Point Coordination Function

Point Coordination Function (PCF ) is a media access method, which is used in WLANs.

This method uses a central station, often in order to coordinate an access point to access the individual stations.

The central control collisions are avoided.

High traffic areas, the access point switches to the polling mode, wherein each client is requested by polling for data transfer.

IPCF

IPCF ( industrial Point Coordination Function ) or Rapid Roaming is an extension of the IEEE 802.11 standard. It is a proprietary method which on a single wireless infrastructure roaming times less than 50 ms. Both the access point and client must support roaming Rapid.

In automation technology, it is necessary in many applications to transfer process data and alarms in real-time ( on the definition of IEEE and IEC). The existing roaming procedure DCF and PCF do not allow to transmit this data without interruption in real-time. This method was developed in the context of Profinet.