Avoid up / down / up / down TXPower changes on ADR.

tiger902 · Jul 4, 2018 · b49af13 · b49af13
1 parent e0c1184
commit b49af13
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Showing 2 changed files with 103 additions and 2 deletions.
diff --git a/internal/adr/adr.go b/internal/adr/adr.go
@@ -32,9 +32,14 @@ func HandleADR(ds storage.DeviceSession, linkADRReqBlock *storage.MACCommandBloc
 
 	// get the max SNR from the UplinkHistory
 	var snrM float64 = -999
+	var historyCount int
 	for _, uh := range ds.UplinkHistory {
-		if uh.MaxSNR > snrM && uh.TXPowerIndex == ds.TXPowerIndex {
-			snrM = uh.MaxSNR
+		if uh.TXPowerIndex == ds.TXPowerIndex {
+			historyCount++
+
+			if uh.MaxSNR > snrM {
+				snrM = uh.MaxSNR
+			}
 		}
 	}
 
@@ -59,6 +64,13 @@ func HandleADR(ds storage.DeviceSession, linkADRReqBlock *storage.MACCommandBloc
 	snrMargin := snrM - requiredSNR - config.C.NetworkServer.NetworkSettings.InstallationMargin
 	nStep := int(snrMargin / 3)
 
+	// In case of negative steps the ADR algorithm will increase the TXPower
+	// if possible. To avoid up / down / up / down TXPower changes, wait until
+	// we have a full history table before making adjustments.
+	if nStep < 0 && historyCount != storage.UplinkHistorySize {
+		return nil, nil
+	}
+
 	maxSupportedDR := getMaxSupportedDRForNode(ds)
 	maxSupportedTXPowerOffsetIndex := getMaxSupportedTXPowerOffsetIndexForNode(ds)
 

diff --git a/internal/adr/adr_test.go b/internal/adr/adr_test.go
@@ -454,6 +454,95 @@ func TestADR(t *testing.T) {
 						},
 						ExpectedError: nil,
 					},
+					{
+						Name: "ADR not decreasing tx power (as we don't have a full history table for the currently used TXPower)",
+						DeviceSession: storage.DeviceSession{
+							DevAddr:               [4]byte{1, 2, 3, 4},
+							DevEUI:                [8]byte{1, 2, 3, 4, 5, 6, 7, 8},
+							EnabledUplinkChannels: []int{0, 1, 2},
+							DR:           5,
+							TXPowerIndex: 3,
+							NbTrans:      1,
+							UplinkHistory: []storage.UplinkHistory{
+								{MaxSNR: -20, TXPowerIndex: 0},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+								{MaxSNR: -20, TXPowerIndex: 3},
+							},
+							ADR: true,
+						},
+						ExpectedError: nil,
+					},
+					{
+						Name: "ADR decreasing tx power",
+						DeviceSession: storage.DeviceSession{
+							DevAddr:               [4]byte{1, 2, 3, 4},
+							DevEUI:                [8]byte{1, 2, 3, 4, 5, 6, 7, 8},
+							EnabledUplinkChannels: []int{0, 1, 2},
+							DR:           5,
+							TXPowerIndex: 3,
+							NbTrans:      1,
+							UplinkHistory: []storage.UplinkHistory{
+								{FCnt: 0, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 1, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 2, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 3, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 4, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 5, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 6, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 7, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 8, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 9, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 10, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 11, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 12, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 13, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 14, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 15, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 16, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 17, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 18, MaxSNR: -20, TXPowerIndex: 3},
+								{FCnt: 19, MaxSNR: -20, TXPowerIndex: 3},
+							},
+							ADR: true,
+						},
+						Expected: []storage.MACCommandBlock{
+							{
+								CID: lorawan.LinkADRReq,
+								MACCommands: []lorawan.MACCommand{
+									{
+										CID: lorawan.LinkADRReq,
+										Payload: &lorawan.LinkADRReqPayload{
+											DataRate: 5,
+											TXPower:  0,
+											ChMask:   lorawan.ChMask{true, true, true},
+											Redundancy: lorawan.Redundancy{
+												ChMaskCntl: 0,
+												NbRep:      1,
+											},
+										},
+									},
+								},
+							},
+						},
+						ExpectedError: nil,
+					},
 				}
 
 				for i, tst := range testTable {