About SubPos.org
SubPos is an open source indoor positioning system that can be used in various environments such as metro lines, shopping malls, car parks, art galleries or conference centers, essentially anywhere GPS doesn't penetrate. SubPos is a complete positioning system that doesn't require expensive licencing, specialised hardware or laborious area profiling and isn't reliant on data connectivity (connection to database/cellphone coverage).
SubPos defines an accurate method for subterraneous positioning in different environments by exploiting all the capabilities of Wi-Fi. SubPos Nodes or existing Wi-Fi access points are used to transmit encoded information in a standard Wi-Fi beacon frame which is then used for position calculation by a device of your choice (as long as it contains a Wi-Fi receiver).