802.11r Physical Rates ========================= .. 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 physical rates in 802.11r?** Physical rates refer to the data transmission speeds at the physical layer defined for 802.11r networks. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11r specify new physical rates compared to previous standards?** No, 802.11r uses the same physical rates as 802.11a and 802.11g but optimizes roaming processes. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How do physical rates affect fast roaming in 802.11r?** Higher physical rates enable faster exchange of authentication and reassociation frames, reducing roaming latency. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are physical rates dynamically adjusted in 802.11r?** Yes, 802.11r devices adapt physical rates based on signal quality and environmental factors during roaming. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What modulation schemes correspond to 802.11r physical rates?** 802.11r inherits OFDM modulation schemes from 802.11a/g, including BPSK, QPSK, 16-QAM, and 64-QAM. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is 802.11r limited to certain frequency bands for physical rates?** No, 802.11r operates in both 2.4 GHz and 5 GHz bands, supporting corresponding physical rates. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11r handle rate adaptation during fast BSS transition?** Rate adaptation algorithms select optimal physical rates quickly to maintain connection quality during roaming. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Do physical rates impact battery consumption in 802.11r devices?** Yes, higher physical rates can reduce transmission time, potentially saving battery life. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are there regulatory constraints affecting physical rates in 802.11r?** Physical rates comply with regional regulations on power and channel usage but are not uniquely restricted by 802.11r. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can physical rates cause roaming failures in 802.11r networks?** Improper rate adaptation or low rates may increase roaming time, but 802.11r mechanisms aim to minimize such risks. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are physical rates the same for control and data frames in 802.11r?** Control frames often use lower rates for robustness, while data frames use higher rates for throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11r support legacy clients with different physical rates?** 802.11r networks support a range of rates to accommodate both legacy and 802.11r-capable clients. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11r specify minimum physical rates for fast roaming?** No explicit minimum rates are mandated, but practical implementation favors higher rates for speed. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is MIMO technology used in 802.11r to enhance physical rates?** 802.11r itself doesn’t define MIMO but can operate alongside 802.11n/ac standards that use MIMO. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How are physical rates negotiated during the reassociation process in 802.11r?** Physical rates are negotiated based on AP and client capabilities and current radio conditions during reassociation. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Do physical rates affect the security handshake in 802.11r?** Physical rates impact the speed of handshake frame exchanges but do not affect security mechanisms directly. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11r physical rates vary across different vendors?** Physical rates follow standard modulation and coding schemes, but vendor optimizations may affect actual performance. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are there tools to measure physical rates in 802.11r deployments?** Yes, network analyzers and Wi-Fi testing tools can monitor and analyze physical rates during operation. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11r enhance user experience through physical rates?** By optimizing physical rates during roaming, 802.11r reduces latency and improves throughput continuity. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`physical_rates in 802.11r ` * :ref:`Reference links ` .. _physical_rates_80211r_step4: .. tab-set:: .. tab-item:: physical_rates in 802.11r ========== === ==== =========== ============ =========== ================ ========= ============ =========== ========== ====== Modulation BW Tsc FSP=BW/Tsc Tdata=1/FSP GI=Tdata/4 Symbol=Tdata+GI 1/Symbol Bits/Symbol Code rate Usable sc Rate ========== === ==== =========== ============ =========== ================ ========= ============ =========== ========== ====== BPSK 5 64 78.125 12.8 3.2 16 0.0625 1 1/2 48 1.5 BPSK 5 64 78.125 12.8 3.2 16 0.0625 1 3/4 48 2.25 QPSK 5 64 78.125 12.8 3.2 16 0.0625 2 1/2 48 3 QPSK 5 64 78.125 12.8 3.2 16 0.0625 2 3/4 48 4.5 16-QAM 5 64 78.125 12.8 3.2 16 0.0625 4 1/2 48 6 16-QAM 5 64 78.125 12.8 3.2 16 0.0625 4 3/4 48 9 64-QAM 5 64 78.125 12.8 3.2 16 0.0625 6 2/3 48 12 64-QAM 5 64 78.125 12.8 3.2 16 0.0625 6 3/4 48 13.5 BPSK 10 64 156.25 6.4 1.6 8 0.125 1 1/2 48 3 BPSK 10 64 156.25 6.4 1.6 8 0.125 1 3/4 48 4.5 QPSK 10 64 156.25 6.4 1.6 8 0.125 2 1/2 48 6 QPSK 10 64 156.25 6.4 1.6 8 0.125 2 3/4 48 9 16-QAM 10 64 156.25 6.4 1.6 8 0.125 4 1/2 48 12 16-QAM 10 64 156.25 6.4 1.6 8 0.125 4 3/4 48 18 64-QAM 10 64 156.25 6.4 1.6 8 0.125 6 2/3 48 24 64-QAM 10 64 156.25 6.4 1.6 8 0.125 6 3/4 48 27 BPSK 20 64 312.5 3.2 0.8 4 0.25 1 1/2 48 6 BPSK 20 64 312.5 3.2 0.8 4 0.25 1 3/4 48 9 QPSK 20 64 312.5 3.2 0.8 4 0.25 2 1/2 48 12 QPSK 20 64 312.5 3.2 0.8 4 0.25 2 3/4 48 18 16-QAM 20 64 312.5 3.2 0.8 4 0.25 4 1/2 48 24 16-QAM 20 64 312.5 3.2 0.8 4 0.25 4 3/4 48 36 64-QAM 20 64 312.5 3.2 0.8 4 0.25 6 2/3 48 48 64-QAM 20 64 312.5 3.2 0.8 4 0.25 6 3/4 48 54 ========== === ==== =========== ============ =========== ================ ========= ============ =========== ========== ====== .. _physical_rates_80211r_step17: .. tab-set:: .. tab-item:: Reference links * Reference links