|Looks simple enough, right?|
OpenBTS is an open source Unix application that helps you build a low-cost, flexible cellular network. Field-tested networks have been built with a 10-mile radius for connectivity. That'd be enough to cover... say... downtown Tehran, or Shiraz, or Tabriz. Link up a few of these, making sure they're high enough up and you've got your own city-wide cellular network, capable of routing calls all over the world.
You can buy the kits online. Or, you could follow some instructions and put together your own. The only downside to this is that you'll need an internet connection to plug your cellular network into (which can be a drawback if your country's internet connections are as unreliable as SMS/mobile).
Here are some links to get your started:
- Build your own cellular network
- Fed up with spring-mobileattizon - build your own cellular network
- Starting your own mobile/cellular telephone provider