Types of Wireless Site Survey

What is Wireless Site Survey ? 

A wireless site survey is the physical inspection of a site where a wireless radio frequency (RF) network will be installed. The survey assesses the environment to determine wireless coverage, data rates, network capacity, roaming capability, and quality of service. The goal is to visualize the wireless coverage areas (generally through heatmaps), so you can know where your signal will be strongest and weakest. Also known as: WLAN site survey, wireless network survey, RF site survey, or networking site survey.
Internet access is essential in every business. You must do everything you can to have faster speeds, reasonable data rates, and no issues with infrastructure inhibiting your signal. For that, we need to ensure a reliable wireless connection for our business. In other words, a survey is conducted to ensure that your business gets the most from your wireless network and saves you money (and frustration) in the long run.
The goal of all of wireless site surveys is to provide detailed information that addresses the site’s radio frequency coverage. Before implementing or attempting to optimize a wireless network, you’ll want to understand all the possible areas of interference, AP placements, power considerations, and wiring requirements that are needed. A wireless site survey can provide all of this information and more, so you have the tools you need to design, implement, and optimize your wireless network.

SITE SURVEY TYPE

Each type of site survey has its own benefits. We need to choose the one that best addresses our network needs as well as our building type and business operations. This will also help us avoid overspending on an expensive survey that you didn’t really need. If you’re still unsure, an eNeoteric expert can help you determine which is better for you. Please contact on info@encse.com / +91-9108015170. Will assist you in identifying your need.
Predictive site surveys

A predictive site survey uses a advance software package to model your rnvironment and simulate the wireless site survey and create different types of Wi-Fi heat maps. This is done offline without any onsite visit.

Passive site surveys

This survey captures data throughout your entire facility where Wi-Fi is a requirement.

Active Site Surveys

On Site Site Survey using AP-on stick

Predictive site surveys

Goal

The goal of a predictive site survey is to determine where to place APs for the best performance throughout the area.
It establishes what is required to deploy a high performing WLAN system.
You will know how many AP’s are required and the location for placement for each.
The predictive survey must be undertaken by professional wireless designers with sound knowledge of RF.

Onsite Visit - Not Required 

Predictive site surveys do not include any information from physical visits and it does not require an onsite visit.

Cost and Timing

This is less costly than Passive / Active Site Survey which need onsite visit.

How predective site survey conducted ?

A predictive site survey uses a software package to simulate not just the construction of the building but also floor plans, offices, conference rooms, cubicles, walls, windows and even filing cabinets and other large objects. 

Our predictive survey relies on industry best practice parameters which vary as per the design and deployment standards. 

The software will then take all of these factors into account and create a prediction of the number of locations of access points and where each one should be located in order for the network to meet required coverage and performance. 

Application Consideration

The software also factors in the types of applications used in the area -- e.g., heavy video use requires high throughput, while VoIP calls don't require high throughput, but do require tight limits on latency and delay. 

Automatic / Manaual Positioning

Virtual APs can be placed automatically or manually in a survey.

1. Automatic Positioning - With automatic location positioning, the software chooses where to place APs, using the same AP model everywhere.

2. Manual Positioning - In Manual placement enables network managers to select locations and specify the proposed AP model for each location -- e.g., a more powerful model in some locations and a less powerful model in others.

Do we need Passive Survey After Predective Site Survey  ?

Predictive site survey does not provide information regarding interference and is heavily dependent on the physical site survey or the information provided by the client in case of new sites. 

Although it is optional to have and it depends on site criticality and budget, a passive site survey should also be conducted to ensure that all critical information is included in the network model.

When to perform Predictive Site Survey ?

Network teams should perform a predictive survey before moving any equipment or furniture into a new space.

FILTER

A predictive site survey is performed without any type of field measurements. It uses RF planning software tools that can predict wireless coverage of the APs. To perform this site survey, a floor-plan drawing (AutoCAD, JPEG, PDF) is a must-have. Predictive site surveys are used when the site or building is not yet built and are helpful for budgeting purposes.

A predictive site survey is performed without field measurements and relies on computer software, floor plans, and WiFi standards. An RF software simulates the building and predicts the number of APs and locations needed to meet the required coverage. 

Predictive site surveys do not require an onsite visit, so they are typically used when deploying WiFi in a new space. They are beneficial when budgeting but are only as reliable as the information provided. With this in mind, it's best to do a passive site survey once a site's built to arm the engineer or designer with as much information as possible.


PASSIVE site surveys

Goal

The goal of a passive survey is to report on all signals at each location, including the installed network and signals from neighboring sites or other devices that generate noise at wireless frequencies.

How passive site survey conducted ?

A physical walk through of the building interior and exterior as well as checking the radio frequency is critical to ensuring that all physical factors that could impact network performance are included in the survey.

Onsite Visit - Required

It consist of a physical survey of the building, both interior and exterior as well as the data collection of the radio frequency readings at the access points.

