HCF Controlled Channel Access (HCCA) is a further development of the Point Coordination Function (PCF) and is used in access points (AP) of WLANs
.access point distributes the transmission right in polling mode
.During the HCCA period, the access point requests the individual stations to transmit one after the other. In this process, the stations are given clearance for a certain period of time and not only for the transmission of a single frame
. Various transmission parameters can be queried via the HCCA signal frame, such as thelatency, the jitter
, etc. A significant advantage of HCCA over the PCF method is that the implementation is mandatory in 802.11e.