@Baozhu @baozhu.zuo 
I have Wio LTE AU Version 1.3b It has Quectel EC21-AU (documented to have band coverage suiting Taiwan).
I am located in Taiwan, and I have a Chunghwa SIM already. It has Voice, sms and data prepaid. Their network has comprehensive coverage of the island.
Should the SIM work, or should it not work ?
If not, then why not ?
Will either the soracom or twilio sims work in Taiwan ? I am needing to send my data to a server across the internet, (it’s part of a global environment monitor network -SmartCitizen) and not needing in to be part of a group or be confined to using a specific server.
Secondly, There exists an AT command that sets the Band coverage. Please advise the band coverage string that I need to send as part of my setup.