How to design a wireless router

Question

router should be able to use most back haul internet technologies eg. GPRS, EVDO, UMTS ect.

Answer 1

You want the circuit diagram or what?

Edit: I was, of course, being sarcastic. It takes electrical engineers months/years and hundreds of thousands of dollars to design and manufacturer your standard consumer router. Let alone one that can also handle a bunch of 2G/3G mobile networks by itself. Already you're complicating things just by adding the SIM card electronics, not to mention the electronics and firmware to handle all these wireless connections. You're obviously not an electrical/network/telecommunications engineer, or a programmer, and I'm guessing you have neither the man hours nor financial resources to undertake such a project. If you're after schematics, spend 5 years at uni, reverse engineer an existing router, then tack on your wireless internet functionality and reprogram the firmware, and voila you have exactly what you need.