Why wait SIFS time before sending ACK?

Question

Question about the MAC-protocol of 802.11 Wifi.

We have learned that when a station has received the data it waits for SIFS time. Then it sends the packet. When searchin

Answer 1

SIFS=D+M+Rx/Tx

Where,

D=(Receiver delay (RF delay) and decoding of physical layer convergence procedure (PLCP) preamble/header)

M=(MAC processing delay)

Rx/Tx=(transceiver turnaround time)

Above all the delays can not be avoided so It has to wait SIFS time before sending acknowledgement