When Alexander Graham Bell developed the first telephone in the latter part of the 19th century, the industrial revolution suddenly changed as more and more people became interconnected to one another thus fueling business transactions. The same era also gave birth to the radio which was initially presented by the Italian Guglielmo Marconi out of the initial works of Nikolai Tesla. It seems to be the perfect combination of discoveries and invention, but the two devices were not actually combined into a single more powerful device up to the early 1950’s when the development of a cellular or mobile phone started.
Today, cellular phones are simply the most common telecom device around the world. Basically, it provides both the basic features of the telephone and a radio in providing the best communication service yet. Let us talk about how this device works.
My Phone is a Radio?
Basically, the mobile phone is a radio. It relies on a radio signal in order to transmit and receive voice and data information. Previously, the radio device can only receive a signal from a commercial station making it a one way communication apparatus. However, by integrating the principles behind Bell’s telephone, the simple radio became a communication device which can also serve as a small transmitter thus giving it the capability to become a mobile phone.
Mobile phones are small radios imbedded with mini transmitters. This means that it actually transmits radio signals when powered on. This is a very important component because it readily gives up your electronic radio location so that calls can be diverted to you or make them.
So how am I able to talk with my friend using a cell phone?
One crucial part in the mobile phone communication is the establishment of relay centers called “base stations". These stations are actually smaller versions of transmitter towers that you will see around the neighborhood in almost any places. The base station serves as the electronic bridge between two mobile phones.
The principle is basically simple, because your mobile phone transmits a certain amount of radio signal, whatever base station nearest to you will capture its presence. Therefore, this gives you an “always online" mode ready to receive calls and texts. When another mobile phone user wants to contact you, his mobile phone will transmit a signal to the nearest base station in his location. This base station will then transmit to a series of telecom relay equipments such as channel towers or satellites until it reaches your local base station wherever you are. The same procedure goes when you are the one to call out to another number.
So how are base stations able to locate me? Won’t these stations become confused considering that there must be millions of cell site towers out there?
Actually, when you dial a particular number, the base station will automatically identify that number and assign an encrypted code on its transmission. Therefore, when the stations send out transmissions, it will only be transmitted to the shortest possible relays that will connect to the exact number you have dialed.
I presume that base stations also have a limited range of transmission, so what if I suddenly change locations?
Actually, the term cellular phone is derived from the “cell" principle of radio transmission. Each base station provides a single “cell" or radio signal span radius. Combining all of these signals in a location makes it appear as cellular compartments. Therefore, when you change your location, you go out of a single cell and enter a new one. With each change in locality, the base station nearest to you will provide you a signal. In some cases, you may arrive at a location when no signal from any base stations is present; this is called a “dead spot".
For more information about cell phones, read about the disadvantages of cell phone tracking.
Cellular Radio Signal Diagram
Picture Credit from