I think you should have Sign boards/Warning Signs are to be provided at Base Station Antenna sites which should be clearly visible and identifiable. A warning sign should be placed at the entrance of such zone.
In case of multiple transmitter sites at a specific locality sharing of a common tower infrastructure, should be explored, as far as possible, which can be coordinated through a nodal agency. Access to Base Station Antenna sites should be prohibited for general public by suitable means such as wire fencing, locking of the door to the roof etc. Access to tower site, even for the maintenance personnel, should be for a minimum period as far as possible.
Are you talking about Mobile towers? then i you should know this that Mobile phone towers installed on top of buildings are a definite threat to human health. According to experts, radiation from mobile phones used for long duration is higher than those from mobile towers.