Modem is short for modulator - demodulator Types of Modems . Types of Modems are used for data transfer from a computer network to another computer network through the telephone lines. The computer network is digital, what is a modem while the analog technology is used to transport massages through telephone lines what is a modem.
Modulator converts the information from analog to digital mode for the transmitting end and the same demodulator converted from analog to digital at the receiving end . what is a modem is A method of converting analog signals from a computer network on digital signals to other computer network so they can be processed by a receiving computer is designated for exploration.
When an analog system for communicating digital data between two devices called Data Terminal Equipment (DTE) is used,what is a modem , modems are used on each end. Types of Modems DTE may be a terminal or computer.
Modulation and demodulation Types of Modems
The modem at the transmission end converts the signal generated by the DTE to an analog signal by modulating a digital carrier signal. The modem on the receiving end demodulates the carrier and hand in the demodulated digital signal to the DTE what is a modem .
Building blocks of a modem Types of Modems
The transmission medium between the two modems can be dedicated or circuit-switched phone system. If a switched telephone circuit is used, the modems are connected to local telephone exchanges what is a modem. Types of Modems Whenever the data transmission connection between the modems is needed is established via telephone exchanges what is a modem.
The types of modems
• modem can be of various Types of Modems and can be classified in a number of ways what is a modem.
• The classification is generally based on Types of Modems the following what is a modem functions basis:
1 Directional capacity Types of Modems : half duplex modem and full duplex what is a modem.
2 Line connection Types of Modems : Modem 2 son and son 4 modem.
3 Transmission mode Types of Modems: asynchronous and synchronous modem modem.
Half-duplex and full-duplex what is a modem
Half Duplex
1 A half-duplex what is a modem allows transmission in one direction at a time Types of Modems.
2 If a vehicle is detected what is a modem in the line by the modem, which provides an indication of the input of the DTE via Types of Modems a control signal of the digital interface.
3 While Types of Modems camel is received; the what is a modem does not permit the DTE to transmit data.
Half and Full Duplex Modem
Full duplex
• A full-duplex what is a modem allows simultaneous transmission in both directions.
• Thus,Types of Modems there are two carriers in line, what is a modem one input and one output. Son and son 4 Modems
• modem line interface Types of Modems can have two or four-wire connection child transmission medium. Son 4 modem
• In port 4 child, Types of Modems a child is used to couple the output means and the other pair is used for the incoming carrier.
• Modes of transmission what is a modem full-duplex and half-duplex data are available in a 4-child connection.
• As the physical what is a modem transmission path for each direction is separated into the same carrier frequency can be used for both directions Types of Modems.
Son 4 modem
Modem 2 son
• son of two modems use the same pair of child for Types of Modems vehicles entering and leaving.
• A rented two wireconrlection is generally cheaper than 4 free son as a single pair of child extends to the subscriber premises what is a modem .
• The data connection is established by what is a modem the telephone exchange is also a two-wire connection Types of Modems .
• In two modems what is a modem child transmission mode half-duplex using the same frequency for both input and output conveyors can be easily implemented Types of Modems .
• For mode Types of Modems of full-duplex operation, it is necessary to have two transmission channels for the transmission direction and one for direction what is a modem .
• This is obtained by frequency division multiplexing two different carrier frequencies what is a modem . Types of Modems These supports are placed within the bandwidth of the voice channel what is a modem .
Half Duplex
Transmit and receive support
Asynchronous and synchronous Types of Modems
asynchronous what is a modem
• Types of Modems can handle asynchronous data bytes with start and stop bits what is a modem .
• No clock or an independent clock between the modem and the DTE what is a modem .
• what is a modem the pulses are synchronized with internal timing repeatedly on the front edge of the start pulse shape.
asynchronous modem
synchronous modem
• synchronous what is a modem can handle a continuous stream of data bits, but requires a clock signal Types of Modems .
• The data bits are always synchronized with the clock signal what is a modem .
• There are separate clocks Types of Modems data bits are transmitted and what is a modem received.
• for synchronous transmission of data bits, what is a modem the DTE can use its internal clock and provide the same for the what is a modem .
synchronous what is a modem
Modulation techniques used Types of Modems:
Basic modulation what is a modem techniques used by a modem for converting digital data into analog signals:
• amplitude Types of Modems shift keying (ASK).
• frequency Types of Modems shift keying (FSK).
• phase Types of Modems shift keying (PSK).
• Differential Types of Modems PSK (DPSK).
These techniques are known as binary continuous wave (CW) modulation Types of Modems .
• Modems are always used in pairs.Types of Modems Any system if simplex, half duplex or full duplex requires a what is a modem to the subject as well as the receiving end Types of Modems.
• For example, Types of Modems a modem acts as the electronic bridge between two worlds - the world of purely digital and the analog world established.
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