Up till now, the CAT-M IoT sim card can roam in Australia and New Zealand. But the roaming is not working in countries such as Italy and HongKong. Do I need to do any specific configurations during roaming?
Italy and Hong Kong do not have carriers that have Cat-M1, currently they only have national NB-IOT (note Hologram does not support NB-IOT at this time, and your modem may not either).
Check https://www.gsma.com/iot/deployment-map/ for a map of countries and their low bandwidth deployments.
For you to get Cat-M1 in a country with a hologram simcard 2 things must be true:
- A carrier in that country has deployed Cat-M1 (remember Hologram doesnt own any towers, they only have agreements with other network operators to use their towers). See my link above to figure this out.
- Hologram has to have a contract with the carrier above to allow Hologram Cat-M1 devices on their network. See: https://hologram.io/pricing/coverage/ to figure this out.
Note that when hologram lists “LTE” they dont mean “LTE Cat-M1” or “NB-IOT” these will be listed separately although in most cases if a carrier has Cat-M1 (see list item 1 above) and allows Hologram on their network (list item 2) then Cat-M1 will work (See Telstra in Australia for example)
Thanks for the info!
Just another one: In spite of the issue of carriers, if I try “at+cops=?” to search for available signals, can I still find the available carriers there but it cannot be connected with, or just cannot find any signals at all?
I would say do not rely on at+cops=? to determine if the device can connect. I dont know the difference between Cat-M1 and normal LTE broadcast messages so
COPS may list towers even if there are no Cat-M1 towers, but hologram or someone more knowledgeable with tower discovery will have to verify.
In many cases, you will be able to see towers that you are not authorized to connect to. The at+cops=? command is like searching for wifi, you will see lots of wifi hotspots available, but if you dont know the password (in this case, if the simcard is not authorized on the network) then you wont be able to successfully connect.