A modem makes it possible to convert analog signals into digital signals and vice versa.
Modem is an acronym made up of two terms: modulation and demodulation . It is a device used in computing to convert digital signals into analog and vice versa , so that they can be transmitted intelligibly.
In computers , the modem is an input/output peripheral that can be both internal and external. Allows you to connect a telephone line or other cable to the computer and access different networks, such as the Internet .
Modem operation
How does a modem work? In its origins, basically its operating system when establishing communication was as follows: the first thing was to proceed to detect the tone of the line, then dialing the corresponding number was carried out and thirdly and lastly it was established. the link.
In the case of the Internet connection via telephone, the modem received analog data, was responsible for demodulating it and converting it into digital. The device also performed the reverse process, allowing communications.
However, they are not the only alternatives. We also find that the connection can be carried out through what is known as UART (Universal Asynchronous Receiver-Transmitter). This is located on the motherboard of the device in question and is responsible for controlling the different ports.
Thanks to a modem, communication can be established between two or more computers.
Classification according to type
Internal modems are expansion cards that can be connected using different types of connectors: AMR (a technology that is no longer used), ISA Bus (also not currently used due to the low speed it offers) and PCI Bus (the most common format). popular of this type of modems).
An internal modem offers the advantage of receiving electrical power directly from the computer. On the other hand, it does not take up space and is usually cheaper than external ones.
External modems , precisely, stand out for the ease of installation and even for the possibility of transporting them and using them on different computers. Another benefit of this hardware is that it has light indicators that allow you to know the status of the connection.
A software modem , on the other hand, is a type of internal modem that does not have specialized chips and other electronic parts; The computer microprocessor, therefore, performs its function through a computer program.
The modem and baud
In addition to all of the above, it must be emphasized that when talking about modems, it is also vital and fundamental to talk about bauds, which are the units of measurement used to determine their speeds. Specifically, baud is equivalent to what would be one symbol (one or more bits) per second.
We currently find a wide variety of modems in terms of the speed they offer. Thus, there is a wide range of devices on the market ranging from those with 300 baud to those that achieve, for example, a total of 8,000 baud.
No less relevant when using a modem is that we keep in mind that there are three different types of them with regard to the types of operating profiles. In this sense, we would highlight that there are three clearly defined groups: user, active and factory.