// wi-fi 7 track · 802.11be
Field notes from Wi-Fi 7 gateway qualification
I qualify Wi-Fi 7 gateways for a living. These posts are what I'm finding at the frame level — things the spec doesn't warn you about. Every post includes a downloadable PCAP captured from real hardware.
mlo · 802.11be
MLO doesn't roam — it negotiates. Here's the difference in the frames.
Your existing tools are reading the wrong MAC address. The MLD MAC (U-MAC) is not the one to filter on.
eht · beacon
Reading an 802.11be beacon: EHT capabilities, MCS 0-13, and beacon protection bits
A field-by-field walkthrough of what's new in the EHT Capabilities IE vs. HE.
320 mhz · puncturing
Preamble puncturing in the wild — what it looks like and when it fires
The spec allows it. Real hardware does it differently. Here's what showed up in my gateway captures.
// why this track exists
Most Wi-Fi 7 content online covers the marketing layer — "47% faster than Wi-Fi 6!" None of it covers what you actually see in a PCAP when MLO negotiates, when preamble puncturing fires, or when a gateway misreports its EHT capabilities to a client. I'm qualifying these devices daily. The captures exist. This is where I publish them.
// mlo modes — emlsr, emlmr, and str compared
MLO in Wi-Fi 7 is not one thing — it is three distinct operating modes. Getting these confused is the most common Wi-Fi 7 misconception.
STR
Simultaneous Transmit & Receive
Hardware
2+ radios, 2+ chains
How it works
True simultaneous — one radio transmits on 5 GHz while the other receives on 6 GHz at the exact same time. No switching.
Performance: Highest throughput. Both links fully active simultaneously.
Limitation
Requires RF isolation between radios. Self-interference risk. Most demanding hardware.
Wireshark: Both L-MACs active simultaneously
EMLMR
Enhanced Multi-Link Multi-Radio
Hardware
2+ radios
How it works
Multiple radios, coordinated but not fully simultaneous. One link is primary, others assist. Fast switching with better interference management than STR.
Performance: High throughput, better resilience than STR.
Limitation
Switching overhead between links. Less peak throughput than true STR.
Wireshark: L-MAC switching visible in capture
EMLSR
Enhanced Multi-Link Single Radio
Hardware
1 radio (time-shared)
How it works
Single radio switches rapidly between links. Not simultaneous — listens on all links but TX/RX on only one at a time. Lowest hardware cost.
Performance: Lower throughput. Best for IoT and battery-constrained devices.
Limitation
Only one link active at a time. Throughput limited by single radio.
Wireshark: Single L-MAC active at any time
// field note — identifying MLO mode in a PCAP
Every MLO device has a U-MAC (MLD address — shown in OS network settings) and one L-MAC per active link. Always filter by L-MAC in Wireshark — not U-MAC. Two L-MACs interleaved with no gap = STR. L-MAC switching with short gaps = EMLMR. Only one L-MAC ever transmitting = EMLSR.
| Feature | STR | EMLMR | EMLSR |
|---|---|---|---|
| Simultaneous TX/RX | Yes | Partial | No |
| Radios required | 2+ | 2+ | 1 |
| Peak throughput | Highest | High | Moderate |
| Battery efficiency | Lower | Medium | Best |
| Hardware cost | Highest | High | Lowest |
| Best use case | Laptops, APs | Smartphones | IoT devices |
| EHT Capabilities | STR bit | EMLMR bit | EMLSR bit |