point interframe space (802.11) (PIFS)
The Interframe Space(IFS) is a priority control in the CSMA/ CA process that works with several different durations: DIFS (Distributed), SIFS (Short), AIFS (Arbitrated) and PIFS (Point).
Point Interframe Space (PIFS) is used for the transmission of time-critical services with medium waiting times. A station with PIFS can transmit when no other stations with Short Interframe Space (SIFS) have a higher priority.