What is a Strong Cell Phone Signal?

Nicholas Jones | July 12, 2018

In this space we talk a lot about weak cell signal. So today I decided to discuss what constitutes a strong signal, the kind we all want wherever we go.

First let’s talk about how we measure the strength of cellular signals – whether inside a home or workspace, in a vehicle or outside in the open.

Most smartphone owners rely on the signal bars graphic displayed by your phone as the measure of signal strength both inside and outside. If a call is dropped or a video begins buffering, how many bars we have is typically the first thing we check.

In reality, however, those bars have little to do with the actual strength of the cell signal your phone is receiving. The number of bars shown on the display varies with the cell carrier, phone manufacturer, or even the way you hold your phone.

You can read a post about it here. What do the Bars on your Phone Mean?

The bottom line is that there is no standard for what these bars mean or what they actually measure, including data or voice performance or signal strength across 3G, 4G, or (soon) 5G networks.


How do we know how strong a cell signal actually is?


So what should you look at to evaluate the signal strength in your home or workspace? It may sound simple, but the only evidence of signal strength that really matters is audio call clarity and the number of dropped calls.

And when we’re talking about data, minimal buffering and faster download speeds indicate you’re getting a strong cell signal.

If you’re not getting these things in your home or where you work, you need to find what your actual level of signal strength is. There are a few reliable methods for accurately testing received signal strength, including the options available to find iPhone field test mode and Android field test mode.

Of course you have the option of working with a professional who can perform a comprehensive site survey using a professional-grade signal meter. These signal meters detect and display cell signal frequency, bandwidth, and strength with very high accuracy.

Which takes us back to our original question….

What exactly is a strong cell phone signal?

Cell phone signal strength is measured in decibels, abbreviated as dBm. Cell signal strength readings can range from approximately -30 dBm at the strongest to -120 dBm at the weakest. The numbers typically have the “minus,” or negative number sign (-) in front of them.

The closer the number is to 0, the stronger the cell signal it indicates. In general, anything better than -85 decibels is considered a fully usable level of cell signal.

If the signal strength in your home or workspace is not hitting this benchmark, it definitely needs some help. Fortunately there are various types of cell amplifiers on the market that can boost the signal.

A cell phone signal booster is one such device. It captures and amplifies the existing cellular signal outside the building, then redistributes it inside so your phone can connect. This solution is flexible and cost-effective for homes, small businesses and even large buildings and commercial spaces.

These signal boosters can improve signal to a level of -70 dBm or stronger, depending on how strong the existing unboosted signal is to begin with.

A microcell or femtocell is another type of device that works with a broadband Internet connection to create a localized cell signal inside a home or office. Your phone connects with the signal just like it’s coming from a cell tower. In the right circumstances they are very effective.

Each of these systems has its respective pros and cons, so it’s important to understand how any system works before you make an investment in getting stronger cell signal and better coverage.

If you’re interested, here’s a video comparing these two cellular amplifier systems. What is a femtocell?


Want to learn more about cell phone boosters? Click below!