Omni ceiling antenna is also called Ceiling mount omni directional antenna.It is for in-building applications such as DAS. The low pim antenna is vertically polarized and operates at 380-6000 MHz supporting also public safety frequencies (TETRA). How to choose a correct antenna to achieve the purpose of amplifying the signal and transmitting it? Usually we can see ceiling antennas like small mushrooms on the top of subways, railway stations, airports and large shopping malls. It's connected by jumper cable with RF passive components.