Ever since man tried to talk with God at Babel we’ve been building towers as a way to communicate. While mobile phone makers fall over themselves to make us buy the latest, greatest and most fashionable handsets they are little more than plastic and shiny lights without a tower to talk to.
The first portable telephones communicated to a tower that was connected to the landline phone system. By just after World War Two, AT&T in the USA had come up with a way for a single tower to host multiple conversations, but they needed Federal Communications Commission (FCC) approval to continue development. The FCC, in their infinite wisdom, decided to grant AT&T enough spectrum to host a massive 23 simultaneous conversations. Clearly, a phone system that could only handle 23 calls wasn’t worth dropping lots of investment dollars into.
Twenty years later, the FCC reconsidered and research started again. One of the big problems with the previous systems was that calls could only be made and completed from one tower. If a caller moved away from one tower to another the call dropped out. In 1970, Amos Edward Joel, an engineer at Bell Labs, developed the call handoff system that facilitated phone call continuity as a caller moved between towers.
The original towers from the 1940s worked by establishing point to point connections with the portable telephone. Where the AT&T system differed was that their towers could transmit and receive signals in three directions. This way, the towers work together to create a coverage mesh that covers a large area. Each tower in the network has three sets of directional antennas aimed in different directions, sending and receiving into three different cells at different frequencies. In this way, each tower covers a hexagonal area.
Today, cell towers are found all over the place. Providing you’re not nervous about the potential effects of the transmitter, having a tower on your property can be a nice revenue source as phone companies pay rent on space for erecting towers.
So, with an established phone system, cell tower technology and all the requisites for working handsets, the time had come for the first mobile phone.
MobileModo is Gizmodo Australia’s look at the rise and rise of the mobile phone, from Bell’s landline to the ubiquitous mobiles of today.
Dam
Wednesday, April 21, 2010 at 10:41 AMI got a doc from Optus in the letter box last week (they are installing a new antenna ).They state that the power is only 60W.
I though it was much more, 60W is quite reasonable.
Techno
Wednesday, April 21, 2010 at 1:08 PMSo, the fact there is a facility radiating at “one tenth the power”, but in the same band as a microwave oven straight at people’s heads doesnt disturb you at all??? Besides that fact, Optus is telling you the power that is fed to the antenna array. There is a slight loss in the tx feed, but a big arsed gain at the antenna. 60W… sheesh, some people are so gullible. On the other side of the coin a bad coverage spot is a bad spot for your head from another perspective…
Dean
Wednesday, April 21, 2010 at 4:14 PM“sheesh, some people are so gullible”
And some people have a such a poor understanding of physics.
Antennas do not increase power output in any way – they cannot create energy out of nothing. What they can do is change the pattern in which the energy is radiated. Antenna gain relates the intensity of an antenna in a given direction to the intensity that would be produced by a hypothetical ideal antenna that radiates equally in all directions.
At most, all the antenna would be able to do is to radiate the entire 60W into a single point rather than spread it out over the area of the cell.
Simon Reidy
Wednesday, April 21, 2010 at 1:53 PMI would welcome a tower on my property. I could use the money and the coverage would be superb! I don’t mind if cancer leaks out my ears.
Tony meman
Thursday, April 22, 2010 at 1:45 AM@Techno Maximum power even with the antenna gain is going to be around more than 1000 – yes THOUSAND- times less than Australian standards. And let’s not forget that current systems vary power depending on number of users in the cell, so power is not always going to be at max level.