As of 2015, the landline telephones in most residential properties are analog—that’s, the speaker’s voice immediately determines the sign’s voltage. Although brief-distance calls could also be dealt with from finish-to-end as analog alerts, increasingly phone service providers are transparently changing the alerts to digital signals for transmission. The benefit of this is that digitized voice data can travel aspect-by-aspect with data from the Internet and may be completely reproduced in lengthy-distance communication . Modulation can be utilized to represent a digital message as an analog waveform. This is often referred to as “keying”—a term derived from the older use of Morse Code in telecommunications—and several other keying techniques exist (these embody phase-shift keying, frequency-shift keying, and amplitude-shift keying). The “Bluetooth” system, for example, uses section-shift keying to change information between various devices.