<div dir="ltr">Hi,<div> </div><div>We are having trouble with band selection on the Quectel BG96. It seems the band selection command executes successfully, but the modem always stays on LTE band 20 regardless of the band selection preference. We are using ModemManager version 1.10.0 patched with commit f2c878e7 to allow setting the band preference without SIGSEGV. </div><div> </div><div>Here we try to configure the modem to avoid band 20. </div><div> </div><div>$ mmcli -m 0 --set-current-bands='eutran-8' successfully set current bands in the modem $ mmcli -m 0 -------------------------------- General | dbus path: /org/freedesktop/ModemManager1/Modem/0 | device id: 6efb0cb14e9698c55a05a847f5c774f135ac7011 -------------------------------- Hardware | manufacturer: Quectel | model: 0 | revision: BG96MAR02A10M1G | h/w revision: 10000 | supported: gsm-umts, lte | current: gsm-umts, lte | equipment id: 860536043902982 -------------------------------- System | device: /sys/devices/platform/soc/30800000.aips-bus/30b20000.usb/ci_hdrc.1/usb2/2-1 | drivers: option1, qmi_wwan | plugin: Quectel | primary port: cdc-wdm0 | ports: ttyUSB0 (qcdm), ttyUSB1 (gps), ttyUSB2 (at), | cdc-wdm0 (qmi), wwan0 (net), ttyUSB3 (at) -------------------------------- Status | lock: sim-pin2 | unlock retries: sim-pin (3), sim-pin2 (3), sim-puk (10), sim-puk2 (10) | state: connected | power state: on | access tech: lte | signal quality: 100% (recent) -------------------------------- Modes | supported: allowed: 2g; preferred: none | allowed: 4g; preferred: none | allowed: 2g, 4g; preferred: 4g | allowed: 2g, 4g; preferred: 2g | current: allowed: 4g; preferred: none -------------------------------- Bands | supported: egsm, dcs, pcs, g850, eutran-1, eutran-2, eutran-3, | eutran-4, eutran-5, eutran-8, eutran-12, eutran-13, eutran-17, | eutran-18, eutran-19, eutran-20, eutran-39 | current: eutran-8 -------------------------------- IP | supported: ipv4, ipv6, ipv4v6 -------------------------------- 3GPP | imei: <redacted> | operator id: 24201 | operator name: TELENOR | registration: home -------------------------------- 3GPP EPS | ue mode of operation: csps-2 -------------------------------- SIM | dbus path: /org/freedesktop/ModemManager1/SIM/0 -------------------------------- Bearer | dbus path: /org/freedesktop/ModemManager1/Bearer/0 $ qmicli -d /dev/cdc-wdm0 -p --nas-get-rf-band-info [/dev/cdc-wdm0] Successfully got RF band info Radio Interface: 'lte' Active Band Class: 'eutran-20' Active Channel: '6400' </div><div>$ mmcli -m 0 --command="AT+QENG=\"servingcell\"" response: '+QENG: "servingcell","NOCONN","CAT-M","FDD",242,01,105ED03,496,6400,20,3,3,78BF,-51,-6,-28,24,76 </div><div> </div><div>Relevant part of the ModemManager log:</div><div> </div><div>ModemManager[6395]: <debug> [1594121691.792737] Setting new list of bands: 'eutran-8' ModemManager[6395]: [/dev/cdc-wdm0] sent message... <<<<<< RAW: <<<<<< length = 39 <<<<<< data = 01:26:00:00:03:01:00:4A:00:33:00:1A:00:17:01:00:01:15:08:00:80:00:00:00:00:00:00:00:12:08:00:00:00:00:00:00:00:00:00 ModemManager[6395]: [/dev/cdc-wdm0] sent generic request (translated)... <<<<<< QMUX: <<<<<< length = 38 <<<<<< flags = 0x00 <<<<<< service = "nas" <<<<<< client = 1 <<<<<< QMI: <<<<<< flags = "none" <<<<<< transaction = 74 <<<<<< tlv_length = 26 <<<<<< message = "Set System Selection Preference" (0x0033) <<<<<< TLV: <<<<<< type = "Change Duration" (0x17) <<<<<< length = 1 <<<<<< value = 01 <<<<<< translated = permanent <<<<<< TLV: <<<<<< type = "LTE Band Preference" (0x15) <<<<<< length = 8 <<<<<< value = 80:00:00:00:00:00:00:00 <<<<<< translated = 8 <<<<<< TLV: <<<<<< type = "Band Preference" (0x12) <<<<<< length = 8 <<<<<< value = 00:00:00:00:00:00:00:00 <<<<<< translated = (null) ModemManager[6395]: [/dev/cdc-wdm0] received message... <<<<<< RAW: <<<<<< length = 20 <<<<<< data = 