802.11h 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 the context of 802.11h?** Physical rates refer to the raw data transmission speeds supported at the physical layer of 802.11h devices. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11h define new physical rates?** No, 802.11h primarily focuses on regulatory compliance (DFS and TPC) and uses the physical rates defined in 802.11a. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What frequency bands does 802.11h operate in?** 802.11h operates mainly in the 5 GHz band, which supports the physical rates defined in 802.11a. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What are typical physical data rates supported under 802.11h?** Rates range from 6 Mbps to 54 Mbps using OFDM modulation as defined in 802.11a. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does Transmit Power Control (TPC) affect physical rates?** TPC adjusts transmit power but does not directly change physical rates; however, lower power can affect signal quality and thus throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are physical rates in 802.11h affected by Dynamic Frequency Selection (DFS)?** DFS selects channels to avoid radar, but physical rates on those channels remain consistent with 802.11a standards. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can devices dynamically change physical rates in 802.11h networks?** Yes, rate adaptation algorithms adjust the physical rate based on link quality and interference. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11h specify rate adaptation mechanisms?** No, rate adaptation is handled by implementations and is not defined by 802.11h itself. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are there any rate limitations imposed by 802.11h regulations?** No direct rate limitations, but power restrictions can indirectly affect achievable throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How do power constraints in 802.11h impact physical rates?** Reduced transmit power may lead to lower signal-to-noise ratio, causing devices to select lower physical rates for reliability. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are all 802.11a rates supported in 802.11h?** Yes, 802.11h supports the full range of OFDM rates defined in 802.11a. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does channel switching under DFS impact physical rates?** Channel switching can cause temporary rate drops due to re-association and link adaptation. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are MIMO or newer physical rate technologies part of 802.11h?** No, 802.11h predates MIMO and focuses on 5 GHz regulatory mechanisms. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can physical rates be different in various regulatory domains for 802.11h?** The rates are consistent, but allowed transmit power varies by region, impacting effective throughput. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How do environmental factors affect 802.11h physical rates?** Interference, distance, and obstacles influence signal quality, prompting rate adaptation for best performance. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is there a minimum physical rate defined in 802.11h?** The minimum rate follows 802.11a standards, typically 6 Mbps. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are control and management frames sent at different physical rates in 802.11h?** Control frames often use lower robust rates to ensure delivery, consistent with 802.11a practices. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11h impact data throughput?** Indirectly, through power control and channel management, but it does not specify throughput enhancements. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`physical_rates in 802.11h ` * :ref:`Reference links ` .. _physical_rates_80211h_step4: .. tab-set:: .. tab-item:: physical_rates in 802.11h ========== === ==== =========== ============ =========== ================ ========= ============ =========== ========== ====== 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_80211h_step17: .. tab-set:: .. tab-item:: Reference links * Reference links