Plain old telephone service

Plain old telephone service (POTS), or publicly offered telephone service, is basic <a href="/facts/Voice_band/XTQ6l9zo">voice-grade telephone service</a>. Historically, POTS has been delivered by <a href="/facts/Analog_signal/xDbb4uB5">analog signal transmission</a> over copper loops, but the term also describes <a href="/facts/Backward_compatibility/FbHFBu5y">backward-compatible</a> analog connections offered by digital telephone systems. 
Copper loop POTS was the standard service offering from telephone companies in the United States from 1876 until 1988, when the <a href="/facts/Integrated_Services_Digital_Network/zcV99rUb">Integrated Services Digital Network</a> (ISDN) Basic Rate Interface (BRI) was introduced, followed by the development of <a href="/facts/Mobile_phone/H3EcqD9h">cellular telephone</a> systems and <a href="/facts/Voice_over_internet_protocol/5QGBbXYg">voice over internet protocol</a> (VoIP).
Despite the advent of these technologies, copper loop POTS remains a basic form of residential and small business connection to the <a href="/facts/Telephone_network/m46X3BJl">telephone network</a> in many parts of the world. The term encapsulates a technology that has been available since the introduction of the public telephone system in the late 19th century, remaining largely unchanged despite the introduction of innovations such as <a href="/facts/Touch-Tone/vg5vFo0X">Touch-Tone</a> dialing, electronic <a href="/facts/Telephone_exchange/PaRpGm8I">telephone exchanges</a> and <a href="/facts/Fiber-optic_communication/dc6S0Hg5">fiber-optic communication</a> into the <a href="/facts/Public_switched_telephone_network/eVrCTDU7">public switched telephone network</a> (PSTN).

Plain old telephone service open-in-new

Plain old telephone service