Constant increase in use of wireless infrastructure networks for business purposes created a need for strong safety mechanisms. This paper describes WEP (Wired Equivalent Privacy) protocol for the protection of wireless networks, its security deficiencies, as well as the various kinds of attacks that can jeopardize security goals of WEP protocol: authentication confidentiality and integrity. The paper, also, gives a summary of security improvements of WEP protocol that can lead to the higher level of wireless network infrastructure protection. Comparative analysis shows the advantages of the new 802.11i standard in comparison to the previous security solutions. A proposal of possible security improvements of RSNA (Robust Security Network Association) is presented.