Pre-Deployment vs Post-Installation RF Site Surveys: What’s the Difference?

Category: RF Site Surveys  |  7 min read  |  By Baiden Group

An RF site survey is one of the most important steps in any enterprise Wi-Fi project, yet one of the most frequently skipped. One of the most common questions we get from enterprise IT managers and facilities teams is: “Do we need an RF site survey before we install Wi-Fi, after, or both?”

The short answer: ideally both, and for good reason. A pre-deployment RF site survey and a post-installation RF site survey serve entirely different purposes, and understanding the distinction can save your organization significant time, money, and frustration down the road.

What Is a Pre-Deployment RF Site Survey?

A pre-deployment RF site survey (also called a predictive survey or design survey) takes place before any access points are physically installed. Its purpose is to design the wireless network, determining where APs should go, what channels they should use, what transmit power settings are appropriate, and how many APs are needed to achieve the required coverage and performance.

Types of Pre-Deployment Surveys

1. Passive Survey (Manual Walkthrough)
A Wi-Fi engineer physically walks the space with survey software (such as Ekahau or AirMagnet) to measure existing RF conditions, identify interference sources, and map out the physical environment.

2. Predictive (Virtual) Survey
Using a detailed floor plan and RF propagation modelling software, the engineer simulates signal coverage based on building materials, wall types, ceiling heights, and AP placement options. Cost-effective for new construction or spaces where a physical walkthrough is difficult.

3. Active Pre-Deployment Survey
A temporary AP is placed at candidate locations to take live measurements, particularly useful for environments with unusual materials such as concrete vaults, shielded rooms, or industrial facilities with heavy machinery.

What a Pre-Deployment Survey Delivers

• AP placement map: where each access point should be mounted
• Channel plan: which channels each AP should use to minimize co-channel interference
• Power settings: recommended transmit power per AP
• Equipment recommendations: AP models suited to the environment
• Coverage prediction: modelled RSSI and SNR heat maps
• Bill of materials: number and type of APs required

What Is a Post-Installation RF Site Survey?

A post-installation RF site survey (also called a validation survey) takes place after the access points have been physically installed and configured. Its purpose is to verify that the real-world deployment matches the design intent.

What a Post-Installation Survey Measures

• Actual RSSI coverage: does the signal reach where it needs to go at the required strength?
• SNR (Signal-to-Noise Ratio): is the signal clean enough for the intended applications?
• Channel overlap and co-channel interference: are APs interfering with each other?
• Roaming behaviour: are clients transitioning between APs smoothly?
• Data rate distribution: are clients connecting at appropriate speeds?
• Application-specific validation: for VoIP, video, or IoT, are thresholds met?

Key Differences at a Glance

Why Every Enterprise Needs Both RF Site Surveys

The Pre-Deployment Survey Prevents Costly Mistakes

Installing Wi-Fi without a pre-deployment survey is one of the most common, and expensive, mistakes enterprises make. Without it, AP placement is often based on guesswork, resulting in:

• Coverage gaps in areas where users need connectivity
• Over-provisioning: too many APs, leading to co-channel interference
• Under-provisioning: too few APs, resulting in overloaded radios
• Poor roaming: APs placed too far apart for clients to transition cleanly
• Interference from building materials: concrete, glass, and metal shelving attenuate signals in ways impossible to predict without measurement

The Post-Installation Survey Confirms You Got It Right

Even with a perfect pre-deployment design, real-world conditions can differ. Walls may have been modified, construction may have introduced new materials, and furniture placement affects RF propagation. A post-installation survey closes the loop, it gives you documented, objective evidence that your network performs as designed.

For regulated industries like healthcare, it also provides the compliance documentation required by standards like the Joint Commission or HIMSS.

When Is Each Survey Appropriate?

You Need a Pre-Deployment Survey If:

• You’re deploying Wi-Fi in a new facility or space
• You’re upgrading from Wi-Fi 5 to Wi-Fi 6
• You have specific application requirements (VoIP, real-time video, clinical devices, IoT)
• You want to avoid the cost of re-cabling or re-mounting APs after the fact

You Need a Post-Installation Survey If:

• Wi-Fi has just been installed and you want to verify performance
• Users are reporting connectivity issues in specific areas
• You need compliance documentation for your industry
• It’s been 2–3 years since the last survey and the environment has changed

What to Expect From a Professional RF Site Survey

At Baiden Group, our RF site surveys use Ekahau: the industry-leading Wi-Fi survey platform trusted by enterprises worldwide, paired with the Ekahau Sidekick for accurate hardware-based spectrum analysis. Ekahau is recognized by the Wi-Fi Alliance as the standard tool for professional RF site survey work. Our process:

1. Discovery call: understanding your environment, applications, and performance requirements
2. Floor plan preparation: obtaining accurate, to-scale floor plans and annotating wall materials
3. On-site survey: physical walkthrough with Ekahau and Sidekick hardware
4. Data analysis: processing heat maps, identifying gaps, reviewing interference sources
5. Report delivery: a detailed, professionally formatted report with findings and recommendations
6. Follow-up: a walkthrough of the report with your IT team to answer questions

Baiden Group provides professional RF site surveys for enterprise facilities across Toronto, the GTA, and across Canada and the USA. Request a free consultation to get started.