[LINK] Introducing geoloc

[Rik Harris]

On 17/01/2011 12:07 PM, Jon Seymour wrote:
> On Mon, Jan 17, 2011 at 8:33 PM, Paul Brooks
> <pbrooks-link at layer10.com.au>  wrote:
>> On 14/01/2011 1:59 PM, Jon Seymour wrote:
>> "at their usual point of presence" is a bit of a stretch. Personally, every time I've
>> enabled my android hotspot has been well away from my usual location, due to their
>> being no other wifi network available. This feature is more likely to muddy the
>> SSID+MAC-to-location database, as all these 'hotspots' become indexed at such a wide
>> variety of places that it will resemble the song "I've been everywhere, man". Trying
>> to determine a location on the basis that one of these is within range is likely to
>> become extremely misleading.
> It might have been more accurate to state: at their usual point of
> WiFi presence.
>
> In my own case, it pinned me at my work location, and then, when I was
> on holidays at the cafe down the road from where I live.
>
> ...
>
> I was surprised that Google had updated the devices in a relatively
> short period of time. For example, on the first map, there
> is a WiFi device in Dampier, WA whose location changed slightly over
> that period. I haven't worked out how this happened, but it
> strikes me unlikely that Google happened to have street view car way
> out in Dampier in the last two weeks. If it wasn't a Google street
> view car that provided this location adjustment, one wonders on what
> basis the location was updated.
>
> ...
>
> It is possible that the reason my own devices and devices near me have
> their locations updated relatively frequently is that I live not so
> far from a Google office and so are more likely to encounter a street
> view vehicle than the average person.
>
> I am currently running a little experiment to get a better handle on
> how quickly WiFi devices in my neighbourhood are discovered by Google
> and how often their positions are refreshed.
>

 From my casual observance of streetview, I don't think they update it 
very often at
all.  Current streetview of one location in the Melbourne CBD has not 
been updated
for at least 6 months.

I can think of a couple of ways this might work.  I'm sure I'm not smart 
enough
to give Google/Skyhook ideas they don't already have, so...

Every time a location request query comes in, google will get a 
collection of WiFi
MAC addresses, presumably from devices current in the same location.  If 
it gets
10 MAC addresses that are within 100m of each other in their database 
already
and one MAC address that is showing in the database as a completely 
different
suburb, it could update that MAC address to be the same location as the 
10 others.
This could be done at the back-end with no changes whatsoever to the 
protocol
or devices.

Even more accurate would be if it collects and forwards the GPS 
information at the
same time - then every iPhone and Blackberry essentially becomes a 
mobile WiFi
access point mapping tool.  I've not seen any evidence that it's doing 
this, however.
But who knows what data Google Maps is sending back once you say that it's
OK for the application to use your location information.

Lastly, they could make a deal with someone who is already travelling 
around the
country and install automated wardrivers in their vehicles.  Couriers, 
utility meter
readers?  I doubt Australia Post would go for it, though.

regards,
rik.