Knowing where somebody or something is connecting to the network can enable us to do something for them or with them. We can adjust their network experience or give them some directions for where to go. We can locate ‘lost’ devices, locate rogue access points and rogue clients, or simply gain insight into where users spend most of their time. Position information can be used for many location-based security services.
Many people say that Wi-Fi location is like an indoor GPS system. They are places where GPS signal is weak or absent and Wi-Fi might be available. Today almost every person has a Wi-Fi device, and many people even carry multiple devices. There are other location or proximity based solutions being developed, like beacons, but Wi-Fi has been around for some time now and the algorithms for positioning calculations have dramatically improved. For example, Beacons may require the client device to install additional software and accept certain conditions, but Wi-Fi Real -Time Location Tracking (RTLS) has no such requirement.
Some Wi-Fi solutions still require devices or people to wear special tags, but the integrated Aerohive RTLS solution operates simply with Wi-Fi connectivity. What’s more, the client does not even have to be connected to the Wi-Fi network for RTLS system to locate the client and to show its position on the map.
Location-aware WLAN deployment considerations
The accuracy of any location tracking system based on RSSI measurements depends in part on network deployment considerations.
- Minimal Signal Level Thresholds
For mobile devices to be tracked properly, a minimum of three access points (with four or more preferred) should be detecting and reporting the received signal strength (RSSI) of any client station or rogue device being tracked. It is preferred that this detected signal strength level be -62dBm or better.
- Access Point Placement
In a location-ready design, it is important to ensure that access points are not solely clustered in the interior and toward the center of floors. Rather, perimeter access points should complement access points located within floor interior areas. In addition, access points should be placed in each of the four corners of the floor, and at any other corners that are encountered along the floor perimeter.