Editing GSM (section)

== Patents and open source ==
Several [[open-source software]] projects exist that provide certain GSM features,<ref>{{Cite journal|title=Analysing GSM Insecurity|first1=Ene|last1=Donald|first2=Osagie Nosa|last2=Favour|s2cid=212468467|date=October 2016|journal=International Journal of Research & Scientific Innovation|volume=3|issue=10|page=10|issn=2321-2705}}</ref> such as a [[base transceiver station]] by [[OpenBTS]] develops a [[Base transceiver station]] and the [[Osmocom]] stack providing various parts.<ref>{{cite web |url=http://bb.osmocom.org/trac |title=OsmocomBB |publisher=Bb.osmocom.org |accessdate=22 April 2010 |archive-url=https://web.archive.org/web/20110226120714/http://bb.osmocom.org/trac/ |archive-date=26 February 2011 |url-status=dead }}</ref>

Patents remain a problem for any open-source GSM implementation, because it is not possible for GNU or any other free software distributor to guarantee immunity from all lawsuits by the patent holders against the users. Furthermore, new features are being added to the standard all the time which means they have patent protection for a number of years.{{Citation needed|date=June 2010}}

The original GSM implementations from 1991 may now be entirely free of patent encumbrances, however patent freedom is not certain due to the United States' "first to invent" system that was in place until 2012. The "first to invent" system, coupled with "[[patent]] term adjustment" can extend the life of a U.S. patent far beyond 20 years from its priority date. It is unclear at this time whether [[OpenBTS]] will be able to implement features of that initial specification without limit. As patents subsequently expire, however, those features can be added into the open-source version. {{as of|2011}}, there have been no lawsuits against users of OpenBTS over GSM use.{{Citation needed|date=June 2010}}