Maybe this can Help.
Many modern wireless routers are already dual-band, and now router companies are launching tri-band routers.
www.howtogeek.com
Quote from the above link:
"Don’t be too sucked in by the promises of a tri-band router. While a good dual-band router offers real benefits, the benefits of tri-band Wi-Fi won’t be as obvious unless you have a very fast Internet connection and quite a few devices competing for all that Wi-Fi bandwidth.
Is tri-band an upgrade? Sure it is, if you have multiple devices. Is it worth the money? Not necessarily — current tri-band routers are very expensive and you may not even notice the feature on your home network".
