In network transmission, in 1010 to transmit, only one is a high and low level, is a laser switch, and the speed of light and electricity is 300000 kilometers, why ADSL are generally 8 m, and the optical fiber to 100 m?

CodePudding user response:

Optical communication transmission process, the nature of the electromagnetic interference is very small, and the cable transmission in the process of the disturbance is large, and the electrical signal transmission itself will also be affected by wire resistance will decay, long distance transmission repeater is required to enhance the signal, repeater will naturally reduce the transmission speed;
Another reason is the light signal frequency band is wide than electrical signals, the frequency is high also many, although the theory of polishing time and electrical signal from A side to side B may differ not quite, but the light signal is 0/1 of A second jump ability A lot stronger than electrical signals, it is the key that influences the bandwidth of the transmitted data bit, the time from A to B is the impact of time delay