If you’re dealing with weak cell signal inside your home or office—resulting in dropped calls or slow data speeds—a cellular signal booster might be the solution. But before you can install one, you need to figure out what kind of equipment will work best. This is where a site survey comes in. By conducting a site survey, you can assess how strong the signal is outside your building and determine how much space inside needs coverage. This will guide you toward the right booster for your needs.
What’s a Signal Booster?
A signal booster is made up of three main components, all connected by cable:
- An outside antenna that captures the signal from the nearest cell tower.
- An amplifier that boosts the strength of that signal.
- An inside antenna that spreads the boosted signal throughout your building.
With all three working together, your phone, tablet, or other cellular-enabled device will get a much stronger signal indoors.
Can I Do a Site Survey Myself?
Yes, you can! You don’t need any fancy equipment—just a phone or tablet with a cellular connection. The goal of the site survey is to take a few measurements of the signal strength outside and inside your building to figure out where to place the booster components.
Measuring Signal Strength in Decibels (dB)
To get accurate results from your site survey, it’s important to measure signal strength in decibels (dB) rather than relying on the number of bars on your phone. Signal bars can be inconsistent across devices and don’t give you the full picture.
- Decibels are expressed as negative numbers, like -70 dB. The closer the number is to zero, the stronger the signal. For example, -70 dB is a better signal than -90 dB.
- If you’re not sure how to measure decibels on your device, check out our Field Test Mode guide for step-by-step instructions.
Steps for Conducting a Site Survey
There are two key things to figure out during your site survey:
- Where’s the strongest signal outside? Your goal is to find a location—typically as high as possible—where the signal is strongest and most stable. This is usually on the roof, but depending on your environment, it might be somewhere else. You want to focus on finding the spot where you’ll install the outside antenna.
- How big is the area inside that needs better coverage? Measure the square footage of the area inside your home or office that needs a signal boost. This will help you choose the right size system when you're ready to install.
Measuring the Signal Outside
To start, measure the signal strength at different locations outside your building where you might install the outside antenna. While the roof is typically the best spot, it’s important to check different sides of the building to see where the signal is strongest. The goal is to find a spot with the best balance of signal strength and stability, which might not always be the highest point. Sometimes, it depends on where the nearest cell tower is located, so take measurements from different angles.
Measuring the Inside Coverage Area
Once you’ve found the best spot for the outside antenna, it’s time to evaluate the inside. You can check areas where you’re currently getting bad signal or dropped calls to confirm it’s due to weak signal strength. This will help you determine which parts of your building need the most coverage. Keep in mind that the main priority of the site survey is figuring out the outside signal strength and where the best signal is located. That’s what determines the performance of the booster system.
Interpreting Your Site Survey Results
Do You Have a Usable Signal?
The first thing to check is whether you can get a signal outside your building. If you couldn’t pick up a signal at any location outside, it means there’s not enough signal to amplify, and unfortunately, a signal booster won’t be able to help. However, if you did find a signal, you’re ready to move forward with the next steps.
How Strong is the Outside Signal?
Your outside signal strength, measured in decibels (dB), gives you a good indication of how much coverage you’ll be able to get inside. Here’s a general guide:
- -50 to -70 dB: This is a strong signal. With this strength, you can expect excellent performance from most booster systems.
- -71 to -85 dB: This is a moderate signal, and most boosters will still provide solid coverage for your space.
- -86 to -100 dB: A weak signal. You’ll likely need a higher-gain booster to ensure proper coverage.
- Below -100 dB: This is a very weak signal, and you’ll need a powerful booster system to achieve any meaningful coverage indoors.
Is the Signal Stable?
It’s not just about how strong the signal is—it’s also about how stable it is. If your signal fluctuates significantly (for example, going from -80 dB to -95 dB frequently), this instability can impact how well a signal booster performs. A stable signal leads to more consistent booster performance. If you notice fluctuations, try taking readings from different spots to find a location where the signal is more reliable.
Consider Terrain and Obstacles
The environment around your building plays a big role in how your signal behaves. If you’re in an open, flat area, your signal is likely to be more stable and consistent. However, if you’re in a hilly or wooded area, or there are large buildings around, obstacles can cause signal interference or fluctuation. In these cases, your signal may require a more powerful booster, and it might be necessary to adjust the location of the outside antenna to optimize performance.
Choosing the Right Antenna
Based on the results of your site survey, you’ll need to decide whether a directional or omni-directional antenna is best for your situation:
- Directional Antenna: If your signal is weak but stable, a directional antenna is the best option. It focuses on pulling in the signal from one direction, making it ideal for rural areas or when you know the general location of the nearest cell tower. It helps to minimize interference from other directions and maximizes the strength of a stable signal.
- Omni-Directional Antenna: If your signal is moderate to strong, or if the signal is fluctuating and coming from multiple directions (as is common in urban areas or near multiple towers), an omni-directional antenna is the better choice. It can receive signals from all directions, making it more flexible in environments where signal strength is less predictable.
Matching Signal Strength to Coverage Area
The strength of your outside signal will directly impact how much area inside your home or office the booster will cover. Here’s a rough guide based on signal strength:
- With a strong outside signal, a booster should be able to cover a large area, possibly up to 5,000 square feet.
- If you have a moderate signal, you can expect the booster to cover around 2,000 to 3,500 square feet.
- For a weak signal, coverage may be limited to smaller areas, generally under 2,000 square feet.
Ready for the Next Step?
Once you’ve completed your site survey, you’ll have a better understanding of your signal situation. If you need help determining the best signal booster for your specific needs, feel free to give us a call. Our team of experts can help you interpret your results and recommend the right system for your situation. You can reach the UberSignal team at (800) 590-3564 for personalized advice.