Possible Duplicate:
How to fix slow Wi-Fi on Thinkpads or other machines with Intel wireless cards?
After hours of searching the Internet for a solution for extremely slow WiFi connection on Ubuntu 11.10 & 12.04 on Intel wireless, how can I fix this?
Thanks amc for your nice editing of my post. Actually, I do not know what is the reason of the problem and what the solution is for :) :) The reason why I put this post is that it is extremely hard to find a solution for 12.04 and I hope any one can see this post to save time. For 11.10, it is easy because the solution is easily founded (reference No. 1 in my post above). But for 12.04, I did a trick to find the solution. You want to know what it is? Well, I discovered that the file responsible for the solution is changed in the new version of Ubuntu (12.04). I searched for it and found it. Then I replaced the new name by the old one. Then it worked. I put the post, that I founded the solution inside, in the references (No. 2). Mr. James, and Mr. Takkat, thank you all for your reply. Anyway, it is not duplication because the solution for 12.04 is the important one that you really suffer if you try to find it in the Internet!