Editing Pulse dialing (section)

==Successors==
It was recognized as early as the 1910s that push buttons were faster than rotary dials, when the first [[panel switch]]es used keys for dialing at the operator stations. In the 1940s, Bell Laboratories conducted field trials of pushbutton telephones for customer dialing to determine accuracy and efficiency. However, the technology of using mechanical reed relays was too unreliable until transistors transformed the industry. In 1963, the Bell System introduced to the public [[dual-tone multi-frequency]] (DTMF) technology under the name Touch-Tone, which was a trademark in the U.S. until 1984.<ref>The Trademark Electronic Search System on the [[U.S. Patent and Trademark Office]] [http://www.uspto.gov/ web site] shows the trademark with serial number 72109459, registered 1962-09-04 and cancelled 1984-03-13.</ref> The Touch-Tone system used [[push-button telephone]]s. In the decades after 1963, rotary dials were gradually phased out on new telephone models in favor of keypads and the primary dialing method to the central office became touchtone dialing. Most central office systems still support rotary telephones today. Some keypad telephones have a switch or configuration method for the selection of tone or pulse dialing.

[[Mobile telephone]]s and most [[voice-over-IP]] systems use [[out-of-band signaling]] and do not send any digits until the entire number has been keyed by the user. Many VoIP systems are based on the [[Session Initiation Protocol]] (SIP), which uses a form of [[Uniform Resource Identifier]]s (URI) for addressing, instead of digits alone.