How much bandwidth does Microcell really use? Still having some issues with quality

Just curious I know they say 1.5mb is the minimum connection, which is what I have.. But honestly I've ran speed tests while on a call and it came back 1.4mb without really affecting the call. However, sometimes when I'm on the phone even when not using my internet at all, when I go into my bedroom, either the other person tells me that some of my words cut out, or I can hear them cutting out (it's NEVER both so either they can hear me clearly or I can hear them clearly)...

I'm wondering if the connection speed has something to do with this, but I'm kind of skeptical of that because if I go back into the living room near the microcell it doesn't do it. However, my apartment is only 900 square foot so I can't imagine that distance from the micro-cell would have anything to do with it...

I should note that the telco panel (for Cox, AT&T, and U-verse) for my complex is on the other side of my bedroom wall - and I'm starting to wonder if that could be interfering with the 3G signals - however, it does not interfere with the 1XEV signals of Verizon because I also have a Verizon blackberry through my work and it doesn't cut out in the bedroom.

Anyway, at least it's not dropping the calls like it used to!