I’m using Hologram SIM card with a SIM800 modem controlled from an embedded system (no OS), using AT commands.
I used the GSM modem to connect to AWS with MQTT and SSL. So far I can establish a connection and send/receive data, but I see connection is not very reliable, so I get lots of socket errors which disconnect MQTT session.
I can see from the Dashboard that the SIM is using T-Mobile in 2G mode. I’m wondering if this is an issue… I see people here talking about using 3G and 4G, and other providers such as AT&T as well… How can I switch to these 3G or 4G connectivity? Are there specific AT commands for this? I would like to try other modes to see if I can get a more reliable connectivity.