802.11ad 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 timings in 802.11ad?** MAC timings in 802.11ad refer to time intervals and parameters governing how devices schedule and access the wireless medium in the 60 GHz band, including contention-free and contention-based periods. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Why are MAC timings important in 802.11ad?** They ensure efficient use of the wide 60 GHz spectrum, reduce collisions with directional antennas, and maintain low latency especially during service periods. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are CBAPs (Contention Based Access Periods)?** Periods where stations contend for medium access using a scheme similar to DCF, but optimized for directional operations in 802.11ad. :contentReference[oaicite:0]{index=0} .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are Service Periods (SPs) in 802.11ad?** Scheduled, contention-free service windows where the PCP/AP grants exclusive medium access to stations. :contentReference[oaicite:1]{index=1} .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How do CBAPs and SPs together affect latency and throughput?** CBAPs allow more flexible access but potentially more contention, whereas SPs reduce contention and improve throughput for scheduled traffic; the mix balances overall performance. :contentReference[oaicite:2]{index=2} .. panels:: :container: container pb-4 :column: col‑lg‑12 p‑2 :card: shadow **How are beacon intervals used in 802.11ad MAC timing?** Beacons coordinate timing, announce CBAP/SP schedules, and assist with beamforming alignment. :contentReference[oaicite:3]{index=3} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **What is the role of directional switching times?** 802.11ad includes beam steering/training and sector sweeping, which require additional timing to align transmitter and receiver sectors before data exchange. :contentReference[oaicite:4]{index=4} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **Is there a “short interframe space” equivalent in 802.11ad?** While 802.11ad does retain certain rapid response intervals, its major timing differentiators are CBAP vs SP scheduling and sector transitions rather than fixed short IFS intervals like in legacy standards. :contentReference[oaicite:5]{index=5} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **How does the timing of beamforming training affect overall MAC timing?** Beamforming training (antenna sector training) adds overhead, and its scheduling is factored into beacon and SP/CBAP periods. :contentReference[oaicite:6]{index=6} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **What are the challenges of MAC timings in 802.11ad due to high frequency?** 60 GHz signals suffer high path loss and sensitivity to blockage, so timing must accommodate rapid alignment, switching, and faster guard intervals. :contentReference[oaicite:7]{index=7} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **Does 802.11ad use contention‐free periods always?** No; it mixes contention-based CBAPs with scheduled SPs to support both flexible and predictable access. :contentReference[oaicite:8]{index=8} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **How are CBAP durations determined?** Through configuration advertised via beacons; influenced by network usage, traffic types, and load. :contentReference[oaicite:9]{index=9} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **What timing parameters are configurable?** CBAP schedule, SP durations, beacon interval, sector sweep durations. :contentReference[oaicite:10]{index=10} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **Does 802.11ad define slot times like 802.11ac?** Not exactly; a lot depends on the PHY being used (single carrier vs OFDM), directional sector sweep timings, and SP/CBAP schedules. The concept of “slot” exists but is less fixed in directional context. :contentReference[oaicite:11]{index=11} .. panels:: :container: container pb‑4 :column: col‑lg‑12 p‑2 :card: shadow **Where can I find official MAC timing values for 802.11ad?** In the IEEE 802.11ad standard documents, particularly sections on MAC and medium access (Service Period / CBAP scheduling). :contentReference[oaicite:12]{index=12} .. 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