802.11bn 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 802.11bn?** These define how long devices wait between transmissions, timing for acknowledgments, inter-frame spacing, slot times, backoff, and coordination amongst multiple APs/devices. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Will 802.11bn modify SIFS or other spacings compared to earlier standards?** Yes, expectations are that 802.11bn may introduce tweaks (e.g. shorter or more adaptive SIFS, optimized guard times) for ultra-high reliability and low latency. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How will backoff slot duration behave in 802.11bn?** Likely similar to earlier OFDM-based systems but with optimizations: possibly dynamic slot durations depending on channel conditions or device capability. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What about contention window (CW) sizes in 802.11bn?** CWmin and CWmax will be defined; expected to support rapid expansion and contraction depending on network load, especially in dense deployments. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How will ACK timeout be handled in 802.11bn?** The standard is likely to define tighter ACK timeout windows, accounting for faster PHY and reduced delays. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is there going to be adaptive inter-frame spaces in 802.11bn?** Yes, possibly adaptive IFS (including SIFS, AIFS, etc.) based on PHY rate, channel conditions, or device class to reduce latency. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How will inter‐frame spacing affect throughput vs reliability tradeoff?** Shorter spacing improves throughput but risks more collisions; 802.11bn aims to balance this via optimized timing and interference-aware designs. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What timing for retransmissions under high error rate scenarios?** Retry intervals might include increased backoff or adjusted spacing to avoid further collisions and maintain reliability. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How will 802.11bn handle timing in multi‐AP coordination?** Coordinated transmission scheduling may require synchronized timing between APs, guard intervals for overlap, and coordination of contention windows. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is EIFS in 802.11bn and how might it be adjusted?** EIFS would manage extended wait times after errors; 802.11bn may refine its formula (e.g. tighter bounds or adjustable based on MPDU loss stats). .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Will beacon interval timing change in 802.11bn?** Potentially yes — for synchronization, faster roaming, and lower latency, beacon intervals may be tunable or shorter where supported. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the impact of channel bonding or wider bandwidths on MAC timing?** Wider channels may introduce longer signal detection, processing, or guard intervals; 802.11bn might adjust timings accordingly. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How will timing enforce fairness among legacy and 802.11bn devices?** Through protection modes, careful timing of backoff and contention windows, possibly delay penalties for slower devices. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How are NAV durations handled in 802.11bn timing?** NAV values define virtual busy periods; 802.11bn may include optimizations to limit NAV size, reduce wasted airtime. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What about TXOP timings for multi‐frame transmissions?** TXOP (Transmission Opportunity) durations might be extended, better scheduled, especially when using aggregation or multi-user transmissions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are there special timing requirements for ultra-low latency applications?** Yes — 802.11bn aims to support ultra-low latency and high reliability, so timings for control frames, acknowledgments, and retransmissions will be optimized. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How will MAC timing adapt with mobility or device movement?** Movement can introduce delay variations; 802.11bn may include timing allowances or guard intervals to accommodate mobility. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Do timing values depend on PHY features like MIMO, OFDMA or new coding?** Yes, PHY enhancements have impact on MAC delays (encoding/decoding, multi-user scheduling) so MAC timings will be tuned accordingly. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Where can one find the finalized MAC timing values for 802.11bn?** Timing values will be published in the IEEE 802.11bn standard documentation once ratified; in the meantime, draft minutes and contributions from Task Group bn provide proposals. :contentReference[oaicite:0]{index=0} .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`Reference links ` .. _mac_timings_step17: .. tab-set:: .. tab-item:: Reference links * Reference links