EM7511, limited MBIM status information under Mikrotik RouterOS

Running an EM7511 using EM7511 GENERIC Release 14, it appears the software does not return much in the way of status information to the MBIM Cell Info commands sent via Mikrotiks RouterOS v7.1beta2. I would really love it if Sierra development could take a look at the MBIM status requests being sent so I can see more than just RSSI information. I’m looking for the details included in a GSTATUS command, which is displayed for other vendors modems. The EM7511 only shows RSSI… it is missing things like CellID, EARFCN, RSRP, RSRQ, SINR, CQI… etc.

Hi @pkranz

!GSTATUS command: Return operational status
Return specific details about the current operational status of the modem. The response details vary depending on the current RAT. Contact Sierra Wireless for further details if required.

Usage:
• Query: AT!GSTATUS?
Response (Example shown is for LTE; fields will vary depending on RAT)
!GSTATUS:
Current Time: Temperature:
Reset Counter: Mode:
System mode: PS state:
LTE band: LTE bw:
LTE Rx chan: LTE Tx chan:
LTE CA state: LTE Scell band:
LTE Scell bw: LTE Scell chan:
EMM state:
RRC state:
IMS reg state:
PCC RxM RSSI: RSRP (dBm):
PCC RxD RSSI: RSRP (dBm):
SCC RxM RSSI: RSRP (dBm):
SCC RxD RSSI: RSRP (dBm):
Tx Power: TAC:
RSRQ (dB): Cell ID:
SINR (dB):

Please refer to 41111748 AirPrime EM75XX AT Command Reference r2 for more details.
Here is the result on my EM7511 module:

AT!GSTATUS?

!GSTATUS:
Current Time: 42 Temperature: 38
Reset Counter: 6 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B3 LTE bw: 20 MHz
LTE Rx chan: 1700 LTE Tx chan: 19700
LTE SSC1 state:NOT ASSIGNED
LTE SSC2 state:NOT ASSIGNED
LTE SSC3 state:NOT ASSIGNED
LTE SSC4 state:NOT ASSIGNED
EMM state: Registered Normal Service
RRC state: RRC Idle
IMS reg state: No Srv

PCC RxM RSSI: -85 PCC RxM RSRP: -113
PCC RxD RSSI: -94 PCC RxD RSRP: -130
Tx Power: – TAC: 654e (25934)
RSRQ (dB): -8.9 Cell ID: 09024402 (151143426)
SINR (dB): 8.8

OK

AT!GSTATUS is a very useful command in the AT interface I agree…

But my application is using the MBIM interface. This does not use AT commands as far as I understand, but programmatic calls for status information.

Do you have any documentation of this MBIM request? It is not part of the MBIM spec AFAIK. I assume it is a vendor extension from someone? But they probably have public documetation somewhere if they expect anyone to implement it.

Response from Mikrotik is as follows:

MBIM signal status, we implemented in RouterOS MBIM support according to MBIM specification (public document) and RouterOS logs MBIM messages to logs so communcations can be decoded.

In other words, if a Sierra developer who understood the MBIM logging was available, I could send the MBIM transactional data over. It does not look like AT Commands, it looks like this:

image

Well, this answer seems to point to the standard MBIM_CID_SIGNAL_STATE, which only returns RSSI and error rate. Ref section 10.5.11 of the MBIM v1.0 spec.

I see now that I might have misunderstood what you meant by your initial request. I thought you said that RouterOS reported things like CellID, EARFCN, RSRP, RSRQ, SINR, CQI… etc from other MBIM modems than the EM7511 But I guess I read that completely backwards. Sloppy reading… You’d like to see those values - from any MBIM modem, including the EM7511? The problem is that there is no standardized MBIM request for that.

The MBIM spec is freely availble. Just go to https://usb.org/documents?search=mobile+broadband&items_per_page=50 and download the "Mobile Broadband Interface Model v1.0 Errata -1 and Adopters Agreement ". This is the full spec with the errata included, not just the errata.

The status commands that Mikrotik is looking to have supported so that MBIM status details are displayed are as follows:

MBIM_CID_EXT_CONNECT
MBIM_CID_MS_BASE_STATIONS_INFO

Here is the original text from the Mikrotik developer:

“Regarding MBIM signal reporting, we would like what modems reports correct data using MBIM_CID_EXT_CONNECT MBIM_CID_MS_BASE_STATIONS_INFO. Microsoft have very good document about Windows built in MBIM signal reporting https://docs.microsoft.com/en-us/windows-hardware/drivers/network/mb-base-stations-information-query-support, RouterOS implantation is planed to to use the same data.”

Thanks a lot!

The MBIM_CID_MS_BASE_STATIONS_INFO does indeed look like it provides all we need. And as they point out: Microsoft are best in class when it comes to documenting their vendor specific services. I hadn’t noticed that they’ve extended their extention service with this CID and a few more.

I just checked my EM7455 with 02.33.03.00 and see that it only implements CID 7 and 8 in this service:

mbimcli -p -d /dev/cdc-wdm0  --query-device-services
[/dev/cdc-wdm0] Device services retrieved:
        Max DSS sessions: '0'
                Services: (16)
..
                          Service: 'ms-basic-connect-extensions'
                             UUID: [3d01dcc5-fef5-4d05-0d3a-bef7058e9aaf]:
                      DSS payload: 0
                Max DSS instances: 0
                             CIDs: device-slot-mappings (7),
                                   slot-info-status (8)

I haven’t checked EM75xx, but assume the current status is similar. You can check this with mbimcli as shown above.

But I don’t see any reason why this shouldn’t be extended with the new CIDs in later firmware versions.

EDIT: I just switched my EM7565 with i01.11.00.00 nto MBIM mode to check, and it implements quite a few more of the Microsoft extensions. But not yet MBIM_CID_MS_BASE_STATIONS_INFO as you pointed out.

mbimcli -p -d /dev/cdc-wdm0  --query-device-services 
[/dev/cdc-wdm0] Device services retrieved:
        Max DSS sessions: '0'
                Services: (15)

..
                          Service: 'ms-basic-connect-extensions'
                             UUID: [3d01dcc5-fef5-4d05-0d3a-bef7058e9aaf]:
                      DSS payload: 0
                Max DSS instances: 0
                             CIDs: provisioned-contexts (1),
                                   lte-attach-configuration (3),
                                   lte-attach-status (4),
                                   sys-caps (5),
                                   device-caps (6),
                                   device-slot-mappings (7),
                                   slot-info-status (8),
                                   device-reset (10)