When we talk about internet connection, three devices have been the protagonists throughout history: the router , the access point and the modem. All three have been essential so that, at this time, we are reading this comfortably at home. In this article, we are going to talk about one of them. ¿ What is a modem ?
We all name it, but do we know what a modem is?
According to the much consulted Wikipedia, a modem can be defined as "the device that converts digital signals into analog (modulation) and vice versa (demodulation), and thus allows communication between computers through the telephone line or cable modem."
The modem is the device (external or internal in the form of a plate) that makes it possible for us to surf the internet, since it is responsible for connecting to our telephone provider, generally through a fiber optic cable or coaxial cable. The signal offered by the provider (ISP) is analog and must be transformed into a digital signal . And that is exactly what the modem does..
How does a modem work?
It is difficult to explain how a modem works without going into complicated technicalities to understand, but we will try. The information that is transmitted is divided into two signals: modulating and carrier . These waves have three variable characteristics: frequency, amplitude, and phase. The device takes care of "modulating and demodulating" (hence the word modem): the modulator emits the carrier signal. The modulating signal contains the information to be transmitted and modifies the carrier signal to obtain a new signal. When it reaches its destination, the demodulator gets rid of the carrier signal, keeping the modulator.
Brief history of the modem
As is often the case with other technological advances, the first use of the modem was military. Specifically, in the 1950s in the US It was in 1958 that the first modems appeared as part of the SAGE defense system. These devices connected various terminals in air bases, where radars and control centers were located, with the SAGE centers that were located throughout the length and breadth of North America..
Later, the first data network (ARPANET) appeared and, later, what we know as the World Wide Web , a network with countless number of interconnected devices. At this time the telephone network began to be used to surf the Internet. So at first, we couldn't talk on the phone while connected to the internet. It offered us a bandwidth of scarce 56 Kbps and emitted a hellish sound when we connected.
Currently, the modem is only used for analog connections , for example to send a fax. Fortunately, the time of slow connection and strange noises when connecting has passed away..
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