> From unstructured observation, it seeems that new signals tend to show > up fairly quickly, but signals don't disappear from the 'observed set' > until they have not been seen 'for a while.' And that is how all my wifi > adaptors (on laptops) have worked up until now, which is why you are > offered a list of wifi devices that grows over time and if you turn off > a base station nearby it is still offered by your network access system > for a while. I do not know of any other mechanism that could use the > periodic broadcasts put out by the wifi base stations to answer user > queries. If the API were giving us only the Wifi base stations that have > currently been received that would be fine---we would get less data to > send MLS but it would be more accurate for this purpose. However, the > wifi chips have all be designed on the presumption that you want the > data in order to be able to connect to some network, not that you want > real time data about the broadcasts. So my working thesis is that we > have an issue, we should be able to do better, and I need to work on > this someday, among many other issues.
Hi Adrian, I'm currently trying to address this fantom measurements issue: the approach that seems the most reasonable to me is to filter off RSSI measurements using dead reckoning / inertial data, through the recognition of relevant changes in device position, so we can tell which APs have to be filter off because of lack of RSSI updating. Adding them again if updated. In this way, we no longer have to deal with delayed dated measurements. If there are any insights you may want to share please let my know. Joaquin _______________________________________________ dev-geolocation mailing list [email protected] https://lists.mozilla.org/listinfo/dev-geolocation
