Thursday, 23 January 2014

WHY CELL PHONES ARE CALLED AS CELL PHONES?




WHY CELL PHONES ARE CALLED AS CELL PHONES?


Do you know why your cell phones are called as cell phones???
They are connected through a cellular network that is the answer.
What is it? Let us see this in detail.

What is cellular network???



In the mobile communication, if there is only one tower in a city then it cannot cover the entire city.
A tower can have maximum of 25 channels for communication.
It is not possible to have communication for entire city with those 25 channels because it can handle only few users.
If there is more than one tower without any pattern then there is a chance of interference and frequency deficiency.
Hence the city is divided into small cells called as cellular network.
Each cell covers up to 10 square miles. Each cell is of hexagonal shape.
Each cell has a base station that consists of a tower.
By splitting like this we can use the same set of frequencies to all the cells. There comes the concept of frequency reuse. It reduces the cost.
Also we can have more number of users.

How communication takes place?



The communication between two people takes place via MTSO (Mobile Telephone Switching Office). There is only one MTSO.
If a person makes a call from one cell to other then it will first go to base station of that cell and then to MTSO.
The MTSO deliver that call frequency to all base station. And the corresponding base station receives that call.
When you move toward the edge of your cell, your base station will note that your signal strength is diminishing and switch over to nearby cell.
This is called as HAND OFF.


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