the owner says that Dtac pays him to put this thing on his building. I am just curious what it does and if it is for wifi or 3g and can help give me a faster connection if I use a Dtac sim with my aircard for internet. It basically one of those metal poles used for reception and then a large box that is closed and locked.

any idea what this thing does and if i should expect very fast wifi/3g internet because of it?

If it's something like this

with the dish pointing horizontally then its a microwave com link used to relay mobile phone signals to the antenna for local distribution.

Probably a local mobile phone repeater.

A useful source of income for a building owner.

It's commonly called a "base-station", and may support GSM voice, data and in some cases 3G data, with a radio or fixed back-haul. Your proximity to it is likely not overwhelmingly beneficial.

cancer is coming at you, move to a safer building.

Here is some technical info, including danger assessment

http://www.hpa.org.uk/Topics/Radiation/UnderstandingRadiation/UnderstandingRadiationTopics/ElectromagneticFields/MobilePhones/info_BaseStations/

Read and decide for yourself

Your proximity to it is likely not overwhelmingly beneficial.

For the record, I was referring the OP's proximity to the base-station not being beneficial re: some sort of higher-speed data access rather than health-related issues.

Given the directional nature, and height, of these antennas, being directly below a "tower" is probably the safest place? And you're getting signals from the nearby, adjacent towers, rather than the one on the roof of your building.

Given the directional nature, and height, of these antennas, being directly below a "tower" is probably the safest place? And you're getting signals from the nearby, adjacent towers, rather than the one on the roof of your building.

That sounds right to me.