We rarely think of cell phone electromagnetic waves as being made of photons. The reason is that there are so many of these tiny lumps that the lumpiness of the transmitted energy is completely negligible. Let's go through a little calculation. A typical cell-phone frequency is around 109
Hz. Multiplying by Planck's constant we find a photon energy in the range of 10-24
J. The emitted power is typically in the range of 1 W= 1 J/s, so the phone emits about 1024
photons/s. That's a very large number.
Let's say that the cell tower was about a km away. Over each square meter at that distance, about 1017
photons pass per second. There's little point in trying to pay attention to the quantum nature of a flow like that.
Although the radiation from a cell phone isn't isotropic, it is very spread out, not particularly directional. There's no special beaming of the waves. I would guess that the cell towers try to direct their radiation general downward, to avoid wasting power in directions where it won't be used.
(published on 12/17/2011)