01:13:00:80:03:01:02:4A:00:33:00:07:00:02:04:00:00:00:00:00 ModemManager[6395]: [/dev/cdc-wdm0] received generic response (translated)... <<<<<< QMUX: <<<<<< length = 19 <<<<<< flags = 0x80 <<<<<< service = "nas" <<<<<< client = 1 <<<<<< QMI: <<<<<< flags = "response" <<<<<< transaction = 74 <<<<<< tlv_length = 7 <<<<<< message = "Set System Selection Preference" (0x0033) <<<<<< TLV: <<<<<< type = "Result" (0x02) <<<<<< length = 4 <<<<<< value = 00:00:00:00 <<<<<< translated = SUCCESS ModemManager[6395]: [/dev/cdc-wdm0] sent message... <<<<<< RAW: <<<<<< length = 13 <<<<<< data = 01:0C:00:00:03:01:00:4B:00:34:00:00:00 ModemManager[6395]: [/dev/cdc-wdm0] sent generic request (translated)... <<<<<< QMUX: <<<<<< length = 12 <<<<<< flags = 0x00 <<<<<< service = "nas" <<<<<< client = 1 <<<<<< QMI: <<<<<< flags = "none" <<<<<< transaction = 75 <<<<<< tlv_length = 0 <<<<<< message = "Get System Selection Preference" (0x0034) ModemManager[6395]: [/dev/cdc-wdm0] received message... <<<<<< RAW: <<<<<< length = 151 <<<<<< data = 01:96:00:80:03:01:02:4B:00:34:00:8A:00:02:04:00:00:00:00:00:10:01:00:00:11:02:00:10:00:12:08:00:00:00:00:00:00:00:00:00:15:08:00:80:00:00:00:00:00:00:00:16:01:00:00:18:04:00:02:00:00:00:19:04:00:01:00:00:00:1C:05:00:04:08:00:00:04:1D:04:00:00:00:00:00:1F:04:00:02:00:00:00:20:04:00:01:00:00:00:24:08:00:02:00:00:00:00:00:00:00:25:08:00:9F:18:0E:0A:40:00:00:00:26:08:00:9F:18:0E:0A:00:00:00:00:27:11:00:04:08:00:00:00:0A:00:00:00:0B:00:00:00:04:00:00:00 ModemManager[6395]: [/dev/cdc-wdm0] received generic response (translated)... <<<<<< QMUX: <<<<<< length = 150 <<<<<< flags = 0x80 <<<<<< service = "nas" <<<<<< client = 1 <<<<<< QMI: <<<<<< flags = "response" <<<<<< transaction = 75 <<<<<< tlv_length = 138 <<<<<< message = "Get System Selection Preference" (0x0034) <<<<<< TLV: <<<<<< type = "Result" (0x02) <<<<<< length = 4 <<<<<< value = 00:00:00:00 <<<<<< translated = SUCCESS <<<<<< TLV: <<<<<< type = "Emergency mode" (0x10) <<<<<< length = 1 <<<<<< value = 00 <<<<<< translated = no <<<<<< TLV: <<<<<< type = "Mode Preference" (0x11) <<<<<< length = 2 <<<<<< value = 10:00 <<<<<< translated = lte <<<<<< TLV: <<<<<< type = "Band Preference" (0x12) <<<<<< length = 8 <<<<<< value = 00:00:00:00:00:00:00:00 <<<<<< translated = (null) <<<<<< TLV: <<<<<< type = "LTE Band Preference" (0x15) <<<<<< length = 8 <<<<<< value = 80:00:00:00:00:00:00:00 <<<<<< translated = 8 <<<<<< TLV: <<<<<< type = "Network Selection Preference" (0x16) <<<<<< length = 1 <<<<<< value = 00 <<<<<< translated = automatic <<<<<< TLV: <<<<<< type = "Service Domain Preference" (0x18) <<<<<< length = 4 <<<<<< value = 02:00:00:00 <<<<<< translated = cs-ps <<<<<< TLV: <<<<<< type = "GSM WCDMA Acquisition Order Preference" (0x19) <<<<<< length = 4 <<<<<< value = 01:00:00:00 <<<<<< translated = gsm <<<<<< TLV: <<<<<< type = "Acquisition Order Preference" (0x1c) <<<<<< length = 5 <<<<<< value = 04:08:00:00:04 <<<<<< translated = { [0] = 'lte ' [1] = 'none ' [2] = 'none ' [3] = 'gsm '} <<<<<< TLV: <<<<<< type = 0x1d <<<<<< length = 4 <<<<<< value = 00:00:00:00 <<<<<< TLV: <<<<<< type = 0x1f <<<<<< length = 4 <<<<<< value = 02:00:00:00 <<<<<< TLV: <<<<<< type = 0x20 <<<<<< length = 4 <<<<<< value = 01:00:00:00 <<<<<< TLV: <<<<<< type = 0x24 <<<<<< length = 8 <<<<<< value = 02:00:00:00:00:00:00:00 <<<<<< TLV: <<<<<< type = 0x25 <<<<<< length = 8 <<<<<< value = 9F:18:0E:0A:40:00:00:00 <<<<<< TLV: <<<<<< type = 0x26 <<<<<< length = 8 <<<<<< value = 9F:18:0E:0A:00:00:00:00 <<<<<< TLV: <<<<<< type = 0x27 <<<<<< length = 17 <<<<<< value = 04:08:00:00:00:0A:00:00:00:0B:00:00:00:04:00:00:00 </div><div>Resetting the modem doesn't help either. I am not sure whether this mailing list is the correct forum for this question or if I should ask Quectel about this. Any help is very much appreciated.</div><div> </div><div>Best,</div><div>Fredrik</div></div>