LPWAN operates in an unlicensed frequency spectrum in sub-gigahertz range. Although it is unlicensed which means the user doesn't have to apply for permission to transmit and pay huge license fees, it is still regulated and everyone needs to follow the rules imposed by the radio communication authorities of the given country where the device operates. Because unlicensed spectrum is a common good, following the rules ensures that no single entity will prohibit others from accessing it. Another example of an unlicensed spectrum is 2.4GHz and 5GHz used by WiFi, Bluetooth and many other protocols. LPWAN prefers using sub-gigahertz frequencies because it allows for communication over longer distances but because of this longer propagation, the regulations are stricter than short range communication bands. To make things even more complicated different authorities impose different rules, and allocate different bands depending on the region. To help all LPWAN adopters to navigate this complicated labyrinth of rules, a common framework has been developed by the Lora Alliance and is published in a document called the Regional Parameters available on their website.
MXC Supernode servers are designed and configured to comply with the Regional Parameters guidelines, nonetheless they don't define all aspects LPWAN communication and still leave some freedom to network server operators in regards to the specific channel bands, number of channels and other parameters. For example US902-928 region specification used in USA and other regions respecting FCC authority defines 64 possible frequencies channels that can be used by devices but most of existing LPWAN Gateways can only use 8 or 16 of those channels and it is up to the network operator to chose which one to use.