Network Coverage vs. Network Capacity

Picture this: You’re at your local park ready for a Friday night concert to begin. You’re looking for your friends, but you cannot locate them. So, you send them a voice message. Immediately, you receive an “unsent” message from your smartphone. You check to see if your phone has signal. It shows full signal. So then, what’s going on?

Several things are at play here:

One is that the amount of people at the concert is delaying mobile data traffic. We’ll explain this in depth later..

The other is that people have smartphones that are using a higher amount of data. Many people are watching and uploading pictures to social media. They are also sending messages with video and making video calls. Others may have more than one smartphone with them, and other devices that use data as well, such as smartwatches. In addition to that, the city itself could be using data for traffic signals, public safety, first responders, and other needs. All of this adds to the quantity of data being sent.

Lastly, the technologies at the park may not have the capacity to handle such a large volume of data usage by so many people at once.

Let’s get a closer look at what’s happening. When you send a text message, your smartphone emits radio waves to base stations, also called “cell sites.” These cell sites emit radio waves to other cell sites near the person receiving the message, then those cell sites send the message to the receiver.

When many people send messages using the same cell sites, the cell sites become congested. That congestion slows down the capacity for the cell sites to process information at high speeds, and they delay your ability to send and receive information from others.

What’s the difference between coverage and capacity?

Coverage refers to the space or area that a device has to access the network.

Capacity is the amount of traffic that a network can manage, meaning the data that a network can handle at once from all the messages or information being sent.

Let’s go back to the example of the concert at the park. There is coverage, but because there are many people using data to send information, there is traffic congestion, and therefore low network capacity. This slows down the network.

There’s a difference between a “dead zone” — one with no coverage — and a zone where there’s “low capacity.” A zone with low capacity cannot handle the amount of traffic and congestion.

Can a network increase its capacity?

There is a solution to solving low capacity. It’s called network densification. With network densification, even when there are many people at a concert, in a city, or in any given place, they are able to send and receive information without running into a congested network.

To densify the network, mobile operators use macro sites, small cells, and DAS.

“Macro sites” are cell sites that cover large spaces, anywhere from 3 to 50 square miles.

“Small cells” are cell sites that cover less space than macro sites and are smaller structures, as well. Small cells have a range anywhere from 30 to more than 1,000 feet. They are usually placed on top of traffic lights, buildings, and street light fixtures in dense urban areas.

“DAS” are Distributed Antenna Systems. These are antennas that are distributed and placed indoors or outdoors. They are typically deployed when more people are expected to be in a particular area, whether for a hospital during a time of crisis or a stadium during a sporting event.

Increasing network capacity

There are several ways to increase network capacity. These include:

• Depending on the location in rural, urban, and then densely populated city centers, increasing the number of towers, small cells, or DAS.
• Collocating equipment on existing towers. In other words, multiple operators can hang their own equipment on existing towers to increase their network’s capacity.
• Building heavy duty structures that can accommodate equipment configurations needed for network capacity, including 5G installation and beyond.

Each market has its own planning sensitivities. These can include land or building preservation, structural challenges, and radio protection, among others. With a mix of technologies, increasing network capacity is possible.