VHT-SIG-A

Two OFDM symbols of common signalling, sent before the training.

Reading a capture

Everything here has to be decodable by every recipient, which is why per-user parameters wait for VHT-SIG-B after the channel estimate.

Subfields

• VHT-SIG-A1 — Bandwidth, group and stream configuration.
• VHT-SIG-A2 — Guard interval, coding, rate and a CRC.

Where it sits

VHT PPDU > VHT-SIG-A

• 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 §21.3.8.3.3

Verified

Not verified against the standard. Treat this as a claim, not a fact.