public LoRaADRResult ComputeResult(LoRaADRTable table, float requiredSnr, DataRateIndex upstreamDataRate, int minTxPower, DataRateIndex maxDr)
{
// We do not have enough frame to calculate ADR. We can assume that a crash was the cause.
if (table == null || table.Entries.Count < 20)
{
this.logger.LogDebug("ADR: not enough frames captured. Sending default power values");
return(null);
}
// This is the first contact case to harmonize the txpower state between device and server or the crash case.
if (!table.CurrentNbRep.HasValue || !table.CurrentTxPower.HasValue)
{
this.logger.LogDebug("ADR: Sending the device default power values");
return(null);
}
// This is a case of standard ADR calculus.
var newNbRep = ComputeNbRepetion(table.Entries[0].FCnt, table.Entries[LoRaADRTable.FrameCountCaptureCount - 1].FCnt, table.CurrentNbRep.GetValueOrDefault());
(var newTxPowerIndex, var newDatarate) = GetPowerAndDRConfiguration(requiredSnr, upstreamDataRate, table.Entries.Max(x => x.Snr), table.CurrentTxPower.GetValueOrDefault(), minTxPower, maxDr);
if (newNbRep != table.CurrentNbRep || newTxPowerIndex != table.CurrentTxPower || newDatarate != upstreamDataRate)
{
return(new LoRaADRResult()
{
DataRate = newDatarate,
NbRepetition = newNbRep,
TxPower = newTxPowerIndex
});
}
return(null);
}
protected static void AddEntryToTable(LoRaADRTable table, LoRaADRTableEntry entry)
{
var existing = table.Entries.FirstOrDefault(itm => itm.FCnt == entry.FCnt);
if (existing == null)
{
// first for this framecount, simply add it
entry.GatewayCount = 1;
table.Entries.Add(entry);
}
else
{
if (existing.Snr < entry.Snr)
{
// better SNR. Update
existing.Snr = entry.Snr;
existing.GatewayId = entry.GatewayId;
}
existing.GatewayCount++;
}
if (table.Entries.Count > LoRaADRTable.FrameCountCaptureCount)
{
table.Entries.RemoveAt(0);
}
}
public virtual async Task <LoRaADRResult> CalculateADRResultAndAddEntryAsync(DevEui devEUI, string gatewayId, uint fCntUp, uint fCntDown, float requiredSnr, DataRateIndex dataRate, int minTxPower, DataRateIndex maxDr, LoRaADRTableEntry newEntry = null)
{
var table = newEntry != null
? await this.store.AddTableEntry(newEntry)
: await this.store.GetADRTable(devEUI);
var currentStrategy = this.strategyProvider.GetStrategy();
var result = currentStrategy.ComputeResult(table, requiredSnr, dataRate, minTxPower, maxDr);
if (result == null)
{
// In this case we want to reset the device to default values as we have null values
if (table == null ||
!table.CurrentNbRep.HasValue ||
!table.CurrentTxPower.HasValue ||
fCntUp > currentStrategy.MinimumNumberOfResult)
{
result = ReturnDefaultValues(dataRate, currentStrategy.DefaultNbRep, currentStrategy.DefaultTxPower);
}
else
{
result = await GetLastResultAsync(devEUI) ?? new LoRaADRResult();
result.NumberOfFrames = table.Entries.Count;
return(result);
}
}
var nextFcntDown = await NextFCntDown(devEUI, gatewayId, fCntUp, fCntDown);
result.CanConfirmToDevice = nextFcntDown > 0;
if (result.CanConfirmToDevice)
{
if (table == null)
{
// in a reset case, we may not have a table, but still want to store the default
// values that we sent to the client
table = new LoRaADRTable();
}
table.CurrentNbRep = result.NbRepetition;
table.CurrentTxPower = result.TxPower;
await this.store.UpdateADRTable(devEUI, table);
UpdateState(result);
result.FCntDown = nextFcntDown;
}
result.NumberOfFrames = table.Entries.Count;
this.logger.LogDebug($"calculated ADR: CanConfirmToDevice: {result.CanConfirmToDevice}, TxPower: {result.TxPower}, DataRate: {result.DataRate}");
return(result);
}
public Task UpdateADRTable(string devEUI, LoRaADRTable table)
{
// void: the reference is up to date already
return(Task.CompletedTask);
}
