As an end user, this situation really isn't much different than the one we've been living with for mobile phones for the past decade. You typically have to buy one of the phones that your cellular provider supports -- that's actually because different providers used different second-generation (2G) protocols like TDMA, CDMA, GSM, and CDPD. Even GSM uses different frequencies in different countries, so you can't take your GSM phone from North America and use it in Europe. Unless...
Some handset manufacturers offer multi-mode phones that support multiple 2G networks. Using one of those handsets, you can have the same GSM phone work in the US and in Europe (for example). The phone just uses the right protocol to connect to the available 2G network. The same may happen for 3G mobile devices, allowing one devices to roam all over the world by alternating between 3G standards and access procedures as necessary to meet local carrier requirements.
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