List of PPDUs Supported in 802.11bn
What is a PPDU in 802.11bn?
PPDU (Physical Layer Protocol Data Unit) is the physical layer packet transmitted over the air, containing preamble, header, and payload.
What are the main components of an 802.11bn PPDU?
A preamble, PHY header, payload data, and tail bits.
How does the 802.11bn PPDU differ from 802.11b and 802.11n PPDUs?
It supports coexistence of legacy 802.11b and newer 802.11n formats, combining protection and efficiency mechanisms.
What types of preambles are used in 802.11bn PPDUs?
Legacy preamble, mixed-mode preamble, and greenfield preamble optimized for b/n coexistence.
What is the purpose of the mixed-mode preamble in 802.11bn?
To maintain backward compatibility by including legacy preamble fields alongside HT fields.
How does 802.11bn handle frame aggregation in PPDUs?
It supports A-MPDU and A-MSDU frame aggregation to improve throughput and reduce overhead.
What is the maximum number of spatial streams supported in 802.11bn PPDUs?
Up to 4 spatial streams can be transmitted simultaneously.
What modulation and coding schemes (MCS) are supported in 802.11bn PPDUs?
MCS indexes 0-31, supporting BPSK, QPSK, 16-QAM, and 64-QAM with various coding rates.
What is the Greenfield PPDU format in 802.11bn?
A streamlined PPDU format without legacy support, optimized for pure 802.11n operation.
How does coexistence with 802.11b devices affect the PPDU design?
Protection mechanisms like RTS/CTS and legacy preambles increase PPDU duration to avoid collisions.
What is the function of the PHY header in 802.11bn PPDUs?
It conveys essential information for decoding such as rate, length, and format.
What is the maximum PPDU length allowed in 802.11bn?
Up to 4 milliseconds, supporting large frame aggregations.
How does channel bonding affect PPDU transmission in 802.11bn?
Bonding two 20 MHz channels into one 40 MHz channel increases data rates within the PPDU.
What are tail bits in 802.11bn PPDUs?
Bits appended to flush the convolutional encoder to a known state at the end of transmission.
How does Short Guard Interval (SGI) improve 802.11bn PPDU performance?
SGI reduces the guard interval to 400 ns, increasing throughput by decreasing inter-symbol spacing.
Are 802.11b preambles supported within 802.11bn PPDUs?
Yes, to support legacy devices, legacy preambles are included when necessary.
What is the significance of frame aggregation in 802.11bn PPDUs?
It reduces overhead and increases transmission efficiency by combining multiple frames into one PPDU.
How does the receiver identify the PPDU format in 802.11bn?
The preamble and PHY header fields signal the PPDU type and decoding parameters.
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