ETSI - The European Telecommunications Standards Institute (ETSI) was responsible for originally defining the complete GSM standard. This responsibility includes elements relating to SMS that are generated primarily by the SMG4 (Special Mobile Group section 4). ETSI specifications are available by contacting:

ETSI, 650 Route des Lucioles, F-06921 Sophia Antipolis Cedex, France

The ETSI Internet site is http://www.etsi.org
Email secretariat@etsi.org or publications@etsi.org.
Tel: +33 492944200
Fax: +33 493654716
In 2000, the ETSI standards including those for SMS were passed to the Third Generation Partnership Project (3GPP), https://www.3GPP.org