Enum Mode 

#[non_exhaustive]
pub enum Mode {
    EspNow(EspNowConfig),
    EspNowSimplex(SimplexConfig),
    Sniffer(WifiSnifferConfig),
    Station(WifiStationConfig),
    AccessPoint(WifiApConfig),
    Emitter(EmitterConfig),
}

How a node reaches the channel.

This is the model’s extension point and it is deliberately abstract: it names the link a node uses to take part in the network, not a property of CSI measurement itself. Any link that can excite a channel and yield a channel measurement can supply a mode.

Each variant admits only the attribute combinations that are meaningful for that link, and it admits them through its config type rather than through a rule written down somewhere:

Mode	Session role	Sensing role	Reporting
EspNow	initiator or responder	transmitter-receiver	any
EspNowSimplex	source: initiator; peer: responder	source: transmitter; peer: receiver	source: none; peer: report
Sniffer	none (observer)	receiver	report, threshold-based or decimate — never None
Station	initiator or none	transmitter-receiver or receiver	any
AccessPoint	initiator	receiver	any
Emitter	none	transmitter	none

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

EspNow(EspNowConfig)

Connectionless symmetric exchange: auto-pairing, optional forced-PHY unicast replies, no AP and no association. The only mode that admits a star — one initiator against many responders.

EspNowSimplex(SimplexConfig)

Connectionless asymmetric exchange: the source owns all transmit airtime and the peer is receive-only after discovery. The highest CSI rate of any pairing here.

Sniffer(WifiSnifferConfig)

Promiscuous capture on a locked channel. The traffic is whatever is already on air, so this is the one mode that needs no second device — and the one that pairs with an emitter.

Station(WifiStationConfig)

Associates to an ESP softAP or a commercial router and measures the frames it receives.

AccessPoint(WifiApConfig)

Self-contained softAP with DHCP; associated stations generate the uplink that is measured.

Emitter(EmitterConfig)

Unassociated transmit-only sounding: force a TX PHY and loop-inject frames. Needs no peer, no handshake and no protocol, which is what lets it compose with anything.

Implementations

impl Mode

pub fn session_role(&self) -> Option<SessionRole>

This node’s IEEE 802.11bf session role, or None for a node that takes part in no session (an observer).

Computed, never stored: the modes that fix this attribute return a constant, and the modes that admit a choice delegate to their config. There is no second copy of the value on CsiNode that could disagree with the mode it was built from.

pub fn sensing_role(&self) -> SensingRole

This node’s IEEE 802.11bf sensing role: whether it sends the sensing PPDUs, measures them, or both.

pub fn reporting(&self) -> Reporting

Whether, and how often, this node’s measurements leave it, as configured. See runtime_reporting for the value in force.