If you’re planning a new wireless network or trying to solve ongoing WiFi problems, you’ve probably come across two common terms:
🔹 Predictive Wi-Fi Survey
🔹 On-Site WiFi Survey
At first glance they sound very similar, but they’re designed to solve completely different problems.
Choosing the wrong type of survey can lead to unnecessary costs, poor wireless coverage or a network that fails to meet your operational requirements.
Understanding when to use a predictive survey and when an on-site survey is the first step towards building a reliable wireless network.
In this blog, we’ll explain the differences, when each survey should be used and why many businesses achieve the best results by combining both approaches.
What is a predictive WiFi survey?
A predictive WiFi survey is carried out before a wireless network is installed.
Rather than visiting the site to measure an existing network, engineers use detailed floor plans and specialist RF modelling software to simulate how wireless signals are expected to behave throughout the building.
The software considers factors such as:
🔹 Building dimensions
🔹 Wall construction
🔹 Ceiling heights
🔹 Expected device density
🔹 Building materials
🔹 Wireless standards
🔹 Access point specifications
Using this information, engineers create a proposed wireless design before any hardware is purchased or installed.
Predictive surveys are commonly used during:
🔹 New office developments
🔹 Warehouse fit-outs
🔹 Building refurbishments
🔹 New WiFi deployments
🔹 Multi-site rollouts
🔹 Major wireless upgrades
The goal is simple: design the network correctly before installation begins.
What is an on-site WiFi survey?
An on-site WiFi survey measures how a wireless network performs in the real world.
Instead of predicting coverage, engineers visit your premises and collect thousands of wireless measurements using professional survey tools such as Ekahau AI Pro and Ekahau Sidekick 2.
Typical measurements include:
🔹 Signal strength (RSSI)
🔹 Signal-to-noise ratio (SNR)
🔹 RF interference
🔹 Channel utilisation
🔹 Roaming performance
🔹 Capacity
🔹 Coverage
🔹 Access point behaviour
Because the survey measures actual wireless performance rather than predicted performance, it often uncovers issues that aren’t visible during planning.
An on-site survey is ideal for organisations experiencing:
🔹 Slow WiFi
🔹 Dead zones
🔹 Scanner disconnects
🔹 Dropped Teams calls
🔹 Poor roaming
🔹 Inconsistent wireless performance
The simplest way to understand the difference
The easiest way to remember the two survey types is this:
| Predictive WiFi Survey | On-Site WiFi Survey |
|---|---|
|
Predicts wireless performance |
Measures wireless performance |
|
Used before installation |
Used after installation |
|
Uses digital building plans |
Uses live RF measurements |
|
Helps design new networks |
Helps optimise existing networks |
|
Prevents design mistakes |
Identifies real-world problems |
One isn’t better than the other.
They’re simply designed for different stages of the wireless lifecycle.
When should you choose a predictive survey?
A predictive survey is the right choice if you’re planning a wireless network that doesn’t yet exist or is about to undergo significant changes.
Typical projects include:
🔹 New office fit-outs
🔹 New warehouse developments
🔹 Office relocations
🔹 Building extensions
🔹 Distribution centres
🔹 Manufacturing facilities
🔹 Educational campuses
Predictive modelling helps answer questions such as:
🔹 How many access points are required?
🔹 Where should they be installed?
🔹 Will coverage meet operational requirements?
🔹 Will roaming work correctly?
🔹 Can the network support future growth?
Because these questions are answered before installation, predictive surveys reduce the risk of expensive redesign work later.
When should you choose an on-site survey?
An on-site survey is usually the best option when an existing wireless network isn’t performing as expected.
For example:
🔹 Staff complain about poor WiFi.
🔹 Barcode scanners disconnect.
🔹 Microsoft Teams calls drop unexpectedly.
🔹 Dead zones appear around the building.
🔹 Roaming isn’t reliable.
🔹 Users experience inconsistent wireless speeds.
Rather than relying on assumptions, engineers collect live RF data that shows exactly how the network behaves throughout the building.
This makes on-site surveys particularly valuable for troubleshooting and optimisation.
If you’re already experiencing wireless issues, our blog Signs Your Business Needs a WiFi Survey explains the warning signs to look for.
Why warehouse projects often need both
Warehouses are among the most demanding wireless environments.
Unlike offices, warehouses contain:
🔹 Steel racking
🔹 Moving stock
🔹 High ceilings
🔹 Forklift traffic
🔹 Long aisles
🔹 Constant operational change
These factors make accurate wireless planning particularly important.
A predictive survey helps determine:
🔹 Access point locations
🔹 Expected coverage
🔹 Roaming design
🔹 Capacity planning
Once installation has been completed, an on-site survey validates that the network performs as expected under real operating conditions.
This combination provides the highest level of confidence before warehouse operations begin.
Can a predictive survey replace an on-site survey?
Not entirely.
Predictive modelling is extremely accurate, but it’s still based on assumptions.
Real buildings rarely behave exactly as expected.
Factors such as:
🔹 Building modifications
🔹 Different construction materials
🔹 Equipment placement
🔹 Stock density
🔹 RF interference
🔹 Operational activity
can all influence wireless performance after installation.
For this reason, many organisations use:
🔹 Predictive surveys before installation.
🔹 On-site surveys after installation.
This provides both accurate planning and real-world validation.
Which survey is right for your business?
The answer depends on where you are in your wireless journey.
Choose a predictive WiFi survey if you are:
🔹 Designing a new network
🔹 Refurbishing a building
🔹 Expanding a warehouse
🔹 Planning a major upgrade
Choose an on-site WiFi survey if you are:
🔹 Experiencing poor wireless performance
🔹 Investigating dead zones
🔹 Troubleshooting roaming issues
🔹 Validating a recent installation
🔹 Optimising an existing network
If you’re unsure, a professional wireless engineer can recommend the most appropriate approach based on your environment and business objectives.
Improve wireless planning with DTE
At DTE, we help businesses design, validate and optimise enterprise wireless networks across offices, warehouses, manufacturing facilities, healthcare environments and multi-site organisations.
Whether you need predictive RF modelling before installation or an on-site WiFi survey to investigate ongoing wireless issues, our engineers provide practical recommendations backed by real RF analysis and industry-leading wireless survey technology.
If you’re planning a new deployment or trying to understand why your existing wireless network isn’t performing as expected, we’re here to help.
Speak to a Specialist
Provide your details below, email [email protected] or call +44 (0) 845 658 8810.
