We see them all the time. Maps branded in carrier colors showcasing just how extensive their coverage, call quality, and reliability are. But would it surprise you to find out that those maps, by the very nature of cellular service, are not precise and don't reflect a user's individual experience?
If you’re like most people, probably not. Whether it’s friends getting great service when you’re in a dead zone or great service in one room and a dead zone in another; the truth is coverage is personal to you, and no nation-wide map can accurately tell you whether or not one carrier will give you better coverage over another.
Cell phones communicate via radio waves, connecting calls using a system of stations (cell towers) to relay calls between carrier networks. These collections of towers are ultimately what carriers base their network coverage on (and the maps they use to claim better coverage).
The only problem here is that your coverage and overall wireless experience are dependent on how you interact with those carrier towers. We’ll get into the factors that influence this (and your data speed, dead zones, and call reliability), shortly… but first, let’s go over exactly what cell phone signal strength entails.
Cell Phone Signal Strength and Decibels (dB)
When you look at your phone and see the service bars, did you know that the signal strength those bars represent vary from carrier to carrier? In other words, the signal strength represented by 5 bars on a Verizon phone isn’t the same as 5 bars on an AT&T phone. We know, confusing stuff.
So why are we telling you this? Cell phone signal strength is measured in decibels, where -50 dB represents a great signal (full bars), and -110 dB is virtually no signal (dead zone). As we explain what affects your network quality, we’ll occasionally reference decibels to show just how much each factor contributes to your unique experience.
So, What Kills my Cell Phone Reception?
Proximity to Cell Phone Towers
Contrary to popular belief, being too far away from a cell phone tower is just one part of the equation. You can also be too high above or below one or be located opposite where the signal is being transmitted.
Diving deeper, depending on the carrier, the cell phone tower range can vary based on the bandwidth and transmission power of both the tower and your phone itself. For example, 5G service uses three distinct bands (frequencies): Low, Medium, and High. Based on the band available in your area, the service you experience can vary wildly—which is why someone else on a different network may experience better or worse coverage in the same place.
With things gradually returning to normal in the wake of COVID-19, you may find yourself in a crowded area like a stadium, airport, store, etc., only to notice that your service has unexpectedly dropped. Why? Well, network congestion may be the culprit.
Similar to the proximity of cell towers we mentioned earlier, how many people using that specific tower also plays a role in influencing your signal strength. Think of your internet router at home; the more people you have using that router, the more your Wi-Fi signal will slow down. With this in mind, the time of day—especially for people living in crowded areas—can mean more (or less) people relying on a specific cell tower for signal. Take the spike in power outages this past winter, for example:
When unusually cold storms hit southern states causing major wireless connectivity issues. Because of the consistent power outages, residents without power couldn't access Wi-Fi and have begun to rely on their mobile hotspots… putting significant strain on their local cell phone towers.
There is a limited amount of data in the air. Data is transmitted from towers to your device via electromagnetic spectrum waves. These waves operate at different frequencies: low-frequency waves travel far but are weak at penetrating surfaces. In contrast, higher frequency waves are good at penetrating surfaces but unable to travel long distances.
As we mentioned earlier, cellular network traffic is carried via radio waves, so weather conditions can play a part in disrupting the cell signal you experience. Moreover, some weather conditions may impact your experience more than others:
- Rain: Rainstorms are likely to have the greatest effect on cell reception because of the density of water vapor associated with them. The heavier the rain, the more likely it is to absorb energy from radio waves—negatively affecting your reception
- Lightning: Lightning causes electrical interference, again hampering the local cell service you experience.
- Snow: Snow (snowflakes/hail) are less dense than water in liquid form, so they usually have less effect on reception. Heavy snowfall, on the other hand, can refract radio waves hindering reception.
- Wind: By itself, the wind doesn’t really affect cell reception. However, it can certainly lead to damaged cell network equipment and power lines, limiting local service.
Buildings and Building Materials
Concrete, steel, and stone are three of the biggest reasons for dead zones or poor network quality. This is why basements tend to be public enemy number one when it comes to dropped calls, as the radio waves have a difficult time passing through dense building materials. Additional materials that might affect your signal strength include:
- Glass and tinted windows
As you can imagine, virtually every building includes several of these materials. However, each material “dampens” signal strength differently. How those materials are stacked/combined also influences the network quality you experience to make matters more complicated.
Here’s where those decibels we referenced come into play.
As you can see in the chart above, each material takes away decibels from your signal, so say your basement is a “barrier” of concrete, metal, plywood, and plaster, and your yard has heavy foliage…
Brick (-28) + Concrete (-20) + Metal (-50) + Plaster (-16) that’s a total decibel loss of -114 dB.
In this scenario, your basement would be a dead zone.
How Do I Find the Best Coverage for Me?
One option is to look into cell phone signal boosters… but if you don’t want to pay to boost signal, there are a few tips and tricks you can use:
- Remove objects that interfere with your cell signal
- Find your closest cell tower to see if you’re too far away
- Enable Wi-Fi calling on your phone