BORON Force Mux Channel 2 Open?

Firmware
1

I have been testing some new ground-level antennas for my LTE borons. As expected, connectivity isn't great, but I have noticed something interesting while watching the logs during the connection phase.

0000017420 [mux] INFO: Starting GSM07.10 muxer
0000017421 [mux] INFO: Opening mux channel 0
0000017422 [mux] INFO: GSM07.10 muxer thread started
0000017425 [mux] INFO: Opening mux channel 1
0000220844 [mux] INFO: Opening mux channel 2
0000223809 [system.nm] INFO: State changed: IFACE_UP -> IFACE_LINK_UP
0000223811 [system.nm] INFO: State changed: IFACE_LINK_UP -> IP_CONFIGURED
0000223867 [system] INFO: Cloud: connecting
0000223871 [system] INFO: Cloud socket connected

We can see that shortly after "Opening mux channel 2" is logged, the device connects. This pattern has been observed several times. It seems that the OS waits ~200 seconds to open mux channel 2, and shortly thereafter the device connects. I don't have any info as to what opening mux channel 2 does... something like increasing transmit power?

Assuming I'm not out to lunch, I am curious if there is anyway to force mux channel 2 to open earlier, instead of waiting ~200 seconds for the system to take care of it?

Thanks!

2

I don't think it's a cause and effect thing. I believe multiplexer channels are used to communicate with different parts of the cellular modem over a single serial connection. I think channel 2 opened because the link came up, not that the link came up because channel 2 opened.

2 Likes
3

Rick’s correct.

The muxer switches between the serial command channel and the data channel - channel 2 being data, so once the modem establishes the connection it switches to the data channel.
Bad signal will mean that it takes a while. 200s is around the time the modem switches it’s carrier profile, so it’s likely that whichever carrier is being tried first does not have great signal.

Since there is only one serial channel to the modem, that’s the only way to do it.

1 Like
4

Thanks for the info guys!

5

Follow up Q:

Is there a way to make the carrier profile switch happen sooner?

Thanks!

6

No, it's handled automatically, and should be quicker once the modem builds it's list of local carriers.

1 Like