802.11ax MAC Timings ======================= .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are MAC timing parameters in IEEE 802.11ax?** They define precise timing intervals for frame exchanges, medium access, and retransmissions to coordinate wireless communication. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is SIFS in 802.11ax?** Short Interframe Space (SIFS) is the shortest waiting time between frame transmissions, used for ACKs and CTS frames. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is AIFS and how is it used?** Arbitration Interframe Space (AIFS) varies by traffic priority and controls medium access delays in contention-based transmissions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11ax handle backoff timing?** Stations choose random backoff intervals within contention windows to avoid collisions and ensure fair medium access. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the purpose of Slot Time in MAC timings?** Slot Time is the basic unit of time used for counting backoff periods and sensing the channel. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC timing coordinate MU transmissions in 802.11ax?** Trigger frames are scheduled with specific timing to allow multiple users to transmit simultaneously without collisions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What timing changes does 802.11ax introduce over 802.11ac?** Reduced SIFS, optimized AIFS, and flexible timing parameters to support OFDMA and spatial reuse. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the role of the Extended Interframe Space (EIFS)?** EIFS is a longer wait used after detecting erroneous frames to avoid interference during retransmission. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does the MAC layer use timing for power saving?** It uses Target Wake Time (TWT) scheduling to coordinate sleep and wake intervals efficiently. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the impact of timing on throughput?** Proper timing minimizes collisions and idle periods, maximizing channel utilization and throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How is timing handled during retransmissions?** The MAC uses backoff timers and waits defined by AIFS and SIFS before retrying failed transmissions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What timing controls are in place for QoS in 802.11ax?** Different AIFS and contention window sizes are assigned to traffic categories to prioritize delay-sensitive data. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does spatial reuse affect MAC timings?** Spatial reuse mechanisms adjust Clear Channel Assessment (CCA) thresholds and timing to allow simultaneous transmissions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the significance of Multi-User SIFS (MU-SIFS)?** MU-SIFS is a shortened SIFS interval used to separate multi-user transmissions efficiently. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are timing parameters configurable in 802.11ax?** Yes, certain timing values like AIFS and contention windows can be adjusted for traffic management. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does the MAC coordinate uplink and downlink timing?** The AP schedules transmissions using trigger frames and ensures timing synchronization among clients. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the MAC’s role in beacon timing?** Beacons are transmitted at regular intervals to synchronize stations and convey network information. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does MAC timing affect latency?** Reduced interframe spaces and optimized backoff decrease transmission delays, improving latency-sensitive applications. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What timing challenges arise in dense network environments?** Increased contention requires fine-tuned timing parameters to reduce collisions and maintain performance. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How is timing critical for efficient OFDMA operation?** Precise timing ensures resource units are allocated and transmissions are synchronized to avoid overlap and interference. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`Learnings in this section ` * :ref:`Terminology ` * :ref:`Version Info ` * :ref:`mac_timings Basic Setup on Ubuntu using IPv4 ` * :ref:`Reference links ` .. _mac_timings_step1: .. tab-set:: .. tab-item:: Learnings in this section * In this section, you are going to learn .. _mac_timings_step2: .. tab-set:: .. tab-item:: Terminology * Terminology .. _mac_timings_step3: .. tab-set:: .. tab-item:: Version Info * Version Info .. _mac_timings_step18: .. tab-set:: .. tab-item:: mac_timings Basic Setup on Ubuntu using IPv4 * setup .. _mac_timings_step17: .. tab-set:: .. tab-item:: Reference links * Reference links