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Industrial Ethernet Book 103

Technology Fast roaming: a challenge for industrial Wi-Fi applications Fast roaming WiFi offers reliable and secure communication, especially for mobile applications. For train-toground applications and automated guided vehicles, wireless IEEE 802.11 networks are suitable because of long range and high data rates, and when participants can be moving over long distances at high speeds. Application example of train-to-trackside communication. IEEE 802.11 WI-FI WIRELESS NETWORKS are used today in a wide variety of applications. This technology is well known for its long range and high transmission speeds. However, fast roaming is a particular challenge for the quality characteristics of Wi-Fi networks in industrial environments. Fast roaming is especially important when the reliability and security of communication in a mobile application scenario needs to be unaffected. However, due to the complexity of this application, optimizing a wireless network for operation is far from straightforward and offers technical challenges. Wireless networks can offer many new options for the implementation of industrial applications. On the one hand, they offer an easy-to-install option to provide facilities in changing environments with network communications. On the other hand, the use of wireless networks minimizes the cost of applications in which wear and tear would damage or destroy cable connections quickly. In addition, the use of wireless communication systems becomes mandatory whenever communication between mobile clients needs to be implemented. Thanks to their long range and high data rates, wireless IEEE 802.11 networks are suitable for the sophisticated application scenarios of Train-to-Ground Communication and Automated Guided Vehicles (AGVs) in which the participants can be moving over long distances at high speeds. Factoring Wi-Fi network quality The objec t i ve of t rain- to-ground communication is to establish fast and reliable signal transmission between trains and the subway and track-side infrastructure. The network on a train can connect WLAN clients on the train via specialized Wi-Fi with different access points along the route. The communication range of the trackside access points and the wireless network on-train clients are particularly important for the reliability and efficiency of such a system since every switchover (roaming) of a client between two different access points along the route causes an interruption of the train-toground connection. Hence, frequent roaming degrades the connection quality, especially when the interruption is long. The network requirements for the AGV application are very similar in terms of coverage and interruptions. In this case, vehicles are moving autonomously through a manufacturing site to independently fulfil various tasks. The vehicles communicate with the infrastructure about sensitive and timecritical information necessary for autonomous operation, such as receiving control 42 industrial ethernet book 11.2017 SOURCE: BELDEN


Industrial Ethernet Book 103
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