List of PPDUs Supported in 802.11r
========================================


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        **What is a PPDU in 802.11r?**

        PPDU stands for Physical Protocol Data Unit, the basic transmission unit at the physical layer in 802.11r networks.

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        **How does 802.11r PPDU differ from 802.11a/g PPDU?**

        The 802.11r PPDU format remains the same as 802.11a/g, focusing changes at the MAC layer for fast roaming.

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        **What are the main components of the 802.11r PPDU?**

        The PPDU consists of the preamble, header (signal field), and payload data.

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        **Does 802.11r modify the PPDU preamble?**

        No, it uses the same OFDM preamble as 802.11a/g for synchronization and channel estimation.

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        **What modulation types are used in 802.11r PPDU?**

        BPSK, QPSK, 16-QAM, and 64-QAM modulation schemes are used based on link conditions.

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        **Is the channel bandwidth for 802.11r PPDU fixed?**

        Typically, 20 MHz channel bandwidth is used, consistent with 802.11a/g standards.

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        **How is error correction handled in 802.11r PPDU?**

        Through convolutional coding and interleaving techniques similar to 802.11a/g.

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        **Does 802.11r PPDU include any new signaling fields?**

        No, it maintains the existing signal fields for rate, length, and modulation info.

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        **How does 802.11r PPDU support fast BSS transition?**

        The PPDU itself is unchanged; fast transition is achieved through optimized MAC-layer handshakes.

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        **Are there timing changes in 802.11r PPDU?**

        No changes; symbol durations and guard intervals match 802.11a/g specifications.

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        **What is the maximum data rate of 802.11r PPDU?**

        Up to 54 Mbps using 64-QAM with 3/4 coding rate, same as 802.11a/g.

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        **Can non-802.11r devices decode 802.11r PPDUs?**

        Yes, because the PPDU format is backward compatible.

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        **Is there any difference in PPDU security for 802.11r?**

        Security is handled at higher layers; the PPDU just carries encrypted frames.

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        **Does 802.11r PPDU support frame aggregation?**

        Aggregation is introduced in later amendments like 802.11n/ac, not directly by 802.11r.

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        **What role does the PPDU play during a handoff?**

        It carries frames seamlessly before and after roaming to maintain connection continuity.

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        **Is the PPDU payload format changed in 802.11r?**

        No, payloads follow the same MAC frame structures as legacy 802.11 standards.

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        **Does 802.11r affect PPDU transmission power?**

        No, transmission power is controlled by regulatory rules, not the PPDU format.

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        **How is synchronization achieved in 802.11r PPDU?**

        Via the OFDM preamble which includes short and long training symbols.

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        **Are any new PHY features added in 802.11r PPDUs?**

        No new PHY features; improvements focus on MAC layer for fast transition.


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        Topics in this section,

                * :ref:`Reference links <ppdu_80211r_step17>`

.. _ppdu_80211r_step17:

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    .. tab-item:: Reference links

       * Reference links