Editing SMS (section)

=== Initial concept ===
[[File:Telephone-keypad.svg|thumb|[[E.161]], a common mobile keypad alphabet layout]]
Adding text messaging functionality to mobile devices began in the early 1980s. The first action plan of the CEPT Group [[GSM]] was approved in December 1982, requesting that "The services and facilities offered in the public switched telephone networks and public data networks&nbsp;... should be available in the mobile system."<ref>see GSM document 02/82, available on the GSM-SMG Archive DVD-ROM</ref> This plan included the exchange of text messages either directly between mobile stations, or transmitted via message handling systems in use at that time.<ref>These Message Handling Systems had been standardized in the ITU, see specifications X.400 series</ref>

The SMS concept was developed in the Franco-German GSM cooperation in 1984 by [[Friedhelm Hillebrand]] and [[Bernard Ghillebaert]].<ref>See the book Hillebrand, Trosby, Holley, Harris: SMS the creation of Personal Global Text Messaging, Wiley 2010</ref> The GSM is optimized for telephony, since this was identified as its main application. The key idea for SMS was to use this telephone-optimized system, and to transport messages on the [[Signalling System No. 7|signalling paths]] needed to control the telephone traffic during periods when no signalling traffic existed. In this way, unused resources in the system could be used to transport messages at minimal cost. However, it was necessary to limit the length of the messages to 128 bytes (later improved to 160 seven-bit characters) so that the messages could fit into the existing signalling formats. Based on his personal observations and on analysis of the typical lengths of [[postcard]] and [[Telex]] messages, Hillebrand argued that 160 characters was sufficient for most brief communications.<ref name="latimesblogs.latimes.com">{{cite web|url=http://latimesblogs.latimes.com/technology/2009/05/invented-text-messaging.html|title=Technology|access-date=June 14, 2015|date=May 3, 2009|archive-date=September 30, 2021|archive-url=https://web.archive.org/web/20210930082324/https://latimesblogs.latimes.com/technology/2009/05/invented-text-messaging.html|url-status=live}}</ref>

SMS could be implemented in every mobile station by updating its software. Hence, a large base of SMS-capable terminals and networks existed when people began to use SMS.<ref>See GSM document 28/85rev.June 2, 85 and GSM WP1 document 66/86, available on the GSM-SMG Archive DVD-ROM</ref> A new network element required was a specialized short message service centre, and enhancements were required to the radio capacity and network transport infrastructure to accommodate growing SMS traffic.<ref>{{Cite web |last=ETSI |first=TC-SMG |title=Digital cellular telecommunications system (Phase 2+); Technical realization of the Short Message Service (SMS) |url=https://www.etsi.org/deliver/etsi_gts/03/0340/05.02.00_60/gsmts_0340v050200p.pdf |website=etsi.org |access-date=2023-12-12 |archive-date=2023-12-12 |archive-url=https://web.archive.org/web/20231212070051/https://www.etsi.org/deliver/etsi_gts/03/0340/05.02.00_60/gsmts_0340v050200p.pdf |url-status=live }}</ref>