[Enlightened1]

I think you are mixing and matching things with dual band Routers (typically operate in 2.4 ghz and 5 ghz)? That's not the same as 5g from a Wireless Carrier. 

Here is the 5g spectrum illustrated for you below.

 

[Paladin2]

Now that I look at that graphic again, it would seem that 5G means 5th generation.