There is a lot on this subject in Google Scholar... like http://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=5693&context=masters_theses http://discovery.ucl.ac.uk/1470731/11/Thesis_JieXiong2015.pdf https://web.wpi.edu/Images/CMS/PPL/WPI_Pahlavan.pdf WPI seems to have a lot of PhD theses on this topic...
you can further reduce your error bars by superimposing a map of some variety like they did with https://slowchop.com/2008/08/17/wireless-heatmap/ I will give this a try with my WiFi radios which have a S/N ratio close to 1. :( That's why I prefer BTScan if available... Power use at gateways is not really an issue for us, so it is worth a try, especially if it improves performance or feature set. On Fri, Mar 17, 2017 at 9:37 PM, Stephen Ronan <sro...@gmail.com> wrote: > The Dutch telecom provider KPN completed a nationwide LoRaWAN network > early last summer. They're now rolling about geolocation services. > According to a user on the ThingsNetwork forums: > -------------- > you can't get a LoRa KPN abo from KPN themselves, the provider > SIMpoint is delivering this for them. I got the following info from > SIMpoint: > LoRa with Geolocation: (costs per year) > Bundels Uplinks Downlinks Price > Often 36500 3650 € 15,30 > Mostly 109500 900 € 17,75 > I will probably need the 'often option', I have 36500 uplinks a year > with this option, that is 100 a day so more than needed. > https://www.thethingsnetwork.org/forum/t/looking-for-a-lorawan-board-only-geolocation/4419/9 > > ======================== > > And, at least according to their public pronouncements thus far, the > ThingsNetwork via their first generation, soon-to-be-released > kickstarter gateways won't support geolocation based on high > resolution timestamping done at the gateways of messages from nodes. > > However, as of this exchange on their forum last September: > > Johan: "Also, we're going to support localization using WiFi BSSIDs, > also known as the MAC addresses of the access points nearby, directly > in the Handler for a seamless application developer experience. The > idea is that your devices briefly scan WiFi access points using cheap > WiFi chips (e.g. $5 ESP8266), packs it as LoRaWAN uplink message and > sends it to a special port for the Handler to pick it up, decode it > and lookup the location. This is not as low power as LoRa > triangulation, but consumes less power than GPS and is quite accurate > in urban areas (where LoRa triangulation is really bad still). > ----- > hoonppark: Regarding the localization using WiFi BSSIDs, I have a few > questions as follows: > > What would be the accuracy? For example, it would be accurate within > 20 meters or 50 meters range ? > Does it need just one WiFi BSSIDs, or at least three WiFi BSSIDs to work? > What happens if there is no WiFi access point near by? > Does the Handler calculate the location of the node? Or, does each > application need to calculate the location of the nodes? > According to the roadmap, it will be available in Q4 of 2016. Will it > be available by Dec. 31, 2016? > You mentioned "LoRa triangulation is really bad still". Do you mean it > is still bad even with the Semtech’s LoRa Geolocation Solution > announced on June 30, 20161? > Do you think this WiFi BSSID-based localization is better or > comparable to the publicly announced 'CSEM's LoRa-based GPS-free > Positioning Solution2'? > > ----------- > johanLeaderSep '16 > @hoonppark; here are the answers: > > That depends on various factors, see here > <https://en.wikipedia.org/wiki/Wi-Fi_positioning_system>. From our > testing so far using Google Localization API, we're close to 10-20 > meters in the center of Amsterdam > More BSSIDs makes it more accurate, but costs payload. That's the > trade-off application developers need to make > Then you need to fallback on another way of localization. We are > sending the gateway's coordinates in the metadata > The Handler does that for you. Note that depending on the database > we're going to use, we may need an API key of even a subscription for > this > Yes > Yes > It's better in the sense that it will be more accurate in cities, but > not better in terms of power consumption. They positioning is just > standard LoRa triangulation; no extra magic > =========== > > Tangentially, another user posted a link to: EspWiFiTracker > https://revspace.nl/EspWifiTracker > - Stephen Ronan > _______________________________________________ > Hardwarehacking mailing list > Hardwarehacking@blu.org > http://lists.blu.org/mailman/listinfo/hardwarehacking _______________________________________________ Hardwarehacking mailing list Hardwarehacking@blu.org http://lists.blu.org/mailman/listinfo/hardwarehacking