American Tower operates 178.8k towers, supporting the deployment of 5G in layers, in five distinct geographical regions. The company operates towers in the United States (40.6k), India (73.6k), Latin America (40.9k), Africa (18.8k) Europe (4.8k).
5G is accompanied by significant deployments of new spectrum assets across the full range of low-, mid- and high-bands. When a carrier builds a nationwide 5G network capability, they will need different bands of spectrum through which to deploy it.
5G will be deployed by American Tower in three layers. This is because different geographic areas, will have specific topographic and population characteristics. In rural locations, low-band spectrum and some mid-band will be the main components.
Whereas, in suburban areas and highway corridors, where there are more people and more usage, mid-band spectrum is an important component. At the same time, low-band coverage will also broadly deployed.
Finally, in dense urban areas, all three types of spectrum, including high-band, millimeter wave, will be deployed. American Tower will deploy these 5G layers through a combination of rooftop antennas, indoor and outdoor systems, and small cells.
American Tower understands that as a result of the different layers of 5G deployment, a more complex radio access network (RAN) architecture will result. This will require more density, considerably more compute power and more intelligent design to deliver a consistent user experience.
Digital Infrastructure Used for 5G Networks Will Change Depending on Where it is Deployed
In dense urban areas, smaller antennas placed at lower heights will be used to deploy millimeter wave spectrum via small cells. These deployments will occur on streetlights, utility poles and the sides of buildings. Whereas in suburban and rural areas, larger antennas will be placed higher up on towers to deploy low- and mid-band spectrum.
Generally, the lower the spectrum band, the larger the antennas will be on the tower. Hence, why millimeter wave spectrum deployments primarily use small cell infrastructure. Additionally, when antennas are brought from a high-point to a low-point, it reduces the size of the coverage area. In turn, it increases the overall cost of deployment. Therefore, carriers prefer to deploy on towers, whenever possible.
5G Layers Deployed Over Time by American Tower
Timing and phasing of the 5G deployment curve will be made available similar to other important technologies. Initially, 5G will be available in dense urban markets. Ultimately, it will be rolled-out nationwide. For example, users will be able to take advantage of 5G services in Boston, but as they drive less than 20 miles west to Wellesley, Massachusetts they are also going to want to be able to enjoy those same 5G services. To solve these needs, carriers will utilize a mix of the three different bands to be able to deploy their spectrum, ensuring seamless 5G coverage and capacity.
Once all three spectrum bands are deployed, carriers will return to particular cell sites and begin to re-touch all of those cell sites to increase capacity, increase the number of sectors on the sites, to add radios and to add antennas. Carriers will continue this process for a decade or more, similar to what has occurred for 4G networks.
American Tower is Well Positioned to Deploy 5G in Layers
In terms of the real estate, available at the base of the tower, American Tower has the ability to support the carriers as they continually roll-out 5G spectrum from the dense urban markets into the more suburban markets across the United States.
Low Band (Coverage Spectrum)
Low-band spectrum is the base 5G layer, using spectrum that is sub-2 GHz. This base layer has good propagation over several miles of distance and the ability to penetrate buildings.
However, low-band spectrum is a narrow band which results in a trade-off of having limited capacity and less speed. Therefore, less incremental benefit will be provided to the consumer from the 4G to 5G transition, on low-band.
For example, T-Mobile utilizes the 600 MHz frequency to serve a significant component of its 5G coverage plan across the United States. American Tower’s portfolio of nearly 41k sites in the United States is thus positioned well to support a deployment akin to T-Mobile’s. Moreover, American Tower already has 600 MHz low-band spectrum selectively deployed on its towers in the United States, from certain carriers.
Use cases such as having a reliable drone control system, will require low-band 5G deployed on towers. Particularly because low-band deployed on towers provides strong coverage characteristics.
Mid Band (Backbone Spectrum)
Mid-band spectrum offers improved capacity and speeds but lower propagation, as compared to low-band spectrum. Widespread roll-out of mid-band spectrum will occur gradually over time.
Mid-band spectrum is generally situated between 2.5 GHz and 6 GHz frequencies. It offers a strong blend of low-band coverage benefits and high-band capacity benefits. Coverage and capacity are critical attributes to ensuring 5G networks function as promised. United States spectrum assets in the mid-band range include T-Mobile’s 2.5 GHz spectrum, the 3.5 GHz CBRS band, and the C-band spectrum, which is currently held by satellite operators and is situated between the 3.7 GHz and 4.2 GHz frequencies.
Importantly, given that propagation characteristics of mid-band spectrum are not as favorable as low-band, more transmission sites will be necessary to deliver ubiquitous 5G signals. However, in order to enable new 5G use cases in the United States, and do so economically, significant spectrum deployment is going to have to be on tower sites with mid-band spectrum.
High Band (Capacity Spectrum)
High-band, millimeter wave spectrum is used primarily for urban and dense urban markets. The characteristics of high-band, millimeter wave spectrum is that it is very wide, providing a significant increase in capacity.
Because of the greater spectrum width, speed is increased, and latency of the transmission is reduced. However, the drawback is that high-band spectrum does not propagate far. For example, 28 GHz can only travel 500 feet. Therefore, the signal dies out not too far from where it radiates from.
Towers will not support a lot of millimeter wave 5G activity, because the network architecture does not make sense. Millimeter wave spectrum will be deployed on small cells in dense urban areas, metropolitan centers. However, it will not be deployed in suburban and rural areas. Rather, small cells will augment 5G deployments in select areas where there is a specific capacity requirement.