We find out how it is possible for a single telephone wire to carry information for a telephone conversation, file downloads to a computer, WiFi access, and allow us to watch a film and listen to news. Plus we ask can we make an infinitely powerful laser simply by adding more mirrors?
Disclaimer: I've worked as a telecommunications engineer
To add a little to Wolfekeeper's response:
The packets of data over the internet each have an "address" on the front, and a return address (like letters in the Postal Service). The network equipment uses this address to send each packet to the right destination.
BTFON doesn't actually cost you anything; BTFON is essentially a different, lower priority network that shares the same wire and wavelengths (when you're not using it), and if there are pervs on your BTFON network, they're pretty damn stupid, because all their packets are labelled with their (not your) account!
The reason you can get so much information from a single twisted pair is because of superheterodyning (or modulation), putting information on a carrier wave(s), then subtracting the carrier wave frequency to extract the information. Its the same reason why you can have one cable coming into your home yet watch different channels of TV. In its simplest form, superheterodyning circuits created the first carrier wave radio transmission. Your local AM radio station transmits a carrier wave, say 950Mhz, and modulates the audio frequency information-say 10-10Khz, say the traffic report, onto the carrier wave via a mixer. The mixer has two inputs, the desired information and carrier frequency from a local oscillator which are added together. Your phone line has multiple carrier frequencies being transmitted on the same wire, and your individual devices are tuned to receive only specific carrier frequencies that make it so you can have multiple channels of information on one wire. BillionsNbillions, Sun, 9th Sep 2012
Thank you, Billionsnbillions. chris, Mon, 10th Sep 2012
Amplitude and Phase modulation of a Carrier Frequency works well in hardware, when there is a small amount of information in a fairly narrow frequency band (compared to the carrier frequency).
What is the connection with data and frequently imean signals are coming in frequents but we count those thing with giga bytes ARJ, Fri, 31st Oct 2014