Router NVG578LX: how to turn on 2.4GHz with wireless IEEE802.11b/g/n standards

Hi all,

I am using an ARRIS router model NVG578LX provided by an internet provider.

I need some help on how to turn on the 2.4GHz channel with wireless IEEE802.11b/g/n standards.

It is because my desktop doesn’t have a built in wifi adapter hence I have to use an Edimax usb which only works with the IEEE802.11b/g/n standards.

I have successfully turned on the 2.4GHz separated from the combine channel (the primary). I also tried turn on and off the 5Ghz. Unfortunately, the Edimax usb couldn’t find (see) the 2.4GHz network.

Noting that:

1. All the phones and laptops can find/see and access to the 2.4GHz. 
2. I also tried to turn on the Guess wifi with 2.4Ghz (but the Edimax coudn’t find/see the network).
3. the Edimax usb still can see other network providers from the neighbours surrounding. 
4. the Edimax usb worked well with the previous internet provider using a different router (not from ARRIS) but only when I turned on the IEEE802.11b/g/n standards using the settings. it seems this is the key issue. Unfortunately, I couldn’t find the option in the current model.

Thanks for your help.

Andy