Modems are devices that modulate analog carrier signals to encode digital data for transmission and demodulate carrier signals to decode received data. They are used for data conversion. Modems can be classified based on their range (short haul, voice grade, wide band), the type of line used (dialup, leased), and their operation mode (half duplex, full duplex, simplex). Common types include internal and external modems. Modems work by modulating digital signals onto analog carriers for transmission and demodulating the signals back to digital on the receiving end. Modem speeds have increased significantly over time from 300 bps in the 1960s to 56 kbps in 1998 and up to 8 mbps with technologies like ADS

1. Modems Presented ByPalwinderKaur8/19/2010How Modem Works!!1

2. ModemFormal Definition “A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. So it is Data Conversion Equipment”.8/19/2010How Modem Works!!2

3. The Origin of Modem8/19/2010How Modem Works!!3

4. Classification of ModemsBased on RangeShort HaulVoice Grade Wide Band8/19/2010How Modem Works!!4

5. Continue…Based on Line TypeDialup Leased /Private8/19/2010How Modem Works!!5

6. ContinueBased on Operation ModeHalf DuplexFull DuplexSimplex8/19/2010How Modem Works!!6

7. Types of ModemInternal ModemExternal Modem8/19/2010How Modem Works!!7

8. 8/19/2010How Modem Works!!8

9. How it Works8/19/2010How Modem Works!!9

10. 8/19/2010How Modem Works!!10

11. Speed Variations From 1960 to till now!!300 bps - 1960s through 1983 or so1200 bps - Gained popularity in 1984 and 19852400 bps9600 bps - First appeared in late 1990 and early 199119.2 kilobits per second (Kbps)33.6 Kbps56 Kbps - Became the standard in 1998ADSL, with theoretical maximum of up to 8 megabits per second (Mbps) - Gained popularity in 19998/19/2010How Modem Works!!11

12. Future Trends 8/19/2010How Modem Works!!12