March 2000
Intermediate to advanced
632 pages
18h 6m
English
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15
Modems
15.1 Introduction
Modems (MOdulator/DEModulator) connect digital equipment to a telephone line. It connects digital equipment to a speech bandwidth-limited communications channel. Typically, modems are used on telephone lines, which have a bandwidth of between 400 Hz and 3.4 kHz. If digital pulses were applied directly to these lines, they would end up severely distorted.
Modem speeds range from 300 bps to 56 kbps. A modem normally transmits about 10 bits per character (each character has 8 bits). Thus, the maximum rate of characters for a high-speed modem is 2880 characters per second. This chapter contains approximately 15 000 characters and thus to transmit the text in this chapter would take approximately 5 seconds. Text, itself, is ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.