MCS

Modulation and coding index, 0 to 76.

Reading a capture

Seven bits, because HT indexes stream count into the MCS number itself — 0 to 7 is one stream, 8 to 15 is two, and so on. Later PHYs separated the two, which is why their MCS fields are only four bits wide.

Where it sits

HT mixed-format PPDU > HT-SIG > HT-SIG1 > MCS

• 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.