Have I found a mistake here or not?
I think I have found an error in the LMIC code. According to TTN (link below 1) there should be 8 frequencies (channels) for eu868…:
868.1 - SF7BW125 to SF12BW125
868.3 - SF7BW125 to SF12BW125 and SF7BW250
868.5 - SF7BW125 to SF12BW125
867.1 - SF7BW125 to SF12BW125
867.3 - SF7BW125 to SF12BW125
867.5 - SF7BW125 to SF12BW125
867.7 - SF7BW125 to SF12BW125
867.9 - SF7BW125 to SF12BW12
These are also in
lorabase_eu868.h (link below 2 ) with
enum {
EU868_F1 = 868100000, // g1 SF7-12
EU868_F2 = 868300000, // g1 SF7-12 FSK SF7/250
EU868_F3 = 868500000, // g1 SF7-12
EU868_F4 = 868850000, // g2 SF7-12
EU868_F5 = 869050000, // g2 SF7-12
EU868_F6 = 869525000, // g3 SF7-12
EU868_J4 = 864100000, // g2 SF7-12 used during join
EU868_J5 = 864300000, // g2 SF7-12 ditto
EU868_J6 = 864500000, // g2 SF7-12 ditto
};
However, in lmic_eu868.c (link 3) there is only the following :
static CONST_TABLE(u4_t, iniChannelFreq)[6] = {
// Join frequencies and duty cycle limit (0.1%)
EU868_F1 | BAND_MILLI, EU868_F2 | BAND_MILLI, EU868_F3 | BAND_MILLI,
// Default operational frequencies and duty cycle limit (1%)
EU868_F1 | BAND_CENTI, EU868_F2 | BAND_CENTI, EU868_F3 | BAND_CENTI,
};
There are too few channels and channels are awarded twice and it contradicts itself with:
void LMICeu868_initDefaultChannels(bit_t join) {
….
…
(void) LMIC_setupBand(BAND_MILLI, 14 /* dBm */, 1000 /* 0.1% */);
(void) LMIC_setupBand(BAND_CENTI, 14 /* dBm */, 100 /* 1% */);
(void) LMIC_setupBand(BAND_DECI, 27 /* dBm */, 10 /* 10% */);
}
1 :https://www.thethingsnetwork.org/docs/lorawan/frequency-plans/
You may want to look at the context - does LMIC work and has this issue been found before? Or might it be a knowledge gap?
just sayin’ !