Nowadays the use of wireless communications solutions is taken for granted in our daily life. Wireless LAN networks have achieved great popularity and with radio technologies like Bluetooth, data can be shared between various devices quickly and flexibly. Once these technologies had proven their value in private use, attention shifted to their application in the field of business. While the issue of security is not so relevant for the private user, this factor has high priority in business use.

Special points of interest were:

• Show the differences of such a solution compared to a fixed network in the areas of costs, performance and operations.
• Analyse the existing security mechanisms
• Analyse the possibilities for the use of overlaying security mechanisms

In the first part of the diploma thesis a comprehensive overview of the available wireless communications solutions was created. The main attention was directed to the security mechanism of the systems. Moreover, concrete scenarios were used to show whether and under which conditions a wireless network can replace a wired network. Alternatives to the last mile connection were also evaluated. Because of the fact that the existing security implementations show weaknesses and therefore cannot fulfill the companies? needs, the concept of virtual private networks (VPN) was considered.

During the second part the use of IP security (IPSec) was tested for its applicability in SMBs. For this purpose a wireless network was set up and various VPN products were tested.

Based on the knowledge collected during the diploma thesis a recommendation was prepared and an introduction was written.