What is a Modem

[Bronoe]

Hello friends I am a school going kid. My computer test is going to be held today. So I am very keen to gather as much as information to increase my knowledge.kindly help me by giving me adequate information.any help would be appreciated. Thanks in advance.

[Captain Samuel Salt]

It is a device that modulates a signal for encoding the digital information and also demodulates a signal for decoding the transmitted information. It acts as a modulator and demodulator. The main function is to produce a signal which can be transmitted easily and decoded to again produce the original data.

[Ebadaah28]

Modems are used of transferring analog signals from various modes such as led to radio. The Classification of modem depends upon the amount of data the modem can send in a given unit of time, called as bits per second(bps). They are also classified by the symbol rate the y produce which is measured in Baud which is denoted by symbol per second or number of times per second to send a new signal accordingly.

[Bronoe]

Can u kindly elaborate the information or can give me any example please ?? thanks.

[Ebadaah28]

For instance, ITU V.21 which is used for duplex communication between two analogue dial up modems by using audio frequency shift keying for all the different frequencies of the tones. And when two frequencies corresponds to two different symbols or one bit per symbol will carry 300 bits per second by using 300 baud. So the original ITU V.22 will be able to transmit and receive four different symbols by two bits per symbol. Hence, I will handle 1200 bits by sending 600 symbols per second which is 600 baud by the use of phase shift keying.

[Swiz]

There are various types of modems such as:

• Radio modems
  
• Mobile modems and routers
  
• Narrow-band/phone-line dialup modems
  
• Softmodem
  
• Voice modem

[Reese-R]

The Smart modem was introduced in 1981 by Hayes Communication. The smart modem was a standard 103A 300-bit/s modem. It was attached to a small controller that enables the computer to send command and operate the phone lone. The command used to be picking up the phone, hang up or cancel the phone, dial various number and answer the calls.

[Jugo]

A winmodem or softmodem as it was called was a shortened modem that used to complete the tasks traditionally in hardware with software.
This modem is a small and simple interface modem which is designed to create variations in voltage on the telephone line and to use the line of voltage levels.
It will usually convert from digital to analog and vice-versa. Softmodems are relatively cheaper than the traditional models since it is very small and has very few hardware components.
The software generating and interpreting is very complex in this modem and therefore the performance of the computer have to suffer. Therefore for online gaming it would be very hard to use.
All the windows operating systems cannot offer portability to this modem.

[TABLITA]

Narrow-band modems or phone-line dialup modems usually contains two main functional parts. First, an analog section which generates the signal and operates the phone and a digital section for setup and control. This is now functioned in a single chip these days. The modem can be in either of the two modems, data mode in which the data is sent to the computer by using phone lines and command mode in which modem accepts the data from the computer for commands. In the command mode the powering up of modem is done in the computer itself and after that sending the command for dialing a number. After the connection is done to the modem, the modem will gradually goes into data and therefore user can send or receive the data

[Kakashi Hatake]

Mobile modem is a modem which can use a mobile telephone system or techology such as GPRS, UMTS, HSPA, EVDO, WiMax, etc. they are also called as wireless modems. Wireless modems are installed inside a laptop or external of any device. External wireless modems are connect cars, USB modem which are used for mobile broadband and cellular routers. USB wireless modems are used by plugging them in the USB port. in cellular router we can insert external data card. A connect card which is inserted into PC which is also called as PC card or Express card.

[Bronoe]

Thanks a lot friends for giving me such a relevant information about modems. I am really satisfied with it. Really appreciated friends. Now I this topic comes in my test I will find it very easy to answer. Thanks again.