On the verge of 3G reception -- how to find the best position
You might wish to take a look at apps like Network Signal Info and RF Signal Tracker, which allow you not only to monitor signal quality, but also show you which cells you are connected to, plus what kind of connection you had (3G/H+/...). You can follow that on-screen (to find the currently best place), and also log it (if you notice "drops", that might be helpful when discussing things with your provider).

 
Network Signal Info and RF Signal Tracker (source: Google Play; click images for larger variants)