How to change the power for base frequencies?

ivanjme · February 10, 2021, 5:45am

How to change the power for base frequencies (0, 1, 2), except for additional frequencies (3, 4, 5, 6, 7)? It is necessary to increase the power of the transmitter radio1. Backend for gateway used by Semtech UDP packet-forwarder. Thank you

brocaar · February 12, 2021, 4:56pm

Why does radio1 need a higher power?

ivanjme · February 13, 2021, 5:46am

Current gateway configuration:

{
“SX1301_conf”: {
“lorawan_public”: true,
“clksrc”: 1, /* radio_1 provides clock to concentrator /
“antenna_gain”: 0, / antenna gain, in dBi */
“radio_0”: {
“enable”: true,
“type”: “SX1257”,
“freq”: 864500000,
“rssi_offset”: -166.0,
“tx_enable”: true,
“tx_freq_min”: 863000000,
“tx_freq_max”: 870000000
},
“radio_1”: {
“enable”: true,
“type”: “SX1257”,
“freq”: 869000000,
“rssi_offset”: -166.0,
“tx_enable”: false
},
“chan_multiSF_0”: {
“enable”: true, “radio”: 0, “if”: -400000
},
“chan_multiSF_1”: {
“enable”: true, “radio”: 0, “if”: -200000
},
“chan_multiSF_2”: {
“enable”: true, “radio”: 0, “if”: 0
},
“chan_multiSF_3”: {
“enable”: true, “radio”: 0, “if”: 200000
},
“chan_multiSF_4”: {
“enable”: true, “radio”: 0, “if”: 400000
},
“chan_multiSF_5”: {
“enable”: true, “radio”: 1, “if”: 100000
},
“chan_multiSF_6”: {
“enable”: true, “radio”: 1, “if”: -100000
},
“chan_multiSF_7”: {
“enable”: false, “radio”: 1, “if”: 0
},
…
}
}

For the frequency range 868.7 - 869.2 MHz, a power of up to 100 mW is allowed, and for the range of 864.0 - 865.0 MHz, a power of up to 25 mW is allowed. radio_0 (864.0 - 865.0 MHz) are extra channels on the network server.

brocaar · February 21, 2021, 5:09pm

Please note that radio_1 is not used for transmitting, see the tx_enable: false. Note that the frequencies configured are for uplink (thus on which the gateway receives). All downlink transmissions are done by radio_0. What you probably mean is to base the downlink tx power by frequency. For EU868, this is already implemented by:

github.com

brocaar/lorawan/blob/master/band/band_eu863_870.go#L28


	return Defaults{
		RX2Frequency:     869525000,
		RX2DataRate:      0,
		ReceiveDelay1:    time.Second,
		ReceiveDelay2:    time.Second * 2,
		JoinAcceptDelay1: time.Second * 5,
		JoinAcceptDelay2: time.Second * 6,
	}
}
func (b *eu863Band) GetDownlinkTXPower(freq int) int {
	// NOTE: as there are currently no further boundary checks on the frequency, this check is sufficient.
	// TODO: However, there should be some mechanism, that checks the frequency for compliance to regulations.
	if 863000000 <= freq && freq < 869200000 {
		return 14 //25mW
	} else if 869400000 <= freq && freq < 869650000 {
		return 27 //500mW
	} else {
		return 14 // Default case
	}
}

ivanjme · February 22, 2021, 9:38am

yes, that’s what I need. For RU864

github.com

brocaar/lorawan/blob/master/band/band_ru864_870.go#L28


      
          	return Defaults{
          		RX2Frequency:     869100000,
          		RX2DataRate:      0,
          		ReceiveDelay1:    time.Second,
          		ReceiveDelay2:    time.Second * 2,
          		JoinAcceptDelay1: time.Second * 5,
          		JoinAcceptDelay2: time.Second * 6,
          	}
          }
          
          func (b *ru864Band) GetDownlinkTXPower(freq uint32) int {
          	return 14
          }
          
          func (b *ru864Band) GetDefaultMaxUplinkEIRP() float32 {
          	return 16
          }
          
          func (b *ru864Band) GetPingSlotFrequency(lorawan.DevAddr, time.Duration) (uint32, error) {
          	return 868900000, nil
          }

if 868700000 <= freq && freq < 869200000 {
return 20 //100mW
} else {
return 14 // Default case
}

brocaar · February 22, 2021, 4:45pm

Please feel free to create a pull-request for this change, together with some source confirming that 20 is indeed valid for that frequency range