I have been reading 5G propagation studies to assess the viability of 5G as a rural friendly technology. Most of the models and studies focus on urban applications and urban problems, like building shadows, antenna height, wall and window penetration and the miles of fiber need for fronthaul and backhaul networks to feed the needed bandwidth to the small cells required to transmit high capacity 5G signals.
One study, Radio Propagation Path Loss Models for 5G Cellular Networks in the 28 GHz and 38 GHz Millimeter-Wave Bands, simulated the coverage areas for existing 2/3/4G signals to cover a 10-mile square area. To ensure a suitable signal within the 100 square mile target area would require 22 cell sites, on antenna 20 meters high. To cover the same area with 28GHz small cells would require 95 sites, approximately one per square mile.
According to the United States Census Bureau, Nevada City has a total area of 2.2 square miles, requiring approximately three small cells at 28GHz, Grass Valley, 4.7 square miles, requiring about five small cells. Nevada County covers 974 square miles, with 16 being water. For complete coverage of the County at 5G would need 958 small cells.
With vast areas only sparsely populated with few paved roads, it would be difficult to justify installing 5G small cells that would not be used enough to have a return on the investment (ROI). Thus, it is highly unlikely that those small cells will ever be installed, without government intervention to include installation grants and ongoing use subsidies. Not a high probability.
It is about 24 miles from Auburn to Grass Valley. Using the one small cell per square mile, it would require about 24 small cells to provide G5 coverage to US-49 from Auburn to Grass Valley. Again, due to ROI issues, it is unlikely that this section will have small cell G5 coverage.
All the calculations in the model use assume a clear line of sight between the small cell antenna the user antenna. In highly forested areas, maintaining a clear line of sight can be a challenge for providers. More in this issue in a future post.