Thank you for your post.
Indeed the signal and speed should be maintained unchanged if you are in the same room and no furniture is in-between your laptop and the router and reasonable range. Not getting full signal while being next to the router is an indication of a hardware issue.
There is one setting that can affect the range and single strength, this is the transmit power. To access this setting go to device manager, double-click on “network adapters” double click on the Intel® Centrino® Wireless-N 2200 adapter then click on the ‘Advanced’ tab and set the ‘transmit power’ option to highest.
my TX power is at maximum, that isn't the issue.
I'm now downloading newly released driver fromvhttp://downloadcenter.intel.com/Detail_Desc.aspx?ProductID=3507&DwnldID=22495&lang=eng&iid=dc_rss.
I hope it helps.
BTW: the automated driver update check on your website didn't show this driver, i found it via google. The Driverupdate tool shows old driver from 2011 as the most actual version.
UPDATE: the driver download page, that it is 15.6... version, but it is the 15.4 in the installation. Nothing has changed, still the same.