diff --git a/Services/LiveDiscoverySignalSelectionPolicy.cs b/Services/LiveDiscoverySignalSelectionPolicy.cs
new file mode 100644
index 000000000..cf3e02b70
--- /dev/null
+++ b/Services/LiveDiscoverySignalSelectionPolicy.cs
@@ -0,0 +1,66 @@
+using ArIED61850Tester.Models;
+
+namespace ArIED61850Tester.Services;
+
+/// <summary>
+/// Signal Selection policy for broad online MMS discovery.
+///
+/// Online GetNameList/VAA discovery is intentionally exhaustive. It contains process
+/// values together with quality/timestamp companions, nameplate/configuration attributes,
+/// substitution state, control-service structure and other engineering leaves. Those
+/// objects remain available in the typed live model, but they are not independent operator
+/// points and must not leak into Signal Selection.
+///
+/// Static DataSet membership is authoritative and therefore wins over this presentation
+/// noise classifier: an object explicitly configured in a DataSet remains visible even if
+/// its object-level FCD identity is not an exact runtime value leaf.
+/// </summary>
+public static class LiveDiscoverySignalSelectionPolicy
+{
+    private static readonly HashSet<string> NoiseSegments = new(StringComparer.OrdinalIgnoreCase)
+    {
+        "mod", "beh", "health", "eehealth", "namplt",
+        "q", "t", "tm", "d", "du",
+        "origin", "orcat", "orident",
+        "ctlmodel", "ctlval", "ctlnum", "stseld",
+        "sbo", "sbow", "oper", "cancel", "check", "test",
+        "datans", "subena", "subval", "subq", "subid", "blkena",
+        "configrev", "vendor", "swrev", "lnns", "numpts", "olddata"
+    };
+
+    public static bool IsVisible(SignalDefinition? signal)
+    {
+        if (signal is null || string.IsNullOrWhiteSpace(signal.ObjectReference))
+            return false;
+
+        if (!string.IsNullOrWhiteSpace(signal.DataSetReference))
+            return true;
+
+        if (IsProtocolOrEngineeringNoise(signal.ObjectReference))
+            return false;
+
+        return SasOperationalSignalPolicy.IsVisible(signal);
+    }
+
+    public static bool IsProtocolOrEngineeringNoise(string? reference)
+    {
+        if (string.IsNullOrWhiteSpace(reference))
+            return true;
+
+        var normalized = reference.Trim().Replace('$', '.');
+        var slash = normalized.IndexOf('/');
+        var path = slash >= 0 && slash < normalized.Length - 1
+            ? normalized[(slash + 1)..]
+            : normalized;
+        var segments = path.Split('.', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+        // Segment 0 is the Logical Node. Only data/control path segments are classified.
+        for (var index = 1; index < segments.Length; index++)
+        {
+            if (NoiseSegments.Contains(segments[index]))
+                return true;
+        }
+
+        return false;
+    }
+}
diff --git a/SignalSelectionWizardWindow.LiveDiscoveryOperationalFilter.cs b/SignalSelectionWizardWindow.LiveDiscoveryOperationalFilter.cs
new file mode 100644
index 000000000..d34e6e283
--- /dev/null
+++ b/SignalSelectionWizardWindow.LiveDiscoveryOperationalFilter.cs
@@ -0,0 +1,79 @@
+using System.Windows;
+using ArIED61850Tester.Models;
+using ArIED61850Tester.Services;
+
+namespace ArIED61850Tester;
+
+/// <summary>
+/// Owns the Signal Selection presentation contract after a live MMS discovery.
+///
+/// The ARIEC/live SignalDefinition inventory intentionally remains complete enough for
+/// diagnostics, comparison, report planning, persistence and engineering inspection.
+/// Signal Selection is narrower: it shows operator points and mandatory static DataSet
+/// members, never protocol/service leaves such as Mod/Beh/Health/NamPlt/origin/q/t.
+///
+/// This filter is installed on the wizard after its constructor has installed search and
+/// column filters. That lifecycle point is important because a default WPF collection view
+/// can be shared with another DataGrid; a previously installed global filter can otherwise
+/// be replaced by the wizard's own FilterSignal predicate.
