Indoor Positioning, Tracking and Indoor Navigation with Wi-Fi
Indoor positioning and indoor navigation based on Wi-Fi are used in many projects. The reason: A wide range of different types of existing Wi-Fi hotspots can be used for this. In addition, positioning already functions when users have enabled Wi-Fi on their smartphones, no login is required. However, there are some disadvantages to indoor positioning with Wi-Fi: Accuracy is 5-15 meters - less than with Bluetooth Low Energy. Furthermore, iOS devices are excluded from client-based positioning.
How Does Indoor Positioning with Wi-Fi Work?
Each Wi-Fi access point, whether customer hotspot, router or Internet-capable point of sale system, transmits specific data. Using a RSSI (Received Signal Strength Indication) and MAC address (Media Access Control), an app can calculate the current location of the end user device (client-based positioning). This requires a database with information about the locations with which this data can be compared. This method is called fingerprinting. It only functions with Android devices due to technical restrictions. iOS devices cannot be used for Wi-Fi indoor navigation.
Conversely, the data from all Wi-Fi-capable devices (independent of the manufacturer) or Wi-Fi tags can be gathered and sent to the infsoft LocAware platform® by infsoft Locator Nodes for server-based positioning (e.g. for asset tracking or route analysis).
Depending on whether the device is connected to a Wi-Fi network or not, localization is affected by various restrictions. If the Wi-Fi client is not connected, latency times of up to 5 minutes result from the irregular sending of "probe request" (scanning for available access points), which is controlled by the mobile operating system and cannot be influenced. In addition, due to randomly generated, changing MAC addresses ("MAC randomization"), the smart device or the actual number of devices in an area cannot always be determined unambiguously. If the smartphone is connected to a Wi-Fi network, latency times are significantly lower as long as traffic is generated over the network. In addition, there is no MAC randomization, which means that the device can be uniquely assigned. The position accuracy is not affected by the connection to an access point.
The accuracy of Wi-Fi for indoor positioning is typically 5-15 meters because access points are usually used whose position has been optimized for data communication. This precision depends on the shielding through walls, ceilings and people, as well as the number of access points. The use of smartphone sensors can improve the results and the determination of the floor level is also possible.
Use Cases for Indoor Positioning with Wi-Fi
Wi-Fi is used as a location technology in many places. Here are some examples:
At sporting and major events, routes, duration of stay and frequency of visits can be recorded and analyzed. The data provide important key figures to optimize processes, create planning security and enhance the event experience for the visitor.
Software solution used: Indoor Tracking, Indoor Analytics
Sensors used: Wi-Fi
Example of use: Analyzing Visitor Flows at a Major Sports Event
The position of animals, goods, pallets, machines or vehicles can be tracked using an attached Wi-Fi tag.
Software solution used: Indoor Tracking
Sensors used: Wi-Fi