April 11, 2025
Can you believe SDG OpenCAPIF (OCF) is already celebrating its first anniversary? Since kicking off this adventure in January 2024, we’ve released two major code releases, upgrading OpenCAPIF from 3GPP Specs Release 17 to the cutting-edge Release 18. What a journey it’s been!
Along the way, our OCF community faced the exciting challenge of implementing 3GPP standards like TS 23.222 (SA6), TS 29.222 (CT3), and TS 33.122 (SA3), mastering the crucial security components defined in CAPIF. This implementation exercise has proved not only to be beneficial for our OCF community—it has also provided valuable insights back to 3GPP itself!
Along with our implementation efforts, we’ve crafted an extensive testing plan covering both positive scenarios and error cases for REST API responses.
We’ve also addressed aspects initially considered “out of scope” by the original standards, like the administrative registration part which is required to onboard API Invokers and Providers within a CAPIF environment.
But bringing all these learnings back into the 3GPP specification was a whole new challenge for the OpenCAPIF community. Let’s see how we managed to achieve this retro-feedback process and look back on its outcomes…
SDG OCF was born during the Release 19 timeframe from 3GPP:
Figure 1 - 3GPP Releases Timeline
During this cycle, the 3GPP SA6 Working Group started working on a new Technical Report TR 23.946 on CAPIF Guidelines. This new Work Item was approved during SA6#57 meeting in Xiamen (October 2023), just before ETSI SDG OCF was announced. The approved scope was quite explicit and really appealing for us:
TR 23.946 provides guidelines for CAPIF usage for the benefit of the Application developer and API provider communities. This document also describes the use cases, requirements and deployment options in CAPIF.
This was the perfect opportunity for SDG OCF to channel back some of the lessons learnt during the OpenCAPIF code development and testing activities.
But contributing these lessons back to 3GPP wasn’t as simple as writing an email and pressing “send.” Entering the world of contributing to 3GPP specifications means navigating a maze of rituals, terms, calendars and meetings. Terms like “Work Item”, “Change Request,” “Noted,” “Revised,” “WID,” or “SID” can be quite cryptic for someone who starts attending 3GPP meetings. Picture delegates lining up at microphones, passionately debating until a chair expertly steers discussions towards agreement (hopefully before everyone runs out of coffee!).
To effectively share our learnings, we sought for common membership among 3GPP TSG SA WG6 and ETSI SDG OCF and happily found some within OCF’s founding members, who provided critical support in formatting and contributing our feedback into 3GPP.
After announcing SDG OCF creation and holding the kick-off meeting in January 2024, the first opportunity for OCF appeared during the SA6#60 meeting in Changsha (April 2024). Our first goal was to have OpenCAPIF referenced by TR 23.946; which we successfully managed!
Fast forward to SA6#62 meeting in Maastricht (August 2024), we brought several contributions to the CAPIF Guidelines, including practical examples of NEF API publishing and API invocations—completed with a new Annex containing a Postman collection of examples for developers.
By SA6#63 meeting in Hyderabad (October 2024), we were familiar with the process and brought even more to the table, showcasing deployment scenarios with ETSI ISG MEC and presenting a robust testing plan—featuring over 100 test cases! And we didn’t stop there. At the pivotal SA6#64 meeting in Orlando (November 2024), we contributed some valuable guidelines on Vendor Extensibility, empowering developers to include vendor-specific information in APIs Publishing and Discovery.
Finally, 3GPP TR 23.946 was officially published in December 2024, a testament to SDG OCF’s impact in 3GPP. Our collective efforts demonstrated how a dynamic developer community, organized as an ETSI Software Development Group (SDG), can efficiently contribute to enhance 3GPP specifications with real-world examples, detailed tests, and practical clarifications.
Looking ahead, the recent SA6#65 meeting in Athens (February 2025) opened the floor for some exciting discussions on 3GPP Release 20. SDG OCF ambitions have only grown—and we’re now ready to help shape the future of 3GPP CAPIF, not just helping to refine current specs but also laying the groundwork for innovative features yet to come.
Stay tuned; the best chapters of the collaboration between OpenCAPIF and 3GPP are still to be written!
Resources
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