Pulse-amplitude modulation allows data to be transmitted more efficiently, more quickly and in greater volume using conventional copper wires. The available frequency modulations are infinite, so PAM formulas can be continually developed to allow increasing data throughput over existing networks. PAM is also the simplest form of modulation.
Pulse-amplitude modulation is the technique of encoding data in the amplitude of a timed electromagnetic series of pulses. Typically, this is accomplished through manipulation of the voltage, or power amplitude, of the transmitted signal. In this process analog data is converted to a digital signal that is pulsed, either synchronized with the transmission source's wave frequencies, or inverse to it, in order to achieve the communication goal.
As of 2015, in many cases PAM is being replaced by new frequency modulation technology, including pulse-position modulation, pulse-code modulation and quadrature amplitude modulation. However, pulse-amplitude modulation is still heavily used in many standard data applications, such as Ethernet networks.
Ethernet networks that are 100BASE-T2 use 5-PAM modulations carried over four wires to transmit 100 megabits of data per second. Advancements in PAM calculations allow the same four wires, and 5-PAM modulations, to transmit 1000 megabits per second. By increasing the amount of PAM modulations to eight or 12, the network speed has been increased exponentially, to 10 gigabytes per second, over the same copper wires.