I can't speak for 4G but I can tell you in my street, the 3G/2G signal varies enormously literally from minute to minute. Sometimes I can take a call, sometimes not. (I know bars are not an accurate measure but that's all I have to measure with) sometimes I get 3-4 bars, sometimes 1, sometimes none. It's actually really annoying as I'm not in the outback, I'm in a town of 60k or so population size. My bit of the street is slightly sheltered.
I'm hoping as part of the 4G rollout the mast will be uprated or improved somehow, it's getting a bit cold now to be on the roof with my hand held high shouting in my phone as I search for a signal