During warmer season I travel a lot for my busniess so yeah I use the phone as a internet sharing a lot tethered to my laptop via usb. I don't check my GB usages but my bill still same 29.99 plus tax.
Internet Sharing is easier to connect than setting up a "Modem" . Internet Sharing is already avaliable on your Moto but AT&T hide it from view so that why I provide that link on the previous post to install make it visable and icon on your START to click to start Internet Sharing.
I get full bar at my Wal Mart but there is a AT&T tower on top of Wal Mart at my hometown so AT&T probably leasing a spot on Wal Mart roof here.
However Wal Mart is mostly steel building with steel shelves so it will interfere or cut down any brand mobile phone signal. Same if you have lots of treee in surronding area because treee aborsbs singal too and make it weaker. I don't know about subway because I don't have a subway here but I read somewhere that you lose signal in subway and Sprint leases and add antenna inside subway tunnels to lure customer to go with Sprint so probably will not work in subway unless At&T or TMobile (roaming) did add antenna in the subway tunnel too.
It works fine on tall building for me, I was at the tall building several times and I got good signals.
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