You may want to download the latest Intel® wireless driver since several users have reported it has solved the issue for them.
Intel® PROSet/ Wireless Software Downloads
http://www.intel.com/support/wireless/wtech/proset-ws/sb/CS-034041.htm
Additionally you may also check if the router or AP is using WPA(2)-AES, a fixed and least congested 2.4GHz channel, and the latest firmware installed. Other recommendations are available from the following articles:
How do I improve my 802.11n wireless performance?
http://www.intel.com/support/wireless/wlan/4965agn/sb/CS-028449.htm
Possible interference by other wireless devices may impact 802.11n performance
http://www.intel.com/support/wireless/wlan/sb/CS-031509.htm
Access Point (AP) firmware updates may resolve wireless network issues
http://www.intel.com/support/wireless/wlan/sb/CS-006321.htm
Power save polling (PSP) causes connection issues with access points