In digital telephony, the digital milliwatt is a standard test signal that serves as a reference for analog signal levels in the telecommunications network.
[2] When decoding the digital milliwatt, a PCM decoder produces a sinusoidal signal with a frequency of 1 kHz with one milliwatt in power (0 dBm, a reference for dBm0).
It is typically stored in read-only memory (ROM) in the telecommunication equipment.
[1] The digital milliwatt signal is often generated in instruments in place of separate test equipment.
This article incorporates public domain material from Federal Standard 1037C.