AT&T Microcell iPhone 5

I was wondering if the AT&T Microcell would have 4G (HSPA+ not LTE). I'm aksing becuase I at my house I have 1 bar of EDGE and none of 3G, but it has 1 bar of 4G HSPA+, so I am concerned it would output 3G, but my iPhone 5 wouldn't switch to it because it on the 1 bar of 4G. Thanks in advance!!