Which statement accurately describes SIFS in relation to other interframe spaces?

• A. Short Interframe Space (SIFS) has the highest priority.
• B. DIFS has the highest priority.
• C. EIFS has the highest priority.
• D. PIFS has the highest priority.

Answer: (A)

Interframe spaces control medium access timing in Wi‑Fi, and shorter waits mean higher priority for accessing the channel. Short Interframe Space is the smallest of these intervals, so crucial quick responses—like an ACK, CTS, or a data frame sent after receiving another frame—occur after a SIFS. This tiny pause minimizes the chance that another station grabs the medium and helps keep data flowing smoothly. Other intervals are longer: PIFS is used for PCF-related operations and sits between SIFS and DIFS in priority, DIFS governs ordinary contention-based access, and EIFS is the longest, used after certain error conditions to give the network extra time to recover. So SIFS has the highest priority among interframe spaces.