802.11w PHYs ============== .. 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 is 802.11w PHY?** 802.11w does not define a new PHY; it operates on existing PHY layers of 802.11 standards, adding management frame protection. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11w affect modulation or coding schemes?** No, 802.11w operates independently of modulation and coding schemes, which are defined by the underlying PHY (e.g., 802.11a, 802.11n). .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11w improve PHY layer security?** It protects management frames by encrypting them, preventing spoofing and spoofed disassociation attacks that can disrupt PHY communication. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Which frequency bands does 802.11w work on?** 802.11w works on all frequency bands supported by the underlying PHY, including 2.4 GHz and 5 GHz bands. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11w require changes to OFDM or DSSS PHY?** No, 802.11w adds security features at higher layers without altering PHY modulation techniques like OFDM or DSSS. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11w cause PHY layer overhead?** Slightly, due to additional encryption and authentication of management frames, but PHY data rates remain unchanged. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is 802.11w compatible with half-duplex PHY like 802.11a?** Yes, 802.11w works transparently over half-duplex or full-duplex PHY implementations. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11w support MIMO or spatial streams?** 802.11w is PHY-agnostic and thus supports underlying PHY features like MIMO in 802.11n/ac without modifications. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11w affect latency at the PHY?** The added encryption processing may introduce minimal latency, but PHY symbol timing and transmission remain unaffected. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11w impact spectral efficiency?** No direct impact on spectral efficiency since it secures management frames, which are a small portion of overall transmissions. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11w interact with PHY preamble and header?** 802.11w frames use the standard PHY preamble and header defined by the underlying PHY standard without changes. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is 802.11w backward compatible with older PHYs?** Yes, but management frame protection features may be limited or disabled if the peer device does not support 802.11w. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11w operate over 20 MHz and 40 MHz channels?** Yes, it is independent of channel width and functions over any channel supported by the PHY. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11w change channel selection or frequency use?** No, channel planning and frequency use remain governed by the PHY and regulatory rules, unaffected by 802.11w. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **What PHY layers are commonly used with 802.11w?** 802.11a, 802.11b/g, 802.11n, and newer PHY layers commonly incorporate 802.11w for enhanced security. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11w require hardware changes in PHY?** Typically no, 802.11w is implemented mostly in firmware and software layers above the PHY. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **How does 802.11w improve reliability of PHY communication?** By securing management frames, it reduces denial-of-service attacks that can disrupt PHY connectivity. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Is 802.11w mandatory in modern Wi-Fi standards?** Yes, management frame protection is required or strongly recommended in modern standards like 802.11ac and 802.11ax. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Does 802.11w affect PHY transmit power?** No, transmit power settings are managed by PHY and regulatory constraints, unaffected by 802.11w. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Can 802.11w protect management frames in noisy PHY environments?** Yes, encryption and integrity checks enhance protection even when the PHY experiences interference or errors. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow **Summary: How does 802.11w relate to PHY?** 802.11w complements the PHY by securing management frames at higher layers, working transparently with all PHY types without altering physical transmission characteristics. .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: shadow Topics in this section, * :ref:`Reference links ` .. _phy_w_step17: .. tab-set:: .. tab-item:: Reference links * Reference links