List of PPDUs Supported in 802.11r
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.
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.
What are the main components of the 802.11r PPDU?
The PPDU consists of the preamble, header (signal field), and payload data.
Does 802.11r modify the PPDU preamble?
No, it uses the same OFDM preamble as 802.11a/g for synchronization and channel estimation.
What modulation types are used in 802.11r PPDU?
BPSK, QPSK, 16-QAM, and 64-QAM modulation schemes are used based on link conditions.
Is the channel bandwidth for 802.11r PPDU fixed?
Typically, 20 MHz channel bandwidth is used, consistent with 802.11a/g standards.
How is error correction handled in 802.11r PPDU?
Through convolutional coding and interleaving techniques similar to 802.11a/g.
Does 802.11r PPDU include any new signaling fields?
No, it maintains the existing signal fields for rate, length, and modulation info.
How does 802.11r PPDU support fast BSS transition?
The PPDU itself is unchanged; fast transition is achieved through optimized MAC-layer handshakes.
Are there timing changes in 802.11r PPDU?
No changes; symbol durations and guard intervals match 802.11a/g specifications.
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.
Can non-802.11r devices decode 802.11r PPDUs?
Yes, because the PPDU format is backward compatible.
Is there any difference in PPDU security for 802.11r?
Security is handled at higher layers; the PPDU just carries encrypted frames.
Does 802.11r PPDU support frame aggregation?
Aggregation is introduced in later amendments like 802.11n/ac, not directly by 802.11r.
What role does the PPDU play during a handoff?
It carries frames seamlessly before and after roaming to maintain connection continuity.
Is the PPDU payload format changed in 802.11r?
No, payloads follow the same MAC frame structures as legacy 802.11 standards.
Does 802.11r affect PPDU transmission power?
No, transmission power is controlled by regulatory rules, not the PPDU format.
How is synchronization achieved in 802.11r PPDU?
Via the OFDM preamble which includes short and long training symbols.
Are any new PHY features added in 802.11r PPDUs?
No new PHY features; improvements focus on MAC layer for fast transition.
Topics in this section,
Reference links