Ranting and raving

Electricity moves at almost the speed of light. When you push a button, bang, its done. I am wondering how different services can be marketed by the

cable companies. Electricity moves at the same speed no matter what. You can't slow it down. So to have a slow service, you have to send the signal

through a loop or buffer where it stays until another signal asks for it. So are the cable companies just putting devices in their equipment to

divert the signals to make them take more time to execute. That way they can package various services as faster and sell them for a premium price.

Cable companies are selling information, in the form of bits encoded onto a radio-frequency electrical current. The electicity moves fast, yes, but the speed of the information depends on how fast the electric signal can be switched between "0" and "1."

A cable TV feed is around 5 megabits per second, so somewhere in that loop there is some equipment that's doing at least five million switching operations every second. For TV, there's not really any "fast" or "slow" option -- it's always "just fast enough" for a television signal.

Internet connections via cable are a different matter. The "pipe" that carries those five million bits per second is shared by a number of users, typically two to three hundred. Every user has their own individual information stream, so the bits that you're using can't be used by your neighbor. If you want a faster service, you have to have a bigger slice of the collective bitstream, so that's what you pay for.

If the signal has to wait for the switching. is it in a buffer or something similiar. That is were I have the problem unserstanding. I am assumiing it jsut can't pile up. Thanks for your information.

Okay, say you've got a flashlight you're shining at a buddy who's standing on top of the next hill. The beam of light hits him, shining steadily. That's the electricity going between sender and receiver. But there's no signal yet.

You both know Morse code, so you start blinking the flashlight on and off -- dots and dashes (zeroes and ones). Now you have a signal. In telecom-geek terms, the beam of light is the "carrier" and your busy thumb on the flashlight button is the "modulation." When modulation is applied to a carrier, the result is a signal. The signal transmits information.

I say "blinking" here to avoid confusion, because the term "switching" has a special sense in telecom: it means routing a signal from one to another of several possible circuits. This is different from the ordinary sense of switching a light on and off.

Depending on how agile your thumb is, you'll manage maybe eight blinks each second. That's your bandwidth, then -- 8 bits/second. Bandwidth is the amount of information that can be transmitted in a given amount of time. In one minute, you'd probably be able to send a short joke to your buddy.

With a fiber-optic cable connection, the laser "flashlight" blinks millions of times each second. The lowest class of fiber-optic does 45 megabits/second. In that same minute, it could easily transmit all of Shakespeare's works. So bandwidth is directly related to how fast the modulation is. When people talk about the "speed" of a connection, it's really just a loose way of referring to the amount of bandwidth.

Hope this helps...