What makes a 4g phone ..4g?

[nigsy]

Bit of a silly question...but what makes a phone 4g?

Is it a software upgrade (different modem etc)?
Is it different hardware?

Or is it as simple as a SIM switch?

 

[Mehta23]

It'd be both the hardware (different antennae) and the sim I believe.

 

[legalkill]

4G is a term given to the rough 4th generation of cellular network technology. The term is used loosly to apply to LTE and HSPA+ networks. The ability of a phone to receive the faster signals from the growing network is based on the hardware antennas that are in the phone itself. Many phones like the verizon s3 have the presence of all antennas making it a "world Phone" meaning it can technically receive signals from most networks. This is a more indepth read Cellular network - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/4g