Con
tacting a friend, teach or parent is just a matter of a couple buttons presses now a days but if you go back a decade, things were a lot more different than today.
History:
"In essence, a cell phone is a radio. One of the most interesting things about a cell phone is that it is actually a radio -- an extremely sophisticated radio, but a radio nonetheless."
The telephone was brought to life by Alexander Graham Bell 1876, changing the way people could communicate. The idea of telephones being wireless comes from the creation of the radio by Nikolai Tesla in the 1880's.
The early wireless telephones were really big, and to give you an ideal of how big we are talking about, you would have needed to fit the components needed to get the phone working in the passenger seat of a vehicle, or in this case, in the back of a car.
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Purpose: Communications with people near and far, across both land and sea.
Technology:
Signal from cellular devices get sent to radio towers that transmit the signal between your cellular device and the satellite that then transmits the signal to the end user.
For you to be able to talk to the person at the end of the other line, the signal first needs to be transmitted to and back from that person. For this to occur, the signal must first travel through what is called a
Channel. A
Channel is like a gateway or a one-way tunnel for the signal to travel through. As like any other tunnel, only a certain number of cars; in this case, signals, can go through the
channel at any given time. As more and more people were able to afford a cellphone, this caused one issue, not my users could be on the same channel that the signal was being transmitted on.
This lead to the creation of
Cells, which are allowed about 800 frequencies per channel. This meant that about 56 persons could talk simultaneously on the same channel.
When one
Channel gets full, the cellphone will transfer the signal to another frequency. Now when you drive down the road and talk on the phone, you're call never gets interrupted because of one magical thing called
Cells. Throughout the United States and the world, there are Radio Towers spread out to have a coverage area. When you move away from one Radio Tower, your signal gets moved from
Cell to
Cell. Allowing continuous talk.
Better upgrades later, a cellular device could transmit its signal across more than 1,664 channels or more!
Future of Cellphones:
Citations:
http://static.howstuffworks.com/flash/cell-phone.swf
http://www.mat.ucsb.edu/~g.legrady/academic/courses/03w200a/projects/wireless/cell_technology.htm
https://www.artinstitutes.edu/blog/the-history-and-evolution-of-cell-phones
