Wi-Fi Survey Types and Methods

 

Wi-Fi Surveys can be performed in one of three modes. It can be operated in Planner mode (also known as Virtual Predictive Survey), or the default Passive Survey mode and lastly an optional Active Survey mode. Each of the specific modes are used for different purposes. The two most popular software brand packages for surveying are Ekahau or AirMagnet.

PREDICTIVE VIRTUAL SURVEYS
The Planner mode involves the process of creating and adjusting a virtual environment model, utilizing a selection and placement of simulated APs. To create a virtual model of the environment, the physical objects that affect radio wave propagation are input into the application and using the tools to draw the position, size, and type of building materials. Planner mode uses built-in or custom-designed walls, floors, attenuation areas, simulated access points, and a large selection of antenna patterns. The resulting WLAN model can then simulate coverage and output heatmap examples that can be analyzed for theoretical AP placements.

PASSIVE SITE SURVEYS
In a Passive Survey mode, the wireless network card does not associate itself with any particular AP or SSID (Service Set Identifier). Instead, it simply listens to the RF data moving through the site, detecting and recording all RF signals and noises in the environment. Passive Surveys do not have to be performed as AP on a Stick method. Passive Surveys are normally performed either during the pre-planning stage or post-installation stage. During the pre-planning stage Passive Surveys help to determine design around problem areas and working with rogue AP’s. Passive Surveys in the post-installation stage help to validate performance and detect actual coverage of all broadcasting AP’s in designated areas. By default, AirMagnet Survey opens in the Passive Survey mode and can be toggled to Active if needed. Passive Surveys are able to collect both 2.4 GHz and 5.0 GHz data at the same time. Passive Surveys should be used to test multiple AP performance and to detect Rogues.

ACTIVE SITE SURVEYS
In Active Survey mode the wireless network card actively associates itself with just a single selected AP (Wireless Access Point), sending and receiving RF (Radio Frequency) packets to and from the target AP. Active Surveys are normally performed as an AP-on-a-Stick survey. Active surveys are useful for scientific research, lab tests, and finding specific metrics of AP performance, and RF propagation through various types of building materials.

However, In Active Survey mode, surveys are strongly recommended to be conducted separately for 2.4 GHz and 5.0 GHz results.
While using Active mode for AP-on-a-stick surveys, it is possible to choose Dual-band which in theory scans both 2.4GHz and 5.0 GHz bands but results from such surveys are at the mercy of the end-client network interface card and its Wi-Fi choices. The NIC on the end-user device is what decides how to connect to either 2.4 GHz or 5.0 GHz which can leave gaps in survey data collection if Dual-band is selected. The NIC can swap between 2.4 GHz and 5.0 GHz depending on signal integrity using its own internal device computations without the surveyor or user being able to control it. That is why it is better to select one bandwidth at a time for more consistent and reliable results.

Additionally with Active Surveys, inconsistencies in results can arise if the environment is not controlled.
During active association, beamforming is created between the AP and end-client NIC and can cause some skewing of results.

Active surveys should only be used to test singular AP with singular end-client performance. Results will vary if there are multiple clients connected or multiple APs involved (roaming).

Using Passive mode for AP-on-a-stick surveys can collect data for both 2.4 GHz and 5.0 GHz at the same time without gaps in data collection. Results from Passive mode AP-on-a-stick surveys can be more consistent and is far more time-saving.

AP ON A STICK SURVEYS
AP-on-a-Stick (APoaS) methods are most often performed to test a specific predetermined AP model in an environment. This can be a long and tedious task if there are several planned AP placements. AP on a Stick surveys can be performed in either Passive or Active modes but usually have different purposes. AP on a Stick Surveys are typically conducted in the pre-planning stage to test the performance of the predetermined specified AP, and helps to identify the best locations for installation and deployment of wireless access points.

During an AP-on-a-stick Survey, the test wireless access point is usually suspended approximately three meters from the floor and placed on or near the ceiling. Typical installation locations of APs should be placed no higher than four meters and near ceiling height in a spot where it is most likely to give the best wireless availability. In most instances where the ceiling or rafters are unreachable or inaccessible, the AP’s are simply secured to the top rung of a step-ladder for testing purposes.

In situations where there are very high vaulted ceilings more than four meters, AP installations should consider wall-mounting as a primary locations while the AP’s are using their default Omni antennas. The distance from AP to end client will affect connection quality and stability. If proceeding with vaulted ceiling installations, please consider using APs with diversity antennas that can be swapped. Certain types of directional or higher dBi output powered antennas can be used for focusing signals downward or in the proper direction.

The information gathered from multiple readings and surveys can assist in determining the optimal positions for each AP.

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Compartmentalized Wi-Fi Design and Me
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Extending Wi-Fi @ Home
https://phreshdigitalarts.blogspot.com/2022/04/extending-wi-fi-home.html

Extending Wi-Fi @ Home

 

[UPDATED 2022-04-08]
[originally posted 2015-11-24]

Almost everybody is already using Wi-Fi but countless amounts of people want more coverage at home. Maybe your Wi-Fi works great in your living room but not so great once you carry your device to into your kitchen or some other room and suddenly you lose the internet connection.

Many people think that by going out and buying a brand new wireless router and adding it onto their network will solve their Wi-Fi problems. In theory they want to extend the wireless coverage but in actuality, adding a router can cause major havoc to your home network. What you really want to do is add a Wireless Access Point, and NOT a Wireless Router or at least disable the routing DHCP (Dynamic Host Configuration Protocol) features on the new router.

Adding an additional router to your network will cause problems. When you sign up for your internet service your internet service provider company, (whether it be Telus, Bell, Shaw, Rogers etc.) will always provide you with a hardware router and will have one of their technicians install it on premises for you. It is important to only have ONE single router on your home network. It is completely senseless to have more than one router on your small home network. Having more than one router on your home network can potentially cause a network loop and will create internet connectivity problems. The routers will compete with one another to try and hand out IP addresses to devices detected on the network and will cause errors. Some devices won't connect because of IP address conflicts and in some cases, the device may not even get connected to the outside internet. This network loop problem will affect both wired and wireless devices on the network.

There are a couple of solutions to this. If you already went out and bought and installed a router then, the first solution is to disable a feature called "Dynamic Host Configuration Protocol" or "DHCP" or "DHCP Server" within the new router. You would access this by logging into the newly added router and changing it's configuration. Reference your Instruction Manual on how to do this. By turning off the DHCP settings in a router, you are essentially turning the layer-3 network router into a layer-2 network switch. This will alleviate any network conflicts with any existing router. If you want to know about networking, there are actually 7 layers called the Open Systems Interconnection (OSI) Model.

The second solution, if you did not already buy a wireless router, is to just go out and buy a Wireless Access Point. It can be plugged into the network and should work automatically without creating any network problems. You will still need to log into the device and change the Wireless Security Settings to your preferences. Don't leave it at the default state or you could be giving free and open internet access to any Wi-Fi device.