Point Coordination Function (PCF)
Solves Hidden Node problem
- Two computers can not detect each other’s signals
- A computer is near the transmission limits of the AP at one end and another computer is near the transmission limits at the other end of the AP’s range
- Physical carrier sense method will not work
Solution
- First send a Request To Send (RTS) signal to the AP
- Request to reserve the circuit and duration
- AP responds with a Clear To Send (CTS) signal,
- Also indicates duration that the channel is reserved
- Computer wishing to send begins transmitting