Wireless Joint

So again over the past day, lots of connection drops throughout the day and then absolutely zero connection drops between midnight and 9AM. Then they start up again. Same thing happened the day before.

https://i.imgur.com/fHKIKcf.jpg

At this point I think it must be some kind of local issue with ...

Unfortunately I can't find a way into the AT terminal for the modem itself to test that. The GX450 has band selections but they're more general for regions and modes as opposed to specific bands.

Not a bad theory. Seems like the radio is almost always on Band 4 so trying a different one could yield ...

Well I now have a Sierra MP70 on the way thanks to a lowball eBay offer, so I'll have a second modem (also with an MC7354) to compare with once that arrives. Still, it's going to be a few weeks before it shows up so I'd like to try and figure out what the heck is going on here in the meantime.

I've got the latest firmware I believe, both the ATT & the generic ones. It actually has enough space to store two images at a time which is handy. SWI9X15C_05.05.58.00 is what I've got, I downloaded it directly from Sierra's site.

Also more drops today, seems that maybe I just got lucky last night ...

So I started plotting ping data last night, just to get a feel for how the modem was behaving. The following graph is ping times from the last ~12 hours, where the big triangles are loss of connection (average ping time slowly increasing as no pings make it through)

https://i.imgur.com/9gIjuvv.jpg ...

No dice. Generic firmware installed and the same issue just happened again. Same exact log entries as before too.

GPS does seem to die at the same time as cell service. Maybe the entire modem module is experiencing some kind of fault? No clue how I'd even begin troubleshooting that.

I'm giving the generic firmware a shot now. We'll see if it makes any difference.

Part of the SINR fluctuation is likely band changes. I see it regularly switch between bands 2, 4, and 17, among others. However I don't think that's the issue with my connection drops.

I'm not sure what else to test at this point. AT&T support will be useless I'm sure. Perhaps the Sierra Wireless ...

So here's the log from the most recent connection drop.

Here's the two entries prior to the connection failing. Just good signal reports and nothing abnormal.

Jun 22 16:05:58 notice ALEOS_LINKMGMT_linkmon: Current: RSSI=-51, RSRQ=-13, RSRP=-75, SINR=5.8
Jun 22 16:20:58 notice ALEOS_LINKMGMT ...

So here's that command again when I'm in the no service state. This time it shows as RRC Connected but IMS as No Srv.

AT!GSTATUS?
!GSTATUS:
Current Time: 3094Temperature: 39
Bootup Time: 0Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B4 LTE bw: 10 MHz
LTE Rx chan: 2000LTE Tx chan ...

I also noticed SINR being lower compared to the other signal levels. I figure there may be a bit of local interference in the area. I'm also not testing this on the world's greatest antenna, but it should be perfectly serviceable for a downtown location with sites all over the place. ( Laird DBA ...

Here's the output from the debug information tool in the router's web gui (with redactions) when the router gets stuck in the "no service" state:

ATI
Manufacturer: Sierra Wireless, Incorporated
Model: MC7354
Revision: SWI9X15C_05.05.58.00 r27038 carmd-fwbuild1 2015/03/04 21:30:23
MEID: 35xxx
ESN ...

Hi all,

I've been testing out an AT&T 15GB hotspot plan on my Sierra GX450 (a vehicular router with an integrated MC7354).

I've got it up and running on the AT&T network, but I keep loosing service after an inconsistent amount of time. I'm running on a temporary antenna here on my desk, and signal ...

I'm giving the AT&T $35 15GB plan a shot, for this month at least, to see how it performs and to get some data on coverage and speeds.

If it ends up being way better, I may reconsider the Ipad unlimited plan trick. As it turns out, the MC7354 inside the GX450 is actually included in the list of ...

Hi all,

I've got a Sierra GX450 vehicle modem installed in my truck right now. It's a compact router/modem combo with an MC7354 inside. I'm currently running on US Mobile's GSM network, but I'm looking to switch to a better carrier as a) using anything other than phones on their network is ...