6G Spectrum Will Lean Heavily on Millimeter Wave Assets

Though it is too early to say precisely which new bands of spectrum are allocated for 6G, new spectrum allocations have been the underpinning of every next-generation mobile network. And most of the potential new spectrum lies in the millimeter wave bands. 

source: Nokia Bell Labs 

There simply is not very much unencumbered spectrum left in the low-band and mid-band regions that can be allocated to support 6G. 

For reasons of signal propagation, the reliance on millimeter wave spectrum virtually ensures 6G will feature lots of small cell support indoors and outdoors. Outdoor transmitter signals will not generally penetrate walls, requiring new indoor cells to maintain mobile device coverage. 

Both of those requirements for dense networks underpin the move to more-dense outdoor backaul networks (front haul, mid haul and what we traditionally call backhaul as radio access networks are virtualized).

There also will be new value for indoor networks such as Wi-Fi that can maintain data services and voice connectivity indoors when 6G indoor small cells are not available. 

Higher millimeter wave signal loss also means smaller cell sizes for the outdoors network.