EHT Beacon Frame (6 GHz 320 MHz CW)

The EHT (Extremely High Throughput) Beacon Frame is a Wi-Fi 7 (802.11be) management frame which advertises the WLAN capabilities so that client devices can initiate association process based on its capabilities.

Test Scenario- 320 MHz 6 GHz band beacon broacasted on primary channel 37

Filter for beacon frames in wireshark using the below filter

wlan.fc.type_subtype == 0x0008

Verifying Reduced Neighbor report in the beacon frame-

Reduced Neighbor report advertises information about the other band on which WLAN is broadcasted and its channel number.

Expand beacon>IEEE 802.11 Wireless Management>Tagged parameters>Tag: Reduced Neighbor Report

  • Channel Number- 36 (Represents channel on which WLAN is advertised on 5 GHz band)
  • BSSID
  • Same SSID: True

Verifying Multi-Link Common Info-

Expand beacon>IEEE 802.11 Wireless Management>Tagged parameters>Ext Tag: Multi Link (802.11 be)

  • MLD MAC address
  • EMLSR Support
  • Maximum Number of Simultaneous Links (Represents total links-1, in this case 2 (5 GHz/6 GHz)-1=1)

Verifying EHT Capabilities–

Expand beacon>IEEE 802.11 Wireless Management>Tagged parameters>EHT Capabilities

EHT PHY Capabilities Information

  • Support for 320 MHz in 6 GHz
  • SU Beamformer
  • SU Beamformee
  • Beamformee SS (<=80 MHz)
  • Beamformee SS (=160 MHz)
  • Beamformee SS (=320 MHz)

Supported EHT-MCS and NSS Set

  • EHT MCS Map (BW<= 80 MHz)
  • EHT MCS Map (BW=160 MHz)
  • EHT MCS Map (BW=320 MHz)

Verifying EHT Operation (802.11 be)–

Expand beacon>IEEE 802.11 Wireless Management>Tagged parameters>EHT Operation

  • EHT Operation Information Present: True
  • Disabled Subchannel Bitmap Present: False (Channel puncturing is absent)
  • Control:0x04, Channel Width: 320 MHz EHT BSS bandwidth
  • CCFS0: 0x0000002f (Represents the center frequency of primary 160 MHz within the 320 MHz block, hex to decimal of 0x0000002f=47 which is the center frequency of 160 MHz block)
  • CCFS1: 0x0000001f (Represents center frequency of 320 MHz within the 320 MHz block, hex to decimal of 0x0000001f=31 which is the center frequency of 320 MHz block)

Related Blogs

EHT Trigger Frame

Channel Puncturing on Wi-Fi 7

How to Troubleshoot 6 GHz 320 MHz cw client association?