Small Cell 101 | Crown Castle

Crown Castle is deploying small cells in cities and towns around the country. Understandably, many are asking: What are they? What do they do? And why do we need them? These are important questions, because the answers may very well have an impact on your ability to stay connected to the things that matter most to you. So, let’s take a few minutes to answer these questions through the lens of a fictional place we’ll call Anytown, USA.

In our example, let’s imagine that Anytown is a mostly residential, suburban community of modest size. Near Anytown is a cell tower that provides wireless voice and data coverage to the entire town.

Affixed to this tower are several antennas owned by the wireless providers that serve Anytown. They broadcast and pick up signals from residents’ devices, send the data they receive to adjacent equipment near the tower and then a wired connection sends the information on to the internet or phone system.

Twenty-five years ago, when this tower was built, it served the residents of Anytown well. People were using cell phones to talk, and later, text with hardly any issues. With the possible exception of a few dead spots and limited coverage areas during times of high use in smaller areas like sporting or school events, Anytown’s tower has reliably provided good, dependable service that kept residents connected.

Anytown has maintained a pretty steady population throughout the years, but today, residents have started to notice that even when their device shows a signal, they aren’t always able to connect.

Early cell phone users in Anytown had few problems connecting to the wireless carriers’ networks. But as more people use more data, some aren’t able to connect.

What happened? Well, for one, people have more capable smartphones and are using significantly more data. In the US, mobile internet traffic grew 38% each year from 2020-2023.* And Anytown is no exception. Residents are streaming music throughout the day, live chatting with their friends and watching and posting large videos to social media. Many Anytown residents also have multiple connected devices—like smartphones, tablets, smartwatches, home cameras and security devices. Some are even getting connected cars. Anytown also has plans to implement new smart city technologies that will use high-tech sensors and transmitters to control traffic lights, streamline bus schedules and monitor electric, water and other utility usage. So why is this causing problems now?

We need to talk about coverage and capacity.

At this point, there are two terms that we need to understand when talking about wireless service: coverage and capacity. While these two terms are related, the causes—and solutions—to each can vary.

Anytown’s tower is capable of covering the entire town. The wireless providers’ networks are not suffering from coverage constraints.

Coverage

This is the area that a particular type of communications infrastructure covers. In other words, it’s how far the signal reaches. Anytown’s tower is able to send its signal across the entire town. There are a few areas with hills and tall buildings, which can cause the signal to drop in some cases. But Anytown’s coverage hasn’t changed.

Capacity

If you’ve ever had full bars on your device but can’t place a call or load a web page, you have coverage, but not capacity. You aren’t having any issue connecting, but for some reason, your calls are not getting through and your text messages are delayed.

To understand why this happens, we have to introduce one more new term: wireless density. The wireless signals that connect the tower to Anytown residents’ devices are only capable of carrying so much data at once. The more data people use on the network, the slower everyone’s connections become. To solve this problem, we need to find a way to add more wireless density to the networks that serve Anytown.

The signals to and from the tower can only carry so much data. When too many devices try to connect at the same time, things slow down or calls fail to go through.

Given the challenges the town faces, Anytown would be an ideal candidate for a new small cell network. A small cell network consists of a series of small, low-powered antennas that enhance connectivity by increasing capacity of the wireless network in locations closer to consumers and their devices. Small cells are connected by fiber optic cable and may be attached to new or existing infrastructure in the public right of way like utility poles or streetlights. This allows the small cells to be placed where they need to be—close to users’ devices, and easily accessible for maintenance. Similar to a tower, small cells communicate wirelessly over radio waves, and connect signals to the internet or phone system. Because they’re connected with fiber they are able to handle massive amounts of data at fast speeds.

Small cells may be attached to new or existing infrastructure in the public right of way—in this case, a streetlight.

Developing a plan with input from the community.

The people of Anytown have a vested interest in understanding what’s happening in their community and how it affects them. In our scenario, we’ll assume that Crown Castle is building out the new small cell network, which means they will handle all the planning, permitting, construction and ongoing management and maintenance of the network. To effectively do this, representatives from the local Crown Castle office have been meeting with community members and working closely with municipal officials, utilities and other wireless providers. Here are a few key topics that often arise in these discussions:

Permitting: In accordance with all state and federal legislation as well as local ordinances, Crown Castle established which permits will be required, when they need to be submitted and when the town needed to respond.
Design considerations: Crown Castle takes into consideration the existing streetscape, including streetlights and utility poles, when designing small cells to enhance connectivity. This means that small cells may be attached to existing poles, existing poles may need to be replaced to accommodate small cells, or new poles may need to be constructed.
Safety: The scientific and health communities have come to the same general conclusion—there are no known health hazards from exposure to radiofrequency (RF) emissions within the established FCC guidelines. Our facilities comply with all FCC RF rules and guidelines. The installation team will consist of only licensed contractors who specialize in this type of work.
Shared model: Several wireless network providers serve Anytown. The small cell network will be designed so multiple carriers can use it—spreading the benefits as evenly as possible throughout the community.

Through this collaborative process, Anytown now has a clearly defined plan in place to install fiber-connected small cell using existing infrastructure. The new network will work with the tower to add much-needed capacity to Anytown’s wireless network. So, let’s see how that will work.

In Anytown, if too many people were on their devices at the same time, connectivity could slow down or calls could drop. By adding seven new small cells, we’ve multiplied our wireless network density several times over. Each small cell is capable of sending and receiving about the same amount of data as the tower, but since they cover a smaller geographic area, it’s less likely that any one of them will get overwhelmed.

With the addition of new small cells, Anytown’s network is able to handle many more simultaneous connections.

There’s another important benefit. Before, the network originated from one location—the tower. It covered a large area, but in certain areas of town—in the shadow of a building for example—the signal would occasionally get lost. But now the signal originates from separate locations—several of which are much closer to the devices, providing much more consistent coverage throughout Anytown. It’s also a shared infrastructure solution, meaning that multiple wireless network providers can be accommodated on the same pole. This reduces unnecessary equipment redundancy and maximizes the benefits for residents—regardless of which company they get their wireless service from.

Residents’ devices are working as expected again, but this isn’t just a story about people watching more videos and spending more time on social media. They have added peace of mind knowing that the people who are most important to them are always a tap, click or screen away. And there’s more capacity for Anytown residents to reach emergency services when and where they need them. Businesses are also finding new, innovative ways to take advantage of the faster, more dependable service—creating new jobs and economic opportunities. And Anytown has embraced and implemented new smart city technologies, which have eased traffic congestion, aided first responders and led to new efficiencies in the electrical grid, utility monitoring and other public services.

With a new small cell network, Anytown residents can now use their devices and fully embrace the newest technologies.

What about the future?

Anytown now has a modern network with plenty of capacity. This will put them in a great position to embrace new and emerging technologies that improve lives and make the community safer. Because the small cells are fed by fiber-optic cable, they often can easily be upgraded by swapping out equipment on either end. Anytown now knows it’s ready for the future—and the next time you hear about small cells, you’ll know what it means for you.

Learn more about the benefits small cells will bring to 5G.

Crown Castle works closely with communities to make sure local ordinances are followed. With thousands of small cells already deployed around the country, you may have walked by them before and never even noticed. Here are few examples of what a small cell in your community could look like: