I have tmobile when inserted the simcard in my z2 I've noticed that I'm not getting any internet connection so i went to Setting/wireless and networks/internet setting and downloaded all the files then I went to mobile netword and changed it to 4G Tmobile, starting that day I keep losing connection every time I have to go to mobile network and change it manually although it's set on automatic, most of teh times 4g doesn't work and I have to set it to 3g... it's really annoying