How does a modem?
Modern man is hard to imagine life without the Internet.Therefore, the important question is, by what device we are able to make use of a worldwide network of services.One of the most important devices involved in the transmission of digital information can be called a modem.
What is a modem
modem - a rather old invention was widely used before the advent of personal computers in the homes of our citizens.Modems differ in appearance and operation principles, but almost every person met this important device.So what it is and how the modem works?
modem - a device that is used for the physical connection between the two objects, one of which sends data to another.The word "modem" is an acronym made up of the words modulator and demodulator.The modulator converts the signal before transmission in accordance with a communication channel and a demodulator at the point of reception the inverse operation produces providing information to the user in human-readable form.Thus, only the modem establishes a communication link, and to exchange data generated by computers.
modems are used not only in computer networks, but also in the telephone for communication with a remote military command terminals, radar or air bases.
Modern modems on the principle of work are divided into hardware and software.Hardware modems are completely independent and are able to independently convert the signals and to support communication protocols thanks to built-in memory that stores the necessary firmware.Software modems also include only the input and output transducers, and even the controller interface for connecting to a computer, and all the necessary operations to control errors, signal encoding and the protocols installed on the computer performs a special software.
principle of operation of USB-modem
to program the type of modems are popular nowadays USB-modems.a modem interface for communication with the computer, respectively, - USB.How does the USB-modem?Exactly the same as every other, as described above.This compact transceiver uses a network of mobile operators for its operation.Typically, the device is inserted into the SIM-card mobile operator, but now wireless modems are integrated into laptops, phones, tablets, and other devices.
3G-modem What it is and how it works 3G-modem?3G technology - this is the third generation of mobile communication, offering the fastest and most reliable range of services high-speed Internet access.3G-modem looks like a USB flash drive with a USB port for connecting to a computer.Providing transfer speeds up to 3.6 Mbit / sec, a modem allows you to watch movies, to call on Skype and use social networks without a long wait.
hope that article has helped to understand the principles of the modem and give an idea of how USB works and the 3G-modems.