|
Indoor Positioning
WiFi Indoor positioning is a way to find out where things or people are located inside a building by looking at how strong the Wi-Fi signals are. It's a part of what we call Indoor Positioning Systems (IPS), which are helpful in places where GPS doesn't work well, like inside buildings.
There are many different ways of implmenting the positioning. Followings are some of the techniques and short descriptons.
- Signal Strength Measurement:
- We use how strong a Wi-Fi signal is, something called RSSI, to guess how far away a phone or computer is from a Wi-Fi router.
- Devices like phones check how strong the Wi-Fi signal is from routers close by and tell this to the system that figures out where they are.
- Trilateration:
- Just like GPS uses signals from satellites in space, Wi-Fi positioning uses signals from several routers to find out exactly where a device is inside.
- The system looks at how strong the signal is from at least three routers and uses where these signals overlap to figure out where the device is.
- Fingerprinting:
- This method involves making a map of Wi-Fi signal strengths all over a building.
- A device's Wi-Fi signal strength is matched to this map to find out where the device is.
- Dead Reckoning:
- Some systems also use motion sensors in devices, like accelerometers and gyroscopes, to get even more accurate locations.
- This works by starting with a known location and then updating this location based on how much and how fast the device has moved since then.
References
YouTube
|
|