How / When Does a Device Jump from the 2.4 GHz Network to the 5.0 GHz Network

Question

I understand -- through another thread that I started -- that the Guest Network will be both 2.4 GHz as well as 5.0 GHz....I would like to understand how / when does a device jump from the 2.4 GHz network to the 5.0 GHz network as I understand that: the 2.4 GHz network is slower but has greater range relative to the 5.0 GHz network.
Thx...

Answer 1

Bob Timmons wrote:
A device will connect to either the 5 GHz or 2.4 GHz band based on its own capabilities and distance in relation to the router.
So, if you have a 5 GHz capable device that is in close proximity to the router, it will connect at 5 GHz.  If that device moves a few rooms away from the router, it will switch over to the 2.4 GHz band since that signal will be stronger....and likely faster at that location.
Think of 5 GHz as a "same room" connection or "line-of-sight" deal. It might be OK through one wall....if it is thin.
You do have an option to assign a separate name to the 5 GHz band in AirPort Utility. Once you have done that, simply "point" the device at the network with the 5 GHz name. Some users swear by this and some swear at this.
The downside to doing this......the device will likely try to hang on to the 5 GHz connection if it moves a few rooms away from the router.....at a location where the 2.4 GHz signal is stronger and likely faster.
Again, thanks for the very helpful response.
It occurs to me from reading the above that it makes sense to let the device (using your words) connect to either the 5 GHz or 2.4 GHz band based on its capabilities and distance in relation to the router as I can see / understand the downside and issue of manually pointing to or selecting  a specific network.
The reason that I purchased an Apple router is the hope that it will work better than some of the other routers I have tried as far as the 5 GHz / 2.4 GHz dual banding is concerned because in most of these cases I have had to disable the 5 GHz band to maintain a reliable internet connection...hopefully the Aiport Extreme will not require me to do so [i.e. it will work]!
With respect to *BOTH* the Primary Network and the Guest Network being dual band I can only conclude that this work because there are essentially two separates networks [i.e. 10.o.x.x and 172.16.x.x] that are using the send / receive configuration capabilities.
Thx...