The use of cell-phone frequencies is EXACTLY why people who have become Electrically Hyper-Sensitive (EHS) do not want them on their houses. They already have trouble when cell phones are in use near them. I have met many such people, and I have personally observed their reactions to be in direct response to cell phones that were near them without their knowledge.
I agree is it not necessary to transmit information every 30 seconds. One University Professor with EHS reports it is those "burst of information" transmissions that seem to be more troublesome, which belies the idea that the total overall energy transmitted is low. It's like the difference between the constant background noise of a city having a lot of overall sound energy, but it is nowhere near as jarring to a human as someone sneaking up on you and shouting in your ear every 30 seconds.