From a53ed72f4f8fb8d8a1cd5e0d17de75f7cd11a3ec Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?S=C3=A9bastien=20Deronne?= Date: Sun, 16 Apr 2023 13:59:36 +0200 Subject: [PATCH] wifi: Extend design documentation for multiple RF interfaces --- src/wifi/doc/source/wifi-design.rst | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/src/wifi/doc/source/wifi-design.rst b/src/wifi/doc/source/wifi-design.rst index 745f1f7e2..998f09dd6 100644 --- a/src/wifi/doc/source/wifi-design.rst +++ b/src/wifi/doc/source/wifi-design.rst @@ -736,6 +736,35 @@ in the reception chain. After this point, valid Wi-Fi signals cause ``WifiPhy::StartReceivePreamble`` to be called, and the processing continues as described above. +Furthermore, in order to support more flexible channel switching, +the ``SpectrumWifiPhy`` can hold multiple instances of ``WifiSpectrumPhyInterface`` +(:ref:`fig-spectrum-wifi-phy-multiple-interfaces`). +Each of these instances handles a given frequency range of the spectrum, identified by +a start and a stop frequency expressed in MHz, and there can be no overlap in spectrum between them. +Only one of these ``WifiSpectrumPhyInterface`` instances corresponds to the active RF interface of the ``SpectrumWifiPhy``, +the other ones are referred to as inactive RF interfaces and might be disconnected from the spectrum channel. + +.. _fig-spectrum-wifi-phy-multiple-interfaces: + +.. figure:: figures/spectrum-wifi-phy-multiple-interfaces.* + :align: center + + Multiple RF interfaces concept + +If the ``SpectrumWifiPhy::TrackSignalsFromInactiveInterfaces`` attribute is set to true, +inactive RF interfaces are connected to their respective spectrum channels and the ``SpectrumWifiPhy`` +forwards received signals from these inactive RF interfaces to the ``InterferenceHelper`` without processing them. +The benefit of the latter is that more accurate PHY-CCA.indication can be generated upon channel switching +if one or more signals started to be transmitted on the new channel before the switch occurs, +which would be ignored otherwise. This is illustrated in Figure :ref:`fig-cca-channel-switching-multiple-interfaces`, where the parts in red are only generated when ``SpectrumWifiPhy::TrackSignalsFromInactiveInterfaces`` is set to true. + +.. _fig-cca-channel-switching-multiple-interfaces: + +.. figure:: figures/cca-channel-switching-multiple-interfaces.* + :align: center + + Illustration of signals tracking upon channel switching + The MAC model =============