Legacy Long Training Field L-LTF

A guard interval followed by two identical long symbols, used for fine frequency correction and to estimate the channel on every subcarrier.

Reading a capture

The channel estimate made here is what lets the receiver equalise everything that follows. A capture showing frames decoding at low rates but failing at high ones often points at a channel that estimated poorly.

Where it sits

non-HT PPDU > Legacy Long Training Field

• 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 §17.3.3

Verified

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