Industrial Point Coordination Function (iPCF) is an access method for collision-free access to an industrial WLAN, Industrial WLAN
(IWLAN). Since real-time behavior is crucial in IWLANs, the proprietary iPCF method uses a deterministic procedure that cyclically allocates transmit and receive times to the individual stations. The iPCF method supports uninterrupted real-time transmission with fixed delay times for control data and process data, while accelerating roaming between access points
. Since the roaming times are less than 50 ms, this is also referred to as rapid roaming.
With the iPCF method, the clients and the access points must support rapid roaming.