WiFi location tracking is fairly straightforward as far as RTLS goes: A WiFi-based tag sends a beacon message that is received by multiple access points. These access points are time synchronized, so they can time-stamp the message when they receive it. The time stamps are then sent to the location server and the software translates the time stamp and access point data into a location.
WiFi is commonly used in real-time location system (RTLS) integrations, like Ekahau and AiRISTA. If you need to track capital equipment in a healthcare setting, or materials in a manufacturing plant, WiFi could be a great solution. But there are a number of considerations—like tag cost and infrastructure requirements—you’ll want to weigh before pulling the trigger. Below are five factors that can help determine whether WiFi is the right fit, or if you should look at an alternative RTLS technology.
WiFi tracking tags are typically more expensive than other RTLS tags, like active RFID and infrared, simply because WiFi is a more complex technology. Many WiFi tags range from $40-$60 per tag, but could go as high as $90 a tag. They are also typically larger in size and far less power-efficient than their alternatives. Therefore, if you require small WiFi tracking tags—or need to track low-cost assets that don’t merit a high price tag–an alternative solution might be more appropriate.
If you want to deploy a WiFi positioning system, you have to be certain your WiFi infrastructure is dense enough to support it. If it isn’t, you’ll need to upgrade your current WiFi infrastructure, which can be a headache (particularly if your current WiFi system is serving you well otherwise). If upgrading your infrastructure isn’t an option, consider a solution like AirFinder, which has low infrastructure requirements for installment.
3. Location Accuracy
A WiFi location tracking system should give you a level of accuracy ranging from three to five meters. To do this, it uses time difference of arrival (TDOA) measurements with wide bandwidth. Keep in mind that to achieve this kind of accuracy, you need at least three access points to “hear” each tag transmission—which goes back to the discussion of infrastructure. Are you able to install as many access points as are required to keep this level of location accuracy?
Your IT team may express some security concerns about having unmanaged WiFi end nodes on their network. However, security isn’t a real concern with WiFi location tracking, as the majority of tags send a beacon message that isn’t associated with a specific network.
Keep in mind, however, that if you want to integrate other sensors into your WiFi RTLS system—like environmental sensors—those will connect directly to your network. This can lead to some more legitimate security and application concerns.
WiFi is generally ideal for indoor tracking due to its short range. You could technically track outdoors using WiFi, but alternate technologies that support multi-mode tracking through a combination of active RFID, LTE-M, and GPS are often better suited for indoor and outdoor location tracking.
To summarize, if you have newly-installed, fairly dense WiFi coverage that supports RTLS—and you plan to track capital assets that make the cost of the tags worth it—then WiFI location tracking could be a great solution for you. If it seems like an alternative solution may be better suited for your location tracking needs, we invite you to get in touch with us to discuss how AirFinder may be able to help.