To access the internet from a computer or mobile phone, there are several ways such as, for example, cable, wireless, satellite and fiber optic. With so many different names it can be difficult to understand what you are buying when you take out an internet connection subscription also because those who sell them often don't say how it works.
In this article we are going to explain, one by one, all the ways in which a computer can be connected to the internet .
Knowing these basics, in addition to enriching your personal culture, you will be able to discover new types of connection to be taken into consideration the next time you look for subscription offers.
1) Dial-up or analog modem
The first internet connections were based on analog modems, those that were used 10 years ago and made strange noises.
The analog modem transforms these signals from the telephone line into digital signals for the computer and, conversely, transforms the digital signals sent by the computer into analog signals.
An analog signal can be the voice or the music and sounds of nature.
The modem then makes a real phone call to the internet provider talking to us with these analog signals (and occupying the line entirely preventing the use of the phone).
Even if the modems have evolved over time, the principle remains the same: the modem has modulation / demodulation functions (analog or digital numerical) in analog and digital transmissions.
The only thing that has changed is the means that these signals use to travel and the type of signal itself.
With the dial-up modem, the signal is analog and the medium is a telephone line made of a pair of copper wires.
The transmission of analog signals, however, was slow and, even if the modems reported 56k, in reality it was not possible to go more than 33 kbps on average.
Although I'm not sure, I don't think there is any provider selling dial-up connections anymore.
2) DSL connection (telephone line)
DSL stands for Digital Subscriber Line .
The 56k modem could not be a long-term solution because it was slow and because it kept the phone busy.
Telephone companies have therefore developed a way of sending a second signal along their telephone lines, sending it at a higher frequency (and having the so-called broadband)
The method is quite complex and this is not a scientific article, so we explain it with a small analogy.
One can imagine a tube, inside which marbles are thrown every 60 seconds, representing voice communications.
In addition to the green marbles, red marbles can also be sent within the same tube every 5 seconds.
These red marbles represent data that travel at a higher frequency than the voice (the green marbles).
At the other end of the tube, there is a filter that sorts the marbles: the red ones go to the computer, the green ones to the phone (see also figure above).
To make the DSL connection work even better, a small modification has been made with the Asynchronous DSL (ADSL), to improve the download speed (download) at the expense of the upload speed (sending) that certainly affects less.
In fact, it is one thing to send a message on Facebook or an email, another thing is to download a file or receive a streaming video on your computer.
The typical analogy for explaining ADSL is a four-lane road between two cities, one east and one west.
Instead of having two identical roads in each direction, as there is more traffic to go east, there are 3 lanes in one direction and only one in the other direction.
3) Cable connection (coaxial cable)
The coaxial cable is what is used today for satellite TV, with round connections and a copper wire inside thick plastic that acts as an insulator.
The standard
The coaxial cable had been used for decades to send multiple digital signals to which the internet was added.
The standard used is called Data Over Cable Service Interface Specification (DOCSIS) which works similarly to DSL, using a higher frequency for data and a lower frequency for voice
The cable can also use asynchronous data transmission, such as ADSL.
Wired internet connection requires special modems to operate and to separate data from TV channels from data to be transmitted to the computer.
4) Optical fiber
The technologies explained so far use electrical and copper cables to transmit the signal.
The fiber optic connection has a light signal that passes through a particular type of flexible hollow glass or transparent plastic.
Simplistically explained, there is a transmitter that converts the electrical signal into light.
The light travels along the glass cable to the receiver at the other end.
The receiver detects the light and generates an electrical signal that the computer can use.
Since light travels much faster than electricity, optical fiber is the fastest connection medium with a huge bandwidth.
Because then we don't just make fiber optic networks "> ADSL internet without Telecom).
The speed of wireless broadband never reaches that via cable because the wifi is naturally slower than a network cable.
- Mobile Internet
This is the type of connection for smartphones, cell phones, portable modems and USB sticks that work via a SIM card.
The providers of this service call it Mobile Wireless Broadband, although it is not truly broadband.
Wherever there is cellular network coverage, you can have a mobile internet connection.
Mobile Internet works with radio waves, similarly to wireless broadband, with different types of 3G, 4G, LTE data rates .
- Satellite internet
the satellite internet connection works via a satellite dish like that of satellite TV.
The signal is transmitted from above, directly from the satellite and received by the antenna which must be correctly oriented by a technician.
Satellite internet is a bit of a last resort in the absence of other possible alternatives.
The problems are the costs much higher than the normal connections and the distance that the signal must travel which, starting from the sky, arrives on the ground in a rather weak and attenuated way.
Moreover, even if the download speed is more than good, even up to 5 Mbps, the upload of the data that must be sent from the antenna to the satellite is really very slow.
READ ALSO: ADSL test: how is internet speed measured?
