In digital telephony, the digital milliwatt is a test signal consisting of eight 8-bit words corresponding to one pulse-code modulated cycle of a sinusoidal signal approximately 1 kHz in frequency and one milliwatt, rms, in power. A digital system is one that uses numbers, especially binary numbers, for input, processing, transmission, storage, or display, rather than a continuous spectrum of values (an analog system) or non-numeric symbols such as letters or icons. ... A telephone handset A touch-tone telephone dial Telephone The telephone or phone (Greek: tele = far away and phone = voice) is a telecommunications device that transmits speech by means of electric signals. ... Signaling, or signal, may mean: Look up signal on Wiktionary, the free dictionary. ... This article is about the unit of information. ... Pulse-code modulation (PCM) is a modulation technique. ... Sine waves of various frequencies; the lower waves have higher frequencies than those above. ... // Mechanical power In physics, power (symbol: P) is the amount of work W done per unit of time t. ...

The digital milliwatt is stored in ROM. A continuous signal of arbitrary length, i.e. an indefinite number of cycles, may be realized by continually reading out and concatenating the stored information into a data stream to be converted into analog form. Read-only memory (ROM) is used as a storage medium in computers. ... Information is a word which has many different meanings in everyday usage and in specialized contexts, but as a rule, the concept is closely related to others such as data, instruction, knowledge, meaning, communication, representation, and mental stimulus. ... In telecommunications, a data stream is a sequence of digitally encoded signals used to represent information in transmission. ...

The digital milliwatt is used in place of separate test equipment. It has the advantage of being tied in frequency and amplitude to the relatively stable digital clock signal and power (voltage) supply, respectively, that are used by the digital channel bank. In synchronous digital electronics, such as most computers, a clock signal is a signal used to coordinate the actions of two or more circuits. ...

Source: from Federal Standard 1037C and from the Code of Federal Regulations, Telecommunications Parts 0-199 (edited for Wikipedia). Federal Standard 1037C entitled Telecommunications: Glossary of Telecommunication Terms is a U.S. Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. ... The Code of Federal Regulations, Telecommunications, containing the U.S. Federal regulations for telecommunications can be found under Title 47 of the United States Code of Federal Regulations. ...

unsigned char digital_milliwatt[8] = { 0x1e, 0x0b, 0x0b, 0x1e, 0x9e, 0x8b, 0x8b, 0x9e };