You can use 2.4GHz and 5GHz at the same time if you have a simultaneous dual-band router and if your wireless devices support both bands . However, some dual-band routers support only one WiFi network, so you need to choose either the 2.4GHz or 5GHz frequency.
Read moreDoes 5GHz WiFi go through walls?
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.
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