Before operators start to deploy 5G cores and Standalone networks (see separate item), most of the performance boost from current 5G is coming from New Radio’s ability to use spectrum differently. For the first time, there is a standardized way for mobile cellular networks to use millimeter wave bands (something already achieved in the WiFi world with 60 GHz WiGig); and the standards support larger channel sizes and higher degrees of carrier aggregation.
As 5G platforms evolve and mature, more of the performance advantages will be coming from new architectures, particularly the resource flexibility of a software-defined, cloud-native network. But large channels in high capacity, high frequency spectrum bands will remain critical to the new services, especially those with very high bandwidth requirements like virtual reality. And as even more immersive experiences like tactile Internet emerge, the pressure to pursue even bigger swathes of underused spectrum will intensify.
Several new approaches to spectrum will have to be harnessed in parallel to get the most dramatic results. Key elements are:
- Moving even further up the spectrum, even into terahertz spectrum (which is currently the only concrete aspect of early ‘6G’ definitions).
- Using the unlicensed and shared spectrum bands which have, until recently, been barred to cellular.
- Aggregating more, and larger, carriers, including mmWave and unlicensed options.
- Dynamic usage and sharing of different sources of spectrum to maximize their utilization.
All these practices can be used together, in theory, though each one adds further complexity to the radio chipset, the device and the engineering of the network, so trade-offs must be considered, especially for early movers, who may be tapping into new spectrum assets before the ecosystem is fully developed.