Point coordination function
Point Coordination Function (PCF) is a media access method that is used in WLANs .
This procedure works with a central station, often a wireless access point , to coordinate the access of the individual stations.
The central control avoids collisions.
In heavy traffic, the access point switches to this polling order mode in which each client by polling for data transfer is requested.
iPCF
iPCF (industrial Point Coordination Function) or Rapid Roaming is an extension of the IEEE 802.11 standard . It is a proprietary method that supports roaming times of less than 50 ms in a WLAN infrastructure. Both the access point and the client must support rapid roaming.
In automation technology, it is necessary in many applications to transmit process data and alarms in real time (based on the definition of IEEE and IEC). The existing roaming processes DCF and PCF do not allow this data to be transmitted in real-time without interruption. This procedure was developed as part of Profinet .