@BBruce1 - the MicroCell was designed for land based internet only (DSL, cable, or fiber) because lag time, jitter, etc are just too variable for VoIP, among other technical issues.
Sales of the MicroCell were discontinued at the end of 2017 because the MicroCell has reached its EOL. What is recommended now is WiFi-C (WiFi Calling) if your phone supports it. Otherwise a cellular booster, switch carriers, or possibly try Google Voice are your other options.
*The views and opinions expressed on this forum are purely my own. Any product claim, statistic, quote, or other representation about a product or service should be verified with the manufacturer, provider, or party.