gsm downlink 951.4 Mhz can not be parsed with hackrfone

[arifkyi]

Hello Sir,

Need your kindly help, after i scanning the gsm with gr-gsm tools

grgsm_scanner run with hackrfone

ARFCN: 26, Freq: 940.2M, CID: 63012, LAC: 3613, MCC: 510, MNC: 21, Pwr: -54 ARFCN: 80, Freq: 951.0M, CID: 26771, LAC: 3613, MCC: 510, MNC: 21, Pwr: -51 ARFCN: 82, Freq: 951.4M, CID: 32772, LAC: 3725, MCC: 510, MNC: 21, Pwr: -20. --> i choose this RFCN: 84, Freq: 951.8M, CID: 65063, LAC: 3725, MCC: 510, MNC: 21, Pwr: -44 ARFCN: 86, Freq: 952.2M, CID: 7242, LAC: 3613, MCC: 510, MNC: 21, Pwr: -46 ARFCN: 91, Freq: 953.2M, CID: 64917, LAC: 24159, MCC: 510, MNC: 11, Pwr: -43

then i decide use the 951.4M because the strongest one,

then i make this config: cat gr-iridium/examples/hackrf10msp_951.4.conf [osmosdr-source]

device_args='hackrf=0'

#Use the following line to turn on the antenna bias #device_args='hackrf=0,bias=1'

sample_rate=10000000 center_freq=951400000 bandwidth=9000000

# Turn on the pre-amp gain=14

# Moderate gains if_gain=40 bb_gain=20

then i run this command iridium-extractor -D 4 gr-iridium/examples/hackrf10msp_951.4.conf > output.bits attached below is the output.bits output.bits.gz

and then i leave it around 15 to 20 minutes and then run these commands below respectively: python3 iridium-parser.py -p output.bits > output.parsed --> found the output.parsed is zero run again withouth -p python3 iridium-parser.py output.bits > output.parsed
and then run again the output.parsed with, found some result

but i noticed a lot of like this below: RAW: p-1693905457-e000 000946498.6657 0951082315 67% -47.37|-087.90|21.39 0011011000110010 1011001100111100 0110100000110101 00001100 ERR:Message: Access code missing

both result of command below is failed, rifky@rifky-virtual-machine:\~/Desktop/iridium-toolkit\$ ./reassembler.py -i output.parsed -m ida Kept 0/25073 (0.0%) lines 0 valid packets assembled from 0 fragments (1:0.00). 0/0 (0.0%) broken fragments. 0 dupes removed. rifky@rifky-virtual-machine:~/Desktop/iridium-toolkit$ ./reassembler.py -i output.parsed -m lap Kept 0/25073 (0.0%) lines 0 valid packets assembled from 0 fragments (1:0.00). 0/0 (0.0%) broken fragments. 0 dupes removed.

My goal to see the "lap" or IDA" mode in pcap file for the gsm, Need your kindly help for your suggestion and direction sir? br, rifky

[arifkyi]

i also attach the file for the output.parsed.gz just in case need it for the diagnose output.parsed.gz

[Sec42]

This toolkit is for parsing iridium data which is transmitted by the iridium satellites at ~ 1.626 GhZ. It is not intended to work with terrestrial mobile networks (GSM).

Your confusion may be due to the fact that there are Iridium (Satellite) mobile phones which use a protocol very similar to LAPDm which is also used in GSM. This is what gr-iridium can record and iridium-toolkit can decode.

I suspect the documentation could be clarified in that regard.

[arifkyi]

Hello,

thanks for your swift response Sir,

yes my confusion started from this guidance:

Supported modes are currently:

• ida - outputs Um Layer 3 messages as hex

• lap - GSM-compatible L3 messages as GSMtap compatible .pcap

thank you very much for the clarity, i think we can close this issue, thanks

[Sec42]

Thanks for the pointer. I will maybe re-word this to make it a bit clearer.

[arifkyi]

Thanks for the pointer. I will maybe re-word this to make it a bit clearer.

the pleasure is mine, thanks for clarifying 🙏🙏