Modem it’s a acronym formed by two terms: modulation Y demodulation. It is a device used in the computing to convert digital signals to analog and vice versa, so that they can be transmitted intelligibly.
In the computers or computers, the modem is a peripheral input / output which can be both internal and external. Allows you to connect a telephone line to the equipment and access different networks, such as Internet.
How does a modem work? Basically its operating system when establishing communication is as follows: the first thing is to proceed to detect the tone of the line, then the corresponding number is dialed and the link is established third and last.
In the case of Internet connection by telephone, the modem receives analog data, takes care of demodulating it and converts it into digital. The device also performs 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.
The internal modems are expansion cards that can be connected using different types of connectors: AMR (a technology which is no longer commonly used), ISA bus (It is also not used at present due to the low speed it offers) and PCI bus (the most popular format for this type of modem).
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.
The external modemsThey stand out precisely for their 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.
It is known as software modemfinally, to a type of internal modem that does not have specialized chips and other electronic parts; the computer’s microprocessor, therefore, fulfills its function through a computer program.
In addition to all the above, it must be emphasized that when talking about modems, it is also vital and fundamental to talk about baud rates, which are the units of measurement used to determine their speeds. Specifically, the baud is equated 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 making the use of a modem is that we bear in mind that there are three different types of them when it comes to the kinds of operating profiles. In this sense, we would highlight that there are three clearly defined groups: user, active and factory.