Cost and Timing

Passive site surveys are the fastest and easiest to complete. It is the most inexpensive of the three.

When to perform Predictive Site Survey ?

Periodic / Maintenance Survey

Teams should perform passive surveys periodically after they build the site, install equipment and activate the network. These surveys report information on APs and their characteristics, signal strength, signal-to-noise ratios and interference. They might reveal marginal performance changes before users notice.

Remediation / Incident Based Survey

It mostly means the WLAN is not meeting your requirements, you are having problems and it is affecting efficiencies. A gap analysis is done to determine “dead zones”. Client devices “hear” the WLAN at different levels depending on what type of hardware you are using. You will be able to see this on a provided heat map. Some client devices experience “dead zones” when some do not. All hardware is not equal. A gap analysis can show you where your issues are and can assist in the remediation of the issue. A spectrum analysis is also a part of this survey and can be tricky. Interference is not always “on”, it can appear random to the user, however when the interference is tracked down it becomes obvious it is not. Once identified, this interference can be tuned out of the WLAN with proper channel planning. If your organization is big enough, a spectrum policy might be justified and recommended.

Validation / Post Installation Survey

Like the name implies this type of survey validates that a particular WLAN implementation meets the requirements of the project. The WLAN is in place, configured and running as intended. This survey captures data throughout your entire facility where Wi-Fi is a requirement. Once the data is collected on all Wi-Fi channels, it can be analyzed and compared to your requirements to see if it “passes”. Primary signal strength, secondary signal strength (for roaming), Co-channel and adjacent channel interference, interfering networks, Rogue AP’s, misconfigurations, channel-width, channel usage and any additional Wi-Fi areas, should be checked. Anything that does not meet the requirements can be resolved. Once that is done, a second survey should be done to make sure that the WLAN now meets all requirements. This survey is the most important and critical of all surveys and should always be performed to validate what was intended initially with the design.

FILTER

A passive site survey tool listens to existing access points and other signal sources for signal strength, interference, and access point (AP) coverage. In a passive site surveys, the listening WiFi adapters does not need to associate to the AP, it just passively listen to give a picture of the Radio Frequency (RF) characteristics of wireless network site. Passive surveys are often perform when upgrading existing wireless networks such as adding additional APs.

In a passive site survey, we do a physical survey of the building to collect data. A physical walk-through of the site ensures that all factors that may impact network performance are accounted for. The surveying tool is not connected to the WiFi network during the walk-through and only listens to the WiFi environment. The survey software scans specific channels and networks to measure signal strength, signal-to-noise ratios, and interference. 

Passive site surveys are performed once a space is built, both before a network is operational and routinely after going live to monitor and assess performance.

ACTIVE site surveys

Goal

An active site survey will ensure that the upgraded network will meet all critical requirements. 

How active site survey conducted ?

Connection to the network via the access points allows the surveyor to generate network traffic; measure the network performance and some other important metrics including packet loss and the data upload and download speeds.

Active surveys focus on a specific signal or set of specific signals and produce an extensive list of measurements for each AP that generates a studied signal. These measurements include signal strength, throughput, round-trip time, packet loss and retransmission rate throughout the area where the signal is used.

Active site surveys also measure upstream and downstream data rates and might result in teams moving an AP or adding or removing an unneeded AP. Teams should perform active surveys when investigating performance problems.

Onsite Visit - Required

Active site surveys have the same steps as passive site surveys, and they also include onsite visit and connecting to the network’s access points during the survey.

Cost and Timing

Active site surveys are more expensive to conduct and most likely need to take place during business hours; a requirement which could cause some inference with the operation of the customer’s business. They do however, provide information that cannot be obtained with a passive site survey.

When to perform Active Site Survey ?

This is particularly important for retail locations and other businesses that have extensive security requirements.

FILTER

In an active site survey, the survey WiFi adapter is associated to the AP(s). This allows gathering of detailed information such as network traffic, throughput packet loss, and data rates. An active site survey is often performed in conjunction with a passive site survey at start of a new wireless network deployment.

An active site survey is similar to a passive survey, but the survey tools are connected to the network's access points. This allows for an array of information to be gathered, like network traffic, round-trip-time (RTT), throughput, and upload/download speeds. 


Active site surveys are usually used to troubleshoot WiFi networks and measure the real-world performance of your network. They are generally more expensive and need to be conducted during business hours for the most accurate reporting, but it collects information that the other two survey types can’t provide.

Our WIRELESS SITE surveys

Assuring you of our best Wireless Service
When it comes to wireless site surveys, one-size-fits-all strategies don’t work. Don’t take chances with something as important as your wireless network. AbeTech experts can help you determine the most appropriate type of site survey for your company, we will meet with your project manager(s) and or onsite contact(s) to review your current situation existing hardware and performance problems and confirm desired outcomes.


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