HE MU PPDU PPDU

PHY variable HE MU PPDU unverified

A high-efficiency downlink transmission to several stations at once.

Reading a capture

The longest preamble of the 802.11ax family, and worth it only when there are several stations to serve. Sending one small frame this way costs more airtime than sending it single-user — multi-user is an efficiency mechanism for many recipients, not a speed mechanism for one.

Subfields

HE-SIG-A — Two symbols of parameters common to the whole transmission, including how long the HE-SIG-B that follows is.
HE-SIG-B — Which stations are in this transmission, on which resource units, at which rates.
HE-STF — Short training for the HE portion.
HE-LTF — Long training fields, one set per spatial stream.
Data field — The PSDU. Several stations' data, each on its own resource unit.
Packet Extension — Processing time after the data.

Where it sits

HE MU PPDU

Open in the explorer — Ack
Open in the explorer — TCP over IPv4, in a protected QoS Data frame, aggregated
Open in the explorer — Association Request
Open in the explorer — Association Response
Open in the explorer — Beacon
Open in the explorer — Compressed Block Ack
Open in the explorer — CTS
Open in the explorer — Four-way handshake message 1
Open in the explorer — Four-way handshake message 2
Open in the explorer — Four-way handshake message 3
Open in the explorer — Four-way handshake message 4
Open in the explorer — Probe Request
Open in the explorer — Probe Response
Open in the explorer — ARP request in a QoS Data frame
Open in the explorer — ICMP echo over IPv4, in a QoS Data frame
Open in the explorer — UDP over IPv6, in a QoS Data frame
Open in the explorer — TCP over IPv4, in a protected QoS Data frame
Open in the explorer — TCP over IPv4, in an open QoS Data frame
Open in the explorer — UDP over IPv4, in a QoS Data frame
Open in the explorer — RTS
Open in the explorer — Trigger frame

Accuracy

Clause: 802.11-2024 §27.3.11
Verified: Not verified against the standard. Treat this as a claim, not a fact.