Wireless Joint

I finished up building my Rpi3b+ with M.2 EM7565 and have it up and running. So far its working great. I noticed the secondary band it reports using is different compared to my Mofi4500/7455. The 7455 reported B2 for primary and B12 for secondary. The 7565 is reporting B2 and B11. I suspect the 7565 is reporting the wrong band info. Has anyone else ran into this?

at!gstatus?
!GSTATUS:
Current Time: 34106 Temperature: 29
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B2 LTE bw: 20 MHz
LTE Rx chan: 700 LTE Tx chan: 18700
LTE SSC1 state:INACTIVE LTE SSC1 band: B11
LTE SSC1 bw : 10 MHz LTE SSC1 chan: 5110
LTE SSC2 state:NOT ASSIGNED
LTE SSC3 state:NOT ASSIGNED
LTE SSC4 state:NOT ASSIGNED
EMM state: Registered Normal Service
RRC state: RRC Connected
IMS reg state: No Srv

PCC RxM RSSI: -66 PCC RxM RSRP: -102
PCC RxD RSSI: -64 PCC RxD RSRP: -98
SCC1 RxM RSSI: -73 SCC1 RxM RSRP: -90
SCC1 RxD RSSI: -89 SCC1 RxD RSRP: -107
Tx Power: -- TAC: 910a (37130)
RSRQ (dB): -12.6 Cell ID: 06714408 (108086280)
SINR (dB): 15.8


OK

SliverGT wrote: Wed Jan 22, 2020 9:21 pm I finished up building my Rpi3b+ with M.2 EM7565 and have it up and running. So far its working great. I noticed the secondary band it reports using is different compared to my Mofi4500/7455. The 7455 reported B2 for primary and B12 for secondary. The 7565 is reporting B2 and B11. I suspect the 7565 is reporting the wrong band info. Has anyone else ran into this?

at!gstatus?
!GSTATUS:
Current Time: 34106 Temperature: 29
Reset Counter: 1 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B2 LTE bw: 20 MHz
LTE Rx chan: 700 LTE Tx chan: 18700
LTE SSC1 state:INACTIVE LTE SSC1 band: B11
LTE SSC1 bw : 10 MHz LTE SSC1 chan: 5110

A couple of possibilities for the band reporting differences...

The most likely cause may be the different RF characteristics between your MoFi and RPi setups.
That includes the differences in the received signal strength, antenna separation/grounding, antenna pigtail's length and quality, EMI harmonics, enclosure shielding of the RPi (or the lack of), and of course the phase of the moon (well, maybe not that last item;)
A difference of just a few db's (its magnitude changes exponentially) in signal strength could cause the radio (modem) to behave differently as governed by the radio's firmware, which is usually not affected by the router's/RPi's firmware.
You can try upgrading the modem's firmware to the latest version (though some Sierra modems are known to have a band reporting bug), put the RPi into a well shielded metal enclosure, separate the antennas by about 12 inches, and last by not least just leave the modem in auto-band selection mode to let it do its thing. Unfortunately comparing apples with oranges, usually gives different results... usually;).

Thanks, those are good points. The antennas, cabling, grounding are the same for both setups. Both the modem and RPi are on the latest firmware and it's configured for auto band select. I'm using the generic firmware for the 7565. Either the 7565 or RPi appears to be reporting invalid band info.

Band 11 is not listed as being supported in the 7565 manual.
EM7565 LTE DL Cat-12, LTE UL Cat-13; Bands 1-5, 7, 8, 9, 12, 13, 18, 19, 20, 26, 28, 29, 30, 32, 41, 42, 43, 46, 48, 66

Reporting the wrong bands and some of the stats is a known bug in the Sierra Wireless firmware.