There are some demonstrable reasons for customers who like use from wireless technology and this is clear because there are various benefits for using wireless technology. The contrast between wireless usage and security techniques growing, show that the security is not adequate enough for this data growing. It’s obvious that the hackers are able to monitor the transmitted data and hack whatever they want. So we see that these days Companies are investing more money on securing their wireless networks. There are three major type of security in wireless. In this paper, at first we try to completely explain the structure of WEP as a first wireless security technique and discuss about all versions of it. At the second step, we discuss about all problems of WEP and finally explain the solutions and improvements that done on this security technique. Then we are in the next plan witch is explain the structure of two other techniques (WPA, WPA2) and we hope that we will publish a completely comparison among wireless techniques in the near future.