ieee80211: tag datarateSelected with the receiving station

datarateSelected reports the rate chosen for every transmitted frame, so
unlike datarateChanged it also covers interface-wide fixed rates and
per-receiver configured rates, not just adaptive rate control. It was
emitted with the packet as details, which identifies the frame but not
the peer, so the values of several stations arrived interleaved with no
way to separate them.

~IRateSelection::emitDatarateSelected() now emits unicast data frames
with the receiver's station label as a named details object, so a
demux(datarateSelected) result filter can key a per-station series on
it. The condition matches the one under which ~RateSelection applies a
per-receiver configured rate, so the label always names the station
whose rate is being reported. Control, management and group-addressed
frames have no per-station rate and are emitted without details: they
still reach the aggregate statistic.

Both coordination functions emit through the shared helper rather than
each formatting the signal themselves. Unlike datarateChanged, this
signal fires for every transmitted frame, and resolving a station label
sweeps the network's interface tables -- so the label is only computed
when the signal has listeners: with result recording off, transmitting
costs nothing extra.

Author: adamgeorge309

src/inet/linklayer/ieee80211/mac/contract/IRateSelection.cc

@@ -12,8 +12,23 @@
 namespace inet {
 namespace ieee80211 {
 
+using namespace inet::physicallayer;
+
 simsignal_t IRateSelection::datarateSelectedSignal = cComponent::registerSignal("datarateSelected");
 
+void IRateSelection::emitDatarateSelected(cComponent *emitter, const Ptr<const Ieee80211MacHeader>& header, const IIeee80211Mode *mode)
+{
+    double rate = mode->getDataMode()->getNetBitrate().get<bps>();
+    auto dataHeader = dynamicPtrCast<const Ieee80211DataHeader>(header);
+    // resolving the station label sweeps the network, so skip it if nothing listens anyway
+    if (dataHeader != nullptr && !dataHeader->getReceiverAddress().isMulticast() && emitter->mayHaveListeners(datarateSelectedSignal)) {
+        cNamedObject details(getStationLabel(dataHeader->getReceiverAddress()).c_str());
+        emitter->emit(datarateSelectedSignal, rate, &details);
+    }
+    else
+        emitter->emit(datarateSelectedSignal, rate);
+}
+
 std::string IRateSelection::getStationLabel(const MacAddress& receiver)
 {
     // resolve the receiver MAC to the network node that owns it; fall back to the MAC
@@ -32,3 +47,4 @@ std::string IRateSelection::getStationLabel(const MacAddress& receiver)
 
 } // namespace ieee80211
 } // namespace inet
+

src/inet/linklayer/ieee80211/mac/contract/IRateSelection.h

@@ -26,6 +26,15 @@ class INET_API IRateSelection
   public:
     static simsignal_t datarateSelectedSignal;
 
+    // Emits datarateSelected on behalf of a coordination function. Unicast data frames are tagged
+    // with the receiver's station label as a named details object, so that a demux(datarateSelected)
+    // result filter or the statistic bar chart visualizer can key a separate per-station series on
+    // it; this mirrors the condition under which ~RateSelection applies a per-receiver configured
+    // rate, so the label always names the station whose rate is reported. Control, management and
+    // group-addressed frames carry no per-station data rate and are emitted without details: the
+    // aggregate datarateSelected statistic still records them, a bar chart ignores them.
+    static void emitDatarateSelected(cComponent *emitter, const Ptr<const Ieee80211MacHeader>& header, const physicallayer::IIeee80211Mode *mode);
+
     // The label identifying a station in a per-station signal emission: it names the details
     // object emitted with the value, which a demux() result filter and the statistic bar chart
     // visualizer key their per-station series on. The receiver's network node path relative to

src/inet/linklayer/ieee80211/mac/coordinationfunction/Dcf.cc

@@ -102,7 +102,7 @@ void Dcf::transmitControlResponseFrame(Packet *responsePacket, const Ptr<const I
     else
         throw cRuntimeError("Unknown received frame type");
     RateSelection::setFrameMode(responsePacket, responseHeader, responseMode);
-    emit(IRateSelection::datarateSelectedSignal, responseMode->getDataMode()->getNetBitrate().get<bps>(), responsePacket);
+    IRateSelection::emitDatarateSelected(this, responseHeader, responseMode);
     EV_DEBUG << "Datarate for " << responsePacket->getName() << " is set to " << responseMode->getDataMode()->getNetBitrate() << ".\n";
     tx->transmitFrame(responsePacket, responseHeader, modeSet->getSifsTime(), this);
     delete responsePacket;
@@ -166,7 +166,7 @@ void Dcf::transmitFrame(Packet *packet, simtime_t ifs)
     const auto& header = packet->peekAtFront<Ieee80211MacHeader>();
     auto mode = rateSelection->computeMode(packet, header);
     RateSelection::setFrameMode(packet, header, mode);
-    emit(IRateSelection::datarateSelectedSignal, mode->getDataMode()->getNetBitrate().get<bps>(), packet);
+    IRateSelection::emitDatarateSelected(this, header, mode);
     EV_DEBUG << "Datarate for " << packet->getName() << " is set to " << mode->getDataMode()->getNetBitrate() << ".\n";
     auto pendingPacket = channelAccess->getInProgressFrames()->getPendingFrameFor(packet);
     auto duration = originatorProtectionMechanism->computeDurationField(packet, header, pendingPacket, pendingPacket == nullptr ? nullptr : pendingPacket->peekAtFront<Ieee80211DataOrMgmtHeader>());

src/inet/linklayer/ieee80211/mac/coordinationfunction/Hcf.cc

@@ -668,7 +668,7 @@ void Hcf::transmitFrame(Packet *packet, simtime_t ifs)
         }
         auto mode = rateSelection->computeMode(packet, header, txop);
         setFrameMode(packet, header, mode);
-        emit(IRateSelection::datarateSelectedSignal, mode->getDataMode()->getNetBitrate().get<bps>(), packet);
+        IRateSelection::emitDatarateSelected(this, header, mode);
         EV_DEBUG << "Datarate for " << packet->getName() << " is set to " << mode->getDataMode()->getNetBitrate() << ".\n";
         if (txop->getProtectionMechanism() == TxopProcedure::ProtectionMechanism::SINGLE_PROTECTION) {
             auto pendingPacket = channelOwner->getInProgressFrames()->getPendingFrameFor(packet);
@@ -703,7 +703,7 @@ void Hcf::transmitControlResponseFrame(Packet *responsePacket, const Ptr<const I
     else
         throw cRuntimeError("Unknown received frame type");
     setFrameMode(responsePacket, responseHeader, responseMode);
-    emit(IRateSelection::datarateSelectedSignal, responseMode->getDataMode()->getNetBitrate().get<bps>(), responsePacket);
+    IRateSelection::emitDatarateSelected(this, responseHeader, responseMode);
     EV_DEBUG << "Datarate for " << responsePacket->getName() << " is set to " << responseMode->getDataMode()->getNetBitrate() << ".\n";
     tx->transmitFrame(responsePacket, responseHeader, modeSet->getSifsTime(), this);
     delete responsePacket;