“Fiber to the light pole” is one of the ways to think about optical fiber and other backhaul networks for 5G small cells.
Additional spectrum and smaller cell sizes are the two fundamental tools network designers can use to increase network bandwidth. In the pre-5G eras, when networks operated at lower frequencies, a macrocell tower (at 950 MHz) might transmit more than 17 miles, on flat terrain without major obstructions.
A 4G network using 1.8-GHz to 2.1-GHz signals might transmit only about 7.5 miles, by way of comparison. Low-frequency spectrum often is described as assets at and below 800 MHz (450 MHz, 600-MHz, 700 Mhz and 800 MHz). “Mid-frequency” tends to include 1.8 GHz to 2.1 GHz spectrum. “High frequency” traditionally has meant the 2.5-GHz range.
All that will change in the 5G era, as millimeter wave assets are commercialized. When millimeter spectrum is used (28 GHz, 39 GHz), small cells might cover a few to several hundred meters radius. In those cases, small cells might be placed about every other light pole along roads.
The following table shows the dependency of the coverage area of one cell on the frequency of a 3G network.
Frequency (MHz)
|
Cell radius (km)
|
Cell area (km2)
|
Relative Cell Count
|
450
|
48.9
|
7521
|
1
|
950
|
26.9
|
2269
|
3.3
|
1800
|
14.0
|
618
|
12.2
|
2100
|
12.0
|
449
|
16.2
|
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