Question

Internet access over telephone lines has been driver by your desire for higher speed.

Voice bandwidth: 3000 Hz

signal to noise ratio between two phone sets: 30 dB

modeling sample rate: 2400 baud

How was your old modem improved from 2.4 to 9.6 and 28.8 Kbps in speed and why did this improvement stop around 33.6 Kbps?

Answer 1

First Part:

The enhanced speed of 28.8 Kbps was achieved due to the improvement in telephone industry as the telephone lines were becoming digital. This improved the modem speed from 2.4 to 9.6 Kbps to 28.8 Kbps.

Second Part:

The improvement of 33.6 Kbps happened when the modems were compatible with each other and properly configured. At higher speed the noise level during the conversion increases and the line failed to adapt. This caused the speed to decrease eventually and further improvement was not possible.

Hope this helps.