+/// </summary>
+public partial class SignalSelectionWizardWindow
+{
+    private Predicate<object>? _signalSelectionBaseFilter;
+    private Predicate<object>? _signalSelectionOperationalFilter;
+    private bool _signalSelectionOperationalFilterInstalled;
+
+    static SignalSelectionWizardWindow()
+    {
+        EventManager.RegisterClassHandler(
+            typeof(SignalSelectionWizardWindow),
+            FrameworkElement.LoadedEvent,
+            new RoutedEventHandler(OnSignalSelectionOperationalFilterLoaded));
+    }
+
+    private static void OnSignalSelectionOperationalFilterLoaded(object sender, RoutedEventArgs args)
+    {
+        if (sender is SignalSelectionWizardWindow window)
+            window.InstallSignalSelectionOperationalFilter();
+    }
+
+    private void InstallSignalSelectionOperationalFilter()
+    {
+        if (_signalSelectionOperationalFilterInstalled)
+            return;
+
+        _signalSelectionBaseFilter = SignalsView.Filter;
+        _signalSelectionOperationalFilter = item =>
+        {
+            if (_signalSelectionBaseFilter is not null && !_signalSelectionBaseFilter(item))
+                return false;
+
+            return item is SignalDefinition signal &&
+                   LiveDiscoverySignalSelectionPolicy.IsVisible(signal);
+        };
+
+        SignalsView.Filter = _signalSelectionOperationalFilter;
+        _signalSelectionOperationalFilterInstalled = true;
+        Closed -= SignalSelectionOperationalFilter_Closed;
+        Closed += SignalSelectionOperationalFilter_Closed;
+        SignalsView.Refresh();
+        RefreshViewState();
+    }
+
+    private void SignalSelectionOperationalFilter_Closed(object? sender, EventArgs args)
+    {
+        Closed -= SignalSelectionOperationalFilter_Closed;
+
+        // Restore only our own wrapper. If another owner intentionally changed the shared
+        // collection view while this window was open, do not overwrite that newer filter.
+        if (_signalSelectionOperationalFilter is not null &&
+            Equals(SignalsView.Filter, _signalSelectionOperationalFilter))
+        {
+            SignalsView.Filter = _signalSelectionBaseFilter;
+        }
+
+        _signalSelectionOperationalFilterInstalled = false;
+        _signalSelectionOperationalFilter = null;
+        _signalSelectionBaseFilter = null;
+    }
+}
diff --git a/tests/ARSAS.Tests/LiveDiscoverySignalSelectionNoiseRegressionTests.cs b/tests/ARSAS.Tests/LiveDiscoverySignalSelectionNoiseRegressionTests.cs
new file mode 100644
index 000000000..1ad716d4a
--- /dev/null
+++ b/tests/ARSAS.Tests/LiveDiscoverySignalSelectionNoiseRegressionTests.cs
@@ -0,0 +1,153 @@
+using ArIED61850Tester.Models;
+using ArIED61850Tester.Services;
+
+namespace ARSAS.Tests;
+
+public sealed class LiveDiscoverySignalSelectionNoiseRegressionTests
+{
+    [Theory]
+    [InlineData("AA1C1F13R4ADD/GAPC1.Mod.stVal", "GAPC1", "ST", "Boolean", "Status")]
+    [InlineData("AA1C1F13R4ADD/GAPC1.Beh.stVal", "GAPC1", "ST", "Boolean", "Status")]
+    [InlineData("AA1C1F13R4ADD/GAPC1.Health.stVal", "GAPC1", "ST", "Boolean", "Status")]
+    [InlineData("AA1C1F13R4ADD/GAPC1.NamPlt.d", "GAPC1", "DC", "VisString255", "Metadata")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.LocOpnCMDsta.subVal", "GGIO1", "SV", "Boolean", "Status")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.LocOpnCMDsta.subQ", "GGIO1", "SV", "Quality", "Quality")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.LocOpnCMDsta.blkEna", "GGIO1", "BL", "Boolean", "Status")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.LocOpnCMDsta.d.stVal", "GGIO1", "ST", "Boolean", "Status")]
+    [InlineData("AA1C1F13R4Application/LLN0.q.stVal", "LLN0", "ST", "Boolean", "Status")]
+    public void EngineeringAndProtocolLeaves_AreRejectedFromLiveSignalSelection(
+        string reference,
+        string logicalNode,
+        string fc,
+        string dataType,
+        string category)
+    {
+        var signal = NewSignal(reference, logicalNode, fc, dataType, category);
+
+        Assert.True(LiveDiscoverySignalSelectionPolicy.IsProtocolOrEngineeringNoise(reference));
+        Assert.False(LiveDiscoverySignalSelectionPolicy.IsVisible(signal));
+    }
+
+    [Theory]
+    [InlineData("AA1C1F13R4ADD/GGIO1.Mod.Oper.origin.orCat")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.Mod.Oper.origin.orIdent")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.Mod.Oper.ctlVal")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.Mod.Oper.ctlNum")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.Mod.Oper.Check")]
