Precise Measurement of Wireless Network Roaming Functionality and Network Component Parameters Applied for Automation Systems

Abstract

The contemporary wireless networks in use have to solve problems with moving wirelessly connected devices. Such devices can move inside a one wireless network cell or across the several ones in the frame of one network or even from the one network to another. The conventional wireless connection types were designed for providing basic roaming functionality. The same functionality can be used in automation wireless networks. Main problems of roaming in automation networks especially in time-critical applications are speed of roaming procedure, and security of roaming procedure. Automation systems are very sensitive to packet losses and time delays in the communication. Securing of communication link during roaming is also required. Roaming speed goes directly against security level and it's very important to specify requirements of possible automation applications to maximum time delay and minimum security level. Roaming process and time consumption of its particular procedures is in detail described and measured in this paper. Based on required parameters to maximum roaming delay time and security level should be selected optimal compromise between these two parameters. The chapter below is focused on the roaming functionality available in WLANs, their main features, basic principles and concrete testing of these important parameters.