The US is about 8 months away from shutting down 3G. Where are the 4G/LTE modem modules?
We are working on it. Hardware is fine. Firmware is being worked on.
Do you have any details on the exact shutdown date? Last I heard AT&T still hadn't announced a firm date, and T-Mobile said they will continue supporting 3G.
I can confirm that AT&T will be shutting down 3G service in the US in February 2022.
Will it be a direct replacement for the current 3G modem?
For example, will those of us with the "WiFi only" version be able to add the daughterboard to our current setup?
Yes, the 4G module will be a direct replacement for 3G. Can also be added to wifi-only modules as an upgrade.
Good to hear! AT&T says Feb 2022: https://www.att.com/support/article/wireless/KM1324171/
Looking at the European countries, most providers will switch off 3G till end of the year or have already in 2020, while 2G will be kept alive some time in most countries. In Czechia, both 2G and 3G are already dead.
Will you support all the different LTE frequencies all over the world?
Will the module be LTE only, or is it combined with GSM or UMTS?