HT Capabilities HT Cap

What an 802.11n-capable station or AP supports.

Reading a capture

Fixed length, unlike most elements, because every field in it is a capability bitmap rather than a list. That makes it one of the few elements whose offsets can be trusted without reading its length.

Subfields

• HT Capabilities Information — Sixteen bits of radio capability.
• A-MPDU Parameters — The largest aggregate this station can receive, and the spacing it needs between subframes.
• Supported MCS Set — A bitmap of which of the 77 modulation and coding schemes this station can receive, plus its highest supported data rate.
• HT Extended Capabilities — Support for transitioning between PCO channel widths, and for the MCS feedback the beamforming fields below rely on.
• Transmit Beamforming Capabilities — Whether and how this station can participate in beamforming, as sounder or as responder.
• ASEL Capabilities — Antenna selection support.

Where it sits

HT Capabilities

Authored in HT Capabilities element . Drawn in 4 frames.

• Association Request
• Association Response
• Probe Request
• Probe Response

Accuracy

Clause

802.11-2024 §9.4.2.55

Byte order

little-endian — least significant octet first

Verified

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