Tuesday, March 20, 2018

Location RV-Lag

Doug here, with some nerdly information.

When we started travelling around the country with our phones, computers, tablet, and WiFi equipment, I encountered an interesting situation. Quite often I found that my phone or computer would think that I am still in my previous location, and it would take quite awhile for the situation to resolve itself. By the time it did resolve, it would start all over again upon reaching the next location.

I learned that this problem was because Google (and potentially other mapping services) generate a database of the locations of WiFi networks. This can be used to determine the location of a device if GPS is not available or has not been turned on. For phones, this saves power because turning GPS on to pinpoint location can be avoided if the location can be determined by figuring our where you are based on the WiFi access points that your phone can see. It is also useful for determining the location of computers which do not have GPS receivers.

The WiFi location database can be updated for a WiFi network if the network is moved, but it can take quite a bit of time for this to happen. In the meantime, the inaccurate old location will be used and it can cause your phone or computer to think you are still in the old location.

There is a solution to this problem. You can add the suffix _nomap to the ssid of your WiFi network (router). This will cause the Google location service not to map the location of that WiFi network. If you do this change, it may take awhile for the access point to be removed from the database. However, the problem will eventually clear up. You also need to change all the devices accessing that WiFi network to use the new ssid. Don't forget that you also need to change the WiFi configuration of devices like smart TVs, Rokus, Chromecasts, Firesticks, etc.

This will solve most of your problems. However, I still encounter the problem occasionally in close quarter campgrounds with a lot of transient neighbors. This is because my devices can see their networks and if they aren't named with the suffix _nomap then they could still be mapped to an incorrect location.

In this screenshot, my computer thinks that I am in New York, even though I am actually in Florida. The neighbor across the street happens to have New York plates, and I bet he is transmitting a wifi signal which has been mapped to his house in New York.

So, I am encouraging all RVers that carry a WiFi network to change the ssid of those networks to include the suffix _nomap. This will solve the location confusion problem for not only your devices, but also the devices of your neighbors. Print this post

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