[jsjohnst]

Just to confirm, but a GSM module won’t work for AT&T (but will for the time being for T-Mobile) in the US, right? To my knowledge, AT&T has shut down most (all?) of their GSM network and is only LTE (in its various flavors).

[jsjohnst]

Just to circle back here, seems the official date of AT&T shutting down their 2G (GSM/GPRS) happened in Jan 2017. Their 3G (HSDPA/UMTS) network is tentatively scheduled for about 1.5yrs from now.

So my suggestion, if you’re building anything IoT like on AT&T, make sure you are using LTE-A, LTE-M, or NB-IoT for your radios or you’ll have a short operational life, if at all.

[humancell]

Yes ... I work for Twilio as an IoT SE - there are a lot of great and inexpensive modules that you can use. Stay away from anything 2G/3G as they are being shut down as bands are being reallocated. Also, avoid the "quad band" solutions that are advertised.

I usually buy SIMCom modules from Ali Express. The SIM7000A or G, SIM7070G. The A is usually North American bands, and the G is global bands. There are E versions for Europe. These are CAT-M1 and NB-IoT modules, and I usually use the CAT-M.

NB-IoT is a great idea, but depending on where in the world you are it might not exist. Also, Super SIM does not currently support NB-IoT. We have a different T-Mobile SIM for that. If you really want to go NB-IoT, then the SIM7020{x} is a good module to develop with, or the Quectel BC66.

There are also some great projects now running code directly on the cellular modules. Search github for Wiz-IO. Georgi is brilliant in what he's doing, and supports numerous languages running directly on the Quectel modules.

[jsjohnst]

I’ve been using Sierra Wireless Cat-M1 modules for the projects I’ve been prototyping as they include an ARM Cortex A7 and GPS too in a single package. Bit expensive on the BOM, but convenience makes it worth it. Will test them with this once I get a chance.