The End of the PSTN

The Public Switched Telephone Network (PSTN). It’s been around forever. Since 1878 to be precise. To consider its demise seems blasphemous and even suicidal. I ask you to be brave and join me on a journey to explore the possibility of a world without the PSTN, and why you should care.

Why a PSTN?

In 1876, telephones were sold in pairs. If you wanted to talk to your sister on the telephone, you would need to lay cable between your house and hers. In January, 1878, the world’s first telephone exchange was established in New Haven, Connecticut. Call switching was performed manually. Operators manned switchboards repeatedly requesting “Number, Plee-uhz”. As the popularity of the telephone grew, iconic telephone poles became part of the landscape in both urban and rural areas in the United States.

By the late 1880s electromechanical switches were introduced, and in the 1920s, rotary dials on telephones replaced the telegraph key on telephones. Crossbar switches that were capable of completing a call in a tenth of a second were introduced in 1935. Electronic switches that completed calls within nanoseconds were introduced in 1968.

In the 1980s the industry began planning for digital services assuming they would follow much the same pattern as voice services, and conceived end-to-end circuit switched services, known as the Broadband Integrated Services Digital Network (B-ISDN). The B-ISDN vision was overtaken by the disruptive technology of the Internet.

Next week we’ll discuss the role of the PSTN today.