Estimation of speed and direction of travel in a WLAN positioning system
A method for estimating the speed and bearing of a Wi-Fi enabled device using WLAN radio signals in a WLAN based location service is provided. A method used to estimate a speed of travel of a Wi-Fi enabled device comprises the Wi-Fi enabled device receiving signals transmitted by Wi-Fi access points in range of the Wi-Fi enabled device, and using the signals to estimate the speed of and/or direction of travel of the Wi-Fi enabled device.
1. A method of estimating a speed of travel of a Wi-Fi enabled device without requiring position estimates of the Wi-Fi enabled device, the method comprising:
the Wi-Fi enabled device receiving signals transmitted by at least one Wi-Fi access point in range of the Wi-Fi enabled device, the receiving occurring over time;
measuring at least one amount of time during which the Wi-Fi enabled device detects signals transmitted by the at least one Wi-Fi access point;
determining at least one interval of time based on the at least one amount of time during which the Wi-Fi enabled device detects signals transmitted by the at least one Wi-Fi access point; and
estimating the speed of travel of the Wi-Fi enabled device based on the at least one interval of time, so that the speed of travel of the Wi-Fi enabled device can be estimated without requiring position estimates of the Wi-Fi enabled device.
2. The method of claim 1 , wherein the length of time is determined over a given duration of time, or it is calculated during a limited window of time.
3. A system for estimating a speed of travel of a Wi-Fi enabled device without requiring position estimates of the Wi-Fi enabled device, the system comprising:
a computer readable medium including instructions that when executed cause a computer system to:
measure at least one amount of time during which the Wi-Fi enabled device detects signals transmitted by at least one Wi-Fi access point in range of the Wi-Fi enabled device;
determine at least one interval of time based on the at least one amount of time during which the Wi-Fi enabled device detects signals transmitted by the at least one Wi-Fi access point; and
estimate the speed of travel of the Wi-Fi enabled device based on the at least one interval of time, so that the speed of travel of the Wi-Fi enabled device can be estimated without requiring position estimates of the Wi-Fi enabled device.
4. The system of claim 3 , wherein the length of time is determined over a given duration of time, or it is calculated during a limited window of time.