400 MHz and the birth of 6G
In June 2026, in a conference room in Singapore, the people who decide what your phone can do gathered to choose a number: 400. Not a model number or a launch year — a bandwidth figure. Four hundred megahertz, four times the maximum channel width of mid-band 5G. When the delegates of the 3rd Generation Partnership Project voted it into the specification, they were not building a phone. They were writing the recipe that every chip manufacturer, antenna vendor, and network operator on earth would follow for the next decade.
3GPP was formed in December 1998 — a consortium of regional standards bodies whose job is to define how mobile networks work below the surface of what any user sees. Its 1999 release established UMTS, the protocol backbone of 3G. Release 8, in 2008, was LTE — the engine under 4G. Release 15, frozen in June 2018, was 5G New Radio, the standard that put a gigabit in a pocket. Release 21, now underway, will be 6G.
The June 2026 plenary locked the foundational air interface parameters. The waveform is CP-OFDM — the same orthogonal frequency-division multiplexing used by 5G and Wi-Fi — chosen for spectral efficiency and multipath tolerance. Channel coding stays with LDPC for data and Polar codes for control signals, both inherited from 5G, with a third base graph (BG3) added for high-throughput links. One genuinely new addition: multi-layer uplink, supporting up to two simultaneous transmit streams where 5G had allowed only one. Before June, these were engineering debates. After June, they were constraints the industry had to build toward.
Consider who was in the room. Nokia engineers from Finland. Ericsson engineers from Sweden. Qualcomm engineers from San Diego. Huawei engineers from Shenzhen. Samsung engineers from Suwon. In the world outside that conference center, some of these companies face export controls, chip bans, and spectrum restrictions that put them on opposite sides of trade disputes. Inside 3GPP, they are co-authors of the same specification. This is how every cellular generation since GSM has been born: by competitive consensus, under rules that require rough agreement before any text is finalized.
The timeline the plenary established is methodical. Normative specifications will be written through 2028. The code freeze — the moment when the specification becomes implementation-ready — is set for March 2029. Ericsson projects the first commercial 6G systems will appear in 2030. The people in Singapore in June were writing a specification for calls that won’t be made for four more years.
The world’s first GSM call was placed in Helsinki on July 1, 1991, by former Finnish Prime Minister Harri Holkeri, calling the acting chief executive of Tampere — on a standard that delegates had agreed in committee rooms nearly a decade before. The 400 megahertz the engineers voted into existence in Singapore is still just numbers on a page. In four years, they will be moving through walls.
Sources
- Building the 6G standard: What 3GPP’s June 2026 plenary decisions mean for device makers — RCR Wireless — Detailed breakdown of 6G air interface decisions: waveform, bandwidth ceiling, coding architecture, multi-layer uplink.
- 6G standardization: Key milestones and RAN decisions — Ericsson — Ericsson’s overview of the 2026 roadmap, Singapore meeting decisions, and 2030 commercial deployment projection.
- Release 20 — 3GPP — Official 3GPP Release 20 page; context on the parallel 5G Advanced and 6G specification tracks and freeze milestones.