802.11u 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 frequency bands does 802.11u support for physical rates?** 802.11u primarily operates on the 2.4 GHz and 5 GHz bands as defined by underlying 802.11 PHYs. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11u define new physical layer rates?** No, 802.11u is an amendment focused on network interworking, using existing PHY rates from standards like 802.11a/b/g/n. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11u affect rate adaptation algorithms?** It does not directly modify rate adaptation but supports features that improve network selection based on PHY rates. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are the physical rates in 802.11u dependent on underlying 802.11 standards?** Yes, 802.11u uses physical rates defined by the underlying standard (e.g., 6-54 Mbps for 802.11a). .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What modulation schemes correspond to physical rates in 802.11u?** Modulation schemes like BPSK, QPSK, 16-QAM, and 64-QAM from the underlying PHY standards are used. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11u devices dynamically change rates during communication?** Yes, rate adaptation is inherited from underlying PHY implementations. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11u improve throughput with physical rates?** By enabling intelligent network selection and interworking, devices may connect to networks supporting optimal PHY rates. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11u specify channel widths for physical rates?** No, channel widths are defined by the underlying PHY, such as 20 MHz or 40 MHz in 802.11n. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are MIMO and beamforming part of 802.11u physical rate enhancements?** No, these features are part of later standards like 802.11n/ac, not 802.11u. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11u interact with Quality of Service (QoS) regarding physical rates?** While 802.11u manages network access and selection, QoS and rate prioritization are handled by other amendments like 802.11e. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11u enable faster physical rates in public networks?** Indirectly, by allowing seamless roaming to networks that support higher PHY rates. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What is the maximum physical rate supported when using 802.11u?** It depends on the underlying PHY; for example, up to 54 Mbps in 802.11a/g or higher in 802.11n/ac. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How are physical rates advertised in 802.11u?** Through management frames from the underlying PHY standard, not specifically by 802.11u. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11u require new hardware for physical rate support?** No, it leverages existing hardware compliant with underlying PHY standards. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Are physical rates affected by network interworking features of 802.11u?** Physical rates themselves are not affected but interworking can influence which network a device chooses based on rates. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How do physical rates in 802.11u affect roaming?** Devices may select networks offering higher physical rates, improving user experience during roaming. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11u support dual-band operation affecting physical rates?** Yes, through underlying dual-band capable PHYs, enabling operation in 2.4 GHz and 5 GHz bands. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What factors influence physical rate selection in 802.11u networks?** Signal quality, interference, network policies, and device capabilities all play a role. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Where can I find detailed physical rate specifications for 802.11u?** In the underlying PHY standards referenced by 802.11u such as 802.11a/b/g/n documents. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`physical_rates in 802.11u ` * :ref:`Reference links ` .. _physical_rates_u_step4: .. tab-set:: .. tab-item:: physical_rates in 802.11u ========== === ==== =========== ============ =========== ================ ========= ============ =========== ========== ====== 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_u_step17: .. tab-set:: .. tab-item:: Reference links * Reference links