Portal:Telephones

The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by AT&T, that dominated the telephone services industry in North America for over 100 years from its creation in 1877 until its antitrust breakup in 1983. The system of companies was often colloquially called Ma Bell (as in "Mother Bell"), as it held a vertical monopoly over telecommunication products and services in most areas of the United States and Canada. At the time of the breakup of the Bell System in the early 1980s, it had assets of $150 billion (equivalent to $460 billion in 2025) and employed over one million people.

Beginning in the 1910s, American antitrust regulators had been observing and accusing the Bell System of abusing its monopoly power, and had brought legal action multiple times over the decades. In 1974 the Antitrust Division of the U.S. Department of Justice brought a lawsuit against Bell claiming violations of the Sherman Act. In 1982, anticipating that it could not win, AT&T agreed to a Justice Department-mandated consent decree that settled the lawsuit and ordered it to break itself up into seven "Regional Bell Operating Companies" (known as "The Baby Bells"). This ended the existence of the conglomerate in 1984.

Following the breakup, the Baby Bells became independent companies and several of them became large corporations. However, many of the Baby Bells later re-merged, and as a result by 2025 most of the assets and geographical service areas of the former Bell System became spread across two Baby Bells descendants: AT&T and Verizon. (Full article...)

A mobile phone or cell phone is a portable wireless telephone that allows users to make and receive calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones (landline phones). This radio frequency link connects to the switching systems of a mobile phone operator, providing access to the public switched telephone network (PSTN). Modern mobile telephony relies on a cellular network architecture, which is why mobile phones are often referred to as 'cell phones' in North America.

Beyond traditional voice communication, digital mobile phones have evolved to support a wide range of additional services. These include text messaging, multimedia messaging, email, and internet access (via LTE, 5G NR or Wi-Fi), as well as short-range wireless technologies like Bluetooth, infrared, and ultra-wideband (UWB).

Mobile phones also support a variety of multimedia capabilities, such as digital photography, video recording, and gaming. In addition, they enable multimedia playback and streaming, including video content, as well as radio and television streaming. Furthermore, mobile phones offer satellite-based services, such as navigation and messaging, as well as business applications and payment solutions (via scanning QR codes or near-field communication (NFC)). Mobile phones offering only basic features are often referred to as feature phones (slang: dumbphones), while those with advanced computing power are known as smartphones. (Full article...)

In telephony, a special information tone (SIT) is an in-band international standard call progress tone consisting of three rising tones indicating a call has failed. It usually precedes a recorded announcement describing the problem. (Full article...)

William Rae Young, Jr. (October 30, 1915 – March 7, 2008) was one of the Bell Labs engineers that invented the cell phone.

The history of cellular phone technology began on December 11, 1947 with a Bell Labs internal memo written by Douglas H. Ring describing the idea of Rae Young of the hexagonal cell concept for a cellular mobile telephone system. (Full article...)