Using WiFi in work environments is an indispensable tool, but it can also cause some headaches. This is because it is very difficult to predict the propagation of its waves and there are many interferences that can affect the quality of the signal and are not easy to detect.
In a context in which more and more companies have open space offices, and in which the use of mobile devices becomes more common, the installation of a robust wireless network becomes a fundamental requirement.
What is a Site Survey and what is it for?
A Site Survey is a thorough evaluation of wireless networks and their relationship to the physical space of a company. This evaluation allows us to understand in detail how WiFi waves behave and propagate.
The goal of a Site Survey is to provide accurate information to determine how many access points are needed and where they should be located to provide effective and balanced coverage throughout the physical office space.
In turn, a Site Survey detects the presence of interference from different sources – such as microwaves or cordless phones – and that can degrade the performance of the wireless network.
Radio frequency signals are unpredictable. If an access point is placed in a space that includes obstacles of different sizes, shapes and materials, then the RF signals are interrupted and coverage is reduced.
In this sense, without a Site Survey it is impossible to determine with certainty the investment that is needed to implement the efficient wireless network that meets the requirements of use of the company.
As a quick fix, some network administrators install many additional WiFi access points to increase the capacity and range of the wireless network. However, this does not solve the root of the problem. In fact, the presence of too many WiFi access points can increase the interference of channels shared with other existing access points.
Benefits of a Site Survey
Site Surveys include several clear benefits for businesses looking to install a WiFi network. The main ones are:
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Site Surveys allow you to determine the coverage of a Wi-fi signal and its bandwidth, and identify sources of interference, dead spots, and the potential for roaming.
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Performing a Site Survey helps determine which equipment to purchase, how many access points to purchase, where they would need to be installed, and how to configure each to achieve optimal coverage.
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Taking into account that a Site Survey can identify the areas of greatest interference and dead zones, this evaluation helps to build more efficient wireless networks and avoid performance problems for users.
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A Site Survey also helps discover other interference caused by devices such as appliances or cordless phones.
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Finally, a Site Survey helps to define if the installed equipment corresponds to the requirements of the space, and if the number of users and the access policies are the most appropriate for the areas highlighted in the operation plan.
Another aspect to consider: WiFi frequencies
To fully understand why it is important to assess the quality and behavior of wireless networks, we must first know that there are different frequencies of WiFi signals.
In recent years, the use of wireless networks in companies and private homes has grown in importance and in quantity. Among other things, this causes the frequencies to be bombarded by different signals generating interference and a degradation of service.
When we talk about Wi-fi, we normally find two types of frequencies: 2.4 Ghz and 5 Ghz. Let’s see the graphs of its waves:
Each dotted line represents a different Wi-Fi network. In this graph we see that the 2.4 GHz frequency is completely saturated. If to this, we also add the signals from wireless phones and microwaves (which do not appear in this image), we can say that the interference in 2.4 Ghz networks is many.
However, when we see 5 GHz networks, performance is usually efficient, since it has a greater number of channels due to the fact that the propagation wave is different:
Although currently the use of 5 Ghz networks is growing rapidly, the versatility of this network allows us to better position ourselves and achieve a higher quality service (not to mention that higher transmission speeds are achieved on this frequency).
Everything you have to take into account when installing a wireless network
Before installing a Wi-fi network in a work environment, there are several questions that we must answer. Namely:
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What is the best position to place the Access Points?
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How many Access Points do I need to cover the entire surface of the office?
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How should you configure the access points for the best performance?
To answer all these questions we need to do a Site Survey!
How to perform a Site Survey correctly
A Site Survey basically consists of the combination of hardware and software to obtain the information that helps us answer the questions previously posed.
The first step is to perform is the data load, which should include:
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Project information
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A detailed plan of physical space
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The details of the possible obstacles: walls, doors, furniture, and the material from which they are made.
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An access point in Survey mode to perform an analysis of how obstacles affect the performance of the wireless network
Here is an example of a Site Survey that we carry out for one of our clients. First of all, we obtained all the detailed information of the physical space of your office.
Then, we went through the site from end to end to obtain information about the different incoming signals through software.
These data allowed us to understand which signals could interfere from the outside, where each one was located, what intensity it had and which channel it was on.
The objective of this client was to achieve the best possible wireless coverage, since they needed to have IP telephony over Wi-Fi, and that their employees could make regular video calls without any problems.
Returning to the questions we asked ourselves previously, the Site Survey allowed us to obtain the necessary information to answer them:
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What is the best position to place the access points?
In this case, the best position was the center of each office block.
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How many access points do I need to cover the entire surface of the office?
For this customer, it was best to install three access points, one for each block.
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How should you configure the access points for the best performance?
In this example, the equipment used made it possible to automatically census which were the least congested channels for each frequency. For the 2.4 Ghz frequency, the best options were channels 1.6 and 11 with a channel width of 20 Mhz.
While for the 5 Ghz frequency, the best options were channels 36, 100 and 157 with a channel width of 80 Mhz.
Once the Site Survey was completed and the appropriate installations were carried out, this is how the heat map of the wireless networks of this project was formed.
We do this work for one of our SME clients . Your company can also use this tool to achieve maximum performance in the configuration of your Wi-Fi networks.