Cellular problems iPhone 5

Im using LTE and the speed 2mb/s that slow but when i go to places that not support LTE  it  appear 3g and the speed 10-16 mb/s im confused  some says LTE is the best and better then 3g but when i do test that what happen it appear 3g better LTE or my LTE is not working well  ?

Informations about my device

Iphone 5

Ios: 6.1.3

Carrier : viva (kuwait)