Nice idea, but back in reality, the (usable) radio spectrum is a very limited resource that different countries have, for historical reasons stretching back to the dawn of broadcasting, divided up in different ways.
In many countries, LTE is fitting into space freed up by the demise of analogue TV broadcasting - where that space is, and when it will be freed up, varies from country to country. Also, where you have several independent countries close together, there is the whole can of worms cause by radio waves not stopping at a country's borders - so if your neighbouring country is still using analogue tv...
Some bits of the spectrum are "owned" (or leased) by particular firms. For example, in the UK there is a particular problem that one huge mobile carrier, formed by a merger, already owns a huge chunk of already free frequencies that could be used by LTE. If the government allows LTE on that frequency before the analogue TV switchover has finished and the new frequencies auctioned off, it hands a huge monopoly on LTE to one firm.
