How Cell Phones Work: Signals, Waves, Examples

How Cell Phones Work: Signals, Waves, Examples

People all over the world spend quite some time on their mobile phones. While many of us don’t need to know the tech behind a phone’s processor, the basic “magic” behind how a mobile phone operates during a call can prove of interest to some. So in order for you and your friends to get a conversational topic going, we would like to provide you with a few starting points concerning how cell phones work – the history behind mobiles and a practical situation that describes how a call between you and you friend takes place.

Telephone & Radio

Alexander Graham Bell invented the telephone in the 19th century. From that point onward the telecommunications business started to evolve rapidly, as people became more and more interconnected worldwide.

Around the same time period humanity also witnesses the creation of the radio, thanks to Guglielmo Marconi an Italian inventor and electrical engineer that has pioneered the work on long-distance radio transmission and radio telegraph system. Alexander Graham and Mr. Marconi created the “perfect wave storm” for new technological discoveries and inventions. Technology and ideas combined from the telephone and radio waves allowed visionaries such as Martin Cooper from Motorola to build the foundations for the single most dominant device known today as the mobile phone. Martin Cooper mentioned in his interviews that the television series Star Trek was also a great inspiration for him when creating the first portable telephone.

Now let’s see how a mobile device calls process takes place:

Waves, Antenna and Towers

Cell phones utilize radio waves for communication. Radio waves transport data in the form of oscillating electric and magnetic fields called the electromagnetic field (EMF). Here is a simple example to illustrate how EMF translates into a simple call. When you call someone on your mobile phone and start talking the microphone encodes your message into 0s and 1s and thanks to the device’s antenna electromagnetic waves transport your message to the receiver – a friend, family member, etc. The waves travel at the speed of light and in all directions. Surrounding objects in the world like buildings and hills can reflect or absorb the waves before they can reach the receiver. That is why cell towers are located all around the world to facilitate worldwide communications. Cell towers process and redistributes electromagnetic waves so that we can communicate with one another. Today smartphones have more than one antenna such as GPS, Wi-Fi, Bluetooth antennas so means of communications are plentiful, but waves antennas and towers were at the roots of it all.

Signal Strength or “bars”

As mentioned above, a cell phone is a two-way wireless device and requires a signal to work properly, that’s why we have various telephone operators in the world. The magnitude of a signal received from a cell tower is called “Signal Strength,”  indicated by the “bars” on the screen of your cell phone. More bars equal a better connection. The connectivity between a network and phone majorly depends on signals but can be affected by several factors, such as the distance between the cell phone and the cell tower, the number of obstructions between them, and the technology. A weak reception indicates a signal disturbance or longer distance between the tower and cell phone. When your phone has a weak or poor signal, it sends more powerful signals to connect to the cell tower and this may result in the greater battery drain. That’s why smooth signals not only lessens the dropped calls rate but also protects battery life.

What happens when we make a call?

Now that we know the basics of how cellphones work let’s take a step by step approach in order to understand what happens when we make a call.

Imagine you are located in London calling your friend in Chicago:

  1. When purchasing a Sim card from a mobile network operator, each user gets a System Identification Code (SID) that is connected to a specific home Mobile Switching Centre – a central point of a group of cell towers. Home MSC stores a user’s service plans, location, and activity status. Based on your location your MSC changes to a Foreign MSC, but we won’t complicate matters for this example.
  2. When you dial the number of your Chicago friend, a  call request arrives at your home MSC. Upon receiving his or her number that request is forwarded to your friends’ home MSC.
  3. If everything is aligned you are connected and can start communicating long distances. 

To sum it up

We hope this article helped you in understanding how your call process takes place.

Of course, the range of services & communications technologies that a smartphone provides today makes it more of a mini-computer in the palm of your hands. The landline telephone that many us don’t use today, was a feat of great effort, science research, and imagination. Mobile phones are so technologically advanced today on a few centuries ago and would consider them magic.

You know the basic magic behind the workings of a smartphone now, so if you are looking for a new mobile phone Techfiddle is here to help you out.

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