3GPP Madrid meeting sets 6G groundwork for Release 21

What happened

3GPP groups its work into plenary meetings. Plenary #113 brought together the technical groups for radio access, system architecture and the core network, and ended with the radio access session in Madrid. The ComSoc blog, written by Alan Weissberger, and the site 5GWorldPro both summarised the decisions. Release 20 reached full completion of Stage 2, the system architecture stage. Work now moves to Stage 3, where the detailed protocols are written.

5GWorldPro gives the Release 20 timeline. Stage 1, the service requirements, was frozen in June 2025. Stage 2 was about 80 percent complete by June 2026 and was finished at this meeting. Stage 3 is targeted for March 2027, and the final freeze of the formal message definitions for June 2027. Release 20 is the sixth release of 5G, the third of 5G-Advanced and the study phase for 6G.

The group also approved TR 22.870, a report on 6G use cases and service requirements. It is the anchor for Release 21, the first release with normative 6G specifications. 5GWorldPro lists its use case groups as networks run with built-in artificial intelligence, sensing combined with communication, coverage everywhere, immersive communication, very large numbers of connected devices, and support for industry. The report fixes what 6G must achieve, not how it will do it.

On timing, the ComSoc blog says Release 21 aims for its Stage 3 freeze in December 2028. 3GPP plans to send early 6G descriptions to the International Telecommunication Union (ITU) in mid-2027, and a formal candidate proposal in late 2028 or early 2029. The ITU's deadline for evaluating candidates for IMT-2030, its name for 6G, is a meeting in February 2029.

The engineering behind it

A new mobile generation does not replace the old one overnight. Operators run both for years, so engineers must decide how a phone connects to both networks. The ComSoc blog reports that delegates narrowed the options to two. In the first, the phone connects to 6G and 5G at the same time, with 6G as the anchor that controls the link. In the second, the two networks run side by side as separate radio paths without combining traffic at the radio level.

Spectrum is the scarcest resource in mobile networks. Operators will not want to empty a 5G band before using it for 6G. A radio working group reported early results on multi-radio spectrum sharing, where 5G and 6G use the same frequencies at once. The study measured the extra signalling overhead this creates. The ComSoc blog does not give the numbers, but the aim is to protect investment during the move from one generation to the next.

Another topic is integrated sensing and communication. The architecture group finished early designs for letting a base station use its radio energy for sensing as well as data, so it can work like a radar and map objects around it. Channel models in report TR 38.914 were also updated for the new frequency ranges planned for early 6G designs. These models describe how radio waves reflect, scatter and fade, and every simulation depends on them.

5GWorldPro also reports a follow-on work item to move 3GPP systems to post-quantum cryptography. This means replacing today's encryption methods with ones that are believed to resist attack by future quantum computers. Security changes of this kind take years to plan and test, because every phone, base station and core network element must agree on the same methods.

What it means in Nepal

Nepal does not yet have commercial 5G. The Kathmandu Post reported on 21 June 2026 that Nepal, Bhutan and Afghanistan were the only South Asian countries without it. A spokesperson for the Nepal Telecommunications Authority said spectrum preparations for 5G were complete and the regulator was ready to move to an auction. Nepal Telecom said it had decided to launch 5G in major cities and was waiting for frequencies.

The same report gives other details. Nepal Telecom ran 5G trials three to four years earlier, when about 5 percent of handsets could use 5G. A company official said the share is now over 20 percent. Ncell applied in April 2026, for the third time, to run 5G trials. Experts at the event warned that 4G quality still needs work and that operators worry about returns on investment.

For students, this timing matters in a practical way. Nepal's first 5G networks and the first 6G specifications may arrive within a few years of each other. Engineers who understand both the current standards and the direction of 6G will be able to read vendor proposals, plan networks and test equipment with more confidence. 3GPP documents are public, and learning to read them is a skill that grows with practice.