I currently have the 30 walmart plan from tmobile. I want to switch to the Walmart family mobile plan which uses tmobile's network. Am I going to need to unlock the phone so I can use the Walmart family mobile sim or won't it matter since it's the same network? Also they say the data is 3g do they mean the same not really 4g like I have now or something else? I haven't found anywhere that the phone says it's on 3g now just 4g or 2g.