5G is About Boosting Capacity, Pure and Simple

Practically speaking, 5G is needed in some countries and geographies simply because 4G is running out of ability to support data demand growth. Small cells and millimeter wave spectrum are important in that regard. Coverage is another matter.

The other reason small cells make sense, from a capacity perspective, is that a typical user consumes about 80 percent of daily data from just three cells. There is light usage when out and about, while most usage occurs indoors, especially at home (47 percent, in some studies) and work (37 percent).

Outdoor coverage is another matter, in less-dense areas. There, lower frequencies make sense. In other words, 5G does not change the traditional trade off between coverage and capacity.

Demand, as you would guess, is strongest in dense urban areas, and there is a good match between millimeter wave capacity, propagation limits and geography. In various global cities data demand is expected to at least triple, increasing by an order of magnitude in some locations.

That rate of increase cannot be done using 4G platforms alone, most would agree. Small cells help, but 4G bandwidth, and ability to support devices per radio, is outstripped by 5G, especially 5G using millimeter wave spectrum.

source: McKinsey

Compared to 4G, 5G will support bandwidth up to 1,000 times greater, using spectrum efficiency, additional bandwidth, small cells, greater device density and the greater capacity possible by millimeter wave frequencies, compared to lower-frequency signals.

source: Visual Capitalist

Backhaul (fronthaul) requirements for 5G include the need for many small cells, especially to support millimeter wave spectrum. Both indoor and outdoor coverage scenarios must be supported, and most of those will occur at street light level, outdoors. Coverage at indoor and major venue sites will vary, in terms of placement.

source: Ericsson

source: Nokia

Small cells are needed because signals attenuate faster at higher frequencies. That is why lower frequency bands are considered best for coverage, while higher frequencies are better for capacity. Early thinking had been that radio sites therefore would be astronomically more expensive than macrocells. That is turning out not to be the case.

source: Bruegel.org