Release 12 was largely completed on-time in March 2015, with a few exceptional features allowed an extension to later in the year.
A priority in this realese was the use of LTE technology for emergency and security services, with technical specifications for mission-critical application layer functional elements and interfaces being developed in the newly formed SA6 working group. Work advanced well in this release with further progress, on Mission-Critical Press-to-Talk (MC-PTT) and other features, scheduled in Release 13.
Other important features completed in Release 12 include: Small cells and Network densification, D2D, LTE TDD-FDD joint operation including Carrier Aggregation, Security Assurance Methodology (SECAM) for 3GPP Nodes and the integration of WiFi in to mobile operator's offerings.
A 3GPP description document - Overview of 3GPP Release 12 is available on-line, giving a high-level view of the features that are included in the Release.
Some additional background material about the lead-up to Release 12 is on line at;
- Video - "3GPP Status of Rel-12 and Rel-13" (Sept. 2014)
- Understanding 3GPP Release 12 Standards by 4G Americas (Feb. 2015)
- Video on 'Release 12 Prioritization' (Sept. 2013)
- Future-Radio-in-3GPP - RAN Workshop news story (Jun. 2012)
- New opportunities for 3GPP - SA Workshop news story on Rel-12 (Dec. 2012)
- 2020 vision for LTE, an article by Keith Mallinson (Jun. 2012)
Details of the features and work items under each 3GPP Release are kept in the corresponding, on-line, list of features and study items.
Functional freeze date including stable protocols: March 2015 (...what does this mean?)