Common antenna types
There are different type of antennas. The most common types are parabolic and panel antennas associated with mobile phone coverage:
- parabolics - large round dishes or dished grids
- panel antennas.
Other types include omni, dipole or yagi but these are far less common.
Why are there so many antenna/base stations/telecommunication towers needed?
Radiofrequency radiation is stopped by hills, buildings or other solid objects resulting in "dead spots" in the network. Dead spots or particularly high mobile phone traffic areas present coverage problems and so banks of additional antennas are often placed on the rooftops of high buildings, church spires or other high places (hence the antennas on Monash rooftops) to improve coverage. Telecommunications companies have a preference for putting in multiple antenna sites as this reduces the both the emission levels at both the individuals mobile phone and at each antenna site.
Positioning of antennas
Antennas are always placed high in the air in order to minimise interference with the transmission/reception of their radiofrequency signal as well as to make it impossible for any person (other than a hang-glider or abseiler) to physically get within the high intensity area of radiation, which is usually immediately in front of the antenna. The Australian Communications and Media Authority (ACMA) regulates the positioning of base stations and antennas. There is a listing of all of the locations that have telecommunications antenna that are operated by mobile carriers available at the Radiofrequency National Site Archive (www.rfnsa.com.au logging in as a guest requires no password).