You walk into your office, smartphone in hand, ready to tackle the day’s tasks – but then you connect to the Wi-Fi, and everything grinds to a halt. For today’s businesses, a reliable wireless network isn’t just a convenience—it’s a necessity, and that’s why you can’t skip a 802.11 site survey.

In this guide, we’ll dive into 802.11 site surveys, exploring why they’re crucial for optimal network coverage and how they can transform your wireless experience. You’ll learn about different survey types, their pros and cons, and how to choose the right approach for your business.

What Are 802.11 Site Surveys?

An 802.11 site survey is a detailed analysis of a physical environment to determine the best placement of wireless access points (APs) for maximum network coverage and performance. It involves assessing factors such as signal strength, potential interference sources, and capacity requirements to ensure a reliable Wi-Fi network.

Tom Borkowski, founder of TPK Advanced Wireless, says that while many businesses understand the need for wireless networks, they often lack the expertise to maximize their investment. A well-executed site survey addresses this gap by:

• Determining the optimal number and placement of access points
• Assessing signal strength and coverage areas
• Evaluating network capacity requirements
• Detecting dead zones or areas with weak signal
• Identifying interference
• Analyzing potential security vulnerabilities

Types of 802.11 Site Surveys

When it comes to 802.11 site surveys, there are two primary approaches: predictive surveys and on-site surveys. Each method has its own strengths and is suited to different scenarios.

Predictive Surveys

A predictive survey involves using specialized software to create a virtual model of your wireless network.

“You take a floor plan, you upload it into some type of software – usually something like Ekahau or Hemina – and you draw in walls or attenuation areas depending on the type of area it is” Tom says.

This method allows you to:

• Quickly generate coverage maps
• Experiment with different AP placements virtually
• Estimate network performance before physical deployment
• Reduce initial time and cost investment

On-Site Surveys (AP on a Stick)

An on-site survey, often referred to as “AP on a stick,” involves physical measurements in your actual environment.

“An on-site AP on a stick survey involves taking an actual access point – typically one you would ultimately deploy,” Tom says. “Then you would collect actual data and measure the signal strength and the SNR (signal-to-noise ratio) data. You can also collect data pertaining to packet loss or latency to the AP.”

Benefits of this method include:

• Highly accurate real-world data collection
• Detection of unexpected interference sources
• Ability to account for unique environmental factors
• More precise AP placement recommendations

Comparing Predictive and On-Site Surveys

When deciding between predictive and on-site surveys, you need to understand their relative strengths and limitations. Let’s break down the key differences.

Accuracy

Predictive surveys, while useful, have limitations in their accuracy. “Predictive surveys are good, it has its place, but it’s 70-80% accurate depending on the inputs, whereas AP on a stick is 99% accurate,” Tom says.

This significant difference in accuracy can be critical for businesses where network reliability is paramount.

Cost Considerations

The choice between these methods often comes down to balancing upfront costs with long-term benefits. On-site surveys typically require more initial investment in time and resources.

However, as Tom points out, “If you’re a business that requires Wi-Fi and you don’t want to go back and continuously optimize it, AP on a stick is a higher upfront cost but will save you in the long run.”

Time and Labor Intensity

Predictive surveys can be completed relatively quickly using software tools. On-site surveys, being more hands-on, require more time and labor. They involve physically moving access points to different locations and taking multiple measurements throughout the space.

Ability to Detect Unforeseen Obstacles

One key advantage of on-site surveys is their ability to account for real-world factors that might not be apparent in a floor plan.

“I’ve seen cases where somebody in the office had a shelves filled with bottles of wine hanging on the wall – anything that’s liquid will cut the signal,” Tom says. “That’s the thing with predictive surveys: you don’t always know what is on the wall or even what’s in between the walls.  Another time I performed an AP on a stick survey at a facility that had once been used to be a dentist’s office.  The walls were led lined, which required an AP in every room.  A predictive survey would have missed this.”

Conducting a Predictive Survey

Predictive surveys offer a cost-effective way to plan your wireless network before any physical deployment. While not as accurate as on-site surveys, they provide valuable insights into potential coverage and performance.  They are also a good option if the facility has not yet been completed or is too difficult to get to.

Here’s an overview of the predictive survey process:

1. Gather and upload floor plans: Obtain accurate blueprints or CAD drawings of your space.
2. Map attenuation areas: Identify walls, doors, windows, and other obstacles that may affect signal propagation.
3. Select and place virtual access points: Choose appropriate AP models and position them on the digital floor plan.
4. Configure AP settings: Set channels, antenna types, height, and angle for each virtual AP.
5. Analyze coverage predictions: Review heat maps and adjust AP placement as needed.

Performing an On-Site AP on a Stick Survey

On-site surveys provide the most accurate picture of your wireless environment, offering real-world data collection for optimal network design. While more time-intensive than predictive surveys, they provide highly precise results for critical Wi-Fi deployments.

Here’s an overview of the on-site survey process:

1. Pre-configure test access points: Set up APs with settings similar to the final deployment, including channel selection, transmit power, and encryption. 
2. Consider use cases: The design should be in-line with the network requirements.  Consider the device types that need to be supported, the applications that will be used, and what future use cases might need to be supported, such as voice/video/ real-time location services, and 6GHz.
3. Conduct data collection: Move through the space methodically, collecting signal strength, SNR data, packet loss, and latency information at predetermined intervals.
4. Assess neighboring networks: Gather data on surrounding wireless networks and potential sources of interference across all frequency bands you intend to leverage.
5. Create heat maps: Use specialized software to generate visual representations of coverage based on collected data.
6. Iterate and optimize: Adjust AP placement and settings based on initial results, then repeat the survey process to fine-tune the network design.

Factors Affecting Wi-Fi Signal Propagation

Knowing the factors that influence Wi-Fi signal propagation is necessary for conducting effective site surveys. Various elements in your environment can impact wireless performance:

• Building materials (concrete, metal, glass)
• Office layout and furniture
• Electronic devices and appliances
• People and movement within the space
• Outdoor factors (for external-facing APs)

Post-Survey Optimization

Once you’ve interpreted your survey results, it’s time to optimize your wireless network design. This process involves:

• Fine-tuning AP placement based on survey findings
• Adjusting channel allocation to minimize interference
• Optimizing transmit power settings for better coverage and roaming
• Addressing identified sources of interference
• Considering capacity needs in high-density areas

Remember, network optimization is an ongoing process. Regular surveys and adjustments ensure your wireless network continues to meet evolving needs.

When to Conduct a New Site Survey

Wireless environments are dynamic, and regular surveys help maintain optimal performance. Consider conducting a new survey when:

• Major renovations or changes in office layout occur
• There’s a significant increase in network usage or user density
• You’re implementing new wireless technologies (e.g., Wi-Fi 6e or 7)
• Performance issues persist despite troubleshooting efforts
• It’s been more than 12-18 months since your last survey

Regular assessments ensure your wireless network continues to meet your organization’s evolving needs.

Ready to Optimize Your Wireless Network?

Don’t let subpar Wi-Fi hold your business back. TPK Advanced Wireless has nearly two decades of experience ensuring seamless wireless functionality across industries. Our expert team can conduct comprehensive 802.11 site surveys tailored to your specific needs, whether you’re a Fortune 100 enterprise or a small local business.

Take the first step towards a robust, high-performance wireless network. Contact TPK Advanced Wireless today to schedule your 802.11 site survey and experience the difference that expert wireless optimization can make for your business.