I bought Samsung Galaxy Tab 8.9 4G LTE SGH-i957 (AT&T) yesterday. I entered unlock code, and it works T-Mobile's SIM card.

I found that the speed of Internet is very slow. Speedtest shows 180Kbps/150Kbs. When I insert the same SIM card to my Samsung Exhibit II in the same place, it is 4Mbps/1Mbps.

I thought AT&T uses both 4G LTE & HSPA+, and T-Mobile uses HSPA+. I also thought that my tablet supports both bands, especially because it is already unlocked.

Does anybody know why my tablet is so slow through T-Mobile network? I did not see big differences between Galaxy tab 7.0 (T-Mobile) and mine in terms of connectivity.

Thank you.