wi-Fi or Zigbee network. We can avoid channel interference on 2.4 GHz networks by excluding 5 GHz non-IoT devices from 2.4 GHz networks.
At present, most wireless networks use the 2.4 GHz band. We don’t have many networks and devices using the 5 GHz band. In contrast to 2.4 GHz, the 5 GHz band features a large number of channels and they don’t overlap. Therefore, interference issues can be resolved by capitalizing on the benefits of 5 GHz Wi-Fi.
Managing Zigbee Channels
Wi-Fi Bandwidths
When a Zigbee network is on the same channel as a Wi-Fi network, the Zigbee network might interfere with the Wi-Fi network. As mentioned previously, the best solution available to avoid interference between Zigbee and Wi-Fi channels is to upgrade to 5 GHz Wi-Fi.
For a pool of mixed 2.4 GHz and 5 GHz devices, you can set up your Wi-Fi using dual-band access points and routers. Most laptops and phones released in the last couple of years should support 5 GHz connectivity.
Whereas to minimize the load on your Wi-Fi network, you should consider wired ethernet connections for fixed devices such as printers and security cameras.
A 5 GHz network has more benefits compared to a 2.4 GHz network. However, in terms of transmission rate, 2.4 GHz outperforms 5 GHz. Keep this in mind as you plan to shift from 2.4 GHz to 5 GHz Wi-Fi.
Choose Wi-Fi Channels Wisely
Channel planning is vital for Wi-Fi and Zigbee networks to coexist peacefully and seamlessly. Generally speaking, Wi-Fi channels 1, 6, and 11 are preferred because they don't overlap.
However, it is better to keep Wi-Fi channel 11 unoccupied to accommodate Zigbee. When arranging Wi-Fi access points across your home, keep the identical channel APs far from each other to avoid same-channel interference.
To keep Wi-Fi channel 11 unoccupied, proceed with channels 1 and 6 or channels 6 and 11 or another combination of any two preferred channels for the APs.
Reusing Channels
With only two channels available, consider a two-channel reuse plan when arranging access points. A two-channel reuse plan isn't as good as a three-channel plan, but it works just fine when space is required for Zigbee devices.
Choose Zigbee Channels Wisely
Believe it or not, it's easy to choose the right Zigbee channel for your network. You can use a smartphone app to identify the most crowded Wi-Fi channels in your vicinity. Now, you can pick a Zigbee channel as far as possible from the most crowded Wi-Fi channels. For even better results, you can try hardware spectrum analyzers as well.
It is essential to understand that a Zigbee mesh network configured to operate on a particular channel cannot be rechanneled instantly through remote intervention. A manual reset of every single Zigbee device on the mesh network will be required when switching to a different frequency.
For a seamless process, you must choose a Zigbee channel wisely. Zigbee and Wi-Fi channels tend to interfere because both networks use the 2.4 GHz band.
Wi-Fi interference can result in frequent disconnection of Zigbee devices, slow communication across the mesh network, and delayed pairing.
Plan Accordingly
Generally, Zigbee networks generate small data packets and only intermittently. Yet, it's better to keep your Wi-Fi and Zigbee networks on different channels. It is easy to control which Zigbee channels your Wi-Fi may interfere with.
All you really need is proper planning. As mentioned previously, some channels overlap between Wi-Fi and Zigbee, and operating on both channels is actually not recommended.
The placement of Zigbee devices is another important aspect related to network planning. All the Zigbee devices on your network must maintain a healthy connection with the Zigbee hub. Therefore, the distance between the farthest device and the hub should be appropriate.
You can use a dedicated Zigbee repeater to increase the network’s operating range and signal strength. Some Zigbee devices, such as smart plugs, dimmers, and bulbs, can be used as Zigbee repeaters.
The Verdict
There are many ways to resolve the interference between Wi-Fi and Zigbee channels. Consumers should consider upgrading to 5 GHz Wi-Fi to resolve the issue permanently.
1 Comment
Jeff Campbell
There is a lot of incomplete or inaccurate information in this article. For starters, even though 2.4Ghz WiFi and Zigbee have many overlapping channels the impact of WiFi on Zigbee is, in my experience, negligible. Likewise, the impact of Zigbee on WiFi is also negligible unless you have a very busy Zigbee network. Even then, if Zigbee is operating at the edge of a WiFi channel (example, WiFi 11 and Zigbee 20) the interference will be minimal.
In no particular order…
– 2.4Ghz WiFi channels are 20Mhz wide, not 22.
– 5Ghz WiFi channels can overlap just like 2.4Ghz WiFi channels.
– 2.4Ghz WiFi does not outperform 5Ghz WiFi, unless you happen to be running 20Mhz channels on 5Ghz and 40Mhz channels on 2.4Ghz.
– Two close WiFi APs on the same channel do not actually interfere with each other – they will cooperate to try to avoid simultaneous transmissions. They will impact each other’s speed, but it’s not the same as interference. Two close APs on adjacent channels (like channels 1 and 2) will wreak havoc on each other.
– If the Zigbee channel is changed, most devices will find the new channel all by themselves. It might take anywhere from a few hours to a full day, and it’s possible that some errant devices might have to be excluded and re-added, but to say a manual reset of every device on the network is required is incorrect.
There’s more, but I don’t want to re-write the entire article.
–