It's highly dependent on your situation and requirements. If you are working with just a lone Wi-Fi router, then using the same SSID on both bands can help devices stay connected, especially in areas where 5 GHz can't reach but 2.4 GHz can.
By splitting your devices between 2.4GHz and 5GHz, you can maximize your network's performance.
If your device is not 5GHz compatible you'll only have the option to connect to the 2.4GHz SSID. What's also great is that you can connect multiple devices on both 2.4GHz and 5GHz at the same time, so all your devices can access the best possible WiFi available.
Choosing the right channel
Here are some tips on which settings to choose: On the 2.4 GHz band, which is usually Wireless-N, always choose Channels 1, 11, or 6. Try to pick the emptiest of the three, using the Wi-Fi Analyzer as your guide. Channels other than 1, 11, or 6 will receive more interference.
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 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.
Ideally, you'll want to run your 2.4GHz wifi network on channels 1, 6, or 11. You should be able to set your wireless network to a new channel within your router's settings. (And don't forget to do this same analysis for your 5GHz wireless networks as well.)
We already know that changing the channel bandwidth will have a significant impact on the WiFi performance because 20MHz or 40MHz will deliver a far more stable throughput on the 5GHz frequency band (although not that high) in a crowded environment.
Best channels for 5 GHz Wi-Fi
Within the 5 GHz band, the channels 36, 40, 44, and 48 are all designated for domestic use, so we'd recommend sticking to one of those four channels to limit the possibility of interference from other, non-domestic applications (like military or aviation activity).
You can connect to the 5GHz when you're in your main work/recreation space, then switch to the 2.4GHz when you wander a few rooms away. If your devices seem to connect to the 2.4GHz network by default, or if you just really care about optimizing your speed, separate SSIDs are the way to go.
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.
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.
5 GHz networks do not penetrate solid objects such as walls nearly as well as do 2.4 GHz signals. This can limit an access points reach inside buildings like homes and offices where many walls may come between a wireless antenna and the user.
The 2.4 GHz band gives you slower speeds at a longer range, while the 5 GHz band gives you faster speeds at a shorter range. So, if you want the fastest WiFi speeds, you should always use the 5 GHz band. However, the more devices you have on one band, the slower your WiFi will be.
2.4 GHz vs. 5 GHz: Which frequency should you choose? A 2.4 GHz connection travels farther at lower speeds, while 5 GHz frequencies provide faster speeds at shorter range. Your choice of 2.4 GHz or 5 GHz will depend on where and how you use your WiFi connection most.
Outside Interference From Nearby WiFi Networks Negatively Impacts Yours. The signal from nearby wireless networks and access points can impact performance on your network. Access points on the same channel can affect your network performance and cause dropped connections or lost packets while using the internet.
Types of WiFi interference
This occurs when two or more wireless networks are using the same channel or frequency, causing interference and reducing the speed and reliability of both networks.
1. Avoid overlapping channels. We recommend sticking to channels 1, 6 or 11 with 2.4 GHz to achieve the best stability, and for all devices to be able to find the wireless network regardless where and when they were manufactured.
In general, 36, 40, 44, and 48 are the best 5G channels WiFi because they are least likely to overlap with other channels. However, if these channels are already congested in your area, you can try using channels 149, 153, 157, and 161 as they are also less likely to overlap with other channels.
If you're using 2.4 GHz, the answer is simple. The best bandwidth for 2.4 Ghz is 20 MHz. In the majority of cases, using wide widths on 2.4 GHz isn't worthwhile. The performance tradeoffs from interference on overlapping channels will likely outweigh the throughput benefits.
Most modern routers automatically choose a channel for the devices on your network. However, this may not always be the best one. Selecting the best channel yourself, like on the 5 GHz band, can help improve WiFi speeds and avoid interference and overlap.
Set a Band Preference in Android
You can find this under: Settings > Network & internet > Wi-Fi > “Overflow Menu” > Advanced Wi-Fi > Wi-Fi priority.
A dual band router doesn't switch frequencies, it broadcasts on two frequencies simultaneously. 2.4 GHz has longer range and greater penetration of obstructions. 5 GHz offers higher speeds.
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.