how do digital signals transmit information?

Answer 1

There are different ways for digital systems to communicate. At the most trivial level, the communication can be done directly at base-band using electrical wires (without modulations and without optical or radio-air links).

A digital system transmit information as base-band digital signal by encoding the digital signal (a stream of 1’s and 0’s) into a series of voltage level-, voltage difference levels-, or voltage changing edge-pulses and then driving those pulses out on the wires.

For example, the serial port on the rear of a PC is a base-band voltage-level digital port (RS232). The serial port on a Macintosh is a base-band voltage-difference level digital port (RS422). On these ports, the transmitter encodes the stream of 1’s and 0’s of the source info into a series of non-return-to-zero (NRZ) voltage pulses on the wires. The receiver, then, decodes the stream of voltage pulses back to the stream of 1’s and 0’s of the info bits. Even this most basic form of a digital signaling needs to be NRZ so that only the signal, and no net energy, flows from the transmitter to the receiver.

Answer 2

Digital signals transmit information through some coded form.First the signals carrying information are incoded with desired coding system then they are transmitted through desired transmission system and at the receiving end decoded with suitable decoding system and delivered to the end point. There are various digital signal coding and transmission systems. In telecommunications these are; DRS, OFS, electrical transmission through cables, etc.

Answer 3

the signal goes into a tranducer where it it changed from digital to analouge and broard cast to the reiciver where it is changed back. this is similar to the oldschool dial up modems which modulate the digital signal into analouge to travel on your phone line then demodulate back into digital when it gets to the servers modem.