I was achieving less than a quarter of that before I bought high gain arial for sky router as a couple on here recommended I am no maplins shareholder but really recommend this it works simple as well just un screw arial and screw in new one DRAMATIC difference.
my signal strength rarely dips below excellent now on occaision might get a very good signal before it was either marginal or low my wireless card in laptop constant 108mbps.

Best 15 you are likely to spend on such a simple device