@I_A: The 2.4GHz band is typically more congested, but in this case I don’t think that is the OP’s issue at all. He has already stated that the throughput of other devices in the same network is much higher, and the link quality and signal level reported were reasonable too. When he refers to 5GHz band, he probably means the 5.8GHz band, as used by many countries for 802.11a, 802.11n, 802.11ac devices. The firmware in combination with the correct country code usually takes care of the compliance issues for given countries.