+    [InlineData("AA1C1F13R4ADD/GGIO1.Mod.ctlModel")]
+    public void ControlServiceLeaves_AreRejectedFromLiveSignalSelection(string reference)
+    {
+        var signal = NewSignal(reference, "GGIO1", "CO", "Struct", "Control");
+        signal.IsControlSignal = true;
+        signal.ControlCdc = "SPC";
+
+        Assert.True(LiveDiscoverySignalSelectionPolicy.IsProtocolOrEngineeringNoise(reference));
+        Assert.False(LiveDiscoverySignalSelectionPolicy.IsVisible(signal));
+    }
+
+    [Theory]
+    [InlineData("IEDLD/XCBR1.Pos.stVal", "XCBR1", "ST", "Enum", "Position")]
+    [InlineData("IEDLD/MMXU1.A.phsA.cVal.mag.f", "MMXU1", "MX", "Float32", "Measurement")]
+    [InlineData("IEDLD/PTRC1.Tr.general", "PTRC1", "ST", "Boolean", "Protection")]
+    [InlineData("IEDLD/GGIO1.Ind15.stVal", "GGIO1", "ST", "Boolean", "Status")]
+    public void RealOperatorPoints_RemainVisible(
+        string reference,
+        string logicalNode,
+        string fc,
+        string dataType,
+        string category)
+    {
+        var signal = NewSignal(reference, logicalNode, fc, dataType, category);
+
+        Assert.False(LiveDiscoverySignalSelectionPolicy.IsProtocolOrEngineeringNoise(reference));
+        Assert.True(LiveDiscoverySignalSelectionPolicy.IsVisible(signal));
+    }
+
+    [Fact]
+    public void RealPositionControl_RemainsVisible()
+    {
+        var signal = NewSignal("IEDLD/CSWI1.Pos", "CSWI1", "CO", "Struct", "Control");
+        signal.IsControlSignal = true;
+        signal.ControlCdc = "DPC";
+
+        Assert.True(LiveDiscoverySignalSelectionPolicy.IsVisible(signal));
+    }
+
+    [Fact]
+    public void StaticDataSetObjectLevelMember_RemainsVisibleEvenWithoutRuntimeLeaf()
+    {
+        var signal = NewSignal(
+            "AA1C1F13R4ADD/GGIO6.CBOpnd",
+            "GGIO6",
+            "ST",
+            "Boolean",
+            "DataSet");
+        signal.DataSetReference = "AA1C1F13R4Application/LLN0$Digital";
+        signal.DisplayReference = signal.ObjectReference;
+
+        Assert.False(SasOperationalSignalPolicy.IsVisible(signal));
+        Assert.True(LiveDiscoverySignalSelectionPolicy.IsVisible(signal));
+        Assert.DoesNotContain(".stVal", signal.DisplayReference, StringComparison.OrdinalIgnoreCase);
+    }
+
+    [Fact]
+    public void StaticDataSetAuthority_WinsEvenIfConfiguredMemberLooksLikeEngineeringState()
+    {
+        var signal = NewSignal(
+            "IEDLD/LLN0.Beh",
+            "LLN0",
+            "ST",
+            "Enum",
+            "DataSet");
+        signal.DataSetReference = "IEDLD/LLN0$Configured";
+
+        Assert.True(LiveDiscoverySignalSelectionPolicy.IsVisible(signal));
+    }
+
+    [Fact]
+    public void SignalSelectionWizard_InstallsOperationalFilterAfterConstructorFilters()
+    {
+        var source = File.ReadAllText(FindRepoFile("SignalSelectionWizardWindow.LiveDiscoveryOperationalFilter.cs"));
+
+        Assert.Contains("FrameworkElement.LoadedEvent", source, StringComparison.Ordinal);
+        Assert.Contains("_signalSelectionBaseFilter = SignalsView.Filter", source, StringComparison.Ordinal);
+        Assert.Contains("LiveDiscoverySignalSelectionPolicy.IsVisible(signal)", source, StringComparison.Ordinal);
+        Assert.Contains("SignalsView.Filter = _signalSelectionOperationalFilter", source, StringComparison.Ordinal);
+        Assert.Contains("SignalsView.Filter = _signalSelectionBaseFilter", source, StringComparison.Ordinal);
+        Assert.DoesNotContain("RemoveAt(", source, StringComparison.Ordinal);
+        Assert.DoesNotContain("Signals.Clear", source, StringComparison.Ordinal);
+    }
+
+    private static SignalDefinition NewSignal(
+        string reference,
+        string logicalNode,
+        string fc,
+        string dataType,
+        string category)
+        => new()
+        {
+            Name = logicalNode,
+            ObjectReference = reference,
+            FunctionalConstraint = fc,
+            DataType = dataType,
+            Category = category,
+            Source = "ARIEC61850 live discovery",
+            ProbeStatus = "Readable",
+            Value = "0",
+            Quality = "Good"
+        };
+
+    private static string FindRepoFile(string relativePath)
+    {
+        DirectoryInfo? directory = new(AppContext.BaseDirectory);
+        while (directory != null)
+        {
+            var candidate = Path.Combine(directory.FullName, relativePath);
+            if (File.Exists(candidate))
+                return candidate;
+            directory = directory.Parent;
+        }
+
+        throw new FileNotFoundException(relativePath);
+    }
+}