Introduction

Wi-Fi protocol

Wi-Fi 7 introduces the possibility to avoid transmissions on part of the channel bandwidth when it is unfit to stable communication. This is called Channel Puncturing.

For instance, the Access Point, while configured to channel 36 / 80 MHz, could be configured to only transmit over the 20 MHz channels 36 , 44 and 48. The channel 40 would then be “punctured”.

For more details, refer to Chapter 35.15.2 Preamble puncturing operation of the Wi-Fi 7 standard.

EasyMesh specifications

EasyMesh R6 allows the EasyMesh Controller to configure the EasyMesh Agents with specific punctures.

In the Channel Selection Request message, the Controller must set the Disabled_Subchannel_Valid bit in the TLV to one, indicate the desired puncturing pattern in the Disabled_Subchannel_Bitmap field and set the EHT_Operation_Information_Valid bit to zero.

For more details, see chapters 8.2 Channel Selection Request and Report and chapter 17.2.103 EHT Operations TLV.

Architecture

EasyMesh specification and certification

The Static Puncturing Feature is part of the AP MLO feature set. This feature is therefore Mandatory if the EasyMesh R6 Agent supports AP_MLO. It is tested in the Test Case 4.5.4.

The test case configures a specific channel puncture on 6GHz. The test bed verifies the Beacon Frame includes the requested change.

The Channel puncture is defined in the EHT Operation TLV. The main Fields of this TLV related to Channel Puncturing are the following (see EasyMesh R6 -Table 125 EHT Operations TLV)

Disabled_Subchannel_Valid : bit 6 - 0: Not valid - 1 : Valid ; Indicates whether the Disabled_Subchannel_Bitmap field is valid.

Disabled_Subchannel_Bitmap ; 2 octets ; Disabled Subchannel Bitmap subfield in EHT Operation Information field as per Figure 9-1001c of [28] This field is valid only if Disabled_Subchannel_Valid =1

The Subchannel Bitmap is defined in the IEEE 802.11be specification (see Table 36-30—Definition of the Punctured Channel Information field in the U-SIG for an EHT MU PPDU using non-OFDMA transmissions).

Components

prplMesh

Exposes the NB API to configure the Puncture following USP specifications
Conveys the request to the relevant EasyMesh Agent using EasyMesh specifications
Applies the functional change to pwhm DataModel

prplMesh Wireless Hardware Manager (pwhm)

Reconfigures hostapd to get the puncture broadcasted in Wi-Fi beacons and applied by the driver during Wi-Fi 7 transmissions.

Data-Model

Name	Type	Write	Description
Device.WiFi.DataElements.Network.Device.APMLD.AffiliatedAP.DisabledSubChannels	unsignedInt(0:65535)	R	Disabled Subchannel Bitmap subfield from the EHT Operation element in transmitted Management frames. Null value or not present for stations. [EasyMesh] source: Static Puncturing Configuration TLV
Device.WiFi.DataElements.Network.Device.{i}.Radio.BSS.{i}.SetEHTOperations()	command		[ASYNC] This command configures Extremely High Throughput (EHT, aka Wi-Fi 7) operations for this BSS [Section 17.2.103 EHT Operations TLV/EasyMesh]
⇒ DisabledSubchannelBitmap	hexBinary(1)	W	Disabled Subchannel Bitmap subfield in EHT Operation Information field as per [Figure 9-1001c/802.11be]. This enables subchannel puncturing

Example

Disable Channel 48

X_PRPLWARE-COM_WiFiController.Network.Device.1.Radio.BSS.2.SetEHTOperations(DisabledSubchannelBitmap = 0x0008)

Check the current status : Channel 48 on 5GHz is disabled

WiFi.Radio.2.StaticPuncturing.DisabledSubChannels?
WiFi.Radio.2.StaticPuncturing.DisabledSubChannels="48"

X_PRPLWARE-COM_WiFiController.Network.Device.APMLD.AffiliatedAP.DisabledSubChannels?
X_PRPLWARE-COM_WiFiController.Network.Device.APMLD.AffiliatedAP.DisabledSubChannels="48"