Zwave frequencies, as well as regulations, vary between countries/regions. This means that equipment isn't interchangeable, something I'm currently running into - I can't get a zwave electronic door lock for Japan while I could easily have bought one in my home country. But I wouldn't be able to bring it if I wanted to.
Zigbee is basically the same everywhere, however the 2.4GHz band is of course somewhat congested.
Zigbee is basically the same everywhere, however the 2.4GHz band is of course somewhat congested.