HT-SIG

Two OFDM symbols carrying everything needed to decode the HT portion.

Reading a capture

Sent using BPSK rotated 90 degrees from the legacy fields, which is how an HT receiver can tell a mixed-format frame from a plain legacy one before decoding anything.

Subfields

• HT-SIG1 — The first HT-SIG symbol — rate, width and length.
• HT-SIG2 — The second HT-SIG symbol — coding, guard interval and a CRC.

Where it sits

HT mixed-format PPDU > HT-SIG

• 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 §19.3.9.4.3

Verified

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