How do mobile phones and the Internet work?

We use the Internet and mobile phones on a daily basis. But how do they work? Read some short descriptions here.

Last Updated: 04 Mar 2016

What is the Internet?

The Internet is a decentralised, international network of networks. 

Devices, such as computers, connect to each other and form a network. Each network is connected to other networks, which are connected to each other through electronic, wireless and optical networking technologies. 

Multiple interconnected networks form the Internet.

How does the Internet work? 

The Internet works based on protocols which handle chunks of data, known as “packets”. 

Various types of hardware, such as an ethernet network card or a modem, convert our device's binary packet data into network signals and then back into packet data. 

Internet Protocols (IP) are used to direct packets to a specific computer or server. 

Transmission Control Protocols (TCP) are used to direct packets to specific applications on a computer using a port number.

Application Protocols are specific to applications such as and

In short, the Internet is an international network of networks which operates based on protocols which handle and transmit packets of data.

How do we access the Internet?

We access the Internet because our router connects our device to an Internet Service Provider (ISP). 

Internet Service Providers (ISPs), such as Verizon, AT&T and Comcast, give us access to the Internet through a range of technologies. 

A single device is assigned an address when it connects to the Internet: an Internet Protocol (IP) address. This address distinguishes our device in the network from all other devices. 

However, our national ISP can only connect us directly to servers located in our country. If we want to connect to servers located in a different country, then we need that country's ISP to connect us to those servers. 

How do we connect to websites?

In the digital world, almost every connection requires our device to send “packets of data”, which is quite similar to sending letters by post. In both cases, we need an address, a system which handles our letters and a letterbox. 

On the Internet, an example of an address we might want to “send letters to" is Similarly to a post office, our IP address helps direct our “letters”, while the Transmission Control Protocol (TCP) disassembles and reassembles our “letters” into a single port, which can be compared with a letterbox.  

If we are located in Germany and want to access,  for example, our German ISP cannot connect us directly, since the Yahoo servers are located in the U.S. Our local ISP directs us out of Germany and into the U.S through its Internet gateway. Then a U.S. ISP connects us to the Yahoo servers.

However, the fact that our device's data (such as our IP address and browsing cookie) travels through so many nodes in a network until it reaches a website means that it can be tracked long the way. In other words, when we access a website, all the intermediary parties included in the network are aware of it.

How does our device 'talk' to other devices in the network? 

Protocols translate the text of our message into electronic signals, transmit it through the network and translate it back into text once it reaches another device.

How do mobile phones work?

Mobile phones operate within a network based on services which are provided by Telecommunications Service Providers (TSPs).

In particular, mobile phones search for signals in order to operate. This is enabled through cell towers, which are cellular telephone sites where antennae and electronic communications equipment are placed. 

Mobile phones convert our voice into an electronic signal, transmit it as a radio wave and convert it back into sound once it reaches another mobile phone.

Since TSPs allow us to connect to other mobile phones through the cell tower which is the nearest to us, they always know our geolocation. As such, mobile phones are similar to GPS tracking devices. 


(Image: by fisakov on flickr)