When I call to some one the voice will not hear good.we should catch the mobile in our hand and roam every where for signels.I upgraded my idea to 4g for free data 2gb but in my area the signels are so bad and the speed I get for idea 4g is 10 to 20 k/s only.It is slow than idea 3g and 2g.some times the network bars in my mobile shows full network but the speed of internet will be slow.Not only my idea sim but also my friends are facing the same problems.The speed of internet is good before I upgrade to 4g.