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Reply To: XBee and Hologram LTE: issues connecting to internet

Home › Forums › Mayfly Data Logger › XBee and Hologram LTE: issues connecting to internet › Reply To: XBee and Hologram LTE: issues connecting to internet

2020-12-22 at 4:23 PM #14960
Sara Damiano
Moderator
    1. If the SIM provider says you don’t have to do anything to activate the SIM, I’d trust them.
    2. Yes, the “AS” command in the first run sketch does that. (line ~147)
    3. If you’re using an XBee3 LTE-M it *only* supports LTE-M and LTE NB-IoT.  Since your provider doesn’t use NB-IoT, LTE-M will be the only possibility.  That first-run program you’re using sets the bee to use LTE-M preferentially in line 121, which is what you want.
    4. This might be your issue.  Yes, the module can use all of those bands, but you would commonly set it up to use a specific carrier profile that will optimize searching to only the bands that carrier uses.  In the example sketch (line 115), the carrier profile is set to 2/AT&T.  Most of AT&T’s traffic is on bands 2, 4, and 12 (https://www.phonearena.com/news/Cheat-sheet-which-4G-LTE-bands-do-AT-T-Verizon-T-Mobile-and-Sprint-use-in-the-USA_id77933). So if you’re setting your module to AT&T, it will not attempt to use band 3 or band 28.  I think you would want to select “1” as your carrier profile here, which will set the module for “SIM ICCID/IMSI select.”  *Hopefully* your SIM and the module will be friendly enough with each other that the module will then switch its mode to that for your SIM.  This doesn’t always work, though.  I know with a Hologram SIMs in the USA the module will attempt to switch to 100/Standard Europe based on the SIM ICCID, which won’t work.  But with a T-Mobile SIM the “SIM ICCID/IMSI select” setting immediately correctly matched to the 5/T-Mobile profile and the connection worked right away.  If just switching the carrier profile to 1 doesn’t work, there are commands to manually try and force the bands.  Start with the profile, though.
    5. Well, I generally think getting the development board is a good idea if you want to ever do much with the XBee (like test multiple boards or update firmware) but it shouldn’t be strictly needed.