This may not help the OP with their issue, but yours is likely caused by interference on the 2.4GHz band.
If you use a standard wireless router, it will be 2.4GHz. This is the same frequency as fluorescent lights, microwaves, baby monitors and almost all wireless networking equipment. Anything on the same frequency will cause interference when in use.
I use a dual-band router with 2.4 and 5GHz. Not only is there no interference on the 5GHz band, but the throughput is higher (can download faster). I have no problem reaching 4.5-6 mb/s downloads and 1.5-3 mb/s uploads when using 5GHz. When using the 2.4GHz band, I top out at 2 mb/s down, 0.5 mb/s up.