Editing GSM (section)

=== Adoption ===
[[File:Icons on GSM mobile phone Siemens S4 (1996).jpg|thumb|GSM logo icon shown on the face of a Siemens GSM mobile phone from 1996]]
The [[GSM Association]] estimated in 2011 that technologies defined in the GSM standard served 80% of the mobile market, encompassing more than 5 billion people across more than 212 countries and territories, making GSM the most ubiquitous of the many standards for cellular networks.<ref name=gsma_stats>{{cite web|url=http://www.gsmworld.com/newsroom/market-data/market_data_summary.htm |title=GSM World statistics |year=2010 |work=gsmworld.com |publisher=GSM Association |accessdate=8 June 2010 |url-status=dead |archiveurl=https://web.archive.org/web/20100521013451/http://www.gsmworld.com/newsroom/market-data/market_data_summary.htm |archivedate=21 May 2010 }}</ref>

GSM is a second-generation (2G) standard employing time-division multiple-access (TDMA) spectrum-sharing, issued by the European Telecommunications Standards Institute (ETSI). The GSM standard does not include the 3G [[Universal Mobile Telecommunications System]] (UMTS), [[code-division multiple access]] (CDMA) technology, nor the 4G LTE [[orthogonal frequency-division multiple access]] (OFDMA) technology standards issued by the 3GPP.<ref>{{cite web|title= Mobile technologies GSM|url= http://www.etsi.org/technologies-clusters/technologies/mobile/gsm?highlight=YToxOntpOjA7czozOiJnc20iO30=|accessdate= 7 November 2013|archive-url= https://web.archive.org/web/20140330060902/http://www.etsi.org/technologies-clusters/technologies/mobile/gsm?highlight=YToxOntpOjA7czozOiJnc20iO30=|archive-date= 30 March 2014|url-status= dead}}</ref>

GSM, for the first time, set a common standard for Europe for wireless networks. It was also adopted by many countries outside Europe. This allowed subscribers to use other GSM networks that have roaming agreements with each other. The common standard reduced research and development costs, since hardware and software could be sold with only minor adaptations for the local market.<ref>{{Cite book |author= Martin Sauter |title= From GSM to LTE-Advanced : An Introduction to Mobile Networks and Mobile Broadband |edition= Second |publisher= John Wiley & Sons, Incorporated |date= 23 June 2014 |isbn= 9781118861929 }}</ref>