Editing Plain old telephone service (section)

{{short description|Traditional analog land line telephone service}}
'''Plain old telephone service''' ('''POTS'''), or '''publicly offered telephone service''', is basic [[Voice band|voice-grade telephone service]]. Historically, POTS has been delivered by [[Analog signal|analog signal transmission]] over copper loops, but the term also describes [[Backward compatibility|backward-compatible]] analog connections offered by digital telephone systems.<ref>{{Cite web |title=AnyMediaTM Access System: Software Release Description for Software Release 1.0.0.0" (PDF). Lucent Technologies. September 28, 1998. Retrieved February 28, 2020. |url=https://documentation.nokia.com/cgi-bin/dbaccessfilename.cgi/363211104_V1_AnyMedia%20Access%20System%20Release%201.0.0.0%20Software%20Release%20Description.pdf}}</ref>  

Copper loop POTS was the standard service offering from telephone companies in the United States from 1876 until 1988,<ref>{{Cite web |title=I.430 : Basic user-network interface – Layer 1 specification". International Telecommunication Union. 2010-08-23. Retrieved 2015-05-07. |url=https://www.itu.int/rec/T-REC-I.430-198811-S/en}}</ref> when the [[Integrated Services Digital Network]] (ISDN) Basic Rate Interface (BRI) was introduced, followed by the development of [[mobile phone|cellular telephone]] systems and [[voice over internet protocol]] (VoIP).

Despite the advent of these technologies, copper loop POTS remains a basic form of residential and small business connection to the [[telephone network]] 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 [[Touch-Tone]] dialing, electronic [[telephone exchange]]s and [[fiber-optic communication]] into the [[public switched telephone network]] (PSTN).