What is the modem?
Modem Short for modulator-demodulator In communication modem converts the digital data into analog so that it transmits over the phone line because phone line transmits analog data. In the same way on the other hand when data is received modem again convert this analog data into a digital single so that computer store and process on this information.
Modem stands for modulator and demodulator.
Modulator means that converts digital signals into analog signals and send it over telephone lines.
This process is known as modulation.
Demodulator means that receiving modem converts analog signals into digital signals and this process is known as demodulation.
It helps us to transmit data from one computer to another computer using standard telephone lines.
It includes how many bits per second a modem can transmit or receive.
The speed of the modem is determined by the modulation and demodulation standard.
The rate at which a modem converts digital signals into analog signals and sends them over transmission media and modem Converts analog signals into digital signals is called modem speed.
It is measured in bits per second (bps).
Different modems have different speeds
2400 bps, 9600BPS, 56.5KBPS
The modem can test the digital connection with computer and analog connection with the remote modem.
Voice over Data:
It has the facility of voice conversation while data being is transmitted.
It uses different methods to control errors for transmitting data.
Types of modem
There are many types of modem.
. External Modem
. Internal Modem
. Wireless Modem
An external modem is a removable device which is used for communication purpose. This type of modem is externally connected with a computer with com port or USB port and have some lights which indicate the processing status. The external modem may dial-up modem or broadband modems.
An external modem is attached to the computer system with the help of COM1 or COM2 ports.
It is connected to the telephone wall jack by another cable.
External power is supplied to it.
It is very easy to setup.
An internal modem or on-board modem is a type of modem which is installed on the slots of the motherboard. This modem is an expansion card.
An internal modem is a circuit board that can be attached inside the system through expansion slots.
It cannot be moved easily from one pc to another.
It is set up is difficult.
The wireless modem transmits data through the air (using unguided media) instead of cable (guided media).
It is also called radiofrequency modem.
These are designed to work with cellular technology and wireless local area networks.
These are not yet perfected but the technology is rapidly improving.
Fax modem enables a computer to transmit and receive documents on a telephone line normally called fax. With a fax modem, a computer performs like a fax machine.
Dial-up modem transfers the analog signal through ordinary telephone lines. This modem is usually used to connect to isp using analog signals. The dial-up modem may be an external or internal modem.
DSL (digital subscriber line) modem also called broadband modem is used for providing broadband service to a different kind of internet connection. These modem transmit height speed data. Broadband modems typically have transfer rates from 1.5 â€” 8 MBPS (megabytes per second), or higher. DSL modems are suitable for high-speed internet and data transfer over an ordinary phone line.
ISDN stands for integrated services for the digital network is a type of communication standards for simultaneous digital transmission of voice, video data over a single wire or optical fiber. It can operate over a stander telephone, wires or other media. It is completely digital in nature from one end of the connection to another.
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