There are certain network setups where you may need to setup separate SSIDs for the 5GHz and 2.4GHz so all your devices can connect. You can add additional SSIDs with the mobile app or web GUI and choose if you would like it to be 5GHz, 2.4GHz or have automatic band steering.
The idea is to spread out your devices over the two bands so that there's less competition for the same channels. Separating your personal and Internet of Things (IoT) devices can also help your WiFi security. By splitting your devices between 2.4GHz and 5GHz, you can maximize your network's performance.
With the same SSID in 2.4 GHz and 5 GHz bands, client devices will not need to reconnect. The client device (smartphone/tablet/laptop etc.) will choose which 2.4GHz or 5GHz access point to connect to based on the qualities of the data environment, signal strength etc. This mechanism is called Band Steering.
With a dual-band router, you can set it to transmit at both frequencies concurrently. In this case, you typically have two networks (SSIDs) that appear in your network list, with identical names except for a "5G" or "2.4G" at the end. You can then choose to connect each individual device to either network.
With two separate Wi-Fi profiles, the clients are unable to switch quickly - or in some cases even at all - from using 5 GHz for capacity, to 2.4 GHz for range. Switching between bands occurs far more often than one would expect, even for stationary devices such as printers.
By using wireless router multiple SSID, you can create multiple wireless networks on a single router, each with its own unique name and security settings. This is particularly useful if you have guests or employees who need internet access, but you don't want to share your main network with them.
This is because the 2.4 Ghz has more range, so it comes into network range sooner than the 5Ghz, and therefor automatically connects. Once connected, the client will not automatically switch!
Set a Band Preference in Android
You can find this under: Settings > Network & internet > Wi-Fi > “Overflow Menu” > Advanced Wi-Fi > Wi-Fi priority.
In some estimates, this beaconing and probing can make up to 7-10% of airtime utilization. Multiply that percentage by the number of SSIDs on the network and it's easy to see that too many SSIDs can quickly clog the network, degrading its performance.
Find out Whether You Have Band Steering
If your router/access point has band steering, you should only have a single SSID for both bands, so that the access point can pick the best band supported for each device and the user does not need to think about it.
Normally, multiple SSIDs are used to provide different types of wireless network access to different device types and user classes. The downside of enabling more SSIDs is that it creates more channel utilization due to overhead.
Go to the Wireless page of the router. (The entry address is usually provided on the label attached to the back of the router). Go to the 2.4 GHz setting page, and set the Wi-Fi name (SSID) to （XXX）-2.4G, where xxx indicates the Wi-Fi name. Save setting.
5GHz WiFi can pass through walls. That being said, 5GHz networks are more susceptible to interference from physical objects and may not be the best solution in a large home or office with many walls, floors, and other obstacles.
Theoretically, multiple devices connected to Wi-Fi doesn't slow down the internet speed. But in practice, more the number of devices are connected to the internet, the bandwidth is being shared thus affecting the speed.
Wi-Fi 6 vs. Wi-Fi 5 frequency bands differ, which affects the available throughput each Wi-Fi generation can offer. Wi-Fi 5 uses the 5 GHz frequency band for data transmission, while Wi-Fi 6 can use both the 2.4 GHz and 5 GHz bands and, in turn, support better throughput than Wi-Fi 5. Maximum data rate.
Check your router's manual or the manufacturer website where that information should be prominently displayed. Check your router for a sticker or writing indicating that it is dual-band.
Interestingly, you cannot use your Wi-Fi generation to determine which bands your device can connect to. In the case of Wi-Fi 6, also known as 802.11ax, the standard was developed prior to the 6 GHz band being available. Only Wi-Fi 6E can access all three spectrums, including 2.4 GHz, 5 GHz, and 6 GHz.
You can run two routers with the same SSID to increase the range of your Wi-Fi network, but you must set up one router to handle the network administration and the other to act as a bridge back to the primary router.