How ATT Works

AT&T's story is one of innovation, conquest, endurance and revival. Since its birth in 1876, AT&T started a communications revolution, established an invincible monopoly, was dismantled by the government and rose again as a major player in a new era of digital communications.

How Cordless Telephones Work

Cordless phones have been around for about 20 years, but lately they're a lot more sophisticated -- it seems like you need a Ph.D. to buy one! Find out how cordless phones work and how to buy the right one.

How do digital answering machines work?

What exactly are the components of a digital answering machine? How does voice get recorded? And then, how is it played back on demand?

Is it possible to detect if someone is illegally using my phone line?

It's possible and relatively easy for someone to tap into your phone line, especially if you live in a dorm or an apartment building. It's also pretty easy to detect. Find out how to tell if your phone line is tapped.

What do the yellow and black wires in a home telephone jack do?

With all the different colored wires used in communications, what do the yellow and black wires in a home telephone jack do?

What does 900 MHz mean in a cordless phone?

I've been looking at cordless phones and have noticed that this area has gotten fairly complicated! For example, what is the difference between 900 MHz and other systems?

What is digital spread spectrum as used in cordless telephones?

Digital spread spectrum (DSS) technology has its roots back in World War II and has evolved into the technology of choice for the cordless phone. Cordless phones are now truly "ready for prime-time" thanks to affordable DSS